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Dynamics of T cells and TCR excision circles differ after treatment of acute and chronic HIV infection 总被引:5,自引:0,他引:5
Lewin SR Ribeiro RM Kaufmann GR Smith D Zaunders J Law M Solomon A Cameron PU Cooper D Perelson AS 《Journal of immunology (Baltimore, Md. : 1950)》2002,169(8):4657-4666
We quantified T cell proliferation and thymic function in primary HIV infection (PHI; n = 19) and chronic HIV infection (CHI; n = 14) by measuring Ki67 staining and TCR excision circle (TREC) number. After antiretroviral therapy of PHI there is a profound decrease in the number and percentage of Ki67(+) T cells (<6% Ki67(+)) with no significant increase in TREC per million cells and a transient increase in TREC per milliliter. In contrast, after antiretroviral therapy of CHI there is a reduction in the percentage but little change in the total number of Ki67(+)CD4(+) T cells associated with increases in both TREC per million cells and TREC per milliliter. Using a mathematical model that accounts for proliferation, death, and redistribution of T cells, we find that redistribution is consistent with the TREC changes observed during treatment of PHI and that an increase in thymic output is needed to explain the increase in TREC during treatment of CHI. Consideration of TREC per milliliter shows that changes in proliferation alone cannot explain the changes in TREC. In addition, although increased proliferation of memory cells in HIV infection has been established, we find no difference in TREC per million CD45RA(-) "memory" T cells between healthy and infected individuals (p = 0.154 for CD4(+); p = 0.383 for CD8(+)). Finally, although the number of TREC per million cells is always much lower in memory T cells than in naive T cells, in the setting of HIV infection, given that memory cells make up a larger proportion of total T cells, we find that 50% of TREC per milliliter in CD4(+) T cells is harbored in the CD45RA(-) "memory" subset of our infected subjects. 相似文献
14.
Ana C. Santos Joana Cunha F. Veiga A. Cordeiro-da-Silva Antonio J. Ribeiro 《Carbohydrate polymers》2013
Alginate-dextran sulfate (ADS) microgel has been used to protect insulin from gastrointestinal attack and as a carrier to promote insulin permeation through intestinal epithelium. The throughput of ADS submicron particles generation by emulsification/internal gelation is limited by its wide size distribution. 相似文献
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Abstract The IUCN Red Lists assessment provides an internationally accepted system to verify the extinction risk of species. Working Groups of the Italian Botanical Society have recently discussed the importance of producing a reliable list of species at the national level. This list could be the starting point for future in situ and ex situ plant conservation activities. 相似文献
16.
Effect of genetic modifications by selection for immunological tolerance on fungus infection in mice
da Silva AC Bezerra LM Aguiar TS Tavares D Araujo LM Pinto CE Ribeiro OG 《Microbes and infection / Institut Pasteur》2001,3(3):215-222
Two strains of mice genetically selected for extreme phenotypes of immunological tolerance to ovalbumin, susceptible (TS) and resistant (TR), were experimentally infected with Sporothrix schenckii. The objective was to observe whether the genetic modifications produced by the selection might be associated with interstrain differences in adaptive immune and innate responses to infection. Therefore, we evaluated the LD(50), CFU, phagocytic index, fungicidal activity, pro-inflammatory cytokines, specific antibody titres, and the delayed-type hypersensitivity reactivity. TR mice were tenfold more susceptible to infection than TS mice, as shown by LD(50) (5 x 10(6) conidia i.v.). In TS mice, the resistance was a consequence of the tissue fungal load reduction, consistent specific T-cell-mediated immunity, and tumour necrosis factor (TNF)-alpha activity at onset of infection. In TR mice, these responses were not precociously detected. Therefore, the absence of CD4(+) T-cell response in the first week of infection might explain the non-clearance of pathogen in TR mice. However, TR mice did show an increase in TNF level and delayed-type hypersensitivity response after the first week post-infection; there was also expansion and increase in granulomatous foci and CFU in the spleen. The expansion of granulomatous foci and the increase in TNF-alpha and tissue fungal load to damaging levels induced severe tissue destruction, general failure of the organs, cachexy and death in TR mice. The results show that genetic selection for extreme phenotypes of immunological tolerance also modified the responses to S. schenckii infection. 相似文献
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Infestation of Trialeurodes variabilis (Quaintance) was observed in October 2004, in papaya plants of cultivar Sunrise Solo, under screenhouse conditions, in Cruz das Almas, State of Bahia, Brazil. In infested leaves, around 20% of parasitism on nymphs was verified. Leaves with parasitized nymphs were kept in laboratory until emergence of the parasitoid, identified as Encarsia hispida De Santis. This is the first time that this parasitoid was detected on T. variabilis nymphs in Brazil. 相似文献
18.
Leandro Freire dos Santos Ana Lucia Zanatta Vanete Thomaz Soccol Maria Fernanda Torres Sandro José Ribeiro Bonatto Rosália Rubel Carlos Ricardo Soccol 《Biotechnology and Bioprocess Engineering》2013,18(1):201-208
The ability of Pleurotus ostreatus biomass, cultived by submerged fermentation, to produce beneficial effect on lipid profile and macrophages activity during a high-fat diet (HFD) for a long-term intake was investigated. Blood samples were collected through cardiac puncture to measure the plasma cholesterol, triglycerides, low-density protein (LDL), high-density protein (HDL), aspartate aminotransferase (AST) activity, urea-blood urea nitrogen (BUN)/creatinine ratio of rats fed on an HFD for 4 months. Dosage of lipid hydroperoxides was carried out on methanolic extract of liver tissue. Peritoneal macrophages activity was evaluated in relation to the superoxide anion, hydrogen peroxide and nitric oxide production, phagocytosis and lysosomal volume. The administration of P. ostreatus significantly altered the lipid profile and oxidative stress as related to the LDL and triglycerides decrease and inhibitory effects on superoxide anion and hydrogen peroxide production. All findings of this study lead us to suggest that the P. ostreatus maybe a beneficial agent in the hyperlipidemia and atherosclerosis treatments. 相似文献
19.
Ferreira-Gomes MS González-Lebrero RM de la Fuente MC Strehler EE Rossi RC Rossi JP 《The Journal of biological chemistry》2011,286(37):32018-32025
In this work, we set out to identify and characterize the calcium occluded intermediate(s) of the plasma membrane Ca(2+)-ATPase (PMCA) to study the mechanism of calcium transport. To this end, we developed a procedure for measuring the occlusion of Ca(2+) in microsomes containing PMCA. This involves a system for overexpression of the PMCA and the use of a rapid mixing device combined with a filtration chamber, allowing the isolation of the enzyme and quantification of retained calcium. Measurements of retained calcium as a function of the Ca(2+) concentration in steady state showed a hyperbolic dependence with an apparent dissociation constant of 12 ± 2.2 μM, which agrees with the value found through measurements of PMCA activity in the absence of calmodulin. When enzyme phosphorylation and the retained calcium were studied as a function of time in the presence of La(III) (inducing accumulation of phosphoenzyme in the E(1)P state), we obtained apparent rate constants not significantly different from each other. Quantification of EP and retained calcium in steady state yield a stoichiometry of one mole of occluded calcium per mole of phosphoenzyme. These results demonstrate for the first time that one calcium ion becomes occluded in the E(1)P-phosphorylated intermediate of the PMCA. 相似文献
20.
Ernetti Julia R. Boschetti Joana P. Delazeri Francieli De Bastiani Veluma I. M. Pontes Mariana R. Ribeiro Luisa P. Lingnau Rodrigo Toledo Luís Felipe Lucas Elaine M. 《Hydrobiologia》2020,847(16):3355-3364
Hydrobiologia - Pithecopus rusticus is an endemic amphibian restricted to the type locality, in southern Brazil, and possibly endangered to extinction, due to habitat degradation. However, an... 相似文献