Objective To isolate and culture the neural stem cells (NSCs) from the cerebral cortex of newborn rats, and investigate the cell-replace responses of the NSCs transplanted into the sibling rats with focal cerebral cortex ischemic lesion. Methods The serum-free medium DMEM/F12 (1∶1) containing basic fibroblast growth factor (bFGF or FGF2) and epidermal growth factor (EGF) was used to culture the neural stem cell spheres. The NSCs were identified by detecting the neural stem cell marker nestin with enzyme immune assay and inducing neural stem cell spheres to differentiation. The NSCs which would be used in the transplantation experiment were labeled by BrdU incorporation when cultured in vitro. The focal ischemic models were made by opening the skulls and removing the cerebral menings of 4-day-old rats to stop the blood supply for the neopallium. The BrdU-labeled NSCs were transplanted into the cerebral lesion boundary zones of the focal ischemic sibling rat models. The experiment rats were divided into lesion-transplantation group, lesion-control group and sham-operation-control group. Recipients were killed and the brains were examined by detecting the BrdU-labeled cells with enzyme immunohistochemistry at 4,7,14,30 days postgrafting, indicating the grafts living and migration in the host. Results The neural stem cell spheres, which floated and grew in medium, expressed nestin, as well as gave rise to neurons and astrocytes, could be obtained through culturing the cells derived from the cerebral cortex of newborn rats in vitro for a week. In the transplantation of the NSCs, the grafts were easy to migrate along the boundary zones of the focal ischemic lesions, and promoted the restore of the tissue structures in the damaged areas, the damage recovered well through the cell-replace responses. The BrdU-labeled positive cells in the lesion areas were full of the visual fields under microscope, the greatest density of the positive cells were focused in the granular layer of the injured cerebral cortex and not found in remote sites from the lesion. The number of BrdU-labeled cells gradually decreased in the brains of the sham-operation-control rats, only a few positive cells were found when examined at 14 days postgrafting, significantly less than that in the lesion-transplantation rats. Conclusions NSCs exist in the cerebral cortex of newborn rats. The ischemia can promote proliferation and graft of NSCs. The grafted NSCs play an important role in the recovery of focal cerebral cortex ischemic lesion.

0.05) . No significant differences were observed between the expansion folds of hNSC derived from various fetal brain samples when cultured under the same conditions. LIF played great roles on cell proliferation,in LIF + groups, hNSC cell number increased ranging from 4 000-8 400 folds, no cell differentiation occurred; and in LIF" groups,only 43 to 96 folds.The differentiation phenomenons were watched when cultured more than two months. In the course of cell culturing, observed that the effects of LIF on hNSC expansion were obviously demonstrated 50-60 days after inoculation.The number of neurons and astrocytes differentiated from the cultured hNSC were respectively identified by means of Immuno-cytochemical fluorescent assay, and the percentages of neurons(as a proportion of neuron and astrocyte number) were calculated,which were ranging from 12% to 83% in LIF+ cultures, significantly higher than 8% to 23% in LIF- ones(P

AIM: Site-specific functional neurons of brains were with different cellular morphology. It has not been fully understood whether the grafted neural stem cells could differentiate into the site-specific neurons. This experiment is to investigate the neuronal differentiation of the neural stem cells derived from a human fetal brain after transplanted into young rats' brains, to study the possibility of cell-replacement therapy for children's brain disorders with neural stem cells. METHODS: Experiments were performed at the Cell Laboratory of Naval General Hospital from April to July 2007. ①Human fetal brain tissues of 16 week gestation were provided by Department of Gynaecology and Obstetrics of Naval Hospital. Pregnant woman and family members signed an informed consent. Experimental intervention was approved by Hospital Ethical Committee. Fourteen clean brood young SD rats aged 10 days, irrespective of gender, were provided by Experimental Animal Center of Medical College of Peking University. Animal intervention met the animal ethical standards. ②The neural stem cell spheres were derived from the fetal brain tissues of 16 week gestation. The differentiation multipotency of the neurosphere was identified when cultured in a child's cerebrospinal fluid (CSF). The neurospheres cultured in vitro for 14 days were injected into the lateral ventricles of young rats of 10 days old. The rats were respectively killed at days 4, 7 and 14 after transplantation. The special immuno-fluorescent assays were performed using anti-human neurofilament (anti-hNF) to show the location and morphology of graft neurons. RESULTS: ①The typical floating neurospheres were obtained, with the potency to differentiate into neurons, astrocytes and oligodendrocytes. ②The neuronal differentiation of grafts was detected with the mixture of three monoclonal antibodies against human neurofilament. Four days after transplantation, the immune response positive cells lied within the granule cell layer of cerebral cortex were shown in the shape of granule cells, or within the pyramid cell layer in the shape of pyramid cells with long processes, and the interneuron-like cells also were seen. The Purkinje cells arranging in a monolayer were detected in the cerebellum. Compared the results at different time points, the location of grafts were the same. The graft cells were less and the processes were longer over time. CONCLUSION: The in vitro cultured neurosphere cells can migrate into brain tissues and differentiate into site-specific neurons in shape after transplanting into the lateral ventricles of young rats. It is suggested that the host brain tissue microenvironment played an important role in guiding the graft differentiation into neurons. The results have an important significance for understanding cell replacement of developing brain disorders.

Objective To investigate the clinical practice pressure and mental health of medical students with type D personality.Methods Type D Scale-14 (DS14) and Beck-Srivastava Stress Inventory (BSSI) test were applied to 371 medical students to assess the personality types and pressure.The symptom checklist 90 (SCL-90) was used to evaluate the psychological health.Results ①The detection rate of type D personality of medical students was 36.39％.②The average score in BSSI of medical students of type D personality was (99.27± 10.51),which was higher than medical students of non-type D personality (87.60± 11.37),and the difference was statistically significant (t=9.9711,P=0.0000).The medical students' score of type D personality in SCL-90 of 9 factors were all higher than medical students of non-type D personality,but the statistically significant difference were only in the score of depression,anxiety and psychosis-like symptoms (t=2.4409,P=0.0151;t=2.8662,P=0.0044;t=2.7783,P=0.0057).Conclusion In face of the same pressure of medical clinical practice,the medical students of type D personality are more likely to have a heavier psychological burden,and the college should pay special attention to the problem and try to intervene the problem,so as to reduce the pressure caused by a variety of psychological problems.

Objective To investigate the clinical value of mean channel of neutrophil volume (MNV), mean channel of neutrophil conductivity (MNC) and mean channel of neutrophil scatter (MNS) in predicting acute bacterial infection.Methods Peripheral blood samples from 112 patients with positive blood cultures for bacteria,70 healthy subjects and 45 non-infectious subjects with high white blood cell count(WBC) were studied using the Coulter LH 750 hematology analyzer.MNV, MNC, MNS and neutrophil volume distribution width (NDW) were retrospectively analyzed and compared with total WBC, percentage of neutrophils,neutrophil left-shift and CRP.112 blood bacterial infections were grouped according to WBC count (A:WBC ＜11.0×109 /L;B:11.0×109/L≤WBC＜15.0×109 /L;C:WBC≥15.0×109 /L) and neutrophil rate (NE ＜ 0.85 and NE ≥ 0.85 ).Results MNV and NDW increased significantly in septic patients (154.17 ± 10.08,24.36 ± 4.14 ) compared with those of healthy control group (142.09 ± 4.13,19.04 ± 1.97) and non-infectious patients with high WBC group ( 150.63 ± 8.14,20.19 ± 4.73 ).There was statistically significant difference (F value were 20.738 and 28.190 respectively,P ＜ 0.01 ). On the contrary, MNS decreased significantly in septic patients (137.15 ± 7.61 ) compared with that of healthy group (144.51±4.36) and nonspetic patients with high WBC group (142.45±7.11) ,there was significant statistical difference (F=5.217,P＜0.01).The MNV, NDW and MNS of A group were 148.09±5.76,22.39±1.97,140.07±6.11 respectively.The MNV, NDW and MNS of B group were 152.83±5.75,24.14±1.35,141.44±5.35 respectively.The MNV, NDW and MNS of C group were 164.28±6.49,29.42±5.93,134.27±9.61 respectively. There was statistically significant difference compared with healthy group (F value were 24.720,31.642,7.931, P ＜ 0.01).The MNV, NDW and MNS in the group with NE ＜0.85 were 149.17±9.06,22.59±2.73,141.19±4.34 respectively.The MNV, NDW and MNS in the group with NE≥0.85 group were 159.03±10.23,27.64±4.51,135.62 ± 8.95 respectively.There was statistically significant difference compared with healthy group ( F value was 23.970,51.309,19.792,P＜0.01).With a cut-off of 150 for the MNV, a specificity of 90% and sensitivity of 70% were achieved.NDW was associated with neutrophil left-shift (r=0.33,P＜0.01).With a cut-off of 23 for the NDW, a specificity of 100% and a sensitivity of 72% were achieved.The sensitivity of the MNV and NDW was better than total white blood cells count (with a cut-off≥ 11.0×109 /L, the sensitivity was 57% ), percentage of neutrophils( with a cut-off≥0.85, the sensitivity was 44% ) and neutrophil shift to left ( with a cut-off ＞5%, the sensitivity was 66% ) and CRP (with a cut-off ≥10 mg/L, the sensitivity was 65% ).Conclusions The MNV and NDW of the neutrophil can reflect the morphologic change of neutrophil sensitively and specificialy in acute infection. As quantitative, objective and more sensitive parameters, MNV and NDW may have a potential role for predicting the acute bacterial infection.

OBJECTIVE: To investigate the effects of human cerebrospinal fluid (CSF) during development phase on migration and differentiation of fetal brain neural stem cells (NSCs).METHODS: Fetal brain cells of gestational age of 16 weeks that were frozen in liquid nitrogen were obtained, resuscitated and incubated in DMEM/F12 medium containing epithium growth factor (EGF), basic fibroblast growth factor (bFGF), B27 and N2. The neurospheres cultured for 14 days were obtained. CSF was absorbed from the subarachnoid cavity and brain ventricle in the embryonic group. CSF was collected by lumbar puncture or ventricular puncture in the child group. The neurospheres cultured for 14 days were transplanted into the pure CSF in an incubator containing 5% CO_2 at 37 ℃. Cellular migration and growth of neurospheres in CSF were observed. Effects of CSF on neural cell differentiation were identified by immunofluorescence. RESULTS: Neural stem cells in the form of neurospheres derived from fetal brain were inoculated into the pure CSF, and cell migration were commonly observed besides few of neurospheres in child CSF culture at 6 hours following culture. Surrounding cells of neurospheres extended processes, forming cell cord that became cell webs after extension. Compared with the embryonic group, positive rate of glial fibrillary acidic protein was significantly increased in the children group (P < 0.01), but positive rates of nerve fiber and nestin were significantly decreased (P < 0.01). In addition, galactocerebroside-positive cells were only found in 3 baby CSF cultures. CONCLUSION: There existed significant affections on both migration and differentiation of human neural stem cells when cultured in pure CSF with different developmental phase, suggesting that CSF is one of major niche factors for central neural system development.

Objective To investigate the clinical effect of human neural stem cells transplantation on severe visual disability infants after cerebral palsy. Methods Cells obtained from the forebrain of an 11-week-old abortive fetus were cultured and expanded for 15 days, then injected into cerebral ventricle of 7 patients. Results Their vision of 4 patients improved, as well as changes of flash visual evoked potential and functional magnetic resonance imaging in a few days after transplantation. Conclusion Neural stem cells transplantation may benefit in some CP children with severe visual disability.

Objective:The aim of this study was to explore the associations of muscle size and density with handgrip strength(HGS)and the Timed Up and Go(TUG)test.Methods:Totally 301 participants living in the Xinjiekou community near Beijing Jishuitan Hospital were recruited for CT imaging of the hip and a 1-cm slice of the mid-thigh.The cross-sectional area and density of the gluteus maximus and the mid-thigh muscles were estimated by the Osirix viewer based on CT images.HGS and TUG were also performed in these subjects.Logistic regression analysis was used to evaluate the correlations of muscle density and size with TUG and grip strength.Results:In women, after adjustment for age and BMI, the density of the gluteus maximus was negatively correlated with TUG( P trend=0.0366), while the size of the gluteus maximus and the mid-thigh muscles was not correlated with TUG.In men, the density or size of these muscles was not correlated with TUG.After adjustment for age and BMI, the density of the gluteus maximus was positively correlated with grip strength( P trend=0.0334)and the size of the mid-thigh muscles was also positively correlated with grip strength( P trend=0.0155)in men, but they were not correlated with grip strength in women. Conclusions:There were sex differences in the relationship between muscle size or density and grip strength or timed up and go.The density of the gluteus maximus is associated with muscle strength and physical performance while the size of the mid-thigh muscles is correlated with muscle strength.