DNA methylation is the best studied of the epigenetic changes that influence the gene expression,and changes in genomic methylation patterns have been observed in many cancer cell lines.Nutrients as methyl donors play essential roles in DNA methylation and may modify cancer risk.This review,with an emphasis on the relationship between nutrition,DNA methylation and cancer,firstly defines methylation with a description of its correlated mechanism,then approaches the molecular mechanism of cancer initiation and development at the methylation level,and lastly summarizes the mechanism underlying the effect of methylation-related nutrients on the process of cancer initiation and development at the molecular level.It also offers some suggestions on cancer prevention at the group nutrition level.

Objective To investigate the risk factors,management and prophylaxis of dangerous placenta previa.Methods The clinical data of 407 cases of placenta previa were reviewed,36 cases of them with dangerous placenta previa.Comparison was made between group A (dangerous placenta previa,36 cases) and group B (non dangerous placenta previa,371 cases) in terms of age,number of pregnancy and number of ceasarean delivery.Results The incidence rates of pregnant women in group A age ≥ 35years,number of pregnancy ≥3times,and cesarean delivery≥2times were 55.6％,61.1％,25.0％,which were significantly higher than those of group B (25.6％,27.7％,2.4％),the differences were statistically significant (x2 =7.71,8.99,21.97,all P ＜ 0.01).Among the 36 cases of dangerous placenta previa,12 cases were diagnosed with concomitant placenta increta.The specificity and sensitivity for detection of placenta increta were 90.5％ (19/21) and 83.9％ (10/12) of ultrasonography respectively,and those were 100.0％ (3/3) and 87.5％ (7/8) of MRI.Of the 36 dangerous placenta previa patients,two patients were treated with induced labour due to unexpected pregnancy under 28 weeks,while the others were refer to surgical operation.5 surgical patients experienced uncontrollable postpartum haemorrhage which necessitated histectomy,while the other 31 cases received conservative operation.Rate of histectomy was 13.9(5/36).Conclusion Dangerous placenta previa is associated with advanced age,multiple pregnancy and multiple cesarean delivery.Accurate preoperational evaluation of the placenta previa should be acquired with ultrasonography and MRI to detect placenta increta,provide information for treatment selection,and prevent postpartum haemorrhage.

A novel method for accurate,fast and sensitive detection of pesticides such as imidacloprid,isocarbophos,phoxim,dursban,imidacloprid,pyridaben and avermectin in environmental water samples has been developed by using ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) coupled with high performance liquid chromatography with ultraviolet detection (HPLC-UV).The UA-DLLME parameters such as types/volumes of extraction/dispersion solvents,ultrasonic time,ionic strength and extraction time were investigated.Under the optimized extraction conditions,the linearity for the detection of six pesticides in the concentration range of 10-600 μg/L was obtained with limits of detections (LODs) of 0.8-3.1 μg/L and relative standard deviations (RSDs) of 4.7％-11.3％.UA-DLLME method exhibited strong enrichment ability for the six pesticides,and the enrichment factor (EFs) were ranged from 58 to 187.This method had perfect linearity,precision and recovery results,and showed obvious advantages and practicality comparing the previously reported methods.

Objective To investigate the association of hepatitis B virus ( HBV) precore ( preC) /C mutations with the pro-gression of liver disease .Methods The HBV genes of 50 chronic hepatitis B , including 30 HBV e-antigen ( HBeAg)-negative and 20 HBeAg-positive patients, were detected with real-time quantification polymerase chain reaction (RT-PCR) and the direct sequencing method.Results The mutations T1762/A176, T1766/A1768, A1896 , and the levels of HBV viral loads significantly correlated with the disease progression .The HBeAg-negative patients had a higher frequency of mutations at T 1762/A1764 , T1766/A1768 , and A 1896 relative to HBeAg-positive patients .Conclusions Patients with advanced liver diseases and with HBeAg-negativity possibly had multi-mutations at T1762/A1764, T1766/A1768, and A1896 in HBV genomes.

Objective To investigate the dynamic changes in intestinal alpha-defensin-5 (RD-5),beta-defensin-2 (BD-2) mRNA after acute liver failure(ALF),and to explore their role in ALF.Methods A total of 60 C57BL5 mice were divided into 4 groups by means of random number table method:normal control group,ALF group,E.coli via gavage group and ALF + E.coli via gavage group.Intraperitoneal injection of D-galactosamine (500 mg/kg) and lipopolysaccharide(10 μg/kg) to make the model,in addition,ALF mice were fed with E.coli,and the observation time was 6 hours,12 hours,and 24 hours after modeling,and each time point had 6 specimens.Real-time PCR was used to test the RD-5 mRNA and BD-2 mRNA levels in the ileum tissue.Results The levels of RD-5 and BD-2 showed dynamic change in the experiment of ALF.Compared with the levels of RD-5 and BD-2(11.25 ±0.74,23.86 ±0.39) of the normal control group,the levels of RD-5 and BD-2 in ALF group and E.coli via gavage group increased at 6 hours after modeling(14.19 ±0.39,26.79 ± 0.36 and 12.57 ± 0.68,26.45 ± 0.85),and the differences were significant(all P＜0.05);at 12 hours after modeling,the RD-5 and BD-2 reached to the maximum concentration(15.76 ±0.33,29.10 ± 0.61 and 12.90 ± 0.96,27.42 ± 0.71),and the differences were statistically signi-ficant (all P ＜ 0.05).The degree of elevation of BD-2 was higher than RD-5.Later,they gradually declined.Conclusions RD-5 and BD-2 may play an important role in the pathogenesis of intestinal endotoxemia in experimental ALF.

Myeloid cell leukemia-1 (MCL-1) is an anti-apoptotic protein that plays a key role in promoting cell survival in multiple myeloma, acute myeloid leukemia and non-Hodgkin lymphoma. MCL-1 is highly expressed in a variety of hematological malignancies, which is one of the important factors leading to poor prognosis and chemoresistance in patients with hematological malignancies. Therefore, MCL-1 is an important therapeutic target for hematological malignancies. Several MCL-1 inhibitors have entered clinical trials, including S63845, AZD5991, S64315, AMG-176, and AMG-397. The treatment plans used for hematological malignancies include monotherapy with MCL-1 inhibitors, as well as combination therapy with B cell lymphoma 2 inhibitors or immunomodulatory drugs, all indicating that MCL-1 inhibitors may be a breakthrough point for targeted treatment of hematological malignancies.

Objective:To study the dosimetric differences and short-term efficacy between intracavitary/interstitial brachytherapy (IC/ISBT) and conventional intracavitary brachytherapy (ICBT).Methods:Forty-five patients with locally advanced cervical cancer were treated with IC/ISBT and ICBT. Points A (A 1, A 2), D 90%, D 100%, organs at risk, and the doses of bladder, colon, rectum and small intestine were calculated and the short-term efficacy was observed between two groups. Results:Point A dose was significantly improved in IC/ISBT compared with ICBT ( P<0.05). The D 90% and D 100% in IC/ISBT were significantly higher than those in ICBT (both P<0.05). After brachytherapy, IC/ISBT could obtain a significantly larger increase in target dose when residual tumor diameter was ≥3 cm compared with ICBT ( P<0.05). The D 2cm 3 and D 0.1cm 3 of bladder, rectum, colon and small intestine did not significantly differ between IC/ISBT and ICBT (all P>0.05). The 1-, 3-and 6-month clinical efficacy did not significantly differ between two technologies (all P>0.05). Conclusion:During brachytherapy for locally advanced cervical cancer (residual tumor diameter ≥3 cm), IC/ISBT significantly increases the doses of target area and point A without increasing the dose of organs at risk or lowering the short-term clinical efficacy, which has significant dosimetric advantages.

Objective:To evaluate the effect of trehalose on oxygen-glucose deprivation and restoration (OGD/R) injury in H9C2 cells and the role of solute carrier family 7 member 11- (SLC7A11)-glutathione peroxidase 4 (GPX4) signaling pathway.Methods:Well-grown H9C2 cells were divided into 4 groups ( n=24 each) by the random number table method: control group (group C), OGD/R group (group O), OGD/R+ trehalose group (group OT) and OGD/R+ trehalose+ erastin group (group OTE). The cells were normally cultured in group C. In O, OT and OTE groups, the DMEM medium was replaced with EBSS medium, the cells were exposed to 5% CO 2-95% N 2 in an incubator at 37 ℃ for 6 h, and then the medium was replaced with DMEM medium supplemented with 6% fetal bovine serum to restore oxygen and glucose supply for 24 h. In group OT, trehalose at a final concentration of 50 mmol/L was added during restoration of oxygen and glucose supply. In group OTE, the SLC7A11 inhibitor erastin at a final concentration of 10 μmol/L was added at 8 h before oxygen-glucose deprivation, and trehalose at a final concentration of 50 mmol/L was added during restoration of oxygen and glucose supply. The cell viability, lactic dehydrogenase (LDH) activity, contents of glutathione (GSH), malondialdehyde (MDA) and iron, and reactive oxygen species (ROS) levels were measured at 24 h of restoration of oxygen and glucose supply. The expression of SLC7A11, GPX4, long-chain fatty acyl coenzyme A synthetase 4 (ACSL4), and ferritin heavy chain 1 (FTH1) was detected by Western blot. The structure of the mitochondrial morphology was observed with a transmission electron microscope. Results:Compared with group C, the cell viability and GSH content were significantly decreased, the LDH activity, contents of MDA and iron, and ROS level were increased, the expression of SLC7A11, GPX4 and FTH1 was down-regulated, and the expression of ACSL4 was up-regulated in group O ( P<0.05). Compared with group O, the cell viability and GSH content were significantly increased, the LDH activity, contents of MDA and iron, and ROS level were decreased, the expression of SLC7A11, GPX4 and FTH1 was up-regulated, and the expression of ACSL4 was down-regulated in group OT ( P<0.05). Compared with group OT, the cell viability and GSH content were significantly decreased, the LDH activity, contents of MDA and iron, and ROS levels were increased, the expression of SLC7A11, GPX4 and FTH1 was down-regulated, and the expression of ACSL4 was up-regulated in group OTE ( P<0.05). Conclusions:Trehalose can inhibit ferroptosis by activating the SLC7A11-GPX4 signaling pathway, thereby attenuating OGD/R injury in H9C2 cells.

Objective To study the short-term efficacy of computed tomography (CT)-guided iodine-125(125I) radioactive seed implantation in the treatment of hypoxic tumors.Methods Twenty-two patients treated with 125I radioactive seed implantation in our department from 2014 to 2016 were divided into hypovascular tumor group (hypoxic group,n =12) and hypervascular tumor group (non-hypoxic group,n=10) based on the hemodynamics of solid tumor evaluated by color Doppler ultrasound.The enhanced CT images were loaded to the three-dimensional particle implantation planning system for preoperative planning.After 125I radioactive seed implantation,the D90 for target volume was verified to be 106-128 cGy.Treatment outcomes were evaluated according to the World Health Organization criteria at 1-3 months after surgery.Results In all the patients,the overall response rate was 82％ at 3 months after surgery.There were no significant differences in response (complete response + partial response) rates at 1,2,or 3 months after surgery between the hypoxic group and the non-hypoxic group (P=0.840,0.696,0.840).Conclusions In the treatment of solid malignant tumor,125I radioactive seed implantation can overcome the resistance of hypoxic tumor to radiotherapy in vitro and achieve satisfactory short-term efficacy.

Objective:To measure the anatomical parameters of the simulated low tibial tunnel of posterior cruciate ligament (PCL) based on knee CT images so as to provide clinical reference for accurate location of the tunnel.Methods:The CT images of 201 healthy knee joints collected at Department of Orthopedics, The Second Hospital of Lanzhou University from June 2016 to September 2021 were used for simulation of the PCL low tibial tunnel. The anatomical parameters of the tibial tunnel were measured using the RadiAnt DICOM Viewer. The primary measures included the angle between tibial plateau and tibial tunnel (ATPT) and the perpendicular distances from the tibial tunnel entrance and exit point to the tibial plateau (L1 and L2). The secondary measures included the angle between tibial plateau and posterior slope (PSA), the angle between tibial anatomical axis and central line of tibial tunnel (ATAA), the angle between posterior tibial slope line and the central line of tibial tunnel (APST), the anterior and posterior diameter of tibial plateau (APD), the length of posterior tibial slope (LPTS), and the length of tibial tunnel (LTT). The measurement results were analyzed according to the body height (divided into 3 groups: a 1.00 to 1.60 m group, a 1.61 to 1.70 m group, and a ≥1.71 m group) and gender using the software IBM SPSS 26.Results:The primary measures: ATPT was 37.0°±4.5°, and L1 and L2 were respectively (57.8±7.4) mm and (34.5±3.3) mm. The secondary measures: PSA 128.1°±5.4°, ATAA 52.7°±4.1°, APST 89.1°±5.9°, APD was (32.9±2.6) mm, LPTS (20.5±2.4) mm, and LTT (40.9±5.7) mm. After grouping by gender, there was no significant difference in PSA between men and women ( P>0.05) while there were significant differences in the other indexes between men and women ( P<0.05). After grouping by body height, there was no significant difference in ATPT, PSA, APST or ATAA between the 3 groups (1.00 to 1.60 m group, 1.61 to 1.70 m group and ≥1.71 m group) ( P>0.05) while there were significant differences in L1, L2, APD, LPTS and LTT between the 3 groups ( P<0.05). Conclusions:Based on the knee CT images, the primary measures of PCL low tibial tunnel are as follows: the angle between tibial plateau and tibial tunnel is 37.0°±4.5°, and the perpendicular distances from the tibial tunnel entrance and exit point to the tibial plateau are (57.8±7.4) mm and (34.5±3.3) mm, respectively. Gender and body height are the important factors influencing the above measurement outcomes.