Objective To propose a novel method for image segmentation based on"catalyst" segmentation method.Methods Feeler image was imported into segmentation algorithm as the"catalyst",and whether the candidate nodes should stop segmentation or not was decided according to whether the catalyst appeared in the segmentation result.Results Image segmentation based on "catalyst" segmentation method could judge the right class number for segmented images.Conclusions Primary experiments shows that "catalyst" segmentation method is simple and useful.

The inter-species differences of thienorphine metabolism were investigated in human, Beagle dog and rat liver microsomes, by comparing enzyme kinetics of the parent drug and the formation of its major metabolites. The incubation systems of thienorphine with liver microsomes of the three species were optimized in terms of thienorphine concentration, microsomal protein content and incubation time. The concentrations of thienorphine and its metabolites in incubates were measured by a LC-MS/MS method. The biotransformation of thienorphine by human liver microsomes was the lowest among the three species. The Km, Vmax, CLint and T1/2 of thienorphine obtained from human liver microsomes were (4.00 ? 0.59) ?mol?L-1, (0.21 ? 0.06) ?mol?L-1?min-1, (117 ? 3.19) mL?min-1?kg-1 and (223 ? 6.10) min, respectively. The corresponding kinetic parameters for dog and rat liver microsomes were (3.57 ? 0.69) and (3.28 ? 0.50) ?mol?L-1, (0.18 ? 0.04) and (0.14 ? 0.04) ?mol?L-1?min-1, (213 ? 1.06) and (527 ? 7.79) mL?min-1?kg-1, (244 ? 1.21) and (70.7 ? 1.05) min, respectively. A total of six phase I metabolites were observed in liver microsomes, including one N-dealkylated metabolite, three oxidative metabolites and two N-dealkylated oxidation metabolites. All these six metabolites were detected in the liver microsomes of the three species. However, the relative amounts of the metabolites generated were different in three species. The results indicated that the major phase I metabolic pathway of thienorphine was similar in the liver microsomes from all three species. However, the inter-species differencesobserved were relative amounts of the metabolites as well as the metabolic characteristics of thienorphine in liver microsomal incubates.

The inter-species differences of thienorphine metabolism were investigated in human, Beagle dog and rat liver microsomes, by comparing enzyme kinetics of the parent drug and the formation of its major metabolites. The incubation systems of thienorphine with liver microsomes of the three species were optimized in terms of thienorphine concentration, microsomal protein content and incubation time. The concentrations of thienorphine and its metabolites in incubates were measured by a LC-MS/MS method. The biotransformation of thienorphine by human liver microsomes was the lowest among the three species. The K(m), V(max), CL(int) and T1/2 of thienorphine obtained from human liver microsomes were (4.00 +/- 0.59) micromol x L(-1), (0.21 +/- 0.06) micromol x L(-1) x min(-1), (117 +/- 3.19) mL x min(-1) x kg(-1) and (223 +/- 6.10) min, respectively. The corresponding kinetic parameters for dog and rat liver microsomes were (3.57 +/- 0.69) and (3.28 +/- 0.50) micromol x L(-1), (0.18 +/- 0.04) and (0.14 +/- 0.04) micromol x L(-1) x min(-1), (213 +/- 1.06) and (527 +/- 7.79) mL x min(-1) x kg(-1), (244 +/- 1.21) and (70.7 +/- 1.05) min, respectively. A total of six phase I metabolites were observed in liver microsomes, including one N-dealkylated metabolite, three oxidative metabolites and two N-dealkylated oxidation metabolites. All these six metabolites were detected in the liver microsomes of the three species. However, the relative amounts of the metabolites generated were different in three species. The results indicated that the major phase I metabolic pathway of thienorphine was similar in the liver microsomes from all three species. However, the inter-species differences observed were relative amounts of the metabolites as well as the metabolic characteristics of thienorphine in liver microsomal incubates.

Objective To investigate the effect of sevoflurane preconditioning combined with postconditioning (Spost) on anoxia/reoxygenation (A/R) injury to neonatal rat cardiomyocytes.Methods Primary cultured neonatal rat cardiomyocytes were isolated from SD rats aged 1-3 days and cultured in DMEM liquid culture medium.The cells were seeded in 24-well plates (1 ml/hole),35 mm diameter dishes (5 ml/dish) or in 50 mm culture flasks (8 ml/flask) with a density of 3 × 105/ml and randomly divided into 9 groups (n =24 each):control group (group C),A/R group,Spre group (group S1),Spre + SB203580 group (group S1 + SB),sevoflurane postcon-ditioning (Spost) group (group S2),Spost + SB203580 group(group S2 + SB),Spre + Spost group (group S3),Spre + Spost + SB203580 group (group S3 + SB),and group SB203580 (group SB).The cells were cultured routinely for 160 min in group C and the cells were exposed to 95％ N2-5％ CO2 in an incubator at 37 ℃ for 120 min followed by reoxygenation for 20 min in the other groups.The cells were incubated with 2.5 ％ sevoflurane for 20 min before anoxia in groups S1,S1 + SB,S3 and S3 + SB and in addition SB203580 (specific p38MAPK inhibitor) 5 μmol/L was added simultaneously in groups S1 + SB and S3 + SB.The cells were incubated with 2.5％ sevoflurane for 20 min after beginning of reoxygenation in groups S2,S2-SB,S3 and S3 + SB,and in addition SB203580 5 μmol/L was added simultaneously in groups S2 + SB and S3 + SB.The cells were incubated with SB203580 5 μmol/L for 20 min before anoxia and after beginning of reoxygenation in group SB.The lactate dehydrogenase (LDH) activity,cell survival rate and apoptotic rate were measured at the end of reoxygenation.The levels of phosphor-p38MAPK (p-p38MAPK) was detected at the end of Spre and Spost.Results Compared with group C,the LDH activity and apoptotic rate were significantly increased,while the cell survival rate was significantly decreased in the other groups (P ＜ 0.05).Compared with group A/R,the LDH activity and apoptotic rate were significantly decreased,while the cell survival rate was significantly increased in groups S1,S2 and S3 (P ＜ 0.05).There was no significant difference in the LDH activity,cell survival rate and apoptotic rate between groups S1,S2and S3 (P ＞ 0.05).The myocardial protective effect of Spre or Spost alone or in combination was eliminated by SB203580 (P ＜ 0.05).Spre or Spost alone up-regulated the expression of p-p38MAPK,Spre combined with Spost offered no additional benefit over Spre or Spost alone,and the up-regulative effect was eliminated by SB203580 (P ＜ 0.05).Conclusion Spre combined with Spost produces similar myocardial protective effect with that of either alone and it may because that both Spre and Spost attenuate A/R-induced injury to cardiomyocytes through p38MAPK signaling pathway.

Objective To investigate mother-to-child transmission of HIV-1 and the factors that affect transmission. Methods 136 children who were born to HIV positive mothers in a high HIV prevalence region were interviewed and blood samples were examined for anti-HIV anti-HGV and HIV RNA or HIV DNA. Results Among 136 children who were born to HIV positive mothers, 50 were infected with HIV. The MTCT rate was 36.8% (50/136). Thirty eight DNA fragments of HIV-1 gag gene P17 obtained from HIV-1 seropositive mothers were amplified by PCR from uncultured peripheral blood mononuclear cells (PBMCs). Sequence analyses showed that all of them were HIV-1 B subtype. The HIV vertical transmission rate among mothers with AIDS (67.4%, 31/46) was significantly greater than among those with HIV alone (21.1%, 19/90), P

Objective To investigate the clinical distribution characteristics of persisters isolated from the chronic infected pa-tients,so as to provide scientific basis for effective clinical measures to prevent,control and treat persister-associated chronic infection.Methods Clinical microbial samples cultured from Jan.2013 to Dec.2014 were analysed by WHONET5.6.Four bacteria species with the highest isolation rate were performed for screening of chronic infection.Concentration of bacteria were detected by viable plate count method and then the growth curve were drew of each sample under the presence of anti-biotics.Persisters were comfirmed according to the specific growth curve under the presence of antibiotics.Results Four highest isolated bacteria species of the clinical samples were Escherichia coli (1 3.2%),Klebsiella pneumoniae (9.6%), Pseudomonasaeruginosa (8%)and Staphylococcusaureus (6.6%).862 chronic infection samples were generated out of 14 216 microbial samples and 41 persisters (4 strains of Escherichia coli,23 strains of Klebsiella pneumoniae,8 strains of Pseudomonasaeruginosa and 6 strains of Staphylococcusaureus)were isolated finally.Conclusion With such a comprehen-sively retrospective analysis of the hospital clinical microbial samples,can tell that the ratio of persisters in chronic infection was not high.And chronic infections are mostly caused by gene-mutated drug-resistant bacteria.However,the isolation rate of Klebsiella pneumoniae was relatively high,of which more attention should be payed to the prevention and control.

There are problems in traditional medical education in China. It is important to cultivate medical talents who are adaptable to social changes and medical advancement. However, the scientific quality and innovative medical students have long been neglected. This paper discussed the essence of scientific quality and innovative talents, and introduced the experience of the program of "long term clinical medicine education" at Peking University Health Science Center. We here delineateded the key points of the scientific quality and innovation education that may provide new ideas for the training of the medical talents.

Objective To determine whether autologous skeletal myoblasts implantation improves the cardiac function after myocardial infarction and the possible mechanism. Methods Myocardial infarction was induced by ligation of the left anterior descending coronary artery in rabbits. At 2 weeks, 1. 34 × 107 to 1.75 × 107 autologous skeletal myoblasts were infused into the lesion via direct intramuscular injection. In the control group, the postinfarction hearts were infused with medium alone. Buxco invasive cardiac function testing and histopathological examination were utilized to evaluate the functional and structural changes in the myocardium 4 weeks later. Results Both maximum rising rate of the left intraventricular pressure [+dp/dtmax,( 1 217.77 +89.91 )mmHg/s vs. (897.83 ±70.04) mmHg/s] and maximum falling rate of the left intraventricular pressure [- dp/dtmax,( -1174.58 ± 91.5 ) mmHg/s vs. ( - 753.67 ± 69.66 ) mmHg/s] were improved in the myoblast transplanted group compared with medium infusion group. The positive desmin immunostaining skeletal myofibers in the myocardium were found throughout the infracted areas and the border zone. Conclusion Autologous skeletal myoblasts can establish muscle tissue when transplanted into postinfarction hearts, and this mucle can treat myocardiac infarction effectively.

Objective To analyze the serotypes distribution characteristics of salmonella infection in infants below 2 years old in Dongguan.Methods Feces samples collected in children below 2 years old with diarrhea,caused by salmonella infection,were cultured for salmonella isolates,which were then identified for serotypes.The distribution characteristics of different serotypes of salmonella were analyzed.Results A total of 369 strains of salmonella were isolated,including 36 serotypes.The most common three serotypes were Salmonella typhimurium(S.ty),Salmonella stanley(S.st) and Salmonella enteritidis(S.en),which accounted for 68.7%.In all infants with diarrhea,there were 253 boys and 143 girls,and the male:female ratio was 1.77∶1.The average age of infants was (9.3±2.3) months.In male and female infants,the most serotype was S.ty,accounting for 62.3% and 53.3%,but the least serotypes in male and female infants were S.st(16.8%) and S.en(19.0%) respectively.S.ty was the most common serotype in different age groups.The least serotypes in low-age group(0-5.99 months) and middle-age group(6-11.99 months)were S.st(18.4%) and S.en(14.4%) respectively.In high-age group(12-24 months),the proportion of S.st and S.en were both 21.8%.The diversity of salmonella serotypes in male infants was higher than female infants,and with the increasing of age,the diversity was more obvious.Conclusion There could be unique serotype distribution characteristics of salmonella infection in infants with diarrhea,and the diversity of salmonella serotypes should be paid more attention.

Objective To examine the correlation of imbalance of urinary exosome Th1/Th2 with diabetic nephropathy (DN).Methods A total of 120 patients with type 2 diabetes mellitus (DM) and 30 healthy volunteers as control were enrolled in the study.According to urinary albumin/creatinine ratio (UACR),type 2 diabetes mellitus patients were divided into 3 groups:diabetes mellitus without nepbropathy group (DM,n=40,UACR＜30 mg/gCr),microalbuminuria group (DN 1,n=50,UACR-30～300 mg/gCr) and clinicoalbuminuria group (DN 2,n=30,UACR＞300 mg/gCr).Urine exosome-interferon-gamma (IFN-γ) and exosome-interleukin 4 (IL-4) levels were determined by enzyme-linked immunosorbent assay (ELISA).Multiple stepwise linear regression was used to analyze the correlation of exosome-IFN-γ/IL-4 with glycated hemoglobin (HbA1c),cholesterol (CH),UACR,Scr and BUN.Results Th1/Th2 ratio in DM,DN1,DN2 groups was significantly higher than that in healthy group (0.8089±0.2458,0.8993 ±0.3515,0.8571±0.2470 vs 0.6198±0.1769,all P＜0.01).Correlation analysis showed that urinary exosomeIFN-γ/IL-4 ratio was positively correlated with UACR (r=0.213,P=0.015) and BUN (r=0.292,P=0.001).Multiple stepwise linear regression analysis showed that BUN was independent determinants for exosome-IFN-γ/IL-4 (β=0.246,P=0.006).Conclusion The imbalance of urinary exosomeTh1/Th2 is correlated with DN,which may play an important role in the pathogenesis of DN.