[Summary] Epigenetics defines heritable changes in gene expression that are not coded in the DNA sequence itself.Three systems,including DNA methylation,RNA-associated silencing and histone modification,are used to initiate and sustain epigenetic silencing.Type 2 diabetes mellitus(T2DM) is a polygenic disorder,which is caused by both genetic and environmental factors.However,pathogenesis of T2DM has not been elucidated.Recent studies have indicated that epigenetics may play an important role in the pathogenesis of T2DM,which is involved in the development and differentiation of β cell,secretion of β cell,insulin sensitivity and so on.Researches related to epigenetics may provide a new measure and target to clarify the pathogenesis of T2DM as well as prevent and treat the disease.

Objective To survey the employment intention of medical students in different universities in China.Methods A total of 1354 fourth-year or above medical students from 6 medical universities in China were selected for survey by random cluster sampling.A self-designed questionnaire was used to investigate the basic information of students and their employment intention.Results Overall 46.5％ (620/1333) of all students choose cities in economically-developed region as their desired working sites.45.5 ％ (363/797) of students studying in 4 Shanghai medical universities and 34.5％ (185/536) in other 2 non-Shanghai universities would first choose their original cities as working sites,respectively.81.3％ (1078/1326) of students preferred working in large public hospital,especially for those studying for higher degrees (88.0％,581/660).51％ of undergraduates expected 4000 RMB as monthly pay for graduation.Male students (54.6％,332/608) expected more income than female (47.9％,335/700),graduates (57.9％,377/651) expected higher payment than undergraduates (44.1％,290/657).Conclusion The survey shows that medical students in China mainly prefer cities and large public hospitals as working sites for their career development.

Objective To explore the factors related with difficulty of laparoscopic cholecystectomy(LC) for acute calculus cholecystitis.Methods A total of 245 patients were retrospectively divided into two groups:easy group(123patients)and difficult group(122patients,including 32patients of conversion to OC)based on surgery time and LC or OC.Results There were statistical differences between the groups in regards to preoperative body temperature,white blood cell count,surgical timing,the thickness of gallbladder wall,gallbladder volume,and diameter of common bile duct(all P

Objective To discuss the therapeutic effects of rhubarb and natrii sulfas for severe acute(pancreatitis)(SAP).Methods Eighty-three patietns with SAP were randomly divided into treatment group(group A,n=45) and control group(group B,n=38).The 2 groups received the same therapy except that group A received rhubarb and natrii sulfas through nasogastric tube.Results In treatment group(compared) to control group,the clinical symptoms such as abdominal pain and distention were more quickly(relieved),with early return to oral food intake,lesser complications and shorter hospital stay(all with P

Objective:To analyze the mortality of extremely preterm infants(EPIs) born at 22 +0-25 +6 weeks of gestation in Tianjin Central Hospital of Obstetrics and Gynecology and then compare it with data from other countries to provide evidence for better healthcare for this population. Methods:Clinical data of EPIs born at 22 +0-25 +6 gestational weeks in our center from January 2011 to December 2017 were retrospectively collected. The enrolled patients were grouped based on their gestational age, birth weight, and admission time in order to analyze the mortality in different groups. According to the inclusion and exclusion criteria, five sets of data regarding the mortality of EPIs born at 22 +0-25 +6 gestational weeks during the same period were retrieved from a multicenter survey involving 15 centers in China, the National Institute of Child Health and Human Development Neonatal Research Network (NICHD-NRN) in the United States, Canadian Neonatal Network TM, Australian and New Zealand Neonatal Network (ANZNN) and Korean Neonatal Network (KNN). The mortality rate among data from different sources was compared using Chi-square test on the condition that the definition of death was the same. Besides, the causes of neonatal death were analyzed. Results:A total of 64 EPIs were enrolled in our center. The total mortality rate was 42.2% (27/64), and were 1/1, 8/10, 50.0%(10/20) and 24.2%(8/33) in EPIs of gestational age of 22 +0-22 +6, 23 +0-23 +6, 24 +0-24 +6 and 25 +0-25 +6 weeks, 5/6, 50.0%(16/32), 25.0%(6/24) and 0/2 in those with birth weight of ≤600 g, >600-≤800 g, >800-≤1 000 g and >1 000 g, respectively. In the 27 death cases in our center, the causes of death were as follows: neonatal respiratory distress syndrome (16 cases, 59.3%), sepsis (two cases, 7.4%), necrotizing enterocolitis (three cases, 11.1%), severe intraventricular hemorrhage (three cases, 11.1%) and others (three cases, 11.1%). The mortality rate was 57.1%(12/21) before 2016(2011-2015), 45.0%(9/20) in 2016 and 26.1%(6/23) in 2017. The total mortality of EPIs in our center was higher than that in Canada [42.2% vs 26.6%(165/621), χ2=7.015, P=0.008], as well as in Australia and New Zealand [42.2% vs 28.2%(140/497), χ2=5.330, P=0.021], while there was no statistically significant difference when compared with that in South Korea [42.2% vs 42.1%(218/518), χ2<0.001, P=0.988]. Conclusions:The mortality of EPIs born at 22 +0-25 +6 gestational weeks is higher in our center when compared with that in some developed countries such as Canada and Australia. Therefore, we should pay more efforts to reduce the mortality of EPIs through quality improvement.

BACKGROUND:Theex-vivo expanded autologous adipose-derived stem cels have the capability of multipotential differentiation and have a broad application prospect in the field of tissue engineering and regenerative medicine. OBJECTIVE:To observe the nasal mucosal structural repair and functional reconstruction usingex-vivo expanded autologous adipose-derived stem cels. METHODS:Ten patients with mucosal damage due to the physical or chemical factors were enroled, including six cases of mucosal scar and four cases of mucosal ulceration. Autologous adipose tissue was extracted forin vitro isolation, culture and expansion of adipose-derived stem cels. Before transplantation, quality safety testing was done. Al the patients were injected adipose-derived stem cels (1×107/cm2 0.1 cm mucosal tissue sample at 30 days before and after transplantation for hematoxylin-eosin staining, Masson ) at an interval of 15 days, totaly for three times. Nasal volume, minimum cross-sectional area, and mucociliary clearance function were determined at 30, 90, 150 days after the final injection. Three of 10 patients were selected to take a 0.1 cm× trichrome staining, and AB-PAS staining. RESULTS AND CONCLUSION:Clinical symptoms were aleviated in al patients undergoing transplantation of adipose-derived stem cels. Compared with the baseline data, the nasal volume and minimum cross-sectional area were both decreased at 30, 90, 150 days after transplantation (P < 0.05), and the mucociliary clearance function was improved but not significantly (P > 0.05). Compared with the baseline data, the inflammation of the nasal mucosa was significantly reduced, colagen fibers arranged neatly, the deposition was decreased, and mucin secreted from goblet cels was increased in the selected three patients at 30 days after cel transplantation. These findings indicate thatex-vivo expanded autologous adipose-derived stem cels can be used to reconstruct the nasal mucosal structure and its function.

Objective:To explore the putative role of CD40 and COX-2 expression in human esophageal squamous cell carcinoma(ESCC)and to analyze their possible relationship with angiogenesis in ESCC.Methods:The expression of CD40 and COX-2 was detected in 79 ESCC and 28 normal esophageal epithelial tissue samples with immunohistochemical staining.The microvessel density by CD34 was determined and the clinicopathological significance of CD40 and COX-2 expression in ESCC was analyzed.In addition,the expression of CD40 and COX-2 in esophageal squamous cell carcinoma cell line Eca109 and primary cultured normal esophageal epithelial cells in vivo was comparatively studied with immunocytochemical staining andWestern blot.Results:Compared with that in normal epithelial tissues,the expression of CD40 and COX-2 in ESCC was significantly higher(54.43%vs 10.71%:69.62%vs 17.86%:respectively,P<0.05).The positive expression rate of CD40 in ESCC cases with lymph node metastasis was significantly higher than that in those without lymph node metastasis(70.37%vs 46.1 5%.P<0.05).No correlation was found between CD40 expression and patient age,sex,tumor location,size and differentiation of tumors.No clinicopathological significanca of COX-2 expression in ESCC was found.There was a positive correlation between CD40 expression and COX-2 expression in esophageal squamous cell carcinoma(P<0.05,φ=0.446).The mean MVD value in ESCC was significantly higher than that in normal esophageal tissue(25.02±5.52 vs 12.09±4.55,P<0.05).MVD value in ESCC was closely correlated with lymph node metastasis.The mean MVD value in ESCC cases with positive CD40 and COX-2 expression was higher than that in those with negative CD40 and COX-2expression(26.37±6.02 vs 22.58±5.25.P<0.05).Western blot results showed that CD40 and COX-2 expression in Eca109 was higher than that in cultured normal esophageal epithelial cells (P<0.05).Conclusion:The expression of CD40 is involved in the carcinogenesis and progression of esophageal squamous cell carcinoma.CD40 may play an important role in the angiogenesis of ESCC through promoting COX-2 expression.

Objective: To summarize the clinical and genetic characteristics of children with mitochondrial epilepsy. Methods: Clinical data of 62 children who were clinically and genetically diagnosed with mitochondrial epilepsy by the Department of Neurology, Beijing Children′s Hospital from October 2011 to December 2018 were analyzed retrospectively, and the control of epilepsy was followed up. T test or χ² test were used to analyze the related factors affecting the prognosis of epilepsy between the effective group and the ineffective group. Results: Of the 62 patients, 33 were male and 29 were female. The age of onset was 3.38 (0-12.00) years; for the type of seizures, 68% (42/62) of the patients had focal seizures, generalized or secondary generalized tonic-clonic seizures were seen in 32% (20/62), myoclonic seizures in 23% (14/62), spastic seizures in 7 cases, tonic seizures in 4 cases, absence seizure, atonic seizure and clonic seizure in 1 case each; 16 cases (26%) had status epilepticus, of whom 6 cases had epilepsia partialis continua; 52% (32/62) had 2 or more types of seizures. The clinical phenotypes were mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) in 29 cases, Leigh syndrome (LS) in 11 cases, combined oxidative phosphorylation deficiency in 6 cases, myoclonus epilepsy with ragged-red fibers in 5 cases, Alpers syndrome in 4 cases, pontocerebellar hypoplasia type 6 and mitochondrial DNA depletion syndrome 9 in 2 cases each, mitochondrial complex Ⅰ deficiency nuclear type 20, progressive cavitating leukoencephalopathy, and biotinidase deficiency in 1 case each. Of the 62 cases, 40 cases (65%) had mitochondrial DNA (mtDNA) variations, of which 26 cases had m.3243A>G variants, 6 cases had m.8344A>G variants, and 3 cases had m.8993T>G/C variants, m.3271T>C, m.3481G>A, m.3946G>A, m.13094T>C, m.14487T>C variant was in 1 case each; nuclear DNA (nDNA) variations were identified in 22 cases (35%), of which 7 cases carrying variations in mitochondrial ammonia acyl tRNA synthetase coding gene, mutations in POLG and the gene encoding complex Ⅰ were in 4 cases each, variations in SUCLG1 and SDHA genes were in 2 cases each, and variations in PDHA1, BTD and TRIT1 genes were in 1 case each. Forty-three patients were followed up, and the follow-up time was 20 (3-84) months. According to the follow-up results, the anti-epilepsy treatment was effective in 19 cases (44%) and ineffective in other 24 cases (56%). The onset age of the effective group was 3.42 (0-11.50) years and that of the ineffective group was 0.92 (0-9.50) years. The onset duration of the effective group was 0 (0-7.00) years and that of the ineffective group was 0 (0-4.83) years. There was no significant difference between the effective group and the ineffective group (t=1.662, 0.860; P=0.104, 0.395). In the effective group and the ineffective group, 12 cases and 9 cases used less than 2 kinds of antiepileptic drugs, 7 cases and 15 cases used more than or equal to 2 kinds of antiepileptic drugs, 13 and 15 cases had first epilepsy, 6 and 9 cases had non-first epilepsy, 14 and 11 cases had mtDNA variation, 5 and 13 cases had nDNA variation, respectively. There was no significant difference between the two groups (χ²=2.794, 0.164, 3.380; P=0.095, 0.686, 0.066). Conclusions The types of seizures with mitochondrial epilepsy in children varied, with focal motor seizures being the most common, followed by generalized or secondary generalized tonic-clonic seizures. Most children have more than two types of seizures. MELAS is the most common clinical phenotype, followed by LS; mtDNA variation is the dominant gene variation, of which m.3243A>G variation is the most common hotspot variation, followed by gene variation encoding mitochondrial aminoacyl tRNA synthase.

Objective:To investigate the effect of 5.8 GHz radiofrequency (RF) radiation on learning and memory along with hippocampal synaptic plasticity in rats, in order to provide theoretical and experimental references for scientific evaluation of potential hazards of 5.8 GHz RF radiation.Methods:A total of 56 healthy adult male Sprague-Dawley rats were randomly divided into sham exposure group ( n=28) and RF exposure group ( n=28). RF groups were exposed to 5.8 GHz RF for 1 h each day in 15 d or 30 d continuously, and the whole-body absorption rate was 1.15 W/kg. The learning and memory ability of rats was tested by Morris water maze (MWM). The hippocampal structure of rats was observed by Nissl stain. The density of dendritic spines in CA1 region of hippocampus was detected by Golgi stain. The expression of synaptic related protein (PSD95, Synaptophysin) in hippocampus was detected by Western blot. The level of hippocampal neurotransmitters was detected by liquid chromatography-mass spectrometry. Results:In MWM experiments, at 15 d and 30 d after RF exposure, there was no statistically significant difference between sham group and RF group in the escape latency, frequency of crossing plateau, percentage of stay time in plateau quadrant and latency of first arrival to the plateau ( P>0.05). Besides, the structure and the number of neurons in the hippocampus, the density of apical and basal dendritic spines of pyramidal neurons in the CA1 region (apical: 5.10±0.20, 4.89±0.24, 4.58±0.27, 4.49±0.24, and basal: 4.81±0.17, 4.79±0.34, 4.20±0.27, 4.22±0.17, named as Sham 15 d group, RF 15 d group, Sham 30 d group, RF 30 d group, respectively), the expression of PSD95 and Synaptophysin and the level of multiple kinds of neurotransmitters in the hippocampus had no significant changes ( P>0.05). Conclusions:In this study, 5.8 GHz RF radiation has no significant influence on the spatial learning and memory ability along with the synaptic plasticity of hippocampal neurons of rats.

Objective:To explore the diagnostic value of quantitative 99Tc m-hydrazinonicotinamide(HYNIC)-prostate specific membrane antigen (PSMA) SPECT/CT in patients with prostate cancer. Methods:From November 2018 to March 2021, the data of 56 patients ((69.8±8.0) years) with clinically suspected prostate cancer, who had elevated radioactive uptake in prostate on 99Tc m-HYNIC-PSMA SPECT/CT images in Henan Provincial People′s Hospital, were retrospectively analyzed. According to the pathological results, patients were divided into prostate cancer group ( n=45) and non-prostate cancer group ( n=11). The xSPECT-QUANT software was used to quantitatively analyze the high uptake area of the prostate, and SUV max was measured. The independent-sample t test, Mann-Whitney U test, ROC curve and Spearman correlation analysis were used for data analysis. Results:The prostate cancer group had higher SUV max than non-prostate cancer group (10.79±5.96 vs 3.60±1.27; t=7.43, P<0.001). When SUV max≥6.46, the AUC of prostate cancer was 0.887, with the diagnostic sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of 73.3%(33/45), 11/11, 100%(33/33), 47.8%(11/23), 78.6%(44/56), respectively. The SUV max of prostate cancer group was positively correlated with Gleason score ( rs=0.632, P<0.001). The SUV max of 29 patients with Gleason score≥8 was higher than that of 16 patients with Gleason score≤7 ( z=-3.89, P<0.001). There was no statistical difference in PSA level between patients with Gleason score≤ 7 and patients with non-prostate cancer ( z=-1.63, P=0.110), but the SUV max was significantly different ( z=-2.22, P=0.026). The SUV max of 23 patients with metastases was higher than that of 22 patients without metastasis (12.99±5.85 vs 8.50±5.28; t=2.69, P=0.010). ROC analysis showed that the AUC was 0.709; with SUV max≥13.02 as the threshold, the sensitivity for diagnosing prostate cancer metastases was 56.5%(13/23), the specificity was 86.4%(19/22), and the accuracy was 71.1%(32/45). Conclusions:The 99Tc m-HYNIC-PSMA SPECT/CT quantitative analysis is feasible in patients with prostate cancer. SUV max of 99Tc m-HYNIC-PSMA can be used in the diagnosis of prostate cancer, assessment of the malignancy and prediction of metastasis.