Objective To establish a better method of isolating andculturing ofneural stem cells(NSCs) in neonatal rat brain. Methods Tissue of brain was isolated from neonatal rats. Different medium and culture concentration were used toculture NSCs of neonatal rat. The culture concentration used were 1×10 4, 1×105, 1×106and 1×107/ml respectively. Ingredient of medium was classified into group 1 to 8 respectively according to whether to add 2% B27, epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) as well as the difference in culture concentration. The cells were induced to differentiate asto be confirmed as NSCs, and then were checked by phase contrast microscopy and identified by immunocytochemistry. Results The cells isolated and cultured gathered into neurospheres. The cells were capable of proliferating and maintaining longterm survival in vitro. The cells could be differentiated into neurons and glia.It was to the benefit of the survival of NSCs to add 5% fetal bovine serum(FBS)into the medium at the beginning of the culturing. When 10% FBS was added intothe medium, the neurospheres differentiated quickly. When concentration 1×106/ ml was used, the growth rate of the cells was the highest of all the concentrations. Reasonably higher cell concentration promoted the proliferation of NSCs. It was necessary to add 2% B27, EGF, and bFGF into the medium. The cells had the best growth when 2% B27, 20 ng/ml bFGF and 20 ng/ml EGF were added into the culture medium. EGF and bFGF had cooperative effect. Conclusion A better method of isolating and culturing of NSCs in neonatal rat brain is established and the foundation for future research is laid.
Objective To study the effects of several neurotrophic factors and growth factors on the survival of human retinal ganglion cells(RGC)in vitro. Methods RGC were isolated from donor eyes and cultured.RGC in cell culture were identified by morphologic criteria and immunocytochemical staining.Various neurotrophic factors and growth factors were added individually to the cultures.Numbers of RGC in wells in which these agents had been added were compared with those from control wells(cultures without supplements). Results No or very few RGC were present in cell cultures containing medium without supplements or those supplemented with neurotrophin-3(NT-3),nerve growth factor (NGF),epidermal growth factor(EGF)amd plateletderived growth factor(PDGF).Numbers of RGC(per 10 fields)in cell cultures containing brain derived neurotrophic factor(BDNF),ciliary neurotrophic factor(CNTF),neurotrophin-4/5(NT-4/5)and basic fibroblast growth factor(bFGF)wer 4.08,1.23,2.63 and 2.65,respectively,significantly more than found in the control cultures. Conclusions BDNF,NT-4/5,bFGF,CNTF improve survival of human RGC in vitro,while NGF,NT-3,EGF and PDGF do not. (Chin J Ocul Fundus Dis, 1999, 15: 149-152)
Objective To observe the expression of related proteins of retina after subretinal implantation with inactive chips.Methods A total of 27 healthy adult New Zealand white rabbits were randomly divided into three groups: operation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina;shamoperation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina which was taken out immediately;the control group (3 rabbits). Animals were sacrified for immunohistological study 7,15,30 and 60 days after surgery.The rabbits in control group group were sacrified for immunohistological study after bred for 30 days.The expressions of glial fibrillary acidic protein (GFAP) and brain derived neurotrophic facor (BDNF) were observed.Results In operation group, the outer nulear layer of retina thinned, and the cells in the inner nulear layer was disorganized 7,15,and 30 days after the surgery;glial cells proliferated 60 days after surgery; the positive expression of BDNF and GFAP was more than that in the shamoperation and control group.In shamoperation group, the positive expression of BDNF and GFAP was more than that in the control group.No obvious difference of expression of BDNF and GFAP between each time point groups was found.Conclusions The expression of neroprotective related proteins increased after subretinal implantation with inactive chips suggests that limited neuroprotective effects might be led by the implantation.
Objective To set up and to evaluate an acute closed brain injury model in rats. Methods The acute closed brain injury was produced in rats by using an impactor consisting of a stand, a guide tube, a weight and a footplate. Ninetysix SD rats were divided into a control group(n＝32, no impact), a mild injury group(n＝32, impact once at force level of 400 g·cm) and a severe injury group(n＝32, impact once at force level of 800 g·cm) to elucidate the physiological responses, the pathophysiological changes and brain edema after brain injury at different injury levels. Results In the mild injury group and the severe injury group, a sudden rise or reduction of blood pressure, deep and fast breath apnea, and pain reflects inhibition were observed. The responses were more obvious in the severe injury group than in the mild injury group. The water content of the brain increased after 6 hours of injury. The pathological contusion and edema of brain were noted or above the impact force level of 800 g·cm. When the impact force rose to or over 1200g·cm, the animals died of persistent apnea mostly. Conclusion Although the established closed brain injury model with different biomechanical mechanisms as the clinical brain injury, it is in conformity with pathological changes and pathophysiological characteristics of acute clinical brain injury, it can be utilized extensively because of its convenient and practice.
ObjectiveTo observe the effects of human umbilical cord mesenchymal stem cells (hUCMSCs) on blood glucose levels and diabetic retinopathy in diabetes mellitus (DM) rats. MethodA total of 45 healthy male Sprague-Dawley rats were randomly divided into normal control group (group A, 10 rats) and DM group (33 rats). Diabetic model was established in DM group by tail vein injection of streptozotocin.The DM group was further randomly divided into 3 groups (11 rats in each group), including group B (no transplantation), group C (hUCMSC was injected through tail vein) and group D (hUCMSC was injected into the vitreous). Blood glucose, retina wholemont staining and expression of brain derived neurotrophic factor (BDNF) in the retina were measured at 2, 4, 6, 8 weeks after hUCMSC injection. The blood glucose was significantly different between A-D groups before injection (t=-64.400, -60.601, -44.065, -43.872; P=0.000) BDNF expression was studied by real time fluorescence quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry staining. ResultsThe blood glucose was significantly different between A-D groups after hUCMSC injection (F=400.017, 404.410, 422.043, 344.109; P=0.000), and between group C and group B/D (t=4.447, 4.990; P < 0.01). Immuno-staining shown that BDNF was positive in ganglion cell layer (RGC) of group A, weak in group B while BDNF expression increased in group C/D. BDNF mRNA expression was significantly different between group B, C and D at 4, 6 and 8 weeks after hUCMSC injection (F=29.372, 188.492, 421.537; P=0.000), and between group B and C/D (t=66.781, 72.401, 63.880, 88.423, 75.120, 83.002; P < 0.01) by RT-PCR analysis. The BDNF mRNA expression was significantly different between C and D groups only at 8 weeks after hUCMSC injection (t=127.321, P=0.005). ConclusionsTail vein injection of hUCMSCs can significantly reduce the blood glucose levels of rats. Intravenous and intravitreal injection of hUCMSCs can increase the expression of BDNF.
Objective To investigate the prognostic value of B-type natriuretic peptide (BNP) for short-term all-cause mortality in patients with acute pulmonary embolism (APE). Methods Such databases as PubMed, EMbase, Central Register of Controlled Trials, CBM, and CNKI (from the date of their establishments to March 2010) were searched. The level of BNP and N-terminal pro-B-type natriuretic peptide (NT-proBNP) was collected to conduct eligible cohort study for assessing their effects on APE prognosis. Quality assessment and data extraction were performed in those clinical trials in line with the inclusion criteria. Then, RevMan 5.0 software was applied to carry out meta-analyses. Results Sixteen relevant studies with 1 126 APE patients were included. Nine studies reported BNP level and seven studies reported NT-pro BNP level. There was less satistical and clinical Heterogeneity among the groups (P=0.94, I2=0; P=0.99, I2=0). The meta-analyses results showed: the BNP or NT-pro BNP level was closely related with the short-term all-cause mortality. SPE was 0.52, + LR was 1.87, –LR was 0.20, PPV was 0.16, NPV was 0.98, SROC area under the curve was 0.830 5, SE (AUC) = 0.033 5.Conclusion While elevated BNP levels can help to identify APE patients at a higher risk of death, the high negative predictive value of normal BNP levels is more useful for doctors to identify patients with less likelihood of adverse events so as to conduct a selective follow-up.
Objective To evaluate the diagnostic value of brain natriuretic peptide (BNP) for cardiac dyspnea.Methods Plasma BNP levels were measured by radioimmunoassay in dyspnea patients with chronic heart failure (CHF) (n=52) or without CHF (n=30) and normal control group (n=28).Results The BNP level in dyspnea patients with CHF was significantly higher than that of dyspnea patients without CHF and normal control group [(649.80±141.72) pg/mL vs (59.08±18.60) pg/mL and (65.20±16.32) pg/mL，respectively,Plt;0.05].There was no significant difference of BNP level between dyspnea patients without CHF and normal group (Pgt;0.05).The plasma BNP level elevated with the worsening of heart failure (NYHA Classiffication).The BNP level in dyspnea patients with CHF was negatively correlated with left ventricle ejection fraction (r=－0.673，Plt;0.001).The receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve (AUC) is 0.91(0.88-0.98，Plt;0.001) with a sensitivity of 87.2% and a specificity of 86.8% at the cutoff value of 206 pg/mL.Conclusion Measurement of plasma BNP is a rapid diagnostic method for cardiac dyspnea.
Objective To investigate the perioperative changes of serum brain natriuretic peptide (BNP) concentrations in patients undergoing cardiac valve replacement. Methods There were 20 patients admitted to the study, the serum BNP concentrations were measured before cardiac surgery, 24 hours, 7days, 14 days, and 30 days after operation. The preoperative NYHA cardiac function and the left ventricular ejection fraction(LVEF) were measured by echocardiogram. Results The preoperative BNP level was the baseline, it elevated markedly and acutely to a peak value 24 hours after operation ( P =0.003), then the BNP decreased 7 days later, but was still higher than the concentration before operation ( P =0.015), 14 days later it reached to the concentration before operation, 30 days later it was mild lower than preoperative BNP level, but there was no significant difference. There was a positive correlation between NYHA and BNP ( r =0.69, P lt;0.05), but no correlation between LVEF and BNP( r =0.29, P gt;0 05). Conclusion The preoperative serum BNP concentration can reflect the preoperative cardiac function in patients undergoing cardiac valve replacement, the high BNP level indicates the poor cardiac function. The BNP sharply elevated in the early time after operation, then gradually decreased in the late phase postoperation.
Objective To explore the pulmonary arterial pressure level in patients with predialysis chronic kidney disease ( CKD) and its relationship to cardiac structure and function. Methods 397 patients with predialysis CKD and 50 healthy subjects were enrolled. Cardiac structure was evaluated by Doppler echocardiography. Glomerular filtration rate ( GFR ) were assessed by radiant 99mTc-DTPA.Differences of PAP, BNP, LA, IVST, LVDd, LVDs, LVEF, LVMI and the correlation of PAP with cardiac structure and function were examined. Results The PAP level in the predialysis CKD patients was much higher than that in the healthy subjects [ ( 33. 13 ±9. 00) mm Hg vs. ( 29. 43 ±3. 71) mmHg, P lt;0. 01] .18. 9% of the CKD patients were complicated with pulmonary hypertension. PAP was higher in the CKD patients in stages 4-5 than those CKD patients in stages 1-3 [ ( 35. 90 ±9. 34) mmHg vs. ( 32. 08 ±8. 62)mmHg, P lt;0. 01) ] , so as to the prevalene of pulmonary hypertension ( 21. 60% vs. 13. 47% , P lt;0. 01) .Compared with the healthy, the level of lnBNP [ ( 3. 59 ±1. 63) pg/mL vs. ( 2. 88 ±1. 51) pg/mL, P lt;0. 01] , LA [ ( 40. 42 ±6. 77) mmvs. ( 36. 75 ±4. 94) mm, P lt; 0. 01) ] , LVPW [ ( 9. 55 ±1. 96) mm vs.( 8. 54 ±0. 88) mm, P lt; 0. 01) ] , IVST [ ( 9. 76 ±1. 75) mm vs. ( 8. 71 ±0. 90) mm, P lt; 0. 01) ] , LVMI[ ( 105. 61 ±36. 47) g/m2 vs. ( 87. 41 ±17. 08) g/m2 , P lt; 0. 01) ] were all much higher. There was a negative correlation between PAP and GFR( r = - 0. 461, P lt;0. 01) , and positive correlations between PAP and LA ( r=0. 491, P lt; 0. 01) , LVPW ( r =0. 298, P lt;0. 01) , IVST ( r = 0. 613, P lt;0. 01) , lnBNP ( r =0. 536, P lt;0. 01) , LVMI ( r = 0. 382, P lt;0. 01) . LVMI and lnBNP were both independent risk factors of PAP. The regression equation: y = 16. 447 + 0. 105x1 + 1. 724x2 ( F = 23. 482, P = 0. 000) , y: PAP( mm Hg) , x1 : LVMI( g/m2 ) , x2 : lnBNP( pg/mL) . Conclusions Pulmonary hypertension is a common morbidity of predialysis CKD patients, and deteriorates with degression of renal function. PAP is related to indexes of cardiac structure ( LVMI, LA, LVPW, IVST) and index of cardiac function ( lnBNP) . LnBNP and LVMI are independent risk factors of PAP.
Aiming at the problem of low recognition accuracy of motor imagery electroencephalogram signal due to individual differences of subjects, an individual adaptive feature representation method of motor imagery electroencephalogram signal is proposed in this paper. Firstly, based on the individual differences and signal characteristics in different frequency bands, an adaptive channel selection method based on expansive relevant features with label F (ReliefF) was proposed. By extracting five time-frequency domain observation features of each frequency band signal, ReliefF algorithm was employed to evaluate the effectiveness of the frequency band signal in each channel, and then the corresponding signal channel was selected for each frequency band. Secondly, a feature representation method of common space pattern (CSP) based on fast correlation-based filter (FCBF) was proposed (CSP-FCBF). The features of electroencephalogram signal were extracted by CSP, and the best feature sets were obtained by using FCBF to optimize the features, so as to realize the effective state representation of motor imagery electroencephalogram signal. Finally, support vector machine (SVM) was adopted as a classifier to realize identification. Experimental results show that the proposed method in this research can effectively represent the states of motor imagery electroencephalogram signal, with an average identification accuracy of (83.0±5.5)% for four types of states, which is 6.6% higher than the traditional CSP feature representation method. The research results obtained in the feature representation of motor imagery electroencephalogram signal lay the foundation for the realization of adaptive electroencephalogram signal decoding and its application.