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161.
162.
Pereira CA Alonso GD Ivaldi S Bouvier LA Torres HN Flawiá MM 《The Journal of eukaryotic microbiology》2003,50(2):132-134
Arginine kinase catalyzes the transphosphorylation between phosphoarginine and ADP. Phosphoarginine is involved in temporal ATP buffering and inorganic phosphate regulation. Trypanosoma cruzi arginine kinase phosphorylates only L-arginine (specific activity 398.9 x mUE-min(-1) x mg(-1)), and is inhibited by the arginine analogs, agmatine, canavanine, nitroarginine, and homoarginine. Canavanine and homoarginine also produce a significant inhibition of the epimastigote culture growth (79.7% and 55.8%, respectively). Inhibition constants were calculated for canavanine and homoarginine (7.55 and 6.02 mM, respectively). In addition, two novel guanidino kinase activities were detected in the epimastigote soluble extract. The development of the arginine kinase inhibitors of T. cruzi could be an important feature because the phosphagens biosynthetic pathway in trypanosomatids is different from the one in their mammalian hosts. 相似文献
163.
Sodium transport and HKT transporters: the rice model 总被引:30,自引:0,他引:30
164.
New virulence-activated and virulence-repressed genes identified by systematic gene inactivation and generation of transcriptional fusions in Bordetella pertussis
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Antoine R Alonso S Raze D Coutte L Lesjean S Willery E Locht C Jacob-Dubuisson F 《Journal of bacteriology》2000,182(20):5902-5905
165.
Antiretroviral treatment induces a shift to type-2 cytokine responses in HIV-1 infected pregnant women 总被引:2,自引:0,他引:2
We report on a cross-sectional study on proliferation and cytokine production (IFN-gamma, IL-12, IL-5 and TNF-alpha) by peripheral blood mononuclear cells (PBMC), activated or not with phytohemagglutinin (PHA) in HIV-1-infected pregnant women, untreated or treated with zidovudine. We compared the results with healthy women, either pregnant or not, and with HIV-1-infected, non-pregnant women. The most significant results indicate that basal IL-5 production in HIV-1-infected pregnant women was higher than in the rest of the groups, being even higher in the zidovudine-treated than in the untreated group. IL-5 and TNF-alpha production by PHA-activated PBMC was also higher in HIV-1 pregnant women than in controls and infected non-pregnant women. IFN-gamma production was much higher in healthy women than in the other groups. Finally, the IFN-gamma/IL-5 (Th1-type/Th2-type-cytokine) ratio was lower in HIV-infected than in uninfected groups. Zidovudine treatment reduced basal IL-12 and increased PHA-stimulated IL-5 production. Our results indicate that both HIV-1 infection and pregnancy favored a Th2-type response by T cells. Interestingly, zidovudine-treated pregnant women had a significantly higher Th2-type response than untreated ones. 相似文献
166.
Quantitative determination of total coliforms and Escherichia coli in marine waters with chromogenic and fluorogenic media 总被引:1,自引:0,他引:1
This study compared the performance of LMX(R) broth (LMX), Chromocult Coliform(R) agar (CC) and Chromocult Coliform agar plus cefsulodin (10 microg ml-1) (CC-CFS), with standard methods multiple tube fermentation (MTF), for the enumeration of total coliforms and Escherichia coli from marine recreational waters. LMX and CC are two media designed to concurrently detect total coliform (TC) bacteria and E. coli by the specific action of beta-galactosidase (total coliforms) and beta-glucuronidase (E. coli). Overall results for the TC test showed that LMX, CC and MTF recovered 2.63, 1.95 and 1.90 times as many TCs as CC-CFS, respectively. Data from the multiple range test showed significant differences (P < 0.05) between TC counts on CC-CFS and LMX. The traditional MTF was less sensitive for E. coli enumeration. However, there was no statistically significant differences between LMX, CC, CC-CFS and the MTF method for E. coli enumeration. Background interference was reduced on CC-CFS and the counts obtained reflected more accurately the number of TCs. Therefore, the contribution of beta-galactosidase positive, non coliform bacteria (Aeromonas spp. and Vibrio spp.) to TC counts should not be neglected. 相似文献
167.
168.
169.
Christoph Ritt Rudi Grimm Silvia Fernández Juan C. Alonso Klaus D. Grasser 《The Plant journal : for cell and molecular biology》1998,14(5):623-631
In contrast to other eukaryotes which usually express two closely related HMG1-like proteins, plant cells have multiple relatively variable proteins of this type. A systematic analysis of the DNA-binding properties of four chromosomal HMG domain proteins from maize revealed that they bind linear DNA with similar affinity. HMGa, HMGc1/2 and HMGd specifically recognise diverse DNA structures such as DNA mini-circles and supercoiled DNA. They induce DNA-bending, and constrain negative superhelical turns in DNA. In the presence of DNA, the HMG domain proteins can self-associate, whereas they are monomeric in solution. The maize HMG1-like proteins have the ability to facilitate the formation of nucleoprotein structures to different extents, since they can efficiently replace a bacterial chromatin-associated protein required for the site-specific β-mediated recombination. A variable function of the HMG1-like proteins is indicated by their differential association with maize chromatin, as judged by their ‘extractability’ from chromatin with spermine and ethidium bromide. Collectively, these findings suggest that the various plant chromosomal HMG domain proteins could be adapted to act in different nucleoprotein structures in vivo. 相似文献
170.
Comparative study of microbiological and histopathological techniques used for the detection of Helicobacter pylori 总被引:3,自引:0,他引:3
Muñoz E Corcuera MT Roldán M Gómez F Picazo A Baquero M Alonso MJ 《European journal of histochemistry : EJH》1998,42(4):297-302
This study evaluates the sensitivity, specificity and predictive values of several techniques commonly used for the detection of Helicobacter pylori in an analysis of 105 biopsy specimens (gastric and duodenal). For comparative purposes, the techniques investigated were divided into 2 groups: histopathological and microbiological. The former included hematoxylin-eosin and Giemsa stains, a Gram stain modified for use in tissue, and immunohistochemical techniques. Microbiological analysis was performed using culture, the urease test and the conventional Gram stain. The immunohistochemical techniques proved to be the most sensitive (93%). The modified Gram stain was sufficiently sensitive (92%) and specific (97%) for the detection of the bacterium. When combined with a microbiological technique such as the urease test, this stain showed increased sensitivity (96%) but its specificity was reduced to 94%. This combination of tests is recommended for the detection of H. pylori in biopsy specimens since it is easily performed at low cost and gives excellent results. For economical reasons, it is suggested that the use of immunohistochemical techniques should be restricted to specific cases. 相似文献