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31.
腺病毒介导的NT-3基因在骨髓间质干细胞中的表达   总被引:1,自引:0,他引:1  
目的:研究腺病毒介导的NT-3基因在培养的大鼠骨髓间质干细胞(mesenchymal stem cells,MSCs)中的表达.方法:在293细胞中培养扩增NT-3重组腺病毒(adenovirus vector for NT-3,Ad-NT-3),测定病毒滴度,然后用Ad-NT-3感染传代培养的MSCs,RT-PCR技术检测NT-3基因的表达.结果:Ad-NT-3扩增后获得了较高滴度的病毒,MSCs经Ad-NT-3感染后有NT-3 mRNA的转录.结论:腺病毒介导的NT-3基因可转入培养的MSCs并高效表达,为NT-3基因治疗的研究奠定了基础.  相似文献   
32.
用印地安墨汁注入活体鸡胚心脏,在体现显微镜下观察112例第10~20期鸡胚第一对弓动脉的发生。第一对弓动脉于第10期出现,至第20期退化消失。第一对弓动脉出现时尚无相应的第一咽弓,随着第一咽弓的出现,第一对弓动脉的起始端形成一个突入第一咽弓内的动脉瘤样隆起,此隆起随着第一咽弓的增大逐渐发育成一对贯穿第一咽弓的弓状血管。第一对弓动脉可以分为位于第一咽弓内的近侧段和位于此咽弓之外,与背主动脉相连的远侧段。  相似文献   
33.
Atrioventricular Conduction Variability. Introduction: Atrioventricular AV) conduction time varies on a beat-by-beat basis in response to the influences of cardiac efferent autonomic activity and rate-dependent electrical recovery processes. The goals of this study were to distinguish these effects on AV conduction time and to compare the variability in sinoatrial and AV nodal function. Methods and Results: The PR interval on the surface ECG served as an index of AV conduction time in this study of 14 adult human subjects undergoing a random interval breathing protocol. P and R waves were located by a template-matching algorithm. Spectral analysis allowed frequency-domain comparisons between PR and RR interval variability. Spectra of PR and RR intervals had similar power distributions, although the power of the RR interval spectra was much greater. Autonomic blockade with atropine plus propranolol reduced the power of both spectra. Standing significantly decreased the spectral power from 0.15 to 0.5 Hz for PR and RR spectra, and introduced a peak near 0.1 Hz in the mean PR and RR spectra, although the latter finding was significant only for the RR interval spectra. Propranolol had no significant effects on the PR and RR interval spectra. Linear regression analysis allowed quantification of the autonomic and recovery effects on AV conduction and showed which effect predominated. Simple linear regression confirmed in adults a previous finding in children that conduction time may be either positively or negatively correlated with cycle length. By multiple regression and transfer function analysis, the inverse relation seen in some subjects was attributed to the effect of recovery from the preceding cycle. With the preceding recovery period accounted for, the conduction time and cycle length of the current beat were positively correlated, presumably due to the parallel autonomic effects on the sinoatrial and AV nodes. The magnitude of the recovery effect predicted by the regression analysis was similar to published values. Conclusion: A noninvasive evaluation of the surface ECG can be used to compare variability in AV conduction time and cycle length and characterize the effects of autonomic efferent activity and rate-related recovery on AV nodal function.  相似文献   
34.
Reduction potentials were determined for various anticonvulsants, including progabide, SL 75.102, CGS 9896, pyridazines, zonisamide, 1,2,3-triazoles, and copper complexes. The values generally were in the range of about -0.1 to -0.6 V for the protonated drugs and the metal complexes. Reduction potentials provide information on the feasibility of electron transfer (ET) in vivo. If the value is relatively positive (greater than about -0.6 V), the agent can act catalytically as an electron acceptor from an appropriate cellular donor. A concomitant favorable influence on abnormal neuronal processes associated with epilepsy could occur. We describe ET as a possible mode of action of anticonvulsants as well as some antiepileptic agents with no electrochemical data based on this hypothetical ET approach.  相似文献   
35.
Embryos from two strains of mice were used to assess the effect of incubation temperature on pronuclear and twocell development to the morula/blastocyst (M/B) stage. Embryos from B6D2F2 and B6SJLF1 strains were cultured in medium M16 at either 37 or 39°C until 120 hr post human chorionic gonadotropin (hCG) or 0, 24, or 48 hr at 37°C and the remaining time at 39°C. Overall M/B development for pronuclear embryos was 0.6, 0, 32.3, and 52.4% for 0—96, 24—72, 48—48, and 96—0 hr at 37 and 39°C, respectively. Only 0—96 and 24—72 hr at 37 and 39°C were not different (P >0.10). Overall M/B development for two-cell embryos was 48.1, 78.1, and 98.0% for 0—72, 24—48, and 72—0 hr at 37 and 39°C, respectively. Percentage development at each time was different (P <.01) for each category. Additionally, the number of nuclei for morulae and blastocysts tended to be higher for embryos initiating culture at the two-cell stage compared to pronuclear embryos. The first cell cycle was most dramatically affected by a 2°C increase in incubator temperature. More advanced embryos can tolerate slight increases in incubator temperature more readily than pronuclear embryos.  相似文献   
36.
研究了吡哌酸与四氯苯醌间的荷移反应.两者在硼砂缓冲溶液中形成1∶1的络合物,其λ_(max)为330.8nm,摩尔吸光系数ε=1.66×10~4,RSD为2.2%。用于测定制剂含量,结果与药典方法一致。  相似文献   
37.
Results are reported on the regioselective C‐deuteriation of 2‐methyl‐tetralone using a series of D‐sources and tertiary amines as potential mediators. The results presented further aid the understanding of kinetic deuteriation of both ‘base‐containing’ and ‘base‐free’ enolates. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
38.
Abstract. The mechanisms responsible for the decreased high density lipoprotein (HDL) cholesterol levels associated with obesity and insulin resistance are not well understood. Lecithin: cholesterol acyltransferase (LCAT) and cholesterol ester transfer protein (CETP) are key factors in the esterification of cholesterol in HDL and the subsequent transfer of cholesteryl ester towards apolipoprotein B-containing lipoproteins. Phospholipid transfer protein (PLTP) may be involved in the regulation of HDL particle size. We therefore measured the activities of LCAT, CETP and PLTP using exogenous substrate assays, as well as lipids, lipoproteins, insulin and C-peptide in fasting plasma from eight healthy obese men (body mass index >27 kg m-2) and 24 non-obese subjects. The obese men had lower levels of HDL cholesterol (P<0·05) and higher levels of plasma triglycerides (P<0·05), insulin (P<0·05) and C-peptide (P<0·01), as compared to the quartile of subjects with the lowest body mass index (BMI <22·4 kg m-2). CETP and PLTP activities were elevated in the obese men by 35% (P<0·01) and by 15% (P<0·05), respectively. LCAT activity was comparable among the quartiles. Linear regression analysis showed that CETP activity was positively correlated with body mass index (P<0·02), fasting blood glucose (P7lt;0·05) and plasma C-peptide (P<0·05). PLTP activity was positively related to body mass index (P<0·01), waist to hip circumference ratio (P<0·001), as well as to fasting blood glucose (P<0·05) and plasma C-peptide (P<0·05) It is concluded that the activities of CETP and PLTP are influenced by adiposity and possibly by insulin resistance. Elevated lipid transfer protein activities may provide a mechanism that contributes to alterations in HDL in insulin resistant states.  相似文献   
39.
抗乙肝胎盘转移因子的特异免疫活性观察   总被引:8,自引:0,他引:8  
本研究由HBVM-Ab阳性胎盘提取的抗乙肝胎盘转移因子(PSTF)的特异免疫活性证明,经注射,小鼠外周血淋巴细胞明显增多,胸腺重量和指数亦显著增加,酯酶染色证明75%属T-样淋巴细胞,25%属Thy-样淋巴细胞,人白细胞或小鼠白细胞体外转移PSTF特异免疫活性、或豚鼠和小鼠体内转移PSTF特异免疫活性,再取其白细胞作白细胞粘附抑制、白细胞移动抑制、特异淋巴细胞转化、小鼠足掌注射和诱生γ-干扰素试验  相似文献   
40.
BACKGROUND: Food allergy to cherry occurs throughout Europe, typically with restricted oral reactions in the central and northern parts but with frequent systemic reactions in the Mediterranean region. Previous studies have demonstrated insufficient sensitivity of commercially available cherry extract reagents in the diagnosis of cherry allergy. OBJECTIVE: To assess the diagnostic performance of specific IgE tests based on recombinant cherry allergens in comparison with an extract-based assay and to skin prick test (SPT). A secondary objective was to analyse the frequency of systemic reactions in cherry-allergic subjects across Europe, including the largest population of LTP-sensitized subjects from central Europe studied to date. METHODS: A total of 186 subjects from central Europe and Spain were studied. Serum IgE was analysed with ImmunoCAP tests carrying rPru av 1, 3 and 4, combined and separately, and cherry extract. RESULTS: Among the central European cherry allergics, the mix of rPru av 1, 3 and 4 had a sensitivity of 95%, compared with 65% for cherry extract, and the IgE binding capacity of the recombinant mix was considerably higher. The sensitivity of the two tests was more comparable in the Spanish population, 95% and 86%, respectively. The recombinant allergen ImmunoCAP equalled SPT in terms of sensitivity and specificity. Consistent with previous reports, major geographic differences in sensitization pattern and prevalence of systemic reactions were found. A significantly higher rate of systemic reactions was found in Spanish patients sensitized to Pru av 3 whereas German patients sensitized to LTP only had oral allergy syndrome. CONCLUSIONS: The recombinant cherry allergen ImmunoCAP is a highly sensitive diagnostic tool, clearly superior to any diagnostic method based on cherry extract. Three cherry allergens are sufficient for detecting sensitization in 95% of cherry-allergic subjects. Systemic reactions are common in LTP-sensitized individuals but seem to require at least one additional causative factor.  相似文献   
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