BACKGROUND: Pleiotropia and indeterminateness of the differentiation of neural stem cells (NSCs) cause great difficulties for clinical application.Therefore,it is the key to solving the problem to investigate the proliferation and differentiation condition of NSCs.OBJECTIVE:To observe the effects of epidermal growth factor(EGF)and basic fibroblast growth factor (bFGF) on the proliferation and differentiation of neural stem cells of human embryonic brain.DESIGN: A randomised and controlled experiment taking cultured human embryonic stem cells as subjects.SETTING: Department of Pediatrics of Zhujiang Hospital, the First Military Medical University of Chinese PLA.MATERIALS:This experiment was conducted at the Central Laboratory of the Department of Pediatrics of Chinese PLA from January to May 2004.Two 16-week embryos from induced labor by water bags voluntarily were chosen at random from the Department of Obstetrics in a tertiary hospital in Guangzhou(Informed consent was obtained from the parents of the fetuses).Then,cells in the subventricular zone were cultured in serum-free medium and serum medium, respectively.METHODS:Primary cells of subventricular zone of human embryonic brain were cultured with serum-free nedium containing EGF,bFGF and EGF + bFGF.The concentration of two growth factors was both 20 μg/L;experiment of differentiation was performed on the cell neurospheres cultured from the primary generation with serum culture medium;differentia tive cells were detected with immonohistochemical technique.MAIN OUTCOME MEASURES:The number of neurospheres and the change of neurons and gliocytes from neurospheres in each group.RESULTS:① There was no significant difference in the number of primary neurospheres between bFGF group and EGF+bFGF group [(150.3±14.9) /well vs (173.6±26.4)/we11, P ＞ 0.05] , but the number in the two groups was both more than that in EGF group [(99.5±14.9)/we11, P ＜ 0.01].② The neurons differentiated from neurospheres in bFGF group and EGF+bFGF group outnumbered those in EGF group, but gliocytes in EGF group outnumbered those in EGF + bFGF group.CONCLUSION:① bFGF can promote the proliferation of neural stem cells of subventricular zone of human embryonic brain,and the formed neurospheres can differentiate more neurons.② Combination of EGF and bFGF is not superior to single bFGF in effect,suggesting that there is no synergistic effect.

BACKGROUND: Neural stem cells(NSCs) have been used to treat brain injury or some degenerating diseases of nervous system. Since in vitro culture conditions for NSCs differ from normal physiological conditions, whether the properties of the cultured cells are consistent with those of cells under physiological conditions? Therefore, inducing endogenous NSCs to proliferate and differentiate may be more promising for practise of NSCs.OBJECTIVE: This study was designed to investigate the developmental properties of NSCs in frontal cortex of embryonic human brain at various ages.DESIGN: It was a randomized experimental study.SETTING: This study was conducted at Department of Pediatrics, Zhujiang Hospital, Southern Medical University.PARTICIPANTS: Totally 90 16-to-36-week-old fetuses underwent inducing abortion by water bag were selected at the Obstetrics & Gynecology Department of Zhujiang Hospital Affiliated to Southern Medical University from October 2003 to March 2004. Brain tissue was taken from the frontal cortex of the aborted fetuses. All the mothers had normal physical examination findings. The informed consents on inducing abortion by water bag had been obtained from relatives and the mothers. The study was conducted with a prior permission from the competent department of the First Military Medical University. According to their ages, the fetuses were divided into 6 groups,16-week group, 20-week group, 24-week group, 28-week group and 36-week group, each group containing 15 cases.METHODS: After inducing abortion by water bag, under axenic conditions, the aborted fetus was dissected, with the scalp excisd, the skull opened and the membrane covering brain pull apart. Then the frontal cerebral cortex was taken out, fixed and sliced. Employing immunohistochemical staining and light microscope, distribution, morphological features, phenotypes, growth patterns and quantity of NSCs in the frontal cortex were observed. Morphological features of the cells and expressions of markers in the cells were examined under light microscope. Negative control was set according to the substitution method. Under a × 400 field of microscope, some nestin-positive cells with speckled brown cytoplasmic staining were defined as NSCs. Two slides of each sample were detected and 10 fields of each slide were observed. Based on these observations, in each group, the total number of cells and the number of positive-stained cells in 300 fields were counted. The rates of nestin-positive cells were calculated.MAIN OUTCOME MEASURES: Morphological features, quantitative assessment and developmental features of the nestin-positive NSCs in frontal cortex of embryonic human brain at various ages were main outcome measurements in this study.RESULTS: NSCs were found in frontal cortex of embryonic human brain. They mainly were distributed in the pyramidal layer and the internal granular layer. They were small round-or oval-shaped, most were small round-shaped. These cells had a relatively large vacuolar nucleus with 1 - 3 nucleoli, loose chromatin and marked cytoplasmic staining. Some of the round-shaped cells were mitral cells with short neurites. The oval-shaped cells had 2 neurites. A distinct territorial distribution of NSCs could be observed. Some colonies, consisting of a few NSCs and looked like the neurospheres in in vitro culture, could be seen. Occasionally, symmetrical division of NSCs could be observed. In all the groups, 16-week, 20-week, 24-week,28-week, 32-week and 36-week group, the rates of nestin-positive NSCs in frontal cortex of embryonic human brain decreased with the increase of age (15.59%, 13.48%, 11.62%, 10.52% ,9.87% ,6.68% ,X2 = 1 265. 152, P＜ 0.01).CONCLUSION: The distribution, morphological features, phenotypes, growth pattern and quantity of the NSCs in frontal cortex of embryonic human brain at various ages are different and auto-developmental features exist. The number of these cells decreases with the increase of age.

Objective To evaluate the efficacy and safety of dexmedetomidine aiding spinal -epidural anes-thesia for sedation.Methods Ninety ASAI -II female patients scheduled for elective spinal -epidural anesthesia were randomly divided into 3 groups(30 cases for each group)according to the digital table method.An epidural catheter was inseted at L2 -3 after satisfactory anesthesia,sedative drugs was intravenous.Group A received midazolam 0.05μg/kg initial loading dose for 10min and maintaining with 0.5μg·kg -1 ·h -1 .Group B received midazolam 0.06μg/kg for 5min and maintaining with 0.5mg·kg -1 ·h -1 .Group C received first intravenous injection of propo-fol 0.5 mg/kg,injection time 60s,maintaining with 0.3 -1.2mg·kg -1 ·h -1 .The infusion rate was adjusted to increase or decrease in order to maintain the desired level of sedation(Ramsay score of 3)during operation.The seda-tion efficacy and adverse reactions of three groups were compared.Results The onset time[(11.2 ±2.8)min]in group A was longer than that of group B[(6.4 ±2.4)min],group C[(5.0 ±2.1)min](t =7.12,9.70,all P <0.05).The offset time of group A,B[(12.3 ±2.4)min,(13.8 ±2.5 )min]were longer then those of group C [(7.4 ±2.3)min](t =8.36,7.95,all P <0.05).But 5 and 6 patients in the group B and C occurred hypoxia,and there were 8 and 9 patients developed partial airway obstruction due to relaxation of jaw muscle.At the time 30min, 60min and the end of surgery,the HR of the group A decreased deeply than the other two groups(t =5.02,4.92, 4.90,3.95,5.71,4.09,all P <0.05),10,5,6 patients were given atropine for increasing the HR in the group A,B and C respectively.Conclusion Dexmedetomidine is more safe and effective for the sedation of spinal -epidural an-esthesia,compared with midazolam and propofol,but with lower HR and longer onset time.

Objective To study the development of neural stem cells from human fetal brains at different developmental stages. Methods A total of 100 cases of embryos at 16-32 gestational weeks by induction of labor with water bag were collected for the determination of the distribution, forms, existing modes, and the number of neural stem cells in the hippocampus by SABC immunohistochemical method and light microscopy. Results Neural stem cells were found in the hippocampus at different fetal ages and located in the polymorphic layer, pyramidal, granular and molecular layers of hippocampus, mainly in polymorphic layer, pyramidal layer, and granular layer. Neural stem cells in hippocampus were round, ellipse, triangle, and stellate, particularly round and ellipse. No obvious enation was found. Neural stem cells had plenty of cytoplasm. The nuclei were round and ellipse with rare chromatin and nucleoli from 2 to 6. Most of neural stem cells were distributed among other neurons, and symmetric cleavage was found in some of them, but some neural stem cells were distributed in cluster and nest. The number of neural stem cells in hippocampus were different between groups and gradually decreased with the increasing gestational age. Conclusion Neural stem cells exist widely in the hippocampus at different gestational ages. There are differences in distribution, forms, existing modes, and number of neural stem cells in hippocampus at different gestational ages. Hippocampus may be the new originating region of neural stem cells.

Objective To investigate the application of blood purification for critical disease with non-renal indications in PICU. Methods We retrospectively analyzed the clinical data of 10 critical disease cases with non-renal indications in PICU admitted from Jan to Dec 2009. Five cases were with acute liver failure,2 with autoimmune disease (1 with Guillaln-Barre syndrome, 1 with systemic juvenile rheumatoid arthritis with macrophage activation syndrome) ,2 with severe sepsis,one with metabolic diseases. Results Four cases were treated with plasma exchange combined with continuous veno-venous hemmofiltration. Three cases were treated with continuous veno-venous hemmofiltration. Three cases were treated with plasma exchange.Conclusion CBP is an effective and safe method in the treatment of critical diseases with non-renal indications in PICU.

Objective To investigate the application of continuous blood purification in the children with critical diseases. Methods Eighteen critical patients aged 1 ～ 15 years in PICU underwent continuous blood purification(CBP). Fourteen with acute renal failure (ARF) were treated with continuous veno-venous hemmofiltration(CVVH) ,2 with Guillain-Barre syndrome and 2 with Raye's syndrome were treated with plasma exchange(PE). The changes of clinical symptoms, blood biochemistry , blood gas, and oxygenation were analyzed before and after CBP. Results After CVVH treatment, the BUN and creatinine of 14 patients with ARF were decreased from (48.6 ± 14. 8) mmol/L to(28. 9 ±5.4) mmol/L and (634. 3 ±258. 2) μ mol/L to (318.4 ± 143.5) μmol/L,K+ and pH of serum were maintained in the normal range,oxygenation was significantly improved. Breathing difficulties and muscle strength in 2 patients with GBS were ameliorated and successfully weaned from ventilator after PE. Serum ALT,AST and ammonia of 2 cases with Raye's syndrome decreased significantly and they discharged after comprehensive treatment including PE. Bleeding in puncture region were found in 3 patients, hypothermia in 2 patients. During the treatment, vital signs of patients were stable,blood pressure and pulse were not fluctuated. Conclusion CBP is an effective and safe method in the treatment of critical diseases in children.

Purpose To investigate the 18F-FDG PET/CT manifestation ofextranodal NK/T-cell lymphoma (ENKTCL) for providing important reference for the early diagnosis,accurate staging and guiding treatment of the disease.Materials and Methods The imagings and clinical data of twenty-six patients with nasal ENKTCL were analyzed retrospectively.The diagnosis was confirmed by pathological biopsy and immunohistochemistry.The distribution and metabolic signs of the lesions were summarized,and the influence of PET/CT on nasal ENKTCL staging was analyzed.Results Totally 102 positive lesions were detected in 26 patients.The SUVmax of all lesions was 12.2±5.4 (3.2-28.5).The primary lesions were mainly located in the nasal cavity (16/26,61.5％).Facial soft tissue and paranasal sinus tissue involvement were most common adjacent invasions.The distribution of the remaining affected tissues and organs in the whole body showed no obvious regularity.Lymph node involvement was most common in cervical lymph nodes.The lesion detection rates of PET/CT and conventional imaging (plain scan/enhanced CT,plain scar/ enhanced MRI,ultrasound,etc.) in lymph node and extranodal organ involvement were 96.7％ and 65.5％,respectively,and the accuracy of staging were 92.3％ and 73.1％,respectively.Clinical stages were changed in 15 patients (57.7％)because of PET/CT examination,among which,the staging was improved in twelve cases for finding more lesions,the staging of the suspicious lesions were reduced and the nature was defined in three cases because of their lack of metabolism on the PET/CT,and the treatment plan was affected in nine cases for staging adjustment.Conclusion 18F-FDG PET/CT can accurately show the distribution of nasal ENKTCL lesions.Compared with the conventional imaging methods,more lymph nodes and extranodal organ involvement can be detected by 18F-FDG PET/CT,which makes the staging more accurate and guides the clinical treatment more effectively.

Objective To study the role of deferoxamine(DFO)on regulating hypoxia-inducible factor 1α(HIF-1α)expression after hypoxia-ischemia brain damage(HIBD)in neonatal rats,to explore the therapeutic strategy for HIBD. Methods Postnatal day 10 SD rats were divided into four groups: hypoxia-ischemia(HI)group,DFO-treated group,normal saline(NS)-treated group,and sham operation group. HIBD model was established by the ligation of right common carotid artery following the inhalation of nitrogen-oxygen mixtures containing 92% nitrogen and 8% oxygen. DFO-treated group and NS-treated group were treated by intraperitoneal injection of DFO or NS respectively. The brains were collected at 4 h,8 h,and 24 h after hypoxia. HIF-1α protein expression was detected by Western blot analysis,and HIF-1α mRNA expression was detected by using RT-PCR at each time point. Results The synthetic level of HIF-1α protein increased significantly at 4 h,peaked at 8 h,and decreased at 24 h after HI in HI group,as well as NS-treated group. However,in DFO-treated group HIF-1α protein was peaked at 4 h,maintained higher level at 8 h and 24 h after HI. The level of HIF-1α protein was much higher in HI and DFO-treated groups than those in sham controls(P ＜ 0.05). The synthetic level of HIF-1α protein were higher in DFO-treated groups than those in HI groups at each time point(P ＜ 0.05). HIF-1α mRNA expression was higher in DFO-treated groups than those in HI groups at each time point. Conclusions DFO upregulate HIF-1α protein and mRNA expression in neonatal rats with HIBD. The peak of HIF-1α protein expression are also more advanced and lasted longer after DFO-treatment.

Objective To investigate the situation of oxygen supplement and the incidence and clinical characteristics of long-term oxygen inhalation newborns in neonatal intensive care unit(NICU).Methods The records of oxygen supplement and the related clinical data of 12 155 neonates admitted in our NICU from Oct 2009 to May 2011 were collected and retrospectively analyzed.The results were compared with the data from a survey on 19 hospitals in China which reported by other authors.Results In 12 155 newborns,4 951 were full term,7 204 were preterm.One hundred and two patients (0.84％,102/12 155 ) accepted oxygen for more than 28 days.Among them,88 were preterm,14 were full term,with the average gestational age (31.16 ±3.70) weeks,the average birth weight (1.60 ±0.68) kg and the mean oxygen supplement period (40.60 ± 12.25) d.Finally,98 were cured or improved,4 died.The incidence of bronchopulmonary dysplasia (BPD) in 7 204 preterm infants was 1.22％ ( 88/7 204) according to the standard of continuous oxygen supply more than 28 days after birth.The incidence of BPD in preterm infants less than 32 weeks was 4.92％ (68/1 381 ) according to the standard of continuous oxygen supply more than 28 days after birth,while the rate was only 2.10％ (29/1 381 ) according to the standard of continuous oxygen supply more than 36 weeks postmenstrual age.The rates of BPD according to the two different standards were significantly different ( x2 =16.251,P ＜0.001 ).There were significant differences in the rate of supply oxygen( x2 =119.99) and supply oxygen time( F =109.27 ) among different gestational age groups in overall the 5 499 neonates ( P ＜0.001 ),but no significant differences in the average time of oxygen supply and mechanical ventilation among different gestational age groups in infants with long-term oxygen dependence ( P ＞ 0.05 ).There were significant differences in rates of pulmonary surfactant therapy,heart failure,retinopathy of prematurity,congenital heart disease,other congenital malformation and mortality among different gestational age groups in long-term oxygen dependence infants (x2 =8.789,13.538,23.176,7.778,8.842,8.246,P ＜ 0.05 ).As compared with the data from 19 hospitals,the corrected rate of long-term oxygen supplement in preterm infants in our hospital was obviously lower[0.99％ (71/7204) vsl.54％ (190/12 351),P ＜0.001].Conclusion Theincidence of BPD in our NICU is low.Lower gestational age,immature lung and secondary lung injury may be the mainly cause of neonatal long-term oxygen dependence,but some factors such as congenital heart disease,congenital malformations should be considered in more mature infants.The most appropriate standard for BPD still remains to be discussed.