共查询到20条相似文献，搜索用时 31 毫秒
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Mutants of pertussis toxin suitable for vaccine development 总被引：53，自引：0，他引：53
M Pizza A Covacci A Bartoloni M Perugini L Nencioni M T De Magistris L Villa D Nucci R Manetti M Bugnoli 《Science (New York, N.Y.)》1989,246(4929):497-500
Immunization with chemically detoxified pertussis toxin can prevent severe whooping cough with an efficacy similar to that of the cellular pertussis vaccine, which normally gives unwanted side effects. To avoid the reversion to toxicity and the loss of immunogenicity that may follow chemical treatment of pertussis toxin, inactive toxins were constructed by genetic manipulation. A number of genetically engineered alleles of the pertussis toxin genes, constructed by replacing either one or two key amino acids within the enzymatically active S1 subunit, were introduced into the chromosome of strains of Bordetella pertussis, B. parapertussis, and B. bronchiseptica. These strains produce mutant pertussis toxin molecules that are nontoxic and immunogenic and that protect mice from the intracerebral challenge with virulent Bordetella pertussis. Such molecules are ideal for the development of new and safer vaccines against whooping cough. 相似文献
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根据支气管败血波氏杆菌ptxA基因设计1对引物,扩增特异的872 bp核酸片段,建立了应用PCR检测支气管败血波氏杆菌的方法.特异性试验结果表明,3株支气管败血波氏杆菌参考菌株均能扩增出872 bp特异性的核酸片段,兔源性的大肠杆菌、巴氏杆菌、沙门氏菌、金黄色葡萄菌的扩增结果均为阴性.敏感性试验结果表明,PCR的最低检出限量为210个支气管败血波氏杆菌.利用建立的PCR检测方法对22株从山东省泰安地区某兔场采集的疑似兔支气管败血波氏杆菌病病兔鼻黏液棉拭子进行检测,结果19株为阳性.并同时进行普通血清学方法和细菌学方法,对检测结果进行了比较,结果显示,PCR方法阳性检出率高于其他检测方法. 相似文献
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Compartmentalization of cyclic AMP during phagocytosis by human neutrophilic granulocytes 总被引：4，自引：0，他引：4
K B Pryzwansky A L Steiner J K Spitznagel C L Kapoor 《Science (New York, N.Y.)》1981,211(4480):407-410
Immunocytochemistry shows that early during phagocytosis of zymosan, adenosine 3',5'-monophosphate (cyclic AMP) appears on the cell surface before the phagosome is internalized. The appearance of cyclic AMP on the cell surface is coincident with that of granule products and regulatory subunit of type I cyclic AMP-dependent protein kinase. Guanosine 3',5'-monophosphate is not associated with the initiation site of phagocytosis, but is observed throughout the granular cytoplasmic region. This sharply localized accumulation of cyclic AMP may serve as a signal for the initiation of phagocytosis. 相似文献
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Cyclic adenosine monophosphate in bacteria 总被引：83，自引：0，他引：83
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从 2～ 3月龄病死獭兔的肺病变组织中分离到 3株细菌 ,经形态特征、培养及生化特性、药敏试验和动物实验等表明 ,分离菌株为能运动、无芽孢的革兰氏阴性小杆菌 ,即支气管败血波氏杆菌。该菌在鲜血平板上产生溶血 ,在麦康凯平板上形成光滑、中央突起的珍珠状菌落 ,且能与兔支气管败血波氏杆菌参考株S80 10 3抗血清发生凝集 ,人工接种小白鼠能引起死亡 ,并从病死鼠中回收到相应细菌 相似文献
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Growth inhibition by adenosine 3',5-monophosphate derivatives does not require 3',5' phosphodiester linkage 总被引：3，自引：0，他引：3
Analogs of adenosine 3',5'-monophosphate (cyclic AMP) inhibit the growth of cultured cell lines. The effects of 8-bromo- and N6-butyryl-substituted analogs of cyclic and noncyclic AMP on six cell lines were examined and were equally inhibitory. Variant cell lines with altered cyclic AMP-dependent protein kinase were more resistant to both cyclic and noncyclic nucleotides. We conclude that growth inhibition by analogs of cyclic AMP (i) does not require a 3',5' phosphodiester bond and (ii) may be mediated by a pathway involving endogenous cyclic AMP. 相似文献
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Transplantation of normal bone marrow cells to a gray collie dog with cyclic neutropenia resulted in normal granulocytopoiesis. The finding suggests that cyclic neutropenia occurs because the hematopoietic stem cells are defective. Because of the similarity of human and canine cyclic neutropenia, it also suggests that the human disease may be curable by marrow transplantation. 相似文献
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采用室内培养方法,从吴江市郊长期被多环芳烃污染的土壤中富集到以菲为唯一碳源和能源的菲降解复合微生物菌群,复合菌群在7d内对无机盐液体中菲(含量100mg·L-1)的降解率达到99%。从复合菌群中分离纯化获得两株菲高效降解菌B1和L2,经过菌体形态特征、生理生化特征和16SrDNA序列分析,鉴定菌株B1为百日咳博行特氏菌(Bordetella petrii),菌株L2为墨西哥假黄单胞菌(Pseudoxanthomonas mexicana)。这两株菌在菲含量为100mg·L-1的无机盐培养液中,7d内对菲(含量100mg·L-1)的降解率大约为80%,9d内的降解率可达到99%。将复合菌群和菲污染土壤混合,在光照培养箱中进行培养修复。结果表明,修复88d后,接种复合菌群的低污染浓度(8.22mg·kg-1)处理和高污染浓度(39.65mg·kg-1)处理的菲去除率分别达到95.74%和98.06%。 相似文献
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D L Alkon J Acosta-Urquidi J Olds G Kuzma J T Neary 《Science (New York, N.Y.)》1983,219(4582):303-306
Intracellular iontophoretic injection of the catalytic subunit of cyclic adenosine monophosphate-dependent protein kinase increased input resistance and decreased a delayed voltage-dependent K+ current of the type B photoreceptor in the nudibranch Hermissenda crassicornis to a greater extent than an early, rapidly inactivating K+ current (IA). This injection also enhanced the long-lasting depolarization of type B cells after a light step. These findings suggest the involvement of cyclic adenosine monophosphate-dependent phosphorylation in the differential regulation of photoreceptor K+ currents particularly during illumination. On the other hand, conditioning-induced changes in IA may also be regulated by a different type of phosphorylation (for example, Ca2+-dependent). 相似文献
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１９９５年９月在陕西咸阳首次发现鸡的波德特氏菌病。病鸡以流浆液性鼻液、眼睑肿胀、眼睛流泪及呼吸困难为特征。不同年龄的鸡均可感染，幼龄鸡的发病率和死亡率明显高于成年鸡。分离菌的２４ｈ肉汤培养物（０．２ｍＬ）感染小鼠及豚鼠可于２４ｈ内引起死亡；经鼻感染６０日龄鸡复制出了与自然病例相同的临床表现，病死率６０％，并回收到了接种菌。本文对分离的波德特氏菌的培养特性、形态特征、致病性、抗生素的敏感性、灭活苗的研制及免疫防制进行了深入研究。 相似文献
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Murine lymphoma: augmented growth in mice with pertussis vaccine-induced lymphocytosis 总被引：3，自引：0，他引：3
Injection of Bordetella pertussis vaccine caused an excessive lymphocytosis, associated with an augmented growth of a lymphoma cell homotransplant in mice. A markedly impaired reactive cell proliferation was revealed in the spleens of the vaccine-pretreated mice after stimulation with phytohemagglutinin or Freund's complete adjuvant. 相似文献
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Purified outer segments of bovine rods exhibit phosphodiesterase activity against adenosine and guanosine cyclic 3',5'-monophosphates (cyclic AMP and cyclic GMP). The enzyme hydrolyzed cyclic GMP more rapidly than cyclic AMP at low substrate concentrations. The presence of high phosphodiesterase activity in this highly specialized organelle suggests that this enzyme may function in control of cyclic nucleotide concentration during visual excitation or adaptation. 相似文献
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Three-dimensional instabilities of mantle convection with multiple phase transitions 总被引：1，自引：0，他引：1
The effects of multiple phase transitions on mantle convection are investigated by numerical simulations that are based on three-dimensional models. These simulations show that cold sheets of mantle material collide at junctions, merge, and form a strong downflow that is stopped temporarily by the transition zone. The accumulated cold material gives rise to a strong gravitational instability that causes the cold mass to sink rapidly into the lower mantle. This process promotes a massive exchange between the lower and upper mantles and triggers a global instability in the adjacent plume system. This mechanism may be cyclic in nature and may be linked to the generation of superplumes. 相似文献
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LIU Yan QIN Feng-yan BAO Guo-lian CHEN Hui XIAO Chen-wen WEI Qiang JI Quan-an 《中国农业科学(英文版)》2014,(9):2010-2018
Bordetella bronchiseptica is a Gram-negative pathogen that causes acute and chronic respiratory infection in a variety of animals. To identify useful antigen candidates for diagnosis and subunit vaccine of B. bronchiseptica, immunoproteomic analysis was adopted to analyse outer membrane proteins of it. The outer membrane proteins extracted from B. bronchiseptica were separated by two-dimensional gel electrophoresis and analyzed by Western blotting for their reactivity with the convalescent serum against two strains. Immunogenic proteins were identified by matrix-assisted laser desorption/ionization time of flight-mass spectrometry（MALDI-TOF-MS）, a total of 14 proteins are common immunoreactive proteins, of which 1 was known antigen and 13 were novel immunogenic proteins for B. bronchiseptica. Putative lipoprotein gene was cloned and recombinantly expressed. The recombinant protein induced high titer antibody, but showed low protective indices against challenges with HB（B. bronchiseptica strain isolated from a infected rabbit）. The mortality of mice was 80% compared to 100% of positive controls. The identification of these novel antigenic proteins is an important resource for further development of a new diagnostic test and vaccine for B. bronchiseptica. 相似文献
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Cyclic adenosine monophosphate: possible mediator for norepinephrine effects on cerebellar Purkinje cells 总被引：8，自引：0，他引：8
Microelectrophoretic application of norepinephrine or cyclic adenosine monophosphate reduces the discharge frequency of Purkinje cells in the rat cerebellum. In contrast, other nucleotides accelerate the discharge rate of most units. Parenterally administered theophylline, which inhibits the hydrolysis of cyclic adenosine monophosphate enhances the effects of norepinephrine and cyclic adenosine monophosphate. Therefore, norepinephrine may be able to regulate Purkinje cells functionally by metabolic stimulation of cyclic adenosine monophosphate synthesis. 相似文献
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Guanosine 3',5'-monophosphate in sympathetic ganglia: increase assoicated with synaptic transmission 总被引：11，自引：0，他引：11
Brief stimulation of cholinergic preganglionic nerve fibers resulted in an increase in guanosine 3',5'-monophosphate (cyclic GMP) in the bullfrog sympathetic ganglion. When the release of synaptic transmitter was prevented by a high-magnesium, low-calcium Ringer solution, stimulation of preganglionic nerve fibers did not increase cyclic GMP in the ganglion. The increase in cyclic GMP caused by preganglionic stimulation was also blocked by the muscarinic antagonist, atropine. The data indicate that the increase in cyclic GMP is associated with synaptic transmission and support the possibility that cyclic GMP may mediate the postsynaptic action of acetylcholine at muscarinic cholinergic synapses. 相似文献
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An endogenous polysomal cyclic AMP-dependent protein kinase specifically phosphorylates a 150,000-dalton peptide bound to an adrenocortical polyadenylated messenger ribonucleoprotein complex. There is a possibility that this protein is a physiological substrate of cyclic AMP-dependent protein kinase and that the phosphorylation and dephosphorylation of this substrate may be important in the translation control of adrenal polyadenylated messenger RNA. 相似文献
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Growth arrest and morphological change of human breast cancer cells by dibutyryl cyclic AMP and L-arginine 总被引：3，自引：0，他引：3
The growth in vitro of human breast cancer cells, line MCF-7, was inhibited by a daily supplement of L-arginine (1 milligram per milliliter). Arginine acted synergistically with dibutyryl adenosine 3',5'-monophosphate (cyclic AMP) (10(-6) molar) to enhance the growth inhibitory effect: the cell replication ceased completely within 2 days after treatment. The growth arrest accompanied a change in cell morphology and was preceded by increases in the cellular concentration of cyclic AMP, adenylate cyclase, and type II cyclic AMP-dependent protein kinase activities as well as a decrease of estrogen binding activity. The results suggest that growth of human breast cancer cells is subject to cyclic AMP-mediated regulation and that arginine may play a specific role in this process. 相似文献