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131.
Susana Fuentes Els van Nood Sebastian Tims Ineke Heikamp-de Jong Cajo JF ter Braak Josbert J Keller Erwin G Zoetendal Willem M de Vos 《The ISME journal》2014,8(8):1621-1633
Recurrent Clostridium difficile infection (CDI) can be effectively treated by infusion of a healthy donor faeces suspension. However, it is unclear what factors determine treatment efficacy. By using a phylogenetic microarray platform, we assessed composition, diversity and dynamics of faecal microbiota before, after and during follow-up of the transplantation from a healthy donor to different patients, to elucidate the mechanism of action of faecal infusion. Global composition and network analysis of the microbiota was performed in faecal samples from nine patients with recurrent CDI. Analyses were performed before and after duodenal donor faeces infusion, and during a follow-up of 10 weeks. The microbiota data were compared with that of the healthy donors. All patients successfully recovered. Their intestinal microbiota changed from a low-diversity diseased state, dominated by Proteobacteria and Bacilli, to a more diverse ecosystem resembling that of healthy donors, dominated by Bacteroidetes and Clostridium groups, including butyrate-producing bacteria. We identified specific multi-species networks and signature microbial groups that were either depleted or restored as a result of the treatment. The changes persisted over time. Comprehensive and deep analyses of the microbiota of patients before and after treatment exposed a therapeutic reset from a diseased state towards a healthy profile. The identification of microbial groups that constitute a niche for C. difficile overgrowth, as well as those driving the reinstallation of a healthy intestinal microbiota, could contribute to the development of biomarkers predicting recurrence and treatment outcome, identifying an optimal microbiota composition that could lead to targeted treatment strategies. 相似文献
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133.
Chloroplasts isolated from leaves of Lolium temulentum by differential centrifugation and sucrose gradient centrifugation were found to contain hig 相似文献
134.
135.
Phylogeny of some Fusarium species, as determined by large-subunit rRNA sequence comparison 总被引:16,自引:0,他引:16
Fifty-two strains from eight species of Fusarium were analyzed by rapid
rRNA sequencing. Two highly variable stretches (138 and 214 nucleotides) of
the 5' end of the 28S-like rRNA molecule were sequenced. Such stretches
permit evaluation of the divergence between closely related species and
even between varieties within a species. The phylogenetic tree computed
from the number of nucleotide differences shows seven Fusarium species to
be more closely related to one another than the eighth species, F. nivale,
is to them. On the basis of these data, we discuss both the phylogenetic
value of taxonomical criteria and the impact of our findings on the
demarcation of the genus Fusarium. We conclude that this method is suitable
for establishing a precise phylogeny between closely related species within
a genus.
相似文献
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138.
Summary The contribution of individual leaves towards the flowering response in red clover (Trifolium pratense L.) seedlings at the three-leaf stage is described. Removal of the first (oldest) or first and second leaves resulted in large increases (up to 300%) in both the rate of stem extension and the degree of apical differentiation.Removal of the youngest leaves depressed both processes. Application of cycloheximide to specific leaves produced effects similar to defoliation, but chloramphenicol was generally inhibitory and kinetin substantially ineffective. Translocation patterns between leaves and the shoot apex were studied using [14C] sucrose and [3H] gibberellin A1. There was appreciable movement between leaves, but exposure to long-days depressed the transport of labelled assimilate. Label arriving at the apex was increasingly derived from the younger leaves as floral induction proceeded.Abbreviations CAP
D-threo-chloramphenicol
- CH
cycloheximide
- K
Kinetin
- Tris
Tris(hydroxymethyl) amino methane
- G.S.H.
Glutathione (reduced)
- E.D.T.A.
ethylene diamino tetra acetic acid disodium salt 相似文献
139.
Albumin-conjugated C34 peptide HIV-1 fusion inhibitor: equipotent to C34 and T-20 in vitro with sustained activity in SCID-hu Thy/Liv mice 总被引:1,自引:0,他引:1
Stoddart CA Nault G Galkina SA Thibaudeau K Bakis P Bousquet-Gagnon N Robitaille M Bellomo M Paradis V Liscourt P Lobach A Rivard ME Ptak RG Mankowski MK Bridon D Quraishi O 《The Journal of biological chemistry》2008,283(49):34045-34052
Entry inhibitors of human immunodeficiency virus, type 1 (HIV-1) have been the focus of much recent research. C34, a potent fusion inhibitor derived from the HR2 region of gp41, was engineered into a 1:1 human serum albumin conjugate through stable covalent attachment of a maleimido-C34 analog onto cysteine 34 of albumin. This bioconjugate, PC-1505, was designed to require less frequent dosing and less peptide than T-20 and was assessed for its antifusogenic activity both in vitro and in vivo in the SCID-hu Thy/Liv mouse model. PC-1505 was essentially equipotent to the original C34 peptide and to T-20 in vitro. In HIV-1-infected SCID-hu Thy/Liv mice, T-20 lost activity with infrequent dosing, whereas the antiviral potency of PC-1505 was sustained, and PC-1505 was active against T-20-resistant ("DIV") virus with a G36D substitution in gp41. The in vivo results are the direct result of a significantly improved pharmacokinetic profile for the C34 peptide following albumin conjugation. Contrary to previous reports that the gp41 NHR trimer is poorly accessible to C34 fused to protein cargoes of increasing size (Hamburger, A. E., Kim, S., Welch, B. D., and Kay, M. S. (2005) J. Biol. Chem. 280, 12567-12572), these results are the first demonstration of the capacity for a large, endogenous serum protein to gain unobstructed access to the transient gp41 intermediates that exist during the HIV fusion process, and it supports further development of albumin conjugation as a promising approach to inhibit HIV-1 entry. 相似文献
140.
IFN-alpha secretion by type 2 predendritic cells up-regulates MHC class I in the HIV-1-infected thymus. 总被引:5,自引:0,他引:5
Mary E Keir Cheryl A Stoddart Valerie Linquist-Stepps Mary E Moreno Joseph M McCune 《Journal of immunology (Baltimore, Md. : 1950)》2002,168(1):325-331
The ability of HIV-1 to evade the host immune response leads to the establishment of chronic infection. HIV-1 has been reported to up-regulate MHC I molecules on the surface of thymocytes from HIV-1-infected thymus. We demonstrate in this study that HIV-1 up-regulates MHC I on both HIV-1-infected and uninfected thymocytes in a manner that is independent of Nef, proportional to viral replication, and entirely mediated by IFN-alpha. IL-3Ralpha+ type 2 predendritic cells (preDC2) resident in the thymic medulla secrete IFN-alpha, which acts on IFN-alphabetaR-expressing immature thymocytes to induce MHC I expression. Furthermore, thymic preDC2 are permissive for HIV-1 infection and positive for intracellular p24. These data demonstrate the ability of IFN-alpha secreted by preDC2 to induce MHC I up-regulation in the HIV-1-infected human thymus. 相似文献