The risk and benefit assessment is an important part of ethical review in clinical trials, of which the significance is to minimize the risk and maximize the benefit, thus to protect the rights of the subject. Begin with introducing the nature of the risk and benefit of clinical trial, this paper analyzed the way of ethical review based on risk consideration and discussed some key points of risk and benefit assessment including the minimum risk, the risk and benefit of vulnerable groups, risk informing, benefit of clinical trials, the fairness of recruitment and the importance of strengthening follow-up review. Ethical review should play a role as the balance, which neither-hinder the development of clinical trial to protect the rights of the subjects nor damage the rights and interests of subject to develop clinical trials.

Objective To analyze labor duration in nulliparous women and discuss the change about curve of labor duration. Methods Two thousand, one hundred and forty nulliparous, full-term pregnant, singleton, cephalic presentation and vaginal delivery women who delivered at Peking University First Hospital were included. There were 1 300 cases between January 1, and December 31, 2009, while 840 cases between January 1, and May 31, 2013. A retrospective study was conducted. Data on maternal age, gestational age at delivery, body mass index at delivery, newborn weight, time of labor initiation, cervical dilatation and the amount of bleeding within the first 24 h after delivery were recorded. Data were compared by t test and χ2 test. The median time span corresponding to one-centimeter-increase in cervical dilatation was calculated. Results (1)Compared with data from 2009, the maternal age [(29.0±3.0) vs (29.6±2.8) years, t=4.77], incidence of postpartum hemorrhage [1.8%(24/1 300) vs 4.3%(36/840),χ2=11.17], proportion of induced labor [37.3%(485/1 300) vs 64.0%(538/840),χ2=146.23] and proportion of analgesia during labor [54.2%(705/1 300) vs 61.5% (517/840), χ2=11.15] were all higher in 2013 (all P<0.01). (2)The median (minimum–maximum) time span corresponding to a one-centimeter-increase in cervical dilatation was 3-4 cm which corresponded to 2.2 h(0.8-4.3 h), 4-5 cm which corresponded to 1.9 h(0.6-4.0 h), 5-6 cm which corresponded to 1.8 h(0.5-4.0 h), 6-7 cm which corresponded to 1.6 h(0.5-2.0 h), 7-8 cm which corresponded to 1.8 h(0.8-2.0 h), 8-9 cm which corresponded to 1.3 h(0.2-2.5 h), and 9-10 cm which corresponded to 0.6 h(0.1-2.5 h). The curve of labor duration showed a slow uptrend with time on the horizontal axis and cervical dilatation on the vertical axis. Conclusions The curve of labor duration exhibits a slow uptrend with neither an acceleration phase nor a deceleration phase. It is important to redefine the time span of labor duration in China for appropriate clinical treatment.

AIM: To observe the effects of norepinephrine (NE) on the cardiopulmonary and lung injury in goats with acute respiratory distress syndrome (ARDS) induced by endotoxin. METHODS: A model of septic ARDS was induced by intravenous infusion of low dose endotoxin in six goats. Then 40?10~ -6 NO inhalation was applied to the animals. After 30 min, combined intravenous infusion of NE at concentration of 0.5 mg?kg~ -1 ?min~ -1 was conducted. The dynamic changes in gas exchange and hemodynamics were measured with the aid of Swan-Ganz catheter. Arterial blood gas analysis before and after the onset of ARDS, 30 min after NO inhalation and combined NE was detected. Histology of the lung was also observed. RESULTS: Inhalation of NO rapidly reduced mean pulmonary arterial pressure (MPAP), increased PaO_2, decreased P_ (A-a) O_2 and Qs/Qt in septic ARDS goats. These decrease and increase were more significant than those in NO inhaled alone when animals received NE. The combination of NO inhalation and NE injection resulted in increase in mean arterial pressure. NO inhalation did not ameliorate lung injury and combined NE intravenous injection ameliorated lung injury. CONCLUSION: Injection of low dose norepinephrine improves the beneficial effects of inhaled nitric oxide on lung gas exchange and ameliorates lung injury in goats with acute respiratory distress syndrome induced by endotoxin.

Aim To study the proliferative effect of resveratrol pretreatment on oxygen-glucose deprivation/reoxygenation ( OGD/R ) injury of rat cortical neural stem cells ( NSCs ) in vitro. Methods Isolation and purification of NSCs in neonatal Sprague-Dawley( SD) rats were conducted by suspended cultivation. The third passage NSCs of adherent culture was cultured under oxygen and glucose deprivation for 150 min and reoxygenation for 24 h. The experimental subjects were divided into normal, control, ethanol and resveratrol pretreatment groups. Immunofluorescence was used to identify NSCs. Cell viability was detected with CCK-8 assay. Flow cytometry cell cycle and BrdU assay were used to measure cell proliferation. Results Cells both in suspended and adherent cultivation highly expressed neuroepithelial stem cell protein ( nestin ) . Compared with the control group, NSCs viabilities and prolifera-tion in resveratrol groups (1, 5, 20 μmol·L-1 ) were significantly heightened, and highest in the 5 μmol · L-1 resveratrol group ( P<0. 05 ) . Conclusion Res-veratrol pretreatment can reduce injury and promote proliferation of NSCs after oxygen-glucose deprivation /reoxygenation.

Objective To investigate the clinical effect of phacoemulsification and individualized intraocular lens implantation in senile cataract patients with super high myopia.Methods Thirty-six cases of senile cataract patients with super high myopia with 49 eyes underwent phacoemulsification and individualized intraocular lens implantation,postoperative uncorrected distance visual acuity,best corrected visual acuity,diopter and surgical complications were observed.Results All surgical eyes visual acuity had improved to varying degrees,the postoperative far visual acuity in 0.05-0.30,the near visual acuity in 0.02-0.50,best corrected visual acuity 0.31-0.40 in 22 eyes (44.9％,22/49),≥ 0.5 in 14 eyes (28.6％,14/49).The postoperative diopter ＜-1.00 D in 3 eyes,-1.00 to-2.00 D in 16 eyes,-2.01 to-3.00 D in 27 eyes,and ＞-3.00 D in 3 eyes.Diopter difference with the goal ＜ ± 0.50 D in 21 eyes,± 0.50 D to ± 1.00 D in 18 eyes,＞ ± 1.00 D in 10 eyes.Postoperative corneal edema in 28 eyes,were completely disappeared within 1 week to 3 months,no retinal detachment and corneal decompensation and other serious complications.Conclusion Senile cataract patients with super high myopia are treated with phacoemulsification and individualized intraocular lens implantation,visions improve ideal and have good clinical efficacy.

Aim To investigate the effect of resveratrol on astrocyte activation after cerebral ischemia/reperfusion injury in rats.Methods 45 male Sprague-Dawley rats were divided into sham,control and resveratrol groups, 15 rats in each group.Resveratrol or solvent was intra-peritoneally perfused into the rats for 7 consecutive days after 3h for MCA I /R.Cerebral infarction volume with TTC,neurological function score with Longa score, and pathological change with HE staining,the protein expressions of Caspase-3 with immunohistochemistry at 24h after MCA I /R were examined.The protein ex-pressions of GFAP and NeuN in penumbra were detec-ted with immunohistochemistry and immunofluores-cence at 14d after MCA I /R.Results Resveratrol treatment significantly improved the neurological func-tion score,decreased the infarct volume,reduced neu-ron loss,and inhibited the activation and proliferation of astrocytes,compared with the control group.Con-clusion Resveratrol can inhibit the excessive activa-tion of astrocytes,protect neurons in penumbra and im-prove neurological function.

Objective To investigate the ability of human exfoliated deciduous teeth-derived stem cells (SHED) to differentiate into odontoblast-like cells. Methods SHEDs were isolated by enzyme digestion method. The 3nd passage SHEDs were incubated with 25 ng/mL recombinant human TGF-β3 , or with TGF-β3 in combination with heparin. The DSPP expression was detected by Q-PCR and Western-blotting assay. Alizarin red staining, immunhistochemistry assay and alkaline phosphatase(AKP) activity assay were performed, respectively. Result The AKP activity was enhance by TGF-β3 in combination with heparin. Alizarin red staining was positive in TGF-β3-heparin groups, with the increase of DSPP expression at both mRNA and protein level. Conclusion TGF-β3 in combination with heparin can enhance the differentiation of human exfoliated deciduous teeth-derived stem cells into odontoblast-like cells.

BACKGROUND:Studies have reported that the superfamily of transforming growth factors exert a role in the mineralization of various stem cells, but the combination effects of transforming growth factorβ3 and heparin on proliferation and mineralization ability of stem cells from human exfoliated deciduous teeth remains to be studied. OBJECTIVE:To explore the effect of transforming growth factorβ3 on odontoblast-like differentiation of stem cells from human exfoliated deciduous teeth. METHODS:Human deciduous teeth were col ected using enzyme digestion. The 3rd cells were incubated with 25μg/L recombinant human transforming growth factorβ3, 10 U/mL heparin or their combination. The dentin sialophosphoprotein mRNA and dentinsialoprotein expressions were detected by Q-PCR and western blot assay. Alkaline phosphatase activity was determined using alkaline phosphatase kit. RESULTS AND CONCLUSION:Stem cells from human exfoliated deciduous teeth grew wel after induction. The activity of alkaline phosphatase in the combination group was significantly higher than that in the transforming growth factorβ3, heparin and control groups (P<0.01). After combination induction, the cells were strongly positive for alizarin red staining. Results fromα-PCR and western blot assay showed that the expressions of dentin sialophosphoprotein were both remarkably increased at mRNA and protein levels. In summary, stem cells from human exfoliated deciduous teeth can differentiate into odontoblast-like cells under the induction of transforming growth factorβ3 plus heparin.

Purpose　To introduce a method to isolate cDNA clones using bacteriophage P1-derived artificial chromosome (PAC) or bacterial artificial chromosome (BAC) as probe for hybridization and try to find some novel genes related to hepatocellular carcinoma.　Methods　PAC 579 (D17S926 locus) and BAC 1529 (D17S1529 locus) in the deletion region of chromosome 17p13.3 in human hepatocellular carcinoma were chosen to screening the human liver cDNA library as probe for hybridization. The isolated positive cDNA clones were partially sequenced, then analyzed by computer comparison and Southern blot.　Results　After three cycles of screening, 78 and 8 candidate positive cDNA clones were isolated using PAC 579 and BAC 1529 probes respectively. Further analysis indicated 18 cDNA clones isolated by PAC 579 probe and 5 cDNA isolated by BAC 1529 probe were potential novel genes related to hepatocellular carcinoma.　Conclusions　The isolation of cDNA clones using PAC and BAC probes is effective and practical.

Objective To explore the value of transthoracic echocardiography in diagnosis of univentricle and analyze the sonogram typing. Methods The results of 66 patients with univentricle were reviewed retrospectively,and analayzed their typing connected with the reports in the literature. Results There were 3 ultrasonic types in 66 cases:①Type A(single left ventricle) 19 cases,single ventricle with left ventricular shape,residual cavity in front of it. ②Type B(single right ventricle) 38 cases, single ventricle with right ventricular form,and residual cavity in the rear.③Type C (solitary single-ventricle) 9 cases,there was only one ventricle. Thirty-one of them were treated surgically, 5 cases without operation had MRI or cardiac catheterization examination and the remaining 26 patients were only observed by echocardiography,the positive rate of diagnosis in type was 100%, the results were compared with cardiac catheterization or MRI examination and the operation: 1 cases of mixed type total anomalous pulmonary venous connection was misdiagnosed as heart-type total anomalous pulmonary venous drainage. But 1 case of descending aorta limitations narrow complicated patent ductus arteriosus(PDA), PDA was missed. The rest were completely correct diagnosis. Conclusions The transthoracic echocardiography can be used to evaluate types and all containing malformations of univentricle,and offers reliable information for operation.