Objective To study the spatiotemporal distributions of epithelial proliferation and apoptosis,and the correlation of morphogenesis with them in developing stomach.Methods Serial sections of fetal mice aged 11-15.5 days were made.The morphogenesis of stomach was observed under light microscope.The density of mitotic cells(DMC) and apoptotic bodies(DAB) of epithelium in the developing cardia,pylorus,greater curvature,lesser curvature were measured with stereological method.Results The morphological development of stomach took place on the 11~(th) day of mouse embryo development.The fundus,greater curvature and lesser curvature were observed on the 12~(th) day.The peak value of DMC all appeared before the peak value of DAB.In the epithelium of cardia,no obvious peak value of DMC was observed and the peak value of DAB was on the 11.5~(th),12.5~(th),13.5~(th) day.In the epithelium of pylorus,the peak value of DMC was on the 12.5~(th) day,the peak value of DAB was on the 14~(th) day.In the epithelium of greater curvature,the peak value of DMC was on the 11.5~(th) and 12~(th) day,the DAB value was low.In the epithelium of lesser curvature,the peak value of DMC was on the 11.5~(th) day,the peak value of DAB was on the 12.5~(th) day.Conclusion There was very close spatiotemporal relationship between the cell proliferation,cell apoptosis and the morphological development of stomach.

Objective To study the temporal and spatial expression of Nanog in developing primordial germ cells(PGCs) of mouse.Methods Immunofluorescence technique was taken to qualitatively analyze the expression of Nanog in PGCs of 7.5days(post-coitus days)-15.5days mouse embryo.A further quantitative analysis of Nanog expression change in PGCs of 11.5days-15.5days mouse embryo was done by using SSEA-1 and Nanog double labelling immunofluorescence staining with confocal microscopy.Results The PGCs in mouse allantois,hindgut,dorsal mesentery and genital ridge were Nanog positive.Both of the highest positive ratio and the highest fluorescence intensity appeared in PGCs of 11.5days mouse embryo.For the female mice,Nanog expression drops dramatically after 12.5days,and for the male mice,a noticeable decline of Nanog expression was occurred after 13.5 postcoitus days.Conclusion\ Nanog expresses stably in the proliferating PGCs.The down-regulation of its expression may be related with the differentiation of PGCs.

Objective To find out whether NOTCH receptors can serve as direct downstream targets of transforming growth factor β(TGF-β)/Smad4 signaling in endothelial cells.Methods Real-time PCR and Western blotting were performed to verify whether the expression of notch1 and notch4 was regulated by TGF-β pathway.Luciferase reporter assay was employed to investigate how the promoter of notch1 and notch4 was regulated by TGF-β.Then, ChIP assay was used confirm whether the promoter of notch1 and notch4 physically interacted with SMAD protein.Results TGF-β1 and bone morphogenetic protein 4 (BMP4) treatment increased the expression of both notch1 and notch4 at the transcriptional level.In addition, SMAD4 was physically associated with the SMAD binding sites on the notch4 promoter, which was largely enhanced under the treatment of TGF-β1 and BMP4.Importantly, TGF-β1 and BMP4 failed to transactivate notch4 in the absence of endogenous SMAD4 or the SMAD binding regions on the notch4 promoter.Conclusion The expression of NOTCH receptor can be directly up-regulated by SMAD4-mediated TGF-β/BMP signaling in cerebrovascular endothelial cells.

AIM:Studies on totipotential stem cells using primordial germ cells (PGCs) have the same application prospect as embryonic stem cells, especially for the animals difficult to isolate embryonic stem cells from blastula. In vitro culture condition of embryo germ cells is the key to control this. This study designs a method to effectively amplify PGCs of mice in vitro and establishes an effective culture method of PGCs. METHODS: Experiments were carried out in the Department of Histology and Embryology of Chongqing Medical University and Key Laboratory of Biochemistry and Molecular Pharmacology from October 2006 to August 2007. ①Clean Kunming pregnant mice (embryos 0.5 dpc) were provided by Animal Experimental Center of Chongqing Medical University. Experimental procedures met the animal ethical standards. ②Allantois and surrounding tissues of 8.5 day post coitum (dpc) embryos, the hindhut and surrounding tissues of 9.5 dpc and 10.5 dpc embryos, the gonadal ridges and surrounding tissues of 11.5 dpc and 12.5 dpc embryos were collected and digested with 0.25%pancreatin-0.02%EDTA, then the cells were cultured in the plastic petridishes which are pretreated with 0.1% gelatine. The formation ratio of primary and the first passaged Embryonic germ (EG) clones were compared among those different time points. The SSEA-1 positive ratio of isolated cells was compared between the two days by immunohistochemical method. The assays of clone numbers counting and MTT were used to compare the different proliferation ability of PGCs from the 11.5 dpc and 12.5 dpc embryos. The effects of expanding PGCs from 11.5 dpc and 12.5 dpc embryos by those two ways above were compared. The EG clones were analyzed by the expression of alkaline phosphatase and the immunologic marker SSEA-1,the undifferentiated marker Nanog and the differentiation ability in vitro were also tested. RESULTS:①The formation ratio of primary and the first passaged EG clone from 11.5 and 12.5 dpc embryos was higher than that from 8.5 to 10.5 dpc embryos and efficiency of expansion was increased (P 0.05). On the third day, the number of the primary EG clones from 11.5 dpc embryos was higher than that from 12.5 dpc embryos (P 0.05), but the two groups had different characteristics. ④The EG clones have representative morphology with high level of alkaline phosphatase activity and SSEA-1, Nanog expression, which can differentiate into the cystic embryoid body. CONCLUSION: 11.5 dpc and 12.5 dpc mouse embryos, especially 11.5 dpc embryos are the optional time points to expand PGCs efficiently. Co-culturing with the tissue and isolating the gonadal ridges both of these two ways are practicable.

Objective To reconstruct three-dimensional femoral footprint of the anterior cruciate ligament(ACL) by dual-source CT(DSCT),which can provide a novel positioning system particularly applicable in the anatomic ACL reconstruction under arthroscopy. Methods DSCT scanning was performed for the bilateral knees of 30 healthy volunteers.Three-dimensional reconstruction of the lateral wall of the intercondylar notch was done with 64-slice spiral CT workstation(GE,Volume Share2-AW 4.4 version).Double-bundle footprints of the ACL femoral insertions were identified, outlined and marked on the three-dimensional models.The over-the-top junction of the distal femur and the trochlea of femoral lateral condyle was dotted as a reference point O.The femoral footprint long and short axes,the footprint angle between the line passing through 2 centers of anteromedial and posterolateral bundles and the femoral shaft,the distance between 2 bundle centers,the shortest distance from the footprint edge to the distal femoral cartilage,and the shortest distance from the footprint edge to the posterior margin of the femoral cartilage were measured on the models with a standardized scale. Results All the ACL femoral footprints were successfully reconstructed by DSCT in the 60 knee joints.They were relatively protruding,plain,irregular in shape but identical in grey scale,distinct areas on the image. On the three-dimensional models of femoral lateral condyle,a 3-point-2-angle positioning system applicable in arthroscopic anatomic ACL reconstruction was successfully established and used to define and describe the double-bundle insertions of ACL.The mean long and short axes of ACL femoral footprint were respectively 16.5 ± 1.8 mm and 8.0 ± 1.3 mm; the mean ACL footprint angle was 8.3° ±4.9°; the mean distance between 2 bundle centers was 7.8 ± 1.0 mm; the mean shortest distance from the footprint edge to the distal femoral cartilage was 1.6 ± 1.5 mm; the mean shortest distance from the footprint edge to the posterior margin of the femoral cartilage was 1.7 ± 0.9 mm. Conclusions Three-dimensional ACL femoral footprints can be clearly reconstructed with DSCT.Natural ACL femoral footprints vary from person to person,which indicates a need of individualized reconstruction in order to restore the anatomy in maximum.The 3-point-2-angle positioning system we have developed is just suitable for arthroscopic ACL reconstruction.

Objective To investigate the current situation of healthcare-associated infection(HAI)management in secondary and above medical institutions in Shaanxi Province,analyze development trend,and put forward sugges-tions for improvement.Methods In May-June,2016,170 secondary and above hospitals in 10 cities were selected for surveying through stratified random sampling method.Survey content included basic situation of hospitals,HAI management,HAI monitoring,and so on.Results Available questionnaires were obtained from 165 hospitals (43 tertiary hospitals,and 122 secondary hospitals).Of 165 hospitals,more than 90% have established HAI manage-ment organizations and regulations,but hospital risk management should be paid more attention,only 63.03% of hospitals perfected the risk management system and 66.06% conducted risk assessment.99.09% of hospitals im-plement training on HAI to all staff regularly and 88.41% conducted effective feedback.In the aspect of staff alloca-tion,88.48% of the hospitals assigned enough professionals for HAI management,but only 34.55% have specific training programme for these personnel.Only 33.94% of hospitals have special funds for HAI control;in the aspect of monitoring on HAI,21.21% of hospital installed and used HAI monitoring software;In the aspect of implemen-tation of monitoring programme,about 90% of hospitals developed monitoring on HAI cases and environmental hy-giene,but only 34.55% and 23.64% of hospitals conducted targeted monitoring on intensive care unit and neonatal intensive care unit respectively.Conclusion Organizational structure of HAI management in Shaanxi Province is perfect,relevant rules and regulations are basically established,basic monitoring projects are universal,but the awareness of risk management needs to be strengthened,professional allocation and professional quality develop-ment are both imbalance,informational monitoring is inadequate.

Objective To investigate the value of Pituitrin in neonatal cardiopulmonary resuscitation.Methods Seventy-three cases with neonatal cardiopulmonary arrest admitted in emergency department and NICU in our hospital were collected during 2007 to 2011.Newborns who did not respond to conventional neonatal resuscitation therapy were divided into two groups:epinephrine group 47 cases (control group) and Pituitrin combined with epinephrine group 26 cases (treatment group).Results There were no statistical difference (x2 =0.956,P ＞ 0.05) between treatment group and control group in the rates of initial resuscitation success (23.1％,6/26 vs 34.0％,16/47).Conclusion Pituitrin combined with epinephrine has similar efficacy with the use of epinephrine in neonatal cardiopulmonary resuscitation.

Physiology is the main course in the education of preclinical medicine.And the functional experiment education is one of the important ingredients in it.The teaching style should be open,the students capability of independent thoughts should be raised and at the same time their precise scientism and cooperation spirit should be cultivated following the basic outline of teaching.

Objective To investigate the isolation, purification and culture methods of human embryonic germ cells (EGCs) on feeder layer cells of human embryonic fibroblasts. Methods Primordial germ cells(PGCs) from the genital ridges of 6-11 weeks(post fertilization) human embryos were cultrued on feeder layer cells of human embryonic fibroblasts(HEFs) which were isolated from the 3-4 month embryos and routinely cultured for over 25 passages. The medium composed of growth factors and differentiation inhibitory factors. The cultures were analyzed with the expression of alkaline phosphatase, immunologic markers (SSEA-1,SSEA-4) and the transcription factor Oct-4 that have been used to routinely to characterize EGCS. Results A large-scale EG cells were obtained and meintained on feeder layers for over 8 passages. The cell surface marker showed that the EGCs possess high levels of AP activity. EGCs colonies stained strongly for SSEA-4,SSEA-1 and they expressed the transcription factor Oct-4.Conclusion EGCs have potential to maintain long term proliferation and undifferentiation state on human embryonic fibroblasts in vitro.;

Objective To investigate cleanliness of hospital environmental object surfaces and hands of health care workers(HCWs).Methods The adenosine triphosphate (ATP)bioluminescence assay was used to detect object surfaces and hands of HCWs in a hospital,on-the-spot intervention was conducted.Results The qualified rates of hospital environmental object surfaces and ventilator-relevant object surfaces were 58.14% (200/344)and 69.88%(116/166)respectively,the qualified rate of ventilator tracheal intubation site was low (29.17%);the qualified rate of telephone surfaces was the lowest (27.27%).The qualified rates of ventilator-relevant object surfaces used con-tinuously for ≥48h and <48 h were 56.70%(55/97)and 88.41 %(61/69)respectively,there was significant differ-ence between the two(χ2 =19.26,P <0.01).The qualified rates of HCWs’hands before and after intervention were 34.18% and 85.58% respectively,relative light unit (RLU)values were (1 033.46±106.20)and (80.46±10.68) respectively,the qualified rates and RLU before and after intervention were both significantly different (both P <0.01).Conclusion Contamination of object surfaces and hands’of HCWs in hospital dynamic environment is seri-ous,ATP bioluminescence detection and on-the-spot intervention is helpful for improving cleanliness of hospital en-vironment object surfaces and HCWs’compliance to hand hygiene.