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21.
Limited diversity of the protein D gene (hpd) among encapsulated and nonencapsulated Haemophilus influenzae strains. 下载免费PDF全文
Protein D is a surface-exposed lipoprotein of the gram-negative bacterium Haemophilus influenzae with affinity for human immunoglobulin D myeloma protein. The gene encoding protein D (hpd) in a serotype b strain of H. influenzae was cloned. Escherichia coli carrying the hpd gene bound human myeloma immunoglobulin D. Nucleotide sequence analysis identified an 1,092-bp open reading frame that was more than 99% identical to the hpd gene from a nontypeable H. influenzae strain. In the deduced amino acid sequences for protein D, only 2 of 364 amino acid residues differed. The restriction fragment length polymorphism of the hpd region in different strains was analyzed by Southern blot analyses of PstI- or EcoRI-digested genomic DNA from 100 H. influenzae strains. The analysis was performed by using isolated fragments of the cloned hpd gene, originating from the nontypeable H. influenzae 772, as probes. All strains tested had DNA sequences with a high degree of homology to the hpd probes. The analysis also showed that restriction endonuclease sites within the gene were more conserved than sites adjacent to the hpd gene. An interesting difference between type b strains and unencapsulated strains was observed. The majority of type b strains seem to have a 1.4-kbp DNA fragment upstream of the hpd gene that is absent in nontypeable strains. On the basis of the high degree of conservation of the hpd gene among H. influenzae strains, we conclude that protein D is a possible vaccine candidate. 相似文献
22.
23.
阮强 《中华微生物学和免疫学杂志》1994,(5)
研究资料表明,人巨细胞病毒(HCMv)单一蛋白的单一抗原决定簇只能被部分患者阳性血清识别。组建在血清学诊断中能够替代全病毒抗原的基因工程抗原,需要含有病毒多种主要抗原蛋白的抗原决定簇。为搞清在表达载体中重复插入某一抗原决定簇基因是否能表达出更高抗原效价的融会蛋白,我们用点突变的方法,在表达载体中分别插入了人HCMv的ppUL32蛋白羧基端一个抗原决定簇基因的1个、2个和3个拷贝。在免疫转印检测中,这些克隆表达的融合蛋白与特异性阳性血清的反应性差别不明显。这表明,插入表达载体中目的基因的多寡对表达蛋白的抗原效价没有显著影响。 相似文献
24.
我们以前曾报道,表达单纯疱疹病毒Ⅱ型糖蛋白D(HSV-2gD)的重组痘苗病毒(实验疫苗株)能保护被免疫小鼠抵抗致死量HSV-2病毒的攻击。在此工作基础上,严格按人用疫苗研究要求的实验条件,成功地建立了表达HSV-2gD的重组痘苗病毒活疫苗株。首先将经聚合酶链反应(PCR)修饰的HSV-2gD基因插入痘苗表达质粒pJSB1175,置于痘苗病毒P75K早/晚期启动子控制下。将此重组质粒用Lipofectin方法转染已受野型TK+痘苗病毒天坛761株感染的人胚肺二倍体细胞。经同位素探针(32P-HSV-2gD)原位杂交法和3轮蚀斑纯化,筛选出基因组内整合有HSV-2gD基因的重组痘苗病毒。斑点和Southern杂交证实,HSV-2gD基因已插入痘苗病毒基因组内预期的TK区段,间接免疫荧光检测显示,重组病毒感染细胞后能有效地表达HSV-2gD蛋白。 相似文献
25.
Mei Shuang Jing Liu Mei Xiang Jia Jian Zhong Yang Su Ping Wu Xiao Hong Gong Yan Su Ling Yan Ruan Xiao Ling Yang Dai Zhang 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2004,(1):48-50
The glutamate pathways are involved in diverse processes such as learning and memory, epilepsy, and they play important roles in neural plasticity, neural development, and neurodegeneration. It has been proposed that autism could be a hypoglutamatergic disorder. Recently, Jamain et al. reported that the glutamate receptor 6 (GluR6 or GRIK2) is in linkage disequilibrium with autism. In the present study, the transmission disequilibrium test (TDT) and the haplotype transmission were performed to analyze the four SNPs (SNP1: rs995640; SNP2: rs2227281; SNP3: rs2227283; SNP4: rs2235076) of GluR6 in 174 Chinese Han parent-offspring trios. The TDT demonstrated that the two SNPs (SNP2 and SNP3) showed preferential transmission (TDT P = 0.032). The global chi(2) test for haplotype transmission also revealed an association between GluR6 and autism (chi(2) = 10.78, df = 3, P = 0.013). Our results suggested that GluR6 is in linkage disequilibrium with autism. 相似文献
26.
An animal model of SARS produced by infection of Macaca mulatta with SARS coronavirus 总被引:16,自引:0,他引:16
Qin C Wang J Wei Q She M Marasco WA Jiang H Tu X Zhu H Ren L Gao H Guo L Huang L Yang R Cong Z Guo L Wang Y Liu Y Sun Y Duan S Qu J Chen L Tong W Ruan L Liu P Zhang H Zhang J Zhang H Liu D Liu Q Hong T He W 《The Journal of pathology》2005,206(3):251-259
A new SARS animal model was established by inoculating SARS coronavirus (SARS-CoV) into rhesus macaques (Macaca mulatta) through the nasal cavity. Pathological pulmonary changes were successively detected on days 5-60 after virus inoculation. All eight animals showed a transient fever 2-3 days after inoculation. Immunological, molecular biological, and pathological studies support the establishment of this SARS animal model. Firstly, SARS-CoV-specific IgGs were detected in the sera of macaques from 11 to 60 days after inoculation. Secondly, SARS-CoV RNA could be detected in pharyngeal swab samples using nested RT-PCR in all infected animals from 5 days after virus inoculation. Finally, histopathological changes of interstitial pneumonia were found in the lungs during the 60 days after viral inoculation: these changes were less marked at later time points, indicating that an active healing process together with resolution of an acute inflammatory response was taking place in these animals. This animal model should provide insight into the mechanisms of SARS-CoV-related pulmonary disease and greatly facilitate the development of vaccines and therapeutics against SARS. 相似文献
27.
In order to investigate the role of monocyte/macrophages and their relationship to the expression of macrophage colony-stimulating factor (MCSF) in pulmonary atherosclerosis, lungs were excised from rabbits that had been fed for 60 and 90 days on a diet containing 0.5% cholesterol. In the lungs, fatty streaks and elevated foam cell lesions predominated in the large or medium-sized elastic pulmonary arteries, while massive accumulation of foam cells in the intima of muscular arteries produced marked luminal narrowing and nearly complete occlusion. In these lesions, most of the foam cells were reactive with RbM2, a monoclonal antibody (mAb) against rabbit macrophages, while smooth muscle cell-derived foam cells were detected by mAb against smooth muscle actin in the deeper area of elevated foam cell lesions of elastic arteries. Ultrastructural observation confirmed the presence of monocytes in the intima, their differentiation into macrophages, and their transformation into foam cells in the atherosclerotic lesions. lmmunohistochemical expression of MCSF was demonstrated in the endothelial cells, smooth muscle cells and foam cells. A minor macrophagederived foam cell population was demonstrated to possess a prolif-erative capacity. These data suggest that MCSF is involved in the differentiation of monocytes into macrophages, their transformation into foam cells, and their proliferation during pulmonary atherogenesis. 相似文献
28.
Protection by a taurine supplemented diet from lead-induced deficits of long-term potentiation/depotentiation in dentate gyrus of rats in vivo 总被引:2,自引:0,他引:2
Previous studies have demonstrated that synaptic plasticity, which includes long-term potentiation (LTP) and depotentiation (DP) in hippocampus, is important for learning and memory. The purpose of this study is to evaluate the effect of taurine via drinking water on the lead-induced impairments of LTP and DP in rat dentate gyrus (DG) in vivo. The experiments were carried out in four groups of rats (control, lead-exposed, control and lead-exposed with a taurine-supplement diet, respectively). The input-output (I/O) function, excitatory postsynaptic potential (EPSP) and population spike (PS) amplitude were measured in the DG area of adult rats (60-90 days) in response to stimulation applied to the lateral perforant path. The results show that: 1. chronic lead exposure impaired LTP/DP measured on both EPSP slope and PS amplitude in DG area of the hippocampus; 2. in control rats, taurine had no effect on LTP/DP; 3. the amplitudes of LTP/DP of lead-exposed group were significantly increased by applying taurine. These results suggest that dietary taurine supplement could protect rats from the lead-induced impairments of synaptic plasticity and might be a preventive medicine to cure the cognitive deficits induced by lead. 相似文献
29.
The aim of this study was to examine the effect of age on left ventricular (LV) systolic function in normal healthy adults. Eighty consecutive subjects without cardiovascular disease underwent standard and tissue Doppler (TD) echocardiographic imaging. LV systolic function was assessed by load-dependent indices as ejection fraction (EF) and myocardial systolic velocities by TD as well as by the load-independent index, systolic isovolumic acceleration rate (IVA). None of the echocardiographic measurements of systolic function declined with age (mean IVA for the group, 286 +/- 123 cm s(-2); IVA vs. age, r = 0.21, P = 0.1). Likewise, LV end diastolic dimension, wall thickness, mass and left atrial maximum volume were not significantly related to age. On the other hand, as previously reported, echocardiographic indices of diastolic function showed a significant decline with age (P < 0.05). When the group was stratified by gender, isovolumic velocity and acceleration were higher in men than women, but the differences were not significant (P = 0.12 and 0.37, respectively). No significant relation was observed between age and measurements of LV systolic function by regression analysis in women (P > 0.1). However, in men, a positive correlation was noted between average IVA and age (r = 0.63, P = 0.007). In conclusion, age is not associated with a change in cardiac structure and LV systolic function, but is accompanied by a decline in echocardiographic indices of diastolic function. With respect to gender, age does not appear to influence LV systolic function in women, but is associated with an increase in IVA and septal systolic ejection in men. 相似文献
30.
为研究金丝桃的抗脂质过氧化作用,用分光光度法测定了金丝桃提取物对大鼠离体组织匀浆的脂质过氧化及由Fe2+-H2O2体系、Fe2+-VitC体系和Fe2+-Cys体系诱导的脂质过氧化的抑制作用。发现金丝桃提取物对大鼠肝、心、肾组织匀浆脂质过氧化和线粒体诱导的脂质过氧化具有抑制作用并表现出剂量依赖关系,而且提取物F003的抑制作用要强于F004、F005的抑制作用。认为金丝桃具有较好的抗脂质过氧化作用,具有进一步研究与开发价值。 相似文献