Objective To investigate dynamically characteristics of apparent diffusion coefficient (ADC) of MR diffusion-weighted imaging (DWI) in the rabbit VX-2 tumor model.Methods Forty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity was opened.DWI was carried out periodically and respectively on seventh,fourteenth,and twenty-first day after implantation.Part samples of VX-2 tumors were studied by pathology.The distinction of VX-2 tumors on DWI was assessed by their ADC values.The statistical significance between different time groups,different area groups,or different b-value groups was calculated using SPSS12.0 software,respectively.Results ADC values of 47 VX-2 tumors in the area of tumor periphery,tumor center,and normal parenchyma around tumor were greater when b-value was 100 s/mm2 than those when b-value was 300 s/mm2 and the distinction of VX-2 tumor ADC in the area of tumor periphery,tumor center,and normal parenchyma around tumor between different b-value groups was significant,respectively( F =17.964,P ＜0.01 ; F =13.986,P ＜0.01 ; F =128.681,P ＜0.01 ).The ADC values in the area of normal liver parenchyma around tumor were greater than those in the area of VX-2 tumor periphery and tumor center when the b-value was 100 or 300 s/mm2.When b-value was the same( 100 or 300 s/mm2),the distinction of VX-2 tumor ADC between different areas was significant( F =176.586,P ＜0.01 ; F =55.089,P ＜0.01 ).The ADC of VX-2 tumor in the area of tumor periphery and tumor center became gradually low from seventh to fourteenth or twenty-first day after implantation and the distinction of ADC between different time groups but the area same (?) was significant( b =100 s/mm2,F =48.211,P ＜0.01 ;b =300 s/mm2,F =20.955,P ＜0.01 ).There were not obvious cellular necrosis in VX-2 tumors on seventh and fourteenth day after implantation but ADC of VX-2 tumor decreased unobviously because of cellular edemata in or around tumors.There were obvious cellular necrotic areas in VX-2 tumors on the twenty-first day after implantation.ADC of viable tumor cells in VX-2 tumors were lower on DWI than that in the area of normal liver parenchyma around tumor and ADC of dead tumor cells in VX-2 tumors were unequal,including high values,equal values,and low values but they were higher than that in the area of normal liver parenchyma around tumor after dead tumor cells had been liquified or had become cystic.Conclusions ADC is able to reflect objectively the diffusion of water molecules in the tumor and to reflect indirectly the degree of the growth and liquified necrosis of a tumor.ADC has an important and potential value in monitoring dynamical tumor growth and in evaluating malignant degree and therapeutic effect.

ObjectiveTo investigate its dynamic characteristics and pathological mechanism on magnatic resonance diffusion weighted imaging (DWI) after chemoembolization in rabbit liver VX-2 tumor model.MethodsForty New Zealand rabbits were included in the study and forty-seven rabbit VX-2 tumor models were raised by implanting directly and intrahepatically after abdominal cavity was opened.Forty VX-2 tumor models from them were divided into four groups.DWI was performed periodically and respectively for each group after chemoembolization.All VX-2 tumor samples of each group were studied by pathology.The distinction of VX-2 tumors on DWI was assessed by their apparent diffusion coefficient (ADC) values.The statistical significance between different time groups,different area groups,or different b-value groups was calculated using SPSS 12.0 software.ResultsWhen b-value was 100 s/mm2,ADC values in the area of VX-2 tumor periphery,VX-2 tumor central,or normal liver parenchyma around tumor became gradually low in sixteen hours after chemoembolization,and were the lowest at sixteenth hour,and then they increased gradually from sixteenth hour to fourty-eighth hour after chemoembolization.The distinction of ADC between different time groups was significant,respectively ( F =7.325,P ＜ 0.01 ; F =2.496,P ＜ 0.05 ; F =6.856,P ＜0.01 ).Cellular edema in the area of VX-2 tumor periphery or normal liver parenchyma around tumor increased quickly in sixteen hours after chemoembolization; however,from sixteenth hour to forty-eighth hour,cellular edema in the area of normal liver parenchyma around tumor decreased gradually and that in the area of VX-2 tumor periphery decreased lightly at first and then increased continually.Cellular necrosis in the area of VX-2 tumor periphery after chemoembolization was more significant than that before chemoembolization.The areas of dead cells in VX-2 tumors manifested low signal and high ADC value while the areas of viable cells manifested high signal and low ADC value.ConclusionsDWI is able to detect and discriminate tumor necrotic areas from viable cellular areas before and after chemoembolization.ADC of normal liver parenchyma and VX-2 tumor are influenced by intracellular edema,tissue cellular death,and microcirculation disturbance after chemoembolization.

Objective To investigate the correlation between serum sFas and sLOX-1 with occurrence and development of acute coronary syndrome (ACS).Methods A total of 52 patients definitely diagnosed ACS (ACS group) by coronary artery angiography (CAG) were enrolled,including 23 cases of unstable angina (UA group) and 29 cases of acute myocardial infarction (AMI group),and contemporaneous 58 cases of non-coronary arterial stenosis confirmed by CAG were selected as the control group (NC group).The serum levels of sFas and sLOX-1 were measured by enzyme linked immunosorbent assay.Results Compared with the NC group,the serum levels of sFas and sLOX-1 in the ACS group were increased,the serum levels of sFas and sLOX-1 in the AMI group and UA group were higher than those in the NC group,moreover which in the AMI group were higher than those in the UA group (P＜0.01).The serum sFas level in the ACS group was positively correlated with the sLOX-1 level (r=0.825,P=0.001),but both had no obvious correlation with the serum levels of CK-MB and cTnⅠ (P＞0.05).Conclusion High levels of serum sFas and sLOX-1 may be the risk factors of ACS.

Objectives To evaluate the relationship between body mass index (BMI) and the incidence risk of papillary thyroid microcarcinoma (PTMC).Methods This retrospective study included 1210 PTMC patients who underwent surgery between November 2013 and October 2014 in Peking Union Medical College Hospital,China Academy of Medical Science.A population-based 1∶1 matched case-control study was conducted,and each PTMC patients was matched with one who received thyroid function and ultrasonic to confirm that there was no disease in the thyroid.The clinical profiles of these patients were collected.According to Guidelines for Prevention and Control of Overweight and Obesity in Chinese Adults,all subjects were divided into three groups:underweight (BMI ≤ 18.5 kg/m2),normal(18.5 kg/m2 ＜ BMI ≤ 23.9 kg/m2),overweight (24.0 kg/m2 ＜ BMI ＜ 27.9 kg/m2) and obese group(BMI≥28.0 kg/m2).The relationship between BMI and PTMC incidence risk was analyzed by casecontrol study.Univariate and multivariate logistic regression analysis was applied to analyze the relationship between BMI and PTMC severity.Results The BMI of PTMC patients was significant higher than in normal control [(24.30 ±3.33) kg/m2 vs (23.31 ± 3.50) kg/m2,P ＜ 0.0001].Compared with BMI normal group,the incidence risk of PTMC in underweight group was significantly lower (OR =0.449,95 ％ CI:0.270-0.747),which is higher in overweight and obese group (OR =1.559,95％ CI:1.261-1.928;OR =2.059,95％ CI:1.501-2.823).Histopathological review of 1210 PTMC patients with surgical resection revealed.The proportions of underweight,normal,overweight and obese group of the patients with extrathyroid extension (3.1％,48.0％,36.7％,12.2％) have significant differences with those in the patients whose tumor are limited to the thyroid (0.7％,45.2％,36.0％,18.1％) (P =0.0090).The proportions of 4 group of the patients with multiple lesions (3.2％,49.0％,35.6％,12.2％) were significantly differences to those in the patients with single lesion (0.8％,43.3％,38.7％,17.2％) (P =0.0050).Multivariate analysis showed that underweight is a protective factor of extrathyroidal extension (OR =0.219,95 ％ CI:0.051-0.932;OR =0.279,95 ％ CI:0.085-0.935) and mulifocality,and obese is an independent risk factors(OR =1.556,95％CI:1.047-2.312;OR =1.764,95％CI:1.204-2.584).Conclusions This study identified that the incidence risk of PTMC is positive related with BMI.In PTMC patients,obesity increases the risk of mulifocality and extrathyroidal extension.Attention should be paid to the effect of obesity on the incidence risk of PTMC and the diagnosis and treatment in clinical practice.

Medical ethics has a long history and rich connotations.It has developed from the simple "medical morality" of ancient times to the modem medical ethics.The basic principles of medical ethics include autonomy,non-maleficence,beneficence,justice,and so on.Researchers often conduct clinical researches in the balance between achievements and ethical norms.Clinical researchers of surgery should have a deep understanding of medical ethical principles and strictly abide by medical ethics.Ethics committee should strictly perform their duties and play the role of inspection and supervision.Modem medical knowledges should be popularized throughout the society to make clinical research correctly understood.Adhering principles of ethics first,people orientation and cooperation practice,with patients' benefit as evaluation criteria,balance of surgical "Dao" and "Shu" can be achieved.

ObjectiveTo explore the influence of excessive weight gain during pregnancy in pre-pregnancy overweight and obese women on pregnancy outcomes and neonatal conditions， and to provide scientific evidence for formulating weight management strategies before and during pregnancy and prevent adverse pregnancy outcomes. MethodsClinical data of 2 172 parturients collected from a community in Huangpu District from 2017 to 2021 were retrospectively analyzed， and they were divided into pre-pregnancy overweight and obesity group （n=530）， normal pre-pregnancy weight group（n=937）， and underweight pre-pregnancy group（n=705） according to maternal precursor body mass index （BMI）. Based on their weight gain during pregnancy，the parturient were divided into moderate gestational weight gain （MGWG） group and excessive gestational weight gain （EGWG） group. Meanwhile， the pregnancy and neonatal outcomes such as postpartum hemorrhage， puerperal infection， placental abruption， premature rupture of membranes， mode of delivery， premature birth， stillbirth， fetal distress， admission to the intensive care unit （ICU）， macrosomia， and Apgar score， were recorded. Then the differences in pregnancy and neonatal outcomes between groups were compared. The effects of pre-pregnancy BMI and gestational weight gain on pregnancy outcomes and neonatal conditions was retrospectively analyzed. ResultsThe pre-pregnancy overweight and obese group had higher proportions of placental abruption， premature rupture of membranes， cesarean section， premature birth， fetal distress， and macrosomia compared to the normal pre-pregnancy weight group and the underweight pre-pregnancy group， with Apgar scores lower than the normal pre-pregnancy weight group and the underweight pre-pregnancy group （all P<0.05）. The EGWG group had higher proportions of postpartum hemorrhage， placental abruption， premature rupture of membranes， cesarean section， premature birth， fetal distress， admission to the ICU， and macrosomia than the MGWG group （all P<0.05）. In the pre-pregnancy overweight and obese group， the EGWG group had higher proportions of placental abruption， premature rupture of membranes， premature birth， fetal distress， admission to the ICU， and macrosomia than the MGWG group， with lower Apgar scores than the MGWG group （all P<0.05）. In the normal pre-pregnancy weight group， the EGWG group had higher proportions of placental abruption， premature rupture of membranes， premature birth， fetal distress， admission to the ICU， and macrosomia than the MGWG group （all P<0.05）. In the pre-pregnancy overweight and obese group， the EGWG group had higher proportions of premature rupture of membranes， cesarean section， premature birth， fetal distress， and macrosomia than the EGWG group in the normal pre-pregnancy weight group（all P<0.05）. Logistic regression analysis showed that EGWG in pre-pregnancy overweight and obese women was a risk factor for placental abruption （OR=2.971， 95%CI： 1.098‒8.042）， premature rupture of membranes （OR=4.662， 95%CI： 2.798‒7.770）， cesarean delivery （OR=1.375，95%CI： 1.260‒2.541）， premature birth （OR=4.249， 95%CI： 2.384‒7.573）， fetal distress （OR=3.238， 95%CI： 1.589‒6.598）， admission to the ICU （OR=3.010， 95%CI： 1.265‒7.164）， and macrosomia （OR=5.437， 95%CI： 3.392‒8.716） （all P<0.05）. ConclusionExcessive gestational weight gain in pre-pregnancy overweight and obese women is a risk factors for placental abruption， premature rupture of membranes， cesarean section， premature birth， fetal distress， admission to the ICU， and macrosomia.