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D M Ambrosino D Bolon H Collard R Van Etten M V Kanchana R W Finberg 《Journal of immunology (Baltimore, Md. : 1950)》1992,149(12):3978-3983
Haemophilus influenzae type b polysaccharide-conjugate vaccines elicit protective antibody responses in young infants. One of these conjugates, polysaccharide linked to outer membrane protein complex (PRP-OMPC), is produced by linking the capsular polysaccharide to an outer membrane protein complex derived from group B Neisseria meningitidis. The outer membrane protein complex contains T cell carrier epitopes that elicit T cell-dependent antibody responses. OMPC also has been shown to increase the antibody response to other proteins administered concurrently that are not covalently linked (i.e., acts as an adjuvant). In this study PRP-OMPC immunized mice demonstrated significant increases in spleen size as well as in splenocyte number as compared to saline controls (p < 0.01, p < 0.001, respectively). No such increase was noted after immunization with another H. influenzae type b-conjugate vaccine, oligosaccharide linked to a variant of diphtheria toxin. By analytic flow cytometry, the mice immunized with PRP-OMPC demonstrated an increase in large splenocytes expressing the Ag Mac-1 (CD11b, CR3). Furthermore, the spleens on histologic examination were characterized by an increase in the red pulp area consisting predominantly of cells of macrophage morphology. By immunohistochemical staining, the cells were identified as macrophages due to expression of Mac-1 and p150,95 (CD11C) Ag. After PRP-OMPC immunization, severe combined immunodeficient mice also demonstrated significant splenomegaly with an increase in macrophages identified by expression of Mac-1 and MHC class II Ag. Thus PRP-OMPC vaccine resulted in T cell-independent splenomegaly with an increase number of macrophages. We propose that this unique property may confer increased immunogenicity to PRP-OMPC through macrophage activation and cytokine release. Furthermore, the effect on macrophages may explain the "adjuvant" capacity of OMPC. 相似文献
53.
The subterranean termite Odontotermes obesus is an important pest of the Indian subcontinent, causing extensive damage to major agricultural crops and forest plantation
trees. Control of termites by strategies employing their parasites has limitations because they have evolved a complex social
structure, immune responses, and adaptive behavior toward pathogen-infected individuals. Nonparasitic rhizobacteria that produce
harmful metabolites might facilitate the biocontrol of termites. In the present investigation, three different species of
hydrogen cyanide-producing rhizobacteria were tested for their potential to kill O. obesus. The three bacterial species were found to be effective in killing the termites under in vitro conditions. 相似文献
54.
Majumder A Kirabo A Karrupiah K Tsuda S Caldwell-Busby J Cardounel AJ Keseru GM Sayeski PP 《Biochemistry》2011,50(36):7774-7786
Hyperkinetic Jak2 tyrosine kinase signaling has been implicated in several human diseases including leukemia, lymphoma, myeloma, and the myeloproliferative neoplasms. Using structure-based virtual screening, we previously identified a novel Jak2 inhibitor named G6. We showed that G6 specifically inhibits Jak2 kinase activity and suppresses Jak2-mediated cellular proliferation. To elucidate the molecular and biochemical mechanisms by which G6 inhibits Jak2-mediated cellular proliferation, we treated Jak2-V617F expressing human erythroleukemia (HEL) cells for 12 h with either vehicle control or 25 μM of the drug and compared protein expression profiles using two-dimensional gel electrophoresis. One differentially expressed protein identified by electrospray mass spectroscopy was the intermediate filament protein, vimentin. It was present in DMSO treated cells but absent in G6 treated cells. HEL cells treated with G6 showed both time- and dose-dependent cleavage of vimentin as well as a marked reorganization of vimentin intermediate filaments within intact cells. In a mouse model of Jak2-V617F mediated human erythroleukemia, G6 also decreased the levels of vimentin protein, in vivo. The G6-induced cleavage of vimentin was found to be Jak2-dependent and calpain-mediated. Furthermore, we found that intracellular calcium mobilization is essential and sufficient for the cleavage of vimentin. Finally, we show that the cleavage of vimentin intermediate filaments, per se, is sufficient to reduce HEL cell viability. Collectively, these results suggest that G6-induced inhibition of Jak2-mediated pathogenic cell growth is concomitant with the disruption of intracellular vimentin filaments. As such, this work describes a novel pathway for the targeting of Jak2-mediated pathological cell growth. 相似文献
55.
Shanmugam Saranya Shankar Kanchana Ramachandiran Sivaramakrishnan Naidu Kavitha Kalimuthu Kapilan Muthuvel Arumugam 《International journal of peptide research and therapeutics》2020,26(1):159-169
International Journal of Peptide Research and Therapeutics - The antioxidant and antibacterial potential of various solvent extracts (water, 100% and 80% methanol) of Perna viridis was evaluated.... 相似文献
56.
Chaisuwan P Kongprasertsak T Sangcakul A Smith NW Nachapricha D Wilairat P Uraisin K 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(23):2185-2188
A simple CE-C(4)D method has been developed for the determination of glucosamine by direct injection of human serum and pharmaceutical samples. Glucosamine was electrokinetically injected and analysed in its protonated form using 20mM MES/His (pH 6) as background electrolyte in order to separate it from the matrix and to provide a better response to the C(4)D detector. Separation of glucosamine in human serum and pharmaceutical samples was performed in 3 min without the need for protein precipitation or matrix removal. Good precision in terms of %RSD for the migration time and peak area were less than 1.91% (n = 10). The conductivity signal was linear with glucosamine concentration in the range 0.10-2.50mg/mL, with a detection limit of 0.03 mg/mL. Recoveries of glucosamine in serum and pharmaceutical samples were 86.5-104.78%. The method was successfully applied for the determination of the glucosamine content in pharmaceutical formulations and validated with high performance liquid chromatography (HPLC). Good agreements were observed between the developed method, label values and the HPLC method. Glucosamine could be detected in spiked serum sample by direct injection. This was not possible by HPLC due to co-eluting interferences. 相似文献
57.
Novel dual regulators of Pseudomonas aeruginosa essential for productive biofilms and virulence
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58.
Wolbachia pipientis, an intracellular, α-proteobacterium, is commonly found in arthropods and filarial nematodes. Most infected insects are known
to harbor strains of Wolbachia from supergroups A or B, whereas supergroups C and D occur only in filarial nematodes. Here, we present molecular evidence
from two genes (ftsZ and 16S rDNA) that 2 Orthopterans (the bush cricket species Orocharis saltator and Hapithus agitator; Gryllidae: Eneopterinae) are infected with Wolbachia from the F supergroup. Additionally, a series of PCR tests revealed that these bush cricket specimens did not harbor nematodes,
thus indicating that our positive results were not a by-product of nematodes being present in these cricket samples. Patterns
of molecular variation suggest that (1) strains of F supergroup Wolbachia exhibit less genetic variation than the nematode-specific C and D supergroups but more than the A and B supergroups found
in arthropods and (2) that there is no evidence of recombination within F supergroup strains. The above data support previous
findings that F supergroup Wolbachia is not only harbored in both nematodes and arthropods, but that horizontal transfer has likely occurred recently between
these diverse taxonomic groups (although the exact details of such horizontal transmissions remain unclear). Moreover, the
limited genetic variation and lack of recombination in the F supergroup suggest that this clade of Wolbachia has radiated relatively rapidly with either (1) little time for recombination to occur or (2) selection against recombination
as occurs in the mutualistic C and D strains of Wolbachia – both of which remain to be explored further. 相似文献
59.
Li L Tatake RJ Natarajan K Taba Y Garin G Tai C Leung E Surapisitchat J Yoshizumi M Yan C Abe J Berk BC 《Biochemical and biophysical research communications》2008,370(1):159-163
Steady laminar blood flow protects vessels from atherosclerosis. We showed that flow decreased tumor necrosis factor-α (TNF)-mediated VCAM1 expression in endothelial cells (EC) by inhibiting JNK. Here, we determined the relative roles of MEK1, MEK5 and their downstream kinases ERK1/2 and BMK1 (ERK5) in flow-mediated inhibition of JNK activation. Steady laminar flow (shear stress = 12 dyn/cm2) increased BMK1 and ERK1/2 activity in EC. Pre-exposing EC for 10 min to flow inhibited TNF activation of JNK by 58%. A key role for BMK1, but not ERK1/2 was shown. (1) Incubation of EC with PD184352, at concentrations that blocked ERK1/2, but not BMK1, had no effect on flow inhibition of TNF-mediated JNK activation. (2) BIX02188, a MEK5-selective inhibitor, completely reversed the inhibitory effects of flow. These findings indicate that flow inhibits TNF-mediated signaling events in EC by a mechanism dependent on activation of MEK5-BMK1, but not MEK1-ERK1/2. These results support a key role for the MEK5-BMK1 signaling pathway in the atheroprotective effects of blood flow. 相似文献
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Dinora Lopes Kanchana Rungsihirunrat Fátima Nogueira Aree Seugorn José Pedro Gil Virgilio E do Rosário Pedro Cravo 《Malaria journal》2002,1(1):12-11