Purpose:To investigate the relationship between inactivity of mismatch repair system in colorectal cancer (CRC) in Chinese patients and their age at onset of CRC.Methods:Genomic DNA extracted from colorectal cancer tissues and their normal colon tissues were subjected to analysis for microstallite instability (MSI) in six of DNA markers in 100 colorectal cancer patients.Results:Microsatellite instability positive (MSI + ) was detected in 46 out of 100 (46%) of CRC tissues, MSI + H in 18/100 (18%) and MSI + L in 28/100 (28%). The rate of MSI + in the CRC patients who are younger than 45 years old is higher than that in older patients (≥65 years ) ( P

Objective To observe the transport of hepatitis B virus (HBV)-infected peripheral blood mononuclear cells (PBMC)through placental barrier set up by choriocarcinoma trophoblast cells (Bewo cells),and to explore the biological role of PBMC as a carrier for HBV transport.Methods Bewo cells and PBMC were cultured and their proliferation and activity were detected by cell counting kit (CCK)-8.One hundred μL serum containing 5 ×10 6 copy/mL HBV DNA was used to infect PBMC,and cells infected with HBV were labeled by fluorescent dye carboxyfluorescein diacetate succinimidyl ester (CFSE).A co-culture model of Bewo cells and HBV-infected PBMC was set up by transwell chamber. The migration of HBV-infected PBMC was detected by flow cytometry.Realtime fluorescence quantitative polymerase chain reaction method was used to detect HBV DNA contents of PBMC under transwell chamber.Results PBMC and Bewo cells proliferated at around 24 h and entered into growth stagnation at around 120 h.The contents of PBMC labeled by green fluorescent at 0,12,24 and 48 h during co-culture under chamber were (0.445 ±0.021)%,(21 .180 ± 4.653 )%,(34.830 ± 7.156 )% and (64.185 ± 3.161)%,respectively.The amount of PBMC marked green fluorescence increased over prolonged incubation time (F =68.983,P =0.001 ).PBMC HBV DNA contents at 24 and 48 h of co-culture under chamber were (1.925±0.431)×103 copy/mL and (2.565 ±0.361)×103 copy/mL,respectively,indicating that PBMC under chamber were infected with HBV.Conclusions PBMC may be a target for HBV infection in extrahepatic tissues.Placental trophoblastic barrier built by transwell chambers may provide new ideas to investigate HBV transmission across the placenta in vitro .

Objective To study the relationships between serum hepatitis B virus (HBV) DNA level in chronic HBV infected mothers, free maternal DNA in newborns' peripheral blood and HBV infection of newborns. Methods Free maternal DNA in newborns' peripheral blood was amplified by allele-specific polymerase chain reaction (As-PCR) and heminested polymerase chain reaction (heminPCR). Serum HBV DNA of pregnant women were detected by fluorescence quantitative real-time PCR. The relationships between mothers' serum HBV DNA level, mother-to-fetus DNA transfer and newborns HBV infection were analyzed by SPSS 13. 0 software. Results Thirty-six pairs of motherfetus informative cases were selected and free maternal DNA in the peripheral blood was detected in 26newborns (72. 2%). Statistical analysis indicated that mother-to-fetus DNA transfer was not related with HBsAg, HBV DNA DOsitive in newborns (Fisher exact Drobabilities were 0. 278 and 1.000,respectively; both P > 0. 05), while it was related with HBV infection in the peripheral bloodmononuclear cell (PBMC) of newborns (Fisher exact probability was 0. 026, P<0. 05). Freematernal DNA transfer was not related with mother HBV DNA level (X2 = 2. 097, P>0. 05). Therisk of HBV DNA positive in newborns increased with mother serum HBV DNA increasing ( total X= 62. 21, P<0. 05; tendency X2 =58. 46, P<0. 05). There was no relationship between motherserum HBV DNA level and PBMC HBV DNA positive in newborns (total X2 =4. 82, P>0. 05).Conclusions DNA transfer from HBV infected mother to fetus is related with PBMC HBV infection innewborns, which could be a risk factor of HBV infection in newborns. The risk of serum HBV DNApositive in newborns increases with mother serum HBV DNA level increasing.

Objective To investigate the value of induction chemotherapy in the treatment of stage N2.3M0 nasopharyngeal carcinoma with plasma Epstein-Barr virus (EBV) DNA＞4000 copies/ml.Methods A retrospective study was performed on clinical data from 210 patients with stage N2-3M0 nasopharyngeal carcinoma and plasma EBV DNA＞4000 copies/ml who were admitted to our hospital from 2009 to 2013.In the 210 patients,101 received induction chemotherapy plus concurrent chemoradiotherapy (NCRT) and 109 concurrent chemoradiotherapy alone (CCRT).The survival rates were calculated by the Kaplan-Meier method.The log-rank test was used for the analysis of survival rates and univariate analysis of the impacts of the changes in the plasma EBV DNA level after induction chemotherapy on the prognosis.Results The 3-year sample size was 154.The NCRT group had significantly higher 3-year disease-free survival (DFS) and distant metastasis-free survival (DMFS) rates than the CCRT group (80.1％ vs.70.6％,P =0.029;87.1％ vs.76.0％,P=O.036),while there was no significant difference in 3-year overall survival (OS) rate between the two groups (88.0％ vs.80.4％,P =0.210).Patients with stage N2 disease in the NCRT group had significantly higher 3-year DFS and DMFS rates than those in the CCRT group (P=O.031,O.014).Patients with stage N3 disease in the NCRT group had significantly higher 3-year OS,DFS,and DMFS rates than those in the CCRT group (P=0.029,0.012,0.019).In all the patients,the 3-year OS and DMFS rates were improved with the increase in the cycle number of induction chemotherapy (P =0.020,0.021).In the NCRT group,patients treated with 2,3,and 4 cycles of induction chemotherapy before radiotherapy had plasma EBV-DNA clearance rates of 51.85％,76.92％,and 88.57％,respectively (P=0.004).Using the complete clearance of plasma EBV-DNA as a predictor of progression,the sensitivity for the above three groups was 62.50％,66.67％ and 75.00 (P=0.910),respectively,and the specificity was 57.89％,90.00％ and 96.77％ (P=0.000),respectively.Conclusions In the treatment of nasopharyngealcarcinoma with plasma EBV DNA ＞ 4 000 copies/m1,induction chemotherapy improves DFS and DMFS inpatients with stage N2-3 M0 disease and OS in patients with stage N3 disease;induction chemotherapy dose not improve recurrence-free survival rate.The prognosis and plasma EBV DNA clearance rate are improved with the increase in the cycle number of induction chemotherapy.Using the complete clearance of plasma EBV DNA as a predictor of progression,the sensitivity and specificity in patients treated with 4 cycles of chemotherapy are superior over those in patients treated with 2 or 3 cycles of chemotherapy.

Objective To study the relationship between placenta HBsAg in HBsAg positive pregnant women and serum hepatitis B virus (HBV) markers,HBV DNA levels in newborns.Methods Placenta HBsAg was detected by immunohistochemical affinity hormone-biotin complex (ABC) method in 155 HBsAg positive pregnant women.Serum HBV markers in newborns were detected by enzyme-linked immunosorbent assay (ELISA).Serum HBV DNA levels of newborns were detected by real-time fluorescence quantitative polymerase chain reaction (PCR).The positive rates were compared using x2 test.Results HBsAg was expressed with different levels in various types of cells of placenta in 155 pregnant women.The total placenta HBsAg positive rate was 37.4％ (58/155),and those in decidual cells,trophoblastic cells,villous mesenchymal cells and villous capillary endothelial cells were 37.4％ (58/155),25.8％ (40/155),18.7％ (29/155) and 7.1％ (11/155),respectively.The HBsAg positive rates of placenta gradually decreased from decidual cells of the maternal surface to villous capillary endothelial cells of the fetal surface (tendency x2 =43.01,P=0.00).The positivity of placenta HBsAg was associated with both HBsAg and HBeAg in newborns (x2 =4.88,P＜0.05 and x2 =3.86,P＜0.05,respectively),while that was not associated withanti-HBe and anti-HBc in newborns (x2 =3.36,P＞0.05 and x2 =0.00,P＞ 0.05,respectively).The risk of HBsAg positive in newborns was higher when HBsAg was positive in villous capillary endothelial cells and villous mesenchymal cells (OR=5.31,95 ％CI=1.38-20.40 and OR=3.33,95％CI=1.16-9.52,respectively).The risk of HBeAg positive in newborns was higher when HBsAg was positive in trophoblastic cells and villous mesenchymal cells (OR=3.04,95 ％CI=1.45-6.39 and OR=3.05,95 ％ CI=1.32-7.03,respectively).However,placenta HBsAg positive was not associated with HBV DNA positive in newborns (x2 =0.09,P＞0.05).Conclusion The risk of neonatal HBV serological markers positive is higher when the HBsAg positive placental cells are closer to fetal surface,which indicates that HBsAg enters fetal blood circulation by means of cell transferring layer by layer.

AIM: To explore the expressive role of lipoprotein-associated phospholipase A_2, high sensitive C-reactive protein and matrix metalloproteinase-9 in vulnerable atherosclerotic plaques in a rabbit model. METHODS: Forty eight New Zealand white male rabbits were randomly divided into 4 groups (12 rabbits each): control group, stable plaque group, p53 group, and p53+drug group. Rabbits in control group were fed with a regular diet and underwent sham operation. Rabbits in stable plaque group, p53 group and p53+drug group underwent balloon induced arterial wall injury and then were fed on a diet with 1% cholesterol. The animals were all fed for 3 months, then the rabbits in p53 group and p53+drug group underwent Ad5-CMV p53 transfection at 10th week. Before killed, the animals in p53+drug group underwent pharmacological triggering with Russell's viper venom (RVV) and histamine to induce the rupture of the atherosclerotic plaques. At the 1st day and before sacrifice, the serum was collected for measuring Lp-PLA_2, hs-CRP, MMP-9, HDL, LDL and VLDL. The expressions of Lp-PLA_2, hs-CRP and MMP-9 in tissues were determined by the methods of hybridization and immunohistochemistry. RESULTS: At the end of 12th week, the serum and tissue levels of Lp-PLA_2 and MMP-9 in stable plaque group, p53 group and p53+drug group were significant different from those in control group and in each group at the first day (P<0.05). The serum levels of Lp-PLA_2 and hs-CRP in p53 group and p53+drug group were significantly higher than those in control group and stable group (P<0.05). The serum levels of Lp-PLA_2, hs-CRP and MMP-9 were all significantly different between p53 group and p53+drug group (P<0.05). At the end of 12th week, pathological results showed that 4 groups were normal artery, stable plaque, vulnerable plaque and rupture plaque, respectively. The fabric cap was thicker in plaque groups than that in normal group (P<0.05). The rupture and formation of thrombus were more significant in p53+drug group than those in p53 group. The serum level of Lp-PLA_2 had negative interrelated relationship with fabric cap in plaque groups (r=-0.710, P<0.01), and hs-CRP, MMP-9 had no interrelated relationships with fabric cap in plaque groups. CONCLUSION: Base on the successful establishment of the atherosclerotic plaque animal model, serum Lp-PLA_2 shows better interrelated relationships to plaques stability. Combination with hs-CRP and MMP-9, we can exactly evaluate the nature of plaques.

w biomarker to predict the presence of vulnerable plaque.

Objective To understand the status quo of medical students' integrity in examinations and to explore the influencing factors. Methods 2013-2015 undergraduate students from Clinical Medi-cine, Preventive Medicine and other professional subjects were included in Shanxi Medical University. A total of 221 questionnaires were issued for each grade by stratified random sampling. The database was built with EpiData 3.1. All statical analyses were performed with SPSS software (version 22.0) by means of chi-square test and binary logistic regression. Results Among the 600 medical students, 16.5% of the students had cheating. A statistically significant difference was observed in the cheating rate among the medical stu-dents in terms of gender, grade, academic performance, medical knowledge, memory, family factors, and invigilators' attitude (P<0.05). Litter pressure from the family, the teacher's proctoring is rigorous invigilation, and top scores were the protective factors for medical students' cheating in exams. Conclusion Through the analysis of the influencing factors for the medical students' integrity in examinations, corresponding measures are formulated to provide reference for relevant medical personnel in various medical colleges and universities.

Objective:To explore the application of comprehensive simulated delivery room skill training combined with improved objective teaching in obstetric nursing teaching.Methods:A total of 84 nurses who practiced in the Department of Obstetrics of Nanjing Hospital of Traditional Chinese Medicine from August 2019 to August 2020 were selected as the research objects, and were divided into control group and research group according to the sequence of admission of practice nurses, with 42 nurses in each group. The control group adopted traditional teaching methods, and the research group adopted comprehensive simulated delivery room skill training combined with improved target teaching mode. The teaching effect of the two groups of practice nurses was evaluated by theoretical assessment, skill operation assessment and teaching satisfaction rate. SPSS 22.0 was used for t test and chi-square test. Results:The total score of theory assessment, single choice, multiple choice, blank filling, noun explanation, short answer and case analysis of practical nursing students in the study group were better than those in the control group, with statistically significant differences ( P<0.05). The results of practical skills operation and comprehensive quality ability evaluation of practice nurses in the study group were better than those in the control group, and the difference was statistically significant ( P<0.05). The teaching satisfaction rate of practice nurses in the control group was 80.95%(34/42), and that in the research group was 97.62%(41/42), with statistically significant differences ( χ2=6.10, P=0.014). Conclusion:The skill training of comprehensive simulated delivery room combined with improved objective teaching can improve the theoretical knowledge, practical skills and comprehensive quality of obstetric practice nurses, and improve the teaching satisfaction rate and obstetric nursing teaching quality of practical nurses.

In response to the current situation and teaching status of the medical image processing course on the background of"new medical science",a teaching software which is highly compatible with the teaching process of medical image processing is developed.The teaching software allows for linear grayscale transformation,windowing display,scaling,rotation,mirroring,median filtering,differential sharpening,edge detection,histogram acquisition,and histogram equalization of medical images.Additionally,it enables parameter adjustments within a certain range for linear grayscale transformation,windowing display,scaling,rotation,median filtering,differential sharpening,and edge detection.Meanwhile,it employs different algorithms to achieve the scaling of medical images.The teaching software is used in the theoretical and experimental teaching of medical image processing courses at Baotou Medical College.It can improve students'initiative and enthusiasm in learning,strengthen their understanding of the examination points for radiology technicians,lay a solid foundation for subsequent courses,and ultimately achieve the goal of in-depth integration of"Medical Engineering"and"Medical Science"in the medical image technology major at Baotou Medical College under the background of"new medical science".