Human embryonic stem(ES)cell research has been current hotspot of life science since 1990s.The stem cell is a kind of special and essential cell type found in human body,which can not only be amplified and self renewed,but can be derived into many kinds of cell lines.Scientists forecast that deeper research of ES cells will offer hope of new cures for leukemia,neurodegenerative diseases,and so on.While at the same time,stem cell research leads an important bioethical debate in the all world.

Building a medical multimedia teaching resource library is beneficial to distance medical education and the efficiency of multimedia resource usage. Its construction depends on not only modern information technology and the network, but also a comprehensive design from the angle of resource integration.

OBJECTIVE To investigate the distribution of bacteria detected from blood culture of pediatric patients and to observe the antibiotic resistance of these bacteria. METHODS The BacT/Alert blood culture system was applied for culture.Species identification and antibiotic resistance tests were performed by the VITEK automicroscan system. RESULTS Coagulase-negative staphylococcus(CNS) and Staphylococcus aureus accounted for 67.2% and 7.8%, respectively.The proportion of Gram-negative bacteria was 14.4%.The resistant rate of CNS and S.aureus to oxacillin was 85% and 36%,respectively.The strains producing the extended spectrum beta-lactamases(ESBLs) of Gram-negative bacteria were often detected. CONCLUSIONS Gram-postive bacteria are the main pathogens detected from the blood culture of pediatric patients.Detection rate of CNS is the highest.Multiresistant strains are common.

OBJECTIVE To discuss the efficiency method of improving consciousness and action for occupational infection protection among grass root medical staff.METHODS To conduct multiform health education,found restrict system,inspect and supervise,optimize protection flow,consummate protection establishment,and strengthen important link management in key departments in order to realize the system intervention among grass root medical staff.RESULTS Due to the system intervenion,the understanding rate of occupational infection protection knowledge improved from 48% to 96%,the average rate of occupational infection protection improved from 56.6% to 97.7% with significant differences(P

Objective To study the plasma biochemical indexes among the hypertension in Xining area.Methods According to diagnosis standard of hypertension,104 males who emigrated to Xining area were divided into hypertension group and control group,height,weight,blood routine,renal function,blood lipid of the two groups were measured.Results Among the 104 subjects, 17 cases were hypertensive patients,and other 87 cases were served as control group.The body weight,blood uric acid levels in hy-pertension group were significantly higher than those in the control group(P <0.05),the other indexes had no significant difference between two groups.Conclusion The uric acid may be a risk factor for hypertension people living in plateau area,and the mecha-nism need to be further studied.

Objective To investigate the potential effectiveness of a computer-based gastrointestinal (GI) endoscopy simulator in assessing the competence of GI endoscopy trainees.Methods Fifty trainees working in the endoscopy center of General Hospital of Chinese PLA between February 2009 and October 2011 were enrolled.These participants were divided into four groups based on their prior endoscopic experience:novices (no endoscopy experience),intermediate experienced (≤200 colonoscopies or ≤ 500 gastroscopies),experienced (201-1000 colonoscopies or 501-2000 gastroscopies),and experts (＞ 1000 colonoscopies or ＞ 2000 gastroscopies).Assessment of endoscopic skills was performed during a hand-eye coordination task (Endo Bubble level 1) and was based on parameters measured by the computer system including time to finish,average time between two bubbles,number of times wall touched.Results When GI trainees were categorized by their prior gastroscopy number,the time to finish of each group were (302.43 ± 108.96)s,(188.00 ± 59.88) s,135.00 (40.00) s,150.00 (69.00) s,and the average time between two bubbles were (14.29 ± 5.47) s,(8.82 ± 3.28) s,6.00 (2.00) s,7.00 (4.00) s,respectively.Pairwise comparison showed that except experienced and experts groups (P ＞ 0.05),there were significantly differences between remaining groups (P ＜0.01).However,based on the colonoscopic experiences,the time to finish of each group were 220.00(91.00)s,127.00(28.25)s,155.50(81.00)s,150.00(58.50)s,respectively,which were significantly different between each two groups (P ＜ 0.01).Average time between two bubbles of each group were 10.00 (4.00) s,5.50 (1.50) s,7.00 (3.75) s,7.00 (3.50) s,respectively,which were found significantly different among whole groups (P ＜ 0.05 or P ＜ 0.01),but there were no differences between novice and experienced trainees and between intermediate experienced and experts groups.In contrast,the number of wall-touch was insufficient for assessment.Except the significant difference between novice and experienced group (P ＜ 0.05) as categorized by gastroscopy experience,there were no values to differentiate the trainees of different practical competence on gastroscopy or colonoscopy.Conclusion The parameter,time to finish,during a hand-eye coordination task using a virtual reality simulator might be able to differentiate the competence of operators,which was used prior to training in real-life endoscopy,but lack of accurate discriminatory function between experienced and experts.

Objective To investigate the effects of remote limb ischemic preconditioning (RLIP) on the lung injury in patients undergoing abdominal aortic aneurysm repair.Methods Sixty-two ASA Ⅱ or Ⅲ patients of both sexes,aged 54-72 yr,with body mass index 21-36 kg/m2,undergoing elective abdominal aortic aneurysm repair,were randomly divided to 2 groups ( n =31 each):control group (group C) and RLIP group.RLIP consisted of two 5-min cycles of left upper limb ischemia induced by a blood pressure cuff placed on the left upper arm and inflated to 200 mm Hg,with an intervening 5 min of reperfusion,during which time the cuff was deflated.RLIP was performed after anesthesia induction and before the start of surgery.Arterial and venous blood samples were taken at 10 min after intubation (T0),and 30 min and 4,8,12 and 24 h after aortic unclamping (T1-5) for blood gas analysis and determination of the concentrations of serum interleukin (IL)-6,tumor necrosis factor (TNF)-α,and plasma malondialdehyde (MDA) and superoxide dismutase (SOD) activity.The alveolar-arterial oxygen pressure difference (PA-aO2 ) and respiratory index (RI) were calculated.The peak airway pressure (Ppeak),plat airway pressure (Pplat) and positive end expiratory pressure (PEEP) were recorded at the same time points mentioned above to calculate dynamic lung compliance (Cd) and static lung compliance (Cs).The incidence of hypoxemia,extubation time and duration of stay in intensive care unit (IGU) were also recorded.Results Compared with group C,PA-aO2,RI and the concentration of IL-6 were significantly decreased at T3-5,Cs,Cd and SOD activity were significantly increased at T2-5,and the concentrations of TNF-α and MDA were significantly decreased at T2-5 in group RLIP ( P ＜ 0.05).Compared with group C,the incidence of hypoxemia was significantly decreased,and extubation time and duration of stay in ICU were significantly shortened in group RLIP ( P ＜ 0.05).Conclusion RLIP can reduce the lung injury through inhibition of the inflammatory response and lipid peroxidation in patients undergoing abdominal aortic aneurysm repair.

Objective To investigate the impact and the associated parameters of malnutrition and inflammation status on hospitalization and mortality of maintenance hemodialysis (MHD) patients. Method A total of 118 MHD patients were included in the study with 1 year's follow-up.The malnutrition and inflammation parameters were compared between the hospitalized patients and out-patients.Cox's proportional hazard regression model was used to explore the malnutrition and inflammation parameters which could forecast the risk of hospitalization and mortality. Result The hospitalization rate of MHD patients with mild,moderate and severe malnuttition was 32.93％,56.67％ and 83.33％ respectively,and the mortality was 3.66％,6.67％ and 80.00％ respectively.The hospitalization rate of MHD patients with or without microinflammation status was 56.45％ and 46.43％,and the mortality was 14.29％ and 1.61％.Inpatients had a higher malnutrition-inflammation score(MIS,8.36 vs 5.86,P＜0.05) and subjective global assessment of nutrition (MQSGA,14.49 vs 12.88,P＜0.05),a lower creatinine level (886.83 μmol/L vs 991.76 μmol/L,P＜0.05 ) and a lower albumin level (38.57 g/L vs 40.27 g/L,P＜0.05) than out-patients.Inpatients also had a higher level of TNF-α (65.41 μg/L vs 59.76 μg/L,P＜0.05) than out-patients.Cox proportional hazard model analysis showed that MIS and TNF-α were associated with patient's first hospitalization risk. Conclusions For the MHD patients,the more severe the malnutrition and micro-inflammation status is,the worse the clinical outcome is.The higher levels of MIS and TNF-α result in greater risk of hospitalization.

Objective To investigate the effects of intestinal ischemia-reperfusion (I/R) on the brain in rats. Methods Sixty-four healthy male SD rats weighing 250-300 g were randomly allocated to one of 2 groups (n = 32 each): sham operation group (S) and intestinal I/R group (I/R). Intestinal I/R was produced by occlusion of superior mesenteric artery (SMA) for 90 min followed by reperfusion. Eight animals were sacrificed at each of the following time points: 2, 6, 12 and 24 h of reperfusion (T1-4) in each group. After a median sternotomyblood samples were taken from left ventricle for measurement of plasma TNF-α and IL-6 (by ELISA). Intestine and brain tissue was harvested for microscopic examination and detection of apoptosis ( by TUNEL). The cognitive function was tested using Morris water maze at 24 h. Results No abnormality was found in intestine and brain tissue in group S. Intestinal damage and neurodegeneration were detected in group I/R. Intestinal I/R significantly increased cerebral apoptosis in group I/R compared with group S. Plasma TNF-a and IL-6 concentrations were significantly higher at T1-4 in group I/R than in group S. The escape latency and swimming distance were significantly increased, while the number of crossing the platform was decreased in group I/R compared with group S. There was no significant difference in the swimming speed between the 2 groups. Conclusion Intestinal I/R can induce brain injury and lead to cognitive dysfunction. I/R-induced release of inflammatory mediators and neuronal apoptosis are involved in the underlying mechanism.

Objective To evaluate set-up errors by megavoltage cone-beam CT in head and neck cancers treated with precision radiotherapy. Methods From April 2007 to March 2008, 22 patients with nasopharyngeal carcinoma (15 patients) ,parotid carcinoma (4 patients) and brain glioma (3 patients) were enrolled, among whom 7 patients underwent three-dimensional conformal radiotherapy (3DCRT) and 15 received intensity modulated radiotherapy (IMRT). The radiation dose was 56. 0 -70.4 Gy in 28 -32 fractions within 6 -7 weeks. Megavoltage cone-beam scan was performed weekly before treatment. The isocenter displacement was calculated by comparing megavoltage cone-beam CT and planning CT in left-right (LR), cranio-caudal (CC), and anterior-posterior (AP) directions. Results Totally 129 sets of megavoltage cone-beam CT images were obtained for 22 patients. The frequency of isocenter shift more than 0. 3 cm,0. 4 cm and 0. 5 cm were 28,15 and 9, respectively. The maximum mean set-up error was found in CC, which was about 0. 1 cm more than that in LR and AP. The frequency of isocenter shift direction was almost identical in LR and CC, which was more frequent (about 75%) in the posterior direction. Conclusions During the course of radiation of brain tumor and head and neck cancer, the enlarging tendency of set-up errors has been found in all the three directions. The isocenter shift in AP was more frequent to the posterior direction.