La intervención personal de Dios en la historia de israel. El «yo» de Yahvéh en el libro de Amós

1. EN LOS ORÁCULOS CONTRA ISRAEL Y LOS PUEBLOS VECINOS (AM 1-2). a) La decisión de Yahvéh de castigar a Israel y a los pueblos vecinos por sus rebeldías, es irrevocable. b) La destrucción por un fuego. c) Además del fuego,Yahvéh castigará también de otra manera a los culpables. d) Intervenciones de Yahvéh en el pasado a favor de Israel. 2. EN LAS AMONESTACIONES Y AMENAZAS A ISRAEL (AM 3-6). a) Las tradiciones constitutivas de Israel como pueblo. b) Las ocasiones no aprovechadas (Am 4, 6-12). c) La crítica del culto de Israel (Am 5, 21-27). d) El juramento de Yahvéh. e) Los anuncios del castigo inminente. 3. EN LAS VISIONES DE AMÓS (AM 7, 1 - 9, 1-10). a) En el texto mismo de las cinco visiones. b) En el otro material oracular de esta parte. 4. EN LOS ORÁCULOS DE RESTAURACIÓN (AM 9, 11-15). CONCLUSIÓN

Zinc Piracy as a Mechanism of <i>Neisseria meningitidis</i> for Evasion of Nutritional Immunity

<div><p>The outer membrane of Gram-negative bacteria functions as a permeability barrier that protects these bacteria against harmful compounds in the environment. Most nutrients pass the outer membrane by passive diffusion via pore-forming proteins known as porins. However, diffusion can only satisfy the growth requirements if the extracellular concentration of the nutrients is high. In the vertebrate host, the sequestration of essential nutrient metals is an important defense mechanism that limits the growth of invading pathogens, a process known as “nutritional immunity.” The acquisition of scarce nutrients from the environment is mediated by receptors in the outer membrane in an energy-requiring process. Most characterized receptors are involved in the acquisition of iron. In this study, we characterized a hitherto unknown receptor from <i>Neisseria meningitidis</i>, a causative agent of sepsis and meningitis. Expression of this receptor, designated CbpA, is induced when the bacteria are grown under zinc limitation. We demonstrate that CbpA functions as a receptor for calprotectin, a protein that is massively produced by neutrophils and other cells and that has been shown to limit bacterial growth by chelating Zn²⁺ and Mn²⁺ ions. Expression of CbpA enables <i>N. meningitidis</i> to survive and propagate in the presence of calprotectin and to use calprotectin as a zinc source. Besides CbpA, also the TonB protein, which couples energy of the proton gradient across the inner membrane to receptor-mediated transport across the outer membrane, is required for the process. CbpA was found to be expressed in all <i>N. meningitidis</i> strains examined, consistent with a vital role for the protein when the bacteria reside in the host. Together, our results demonstrate that <i>N. meningitidis</i> is able to subvert an important defense mechanism of the human host and to utilize calprotectin to promote its growth.</p></div

Regulation of <i>cbpA</i> expression.

<p>(A–D, F) Whole cell lysates were prepared from equal amounts of cells (on OD₅₅₀ basis) and analyzed by SDS-PAGE followed by immunoblotting using antiserum directed against CbpA. In panels B, C, D, and F, the CpbA bands were quantified relative to the first lane on the blots and relative expression levels are indicated underneath the lanes. (A) Wild-type strain HB-1 (WT) and its Δ<i>cbpA</i> mutant derivative were grown in RPMI medium. (B) Strain HB-1 was grown in RPMI (-), or on RPMI supplemented with a cocktail of trace metals (All) or with these metals separately. The metal sources used were ZnSO₄, MnCl₂, Na₂MoO₄, CuSO₄, CoCl₂, and FeCl₃ each at a final concentration of 1 µM. (C) Strain HB-1 was grown in RPMI (middle lane) or in RPMI supplemented with 1 µM ZnSO₄ or with 0.5 µM of the zinc chelator TPEN. (D) Strain HB-1 (WT) and its Δ<i>zur</i> mutant derivative were grown in RPMI supplemented with 0.5 µM ZnSO₄. (F) Strain HB-1 (WT) and its Δ<i>misRS</i> mutant derivative were grown in RPMI supplemented with 0.5 µM ZnSO₄. (E) Expression analysis of <i>cbpA</i> as measured in qRT-PCR experiments. Column 1, <i>cbpA</i> expression in strain HB-1 grown in RPMI relative to that in strain HB-1 grown in RPMI supplemented with 0.6 µM ZnSO₄; Column 2, <i>cbpA</i> expression in strain HB-1Δ<i>zur</i> relative to that in strain HB-1 both grown in RPMI supplemented with 0.6 µM ZnSO₄; Column 3, <i>cbpA</i> expression in strain HB-1Δ<i>zur</i> grown in RPMI relative to that in strain HB-1Δ<i>zur</i> grown in RPMI supplemented with 0.6 µM ZnSO₄.</p

<i>N. meningitidis</i> can utilize calprotectin as a zinc source in a CbpA- and TonB-dependent manner.

<p>(A) Strain HB-1 (WT), its Δ<i>cbpA</i>- and Δ<i>tonB</i>-mutant derivatives, and the Δ<i>cbpA</i>-mutant derivative complemented with plasmid pEN11-<i>cbpA</i> were plated on RPMI agar plates supplemented with 10 µM FeCl₃ as an iron source and with 1 µM TPEN to impose strict zinc limitation. In the case of the complemented strain, the medium was either supplemented or not with 100 µM IPTG as indicated. Filter discs containing 24.5 µg of calprotectin were placed on top of the plate and growth around the filter discs was evaluated after incubation overnight at 37°C. (B) Similar experiment as in panel A, except that the medium was not supplemented with TPEN. The filter discs contained either 24.5 µg calprotectin or 50 µg of a mutant form of calprotectin unable to chelate essential nutrient metals as indicated.</p

Sílabo de Derecho de la Competencia

El curso de Derecho de la Competencia proporciona el conocimiento de los principios y normas legales que rigen el desenvolvimiento de los agentes económicos en el mercado, esto es, de los proveedores y consumidores, protegiendo los derechos de estos últimos y a la vez promoviendo una leal y honesta competencia entre aquellos. El curso se encuentra dividido en seis unidades y es de naturaleza teórico aplicativa

CbpA is a cell-surface-exposed outer membrane protein.

<p>(A) OMVs were isolated from cells of strain CE1523 containing pEN-<i>cbpA</i> grown in the presence or absence of isopropyl-β-D-thiogalactopyranoside (IPTG) and analyzed by SDS-PAGE. The gel was stained with Coomassie brilliant blue. The position of CbpA is indicated. (B) Intact cells were treated with proteinase K (Prot K) at the concentrations indicated at the top and analyzed by SDS-PAGE followed by staining with Coomassie brilliant blue (left) or immunoblotting (right) with antibodies directed against the proteins indicated. In all panels, the positions of molecular weight marker proteins (MW) are indicated at the left (in kDa).</p

CbpA synthesis in a variety of meningococcal isolates.

<p>Various meningococcal isolates from our laboratory collection were grown in RPMI medium either supplemented or not with 0.5 µM ZnSO₄ as indicated. After overnight growth, whole cell lysates were analyzed by Western blotting using an antiserum directed against CbpA. Where available <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1003733#ppat.1003733-Bos3" target="_blank">[47]</a>, serogroups and clonal lineages of the strains are indicated. -, the strain was typed by Multi-Locus Enzyme Electrophoresis but could not be assigned to a specific clone.</p

Binding of calprotectin to <i>N. meningitidis</i> cells expressing <i>cbpA</i>.

<p>(A) Cells of strain HB-1Δ<i>cbpA</i> containing pEN11-<i>cbpA</i> were grown in TSB either with or without IPTG as indicated on the top and the protein patterns of samples of the cells were examined by SDS-PAGE. The position of overproduced CbpA is indicated at the right and those of molecular mass standard proteins (in kDa) at the left. (B) After growth, the cells were harvested, washed and incubated for 1 h with or without calprotectin as indicated. After extensive washing of the cells, whole cell lysates were analyzed by Western blotting with a calprotectin-specific mAb. The first lane contains purified calprotectin for reference. The amounts of calprotectin in the lanes were quantified relative to this reference sample and are indicated at the bottom of the blot. (C) Cells of strain HB-1Δ<i>cbpA</i> containing pEN11-<i>cbpA</i> were grown, harvested and washed as in panels A and B and then incubated with calprotectin for 15 h. After extensive washing, the cells were successively incubated with the calprotectin-specific mAb and Alexafluor-594-conjugated goat anti-mouse IgG antiserum. After extensive washing, the cells were examined by bright field (left) and fluorescence (right) microscopy. The scale bar represents 10 µM. (D) Similar experiment as in panel B, except that the binding assay in the last two lanes was done in the presence of 1 µg/ml of ZnSO₄ or MnCl₂ as indicated.</p

Expression of zebrafish in pancreas is regulated by two enhancers containing highly conserved -elements bound by PDX1, PBX and PREP factors-3

deletion constructs were made by enzymatic digestion at the sites indicated. A, B and C conserved regions of approximately 100-bp long are indicated by blue boxes. These DNA constructs were injected into zebrafish embryos and DSRED (-I transgenesis) or GFP (Tol2 transgenesis) transient expression was analysed at 24, 48 and 75 hours of development. The percentage of embryos expressing DSRED/GFP in the retina, the pancreas and the telencephalon versus the total number of embryos expressing DSRED/GFP (n) is indicated in brackets; the number of DSRED/GFP-expressing cells in each tissue (from +++ to +) is shown in the table. For the stable transgenic lines, n is the number of different transgenic founders obtained, and the level of DSRED expression is indicated (from +++ to -). Transient GFP expression in 75 and 48 hpf embryos injected with the full PO (FullP0), the A-deleted (P0-A) and the C-deleted (PO-C) constructs using Tol2-mediated transgenesis. DSRED expression in stable transgenic embryos at 48 hpf harboring the full P0 construct, the A-deleted construct or the B-deleted construct after -I transgenesis. Abbreviations: , I; , I; , I; , I; , pancreas; , retina; , telencephalon. All the embryos are presented in dorsal views with anterior on the left.<p><b>Copyright information:</b></p><p>Taken from "Expression of zebrafish in pancreas is regulated by two enhancers containing highly conserved -elements bound by PDX1, PBX and PREP factors"</p><p>http://www.biomedcentral.com/1471-213X/8/53</p><p>BMC Developmental Biology 2008;8():53-53.</p><p>Published online 16 May 2008</p><p>PMCID:PMC2409314.</p><p></p