Objective To investigate the delivery mode of pregnant women with prior cesarean section in Northern China,and their clinical characteristics.Methods A multi-center observational study of 1 068 women who had prior cesarean delivery in 24 medical centers in Northern China was conducted between December 2013 and May 2014.The clinical data,including general condition,antenatal examination results,delivery mode,and maternal and fetal outcomes,were collected and compared between vaginal delivery and cesarean section.Mann-Whitney U test and Chi-square test were used for statistical analysis.Results The median age of the 1 068 women were 32 years (range,18-45 years).Thirty-seven (3.5％) had a history of prior vaginal delivery.There were seven twin pregnancies and all delivered by cesarean section.Thirty-five women had suspected uterine rupture and underwent cesarean section,but were confirmed without uterine rupture during the operation.There was no maternal and fetal/neonatal death.Of the 1 068 women,43(4.0％) had successful vaginal birth and 1 025 (96.0％) underwent repeat cesarean sections.Compared with cesarean section group,vaginal delivery group tended to have a greater thickness of the lower uterine segment in the third trimester as shown by ultrasound [(3.3 ± 0.9) vs (2.9± 1.1) mm,Z=-2.240,P=0.025],a higher percentage of prior vaginal delivery [16.2％(6/37) vs 4.6％(31/673),x2=9.570,P=0.009],a lower rate of regular antenatal examination [58A％(25/43) vs 73.2％(742/1 0t3),x2=4.737,P=0.026],a shorter hospital stay[(3.7±2.4) vs (5.9±3.8) d,Z=-6.043,P=0.000],and lower 1-min Apgar score (9.1 ±2.2 vs 9.9±3.9,Z=-2.410,P=0.016),but without difference in the 5-min Apgar score (9.9±0.4 vs 9.6± 1.3,Z=-0.947,P=0.344).Conclusions Rate of vaginal delivery for women with prior cesarean section in Northern China is low.Vaginal birth with prior cesarean section is relatively safe,especially for those with a previous history of vaginal delivery.

Objective To determine pathogenesis and the suitable time of operation for myelomeningocele associated with hydrocephalus in neonate.Methods 6 underwent head CT scanning, 2 lumbosacral CT scanning and 6 lumbosacral X radiography on 6 patients myelomeningocele complicated with hydrocephalus.Ventriculoperitoneal shunt and repair of the myelomeningocele were performed respectively for one patient.from 1 day to 28 day old.Operation stage 1 in 5 patients.Repair of the myelomeningocele concurred with ventriculoperitoneal shunt. Intracranial pressure was measured in shunting procedure.Results 4 patients had normal intracranial pressure,2 patients increased intracranial pressure in the 6 patients.The volume of the hernial sac had markedly diminished and status of hernial sac had greatly improved wall in the patient who wnderwent two-stage procedures after shunt procedure. Lumbosacral wound healing was good . No recurrent myelomeningocele was found, no hydrocephalus was seen using head CT scanning and clinical manifestation has improved in these patients who were followed up 6 month to 3 year.Conclusions Hydrocephalus may deteriorate the degree of lumbosacral myelomeningocele. Effecacy of vntriculoperitoneal shunt and repair of the myelomeningocele was excellent in myelomeningocele complicated with hydrocephalus in neonate.Micro-operative technique might prevent the occurrence of tethered cord.

BACKGROUND: Platelet-rich plasma containing various high-concentration growth factors can promote new bone formation and accelerate bone healing. But its effects on distraction osteogenesis remain unclear. OBJECTIVE: To observe the effects of autologous platelet-dch plasma on premaxillary distraction osteogeaesis in rabbits. DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Laboratory of Physiology, North Campus,Sun Yat-sen University between July and August 2007. MATERIALS: Sixteen healthy rabbits, the same number for male and female, aged 3-5 months,weighing 1. 4-1.7 kg,were randomly and evenly divided into an experimental group and a control group. Premaxillary incisor band,outside front distraction mask, and distraction rubber band were self-made.Coagulant was prepared by dissolving 1000 u bovine thrombin in 1 mL of 10% calcium chloride.METHODS: Titanium nails (1.5 mm in diameter) were separately inserted on two sides of left premaxillary suture in rabbits. A self-made distraction device was used. Gelatum-like substance [Vplatelet-rich plasma: V coagulant=9:1] was injected into the left premaxillary suture of experimental group rabbits immediately prior to distraction.In each group, one-week sustained distraction was performed in 4 rabbits,and three-week sustained distraction was performed in another rabbits. MAIN OUTCOME MEASURES: The increase of nail-nail distance on the two sides and histological results following distraction osteogenesis.RESULLTS: Rabbit premaxillary bone moved anterior in the two groups. The experimental group showed greater increase of nail-nail distance, faster bone formation and mineralization, more blood vessels, and thicker and more mature bone trabecula in the distraction interspace in comparison with the control group. CONCLUSION: Platelet-rich plasma will help bone tissue regeneration and promote premaxillary distraction osteogenesis.

Objective To realize basic status of occupational exposure among medical postgraduates,and provide theoretical evidence for making occupational precaution measures.Methods Data about occupational exposure among medical postgraduates in a teaching hospital between January 2011 and December 2013 were analyzed retro-spectively.Results A total of 3 362 medical postgraduates were monitored,56 (1 .67%)sustained occupational ex-posure.The most common occupational exposure sites were left hand thumbs(n=15,26.79%),occupational expo-sure most frequently occurred during operation(n=29,51 .79%),a total of 40(71 .43%)occupational exposure oc-curred during the process of operation and invasive procedure,all were sharp injuries.46(82.14%)exposure sources were with bloodborne-transmitted diseases.Surgery students accounted for 66.07%(n =37)of students sustained occupational exposure,exposure rate in master’s candidates was higher than doctoral candidates(2.31 % vs 0.28%,χ2 =18.325,P <0.001 ).After timely treatment and preventive medication,none of the students were infected. Conclusion It is necessary to strengthen the occupational safety education for medical postgraduates,improve pre-caution awareness,standardize all kinds of procedures,and implement standard precaution;timely and effective treatment after exposure is important for reducing occupational injury among medical postgraduates.

BACKGROUND:Human embryonic stem cels are able to self-renew indefinitely and have the capacity to differentiate into al three germ layers (ectoderm, endoderm and mesoderm). These properties imply great potential in the basic research and clinical application, including regenerative medicine, drug screening and toxins, early human embryo, cel transplantation, gene therapy,etc. However, it is a substantial chalenge to develop efficient techniques for their large-scale culture under defined conditions, and for controling and directing their differentiation. For therapeutic purposes, many scholars are trying to establish methods for maintaining pluripotency in defined xeno-free conditions and scalable culture systems. OBJECTIVE:To discuss the progress of serum-free culture systems in human embryonic stem cel research reported in recent years and to highlight the chalenges and advances being made towards the development of serum-free and xeno-free culture systems suitable for therapeutic applications. METHODS:A computer-based search of CNKI and PubMed academic database was performed for articles addressing serum-free culture systems of human embryonic stem cels published from 2008 to 2015. Repetitive and old articles were excluded. Finaly, 58 articles were summarized. RESULTS AND CONCLUSION:Several groups have attempted to exclude individual animal components by using feeder-free matrices, feeder cels of human origin, or defined xeno-free media, aiming to select a suitable matrix and medium that can minimize or not use heterologous components, in order to obtain cel lines at clinical level. However, the current cel products are far from clinical application. There are stil many problems to be solved, such as standardization, normalization and individualization of cel products. With the normative development of stem cel research and industry, human embryonic stem cel products are expected to be widely used in clinic.

[Objective] To explore the application of Da Vinci robot in laparoscopic pyeloplasty treatment for pediatric hydronephrosis and to improve the effect of operation and shorten the operation time effectively.[Methods] A summary and analysis was performed on the intraoperative cooperation about the clinical data of 14 pediatric hydronephrosis cases (16 sides) whom were performed RALP from November 2015 to July 2016.The intraoperative cooperation includes preoperative education,adequate preparation of surgical instruments,ensuring the normal operation of robot system before surgery and also,the proper body positions,the protection for patients,the establishment of aseptic barrier during operation as well as the maintenance of robot after operation.[Results] All procedures were performed via transperitoneal approach.Docking time was shortened from 40 to 20 min,operation time lasted (115± 38) min.One severe case presented with anastomasis stenosis even after PCN dilatation,and was redid dismembered pyeloplasty half a year later and the ultimate result was good.The other cases recovered well and the overall success rate was 93.75％.There were no robot failure caused by improper cooperation and no complications caused by improper nursing among the 14 pediatric hydronephrosis cases (16 sides) in pediatric hydronephrosis operations.[Conclusion]Da Vinci robot performed well in assisting laparoscopic pyeloplasty treatment for pediatric hydronephrosis,for it leaves light surgical trauma and short duration of operation.Adequate preoperative preparation,medical staff's formal professional technical training and professional cooperation team can not only improve the operation efficiency,but also be the key to the success of the operation.

Objective To investigate the dynamic changes of plasma myoglobin(Mb),troponinⅠ(TnⅠ) and brain natriuretic peptide(BNP)levels in the course of acute myocardial infrction(AMI)and to detect the best marker for early diagnosis and outcome prediction.Methods Plasma Mb,TnⅠand BNP levels were measured in 49 patients with AMI both before and after thrombolysis therapy and 32 controls.Results Plasma levels of all the three markers were significantly higher in the AMI patients than those in the controls(P

In this study,the rDNA ITS sequence of isolate of Lactarius deliciosus(L.)Gray was sequenced.Molecular identification was accomplished using phylogenetic tree analysis of 22 Lactarius nrDNA-ITS nucleotide sequence including the 2 new and 20 GenBank sequence.

Objective: To determine the distribution characteristics of waist circumference (WC), waist height ratio (WHtR) of 6–18 years olds in Guangzhou, and to put forward the WC and WHtR appropriate boundary values for 6–18 years olds on the basis of cardiovascular disease (CVD) risk factor assessment. Methods: We analyzed the height, weight, WC and its metabolic indication data (blood pressure, fasting blood glucose, and blood lipids) of 15 000 children in Guangzhou, aged 6–18, with the receiver-operating characteristic curve (ROC), and explored the best value point of WC and WHtRfor the prediction of cardiovascular diseases. Results: When the WC percent reached P85, and WHtR reached 0.48, the cardiovascular risk factors of fasting blood-glucose, blood pressure, and blood fat were signiifcantly higher. Conclusion: The 85th percentile value of WC and 0.48 of WHtR are the appropriate boundary values in increasing the cardiovascular disease risk factors in Chinese children and teenagers. WC and WHtR as a relatively simple inspection method, can well predict cardiovascular diseases, and be used in the conventional measuring items among students.

ObjectiveTo identify the presence of side population (SP) cells in human ovarian cancer cell line OVCAR-3 and to investigate whether SP cells have the characteristics of cancer stem cells.MethodsSP and non-SP (NSP) cells from OVCAR-3 were isolated by fluorescence-activated cell sorting after being stained by DNA-binding dye Hoechst 33342.Limiting dilution transplantation assay,realtime PCR,and drug sensitivity assay were performed to compare the tumorigenic ability,differentiation ability in vivo,the mRNA expressiou of stemness marker (Oct-4,Klf4,and Nanog) and ATP-binding cassette (ABC) transporter (ABCG2,ABCB1,and ABCC2),and response to multiple drugs (cisplatin,paclitaxel,doxorubicin,and mitoxantrone )between SP and NSP cells.ResultsA few of SP cells [ ( 1.13 ±0.39) ％ ] which were sensitive to reserpine were identified in OVCAR-3 cells.The injection of as few as 102 SP cells initiated tumors in two of five mice.Tumor latency was 52 -61 days.However,the NSP cells did not generate any tumors in mice until 104 NSP cells were injected (two of five mice).Tumor latency was 64 - 98 days.Tumorigenicity of SP cells was enhanced by at least 100-fold than that of NSP cells.The SP cells regenerated both SP [ ( 2.09 ± 0.73 ) ％ ] and NSP populations in vivo with a fraction size that was comparable to the original population.The mRNA expression ofstemness genes Oct-4,Klf4 and ABC transporters ABCG2,ABCC2 genes were elevated in SP cells compared to NSP cells,the fold changes were 1.95±0.41 (P＜0.05),4.26 ±0.63 (P＜0.01),3.22±0.36 (P＜0.01),and 1.76±0.26 (P＜0.01 ),respectively.The relative activity of SP and NSP cells were 0.757 ± 0.105 versus 0.474 ± 0.035 (P＜0.01),0.521 ±0.092 versus 0.384 ±0.073 (P＜0.05),0.742 ±0.051 versus 0.526 ±0.088 (P ＜0.01 ),and 0.690 ± 0.096 versus 0.466 ± 0.112 ( P ＜ 0.01 ) when they exposed to 0.25 μg/ml cisplatin, 0.01μmol/Lpaclitaxel, 0.25μmol/Ldoxorubicin, and0.05μg/mlmitoxantrone,respectively.ConclusionsSP cells from OVCAR-3 have enhanced self-renewal,differentiation,and tumorinitiating capacity compared to NSP cells.The mRNA expression of stemness genes and ABC transporters are markedly elevated in SP cells,which showed resistance to multiple chemotherapeutic drugs and have characteristics of cancer stem-like cells.Therefore,SP phenotype could be used as a marker to isolate the cancer stem-like cells in ovarian cancer.