Characterization of the mid-foregut transcriptome identifies genes regulated during lung bud induction.

To identify genes expressed during initiation of lung organogenesis, we generated transcriptional profiles of the prospective lung region of the mouse foregut (mid-foregut) microdissected from embryos at three developmental stages between embryonic day 8.5 (E8.5) and E9.

T cell activation by TLRs: a role for TLRs in the adaptive immune response.

Toll-like receptor (TLR) activation is primarily thought to affect antigen-presenting cells (APCs) by inducing an innate immune response that can subsequently activate the adaptive immune system. However, there are increasing data that demonstrate expression and activation of TLRs on T cells, thus providing evidence for a direct role for TLRs in the activation of an adaptive immune response. A study recently demonstrated that Pam3CSK {N-palmitoyl-S-[2,3-bis(palmitoloxy)-(2RS)-propyl]-Cys-Ser-Lys(4)}, a TLR2 agonist lipopeptide, activates T helper 1 (T(H)1) cells and induces interferon-gamma (IFN-gamma) production, even in the absence of TLR1, which differs from its mechanism of activation of APCs.

Factor H binding and function in sialylated pathogenic neisseriae is influenced by gonococcal, but not meningococcal, porin.

Neisseria gonorrhoeae and Neisseria meningitidis both express the lacto-N-neotetraose (LNT) lipooligosaccharide (LOS) molecule that can be sialylated. Although gonococcal LNT LOS sialylation enhances binding of the alternative pathway complement inhibitor factor H and renders otherwise serum-sensitive bacteria resistant to complement-dependent killing, the role of LOS sialylation in meningococcal serum resistance is less clear. We show that only gonococcal, but not meningococcal, LNT LOS sialylation enhanced factor H binding.

Induction of cell signaling events by the cholera toxin B subunit in antigen-presenting cells.

Cholera toxin (CT) is one of the most effective and widely studied mucosal adjuvants. Although the ADP-ribosylating A subunit has been implicated in augmenting immune responses, the receptor-binding B subunit (CT-B) has greater immunogenicity and may be a repository of adjuvant activity without potential toxicity. In order to elucidate mechanisms of immune modulation by CT-B alone, primary B cells and macrophages were assessed for responses to CT-B in vitro, as measured by the expression of cell surface markers, cellular signaling events, and cytokine secretion.

Effect of undertreatment on the disparity in age-related breast cancer-specific survival among older women.

Objectives: Assess the relationship between age and breast cancer-specific survival among older women and determine whether the observed age-related disparities in survival is explained by differences in breast cancer treatments received.

Methods: Women > or =65 years old at diagnosis with stage I-IIIA breast cancer diagnosed between 1997 and 1998 were recruited from four regions of the United States and followed prospectively for 5 years after diagnosis. Data was obtained from tumor registries, medical records, and telephone interviews.

Toll-like receptor 2-mediated human B cell differentiation.

Human B cells likely have a major role in the adjuvant activity of Toll-like receptor (TLR) 9 agonists by enhancing innate and adaptive immune responses. As several TLR2 ligands are promising vaccine adjuvant candidates, our aim was to characterize the effects of TLR2 stimulation on human B cell activation and differentiation using cells derived from healthy peripheral blood (PB), spleen, and diseased tonsils. We found a subset of partially differentiated TLR2+ PB and splenic B cells which responds to TLR2 agonists by mediating events involved in germinal center formation, such as upregulating CD77 and secreting chemokines.

Fimbria-dependent activation of pro-inflammatory molecules in Porphyromonas gingivalis infected human aortic endothelial cells.

Epidemiological studies support that chronic periodontal infections are associated with an increased risk of cardiovascular disease. Previously, we reported that the periodontal pathogen Porphyromonas gingivalis accelerated atherosclerotic plaque formation in hyperlipidemic apoE-/- mice, while an isogenic fimbria-deficient (FimA-) mutant did not. In this study, we utilized 41 kDa (major) and 67 kDa (minor) fimbria mutants to demonstrate that major fimbria are required for efficient P.

Meningococcal porin PorB binds to TLR2 and requires TLR1 for signaling.

TLR2 plays a key role in the initiation of the cellular innate immune responses by a wide range of bacterial products. TLRs signaling, including TLR2 and its coreceptors TLR1 and TLR6, is mediated by a number of specific ligands. Although many of the TLR-mediated cell signaling pathways have been elucidated in the past few years, the molecular mechanisms that lead to cell activation are still poorly understood.

Innate immune signaling and Porphyromonas gingivalis-accelerated atherosclerosis.

Periodontal diseases are a group of diseases that lead to erosion of the hard and soft tissues of the periodontium, which, in severe cases, can result in tooth loss. Anecdotal clinical observations have suggested that poor oral health may be associated with poor systemic health; however, only recently have appropriate epidemiological studies been initiated, with defined clinical endpoints of periodontal disease, to address the association of periodontal disease with increased risk for cardiovascular and cerebrovascular disease. Although conflicting reports exist, these epidemiological studies support this connection.

Pathogen-accelerated atherosclerosis occurs early after exposure and can be prevented via immunization.

Here we report on early inflammatory events associated with Porphyromonas gingivalis-accelerated atherosclerosis in apolipoprotein E knockout (ApoE-/-) mice. Animals challenged with P. gingivalis presented with increased macrophage infiltration, innate immune marker expression, and atheroma without elevated systemic inflammatory mediators.

Characterization of a peptide vaccine candidate mimicking an oligosaccharide epitope of Neisseria gonorrhoeae and resultant immune responses and function.

The 2C7 epitope is a conserved oligosaccharide structure, a part of lipooligosaccharide (LOS) on Neisseria gonorrhoeae, present in 95% of clinical gonococcal isolates. 2C7 may represent a potential candidate for an anti-gonococcal vaccine. To circumvent the limitations of saccharide immunogens in producing long lived immune responses, we identified a peptide that mimics the 2C7 epitope using a random peptide library, characterizing linear and cyclic forms and formulating a multiple antigenic peptide.

Improved purification of native meningococcal porin PorB and studies on its structure/function.

The outer membrane protein PorB of Neisseria meningitidis is a pore-forming protein which has various effects on eukaryotic cells. It has been shown to (1) up-regulate the surface expression of the co-stimulatory molecule CD86 and of MHC class II (which are TLR2/MyD88 dependent and related to the porin's immune-potentiating ability), (2) be involved in prevention of apoptosis by modulating the mitochondrial membrane potential, and (3) form pores in eukaryotic cells. As an outer membrane protein, its native trimeric form isolation is complicated by its insoluble nature, requiring the presence of detergent throughout the whole procedure, and by its tight association with other outer membrane components, such as neisserial LOS or lipoproteins.

Rapamycin ameliorates proteinuria-associated tubulointerstitial inflammation and fibrosis in experimental membranous nephropathy.

Proteinuria is a risk factor for progression of chronic renal failure. A model of proteinuria-associated tubulointerstitial injury was developed and was used to examine the therapeutic effect of rapamycin. Two studies were performed.

Lithium activates the Wnt and phosphatidylinositol 3-kinase Akt signaling pathways to promote cell survival in the absence of soluble survival factors.

Mouse proximal tubular cells (BUMPT), when cultured in the absence of growth factors, activate a default apoptotic pathway. Although Wnt signaling antagonizes the effect of proapoptotic triggers, its role in regulating the default pathway of apoptosis is less well defined. The present study examines the hypothesis that lithium (Li(+)) and (2'Z,3'E)-6-bromoindirubin-3'-oxime (BIO), two glycogen synthase kinase-3beta (GSK3beta) inhibitors, promote survival of growth factor-deprived renal epithelial cells by activating the Wnt pathway.

Complement mediates nephrin redistribution and actin dissociation in experimental membranous nephropathy.

Background: The onset of proteinuria in passive Heymann nephritis, (PHN), a rat model of human membranous nephropathy (MN), is complement-dependent and is associated with altered podocyte slit diaphragm integrity and dissociation of nephrin from the actin cytoskeleton. These studies examined if complement is responsible for these podocyte changes.

Methods: PHN was induced with sheep anti-Fx1A.

Neisserial lipooligosaccharide is a target for complement component C4b. Inner core phosphoethanolamine residues define C4b linkage specificity.

We identified Neisseria meningitidis lipooligosaccharide (LOS) as an acceptor for complement component C4b (C4b). Phosphoethanolamine (PEA) residues on the second heptose (HepII) residue in the LOS core structure formed amide linkages with C4b. PEA at the 6-position of HepII (6-PEA) was more efficient than 3-PEA in binding C4b.

HSP72 inhibits apoptosis-inducing factor release in ATP-depleted renal epithelial cells.

Inhibition of the mitochondrial release and nuclear translocation of apoptosis-inducing factor (AIF) by heat stress protein (HSP)72 may ameliorate apoptosis in renal epithelial cells exposed to a metabolic inhibitor. To evaluate this hypothesis, cells were transiently exposed to 5 mM sodium cyanide in the absence of medium glucose, a maneuver known to induce apoptosis. ATP depletion for 1-2 h resulted in the progressive accumulation of mitochondrial AIF in the cytosol of samples obtained by selectively permeabilizing the plasma membrane with digitonin.

The role of Toll-like receptor 2 in microbial disease and immunity.

Cells expressing Toll-like receptor (TLR), TLR2 in association with TLR1, TLR6 or some other unknown co-receptor can respond upon interaction with a large variety of microbial ligands. The variety of TLR2 ligands is the greatest among all the TLRs and this is due to the heterodimerization needed for TLR2 mediated responses. Like other TLRs, TLR2 signaling induces antigen presenting cell activation, pro-inflammatory cytokine production and increased expression of co-stimulatory ligand expression.

Chemical anoxia of tubular cells induces activation of c-Src and its translocation to the zonula adherens.

Cyanide (CN)-induced chemical anoxia of cultured mouse proximal tubular (MPT) cells increased the kinase activity of c-Src by approximately threefold. 4-Amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine (PP2), a specific inhibitor of c-Src, prevented Src activation. CN also increased the permeability of MPT cell monolayers, an event ameliorated by PP2.

The gonococcal fur regulon: identification of additional genes involved in major catabolic, recombination, and secretory pathways.

In this study, we have characterized the in vitro binding of Neisseria gonorrhoeae Fur to several well-defined iron transport genes, as well as to additional genes involved in major catabolic, secretory, and recombination pathways of gonococci. The gonococcal Fur protein was recombinantly expressed in Escherichia coli HBMV119. Fur was isolated from inclusion bodies and partially purified by ion-exchange chromatography.

Critical care issues in the patient with chronic renal failure.

The metabolic abnormalities associated with chronic renal failure and complications of the dialysis procedure present unique challenges in critical care medicine. Understanding how renal failure impacts the development and management of cardiovascular disease, bleeding tendencies, infection, and malnutrition is necessary to provide optimal care for these patients. The recognition of ESRD as a state of chronic inflammation and increased oxidative stress ultimately should lead to more effective treatment approaches for several of the comorbid conditions common in this patient population.

Acute renal failure in the critically ill patient.

This article focuses on the epidemiology, pathogenesis, and prevention of the most common forms of acute renal failure encountered in the critically ill. These include pre-renal azotemia and acute tubular necrosis that occurs postoperatively, in patients with rhabdomyolysis, or as a complication of sepsis. In addition, some unusual causes of acute renal failure that occur predominantly in the intensive care unit are briefly discussed.

Regulation of the mannan-binding lectin pathway of complement on Neisseria gonorrhoeae by C1-inhibitor and alpha 2-macroglobulin.

We examined complement activation by Neisseria gonorrhoeae via the mannan-binding lectin (MBL) pathway in normal human serum. Maximal binding of MBL complexed with MBL-associated serine proteases (MASPs) to N. gonorrhoeae was achieved at a concentration of 0.