Sepsis gene expression profiling: murine splenic compared with hepatic responses determined by using complementary DNA microarrays.

Objective: DNA microarrays allow genome-wide assessment of changes in relative messenger RNA abundance and thus can be used to monitor changes in gene expression. The aim of this series of experiments was to gain experience in sepsis gene expression profiling in a well-accepted model of murine polymicrobial abdominal sepsis and begin characterizing (in the parlance of genomics) the sepsis "transcriptome."

Design: Prospective animal study.

Myeloperoxidase produces nitrating oxidants in vivo.

Despite intense interest in pathways that generate reactive nitrogen species, the physiologically relevant mechanisms for inflammatory tissue injury remain poorly understood. One possible mediator is myeloperoxidase, a major constituent of neutrophils, monocytes, and some populations of macrophages. The enzyme uses hydrogen peroxide and nitrite to generate 3-nitrotyrosine in vitro.

Endothelial cell apoptosis in sepsis.

Objective: To discuss a potential role for endothelial cell apoptosis in the pathogenesis of sepsis.

Data Sources: Studies published in biomedical journals and studies from the authors' laboratory.

Study Selection: In vitro and in vivo studies of endothelial cell apoptosis in endotoxin and sepsis models.

Inhibition of intestinal epithelial apoptosis and survival in a murine model of pneumonia-induced sepsis.

Context: Increased intestinal epithelial apoptosis is present in both human autopsy studies and animal models of sepsis. Whether altering gut apoptosis decreases mortality in sepsis induced by pathogenic bacteria outside the gut is unknown.

Objective: To determine if decreasing levels of intestinal cell death improves survival in a murine model of Pseudomonas aeruginosa pneumonia-induced sepsis.

Overexpression of Bcl-2 in the intestinal epithelium improves survival in septic mice.

Objectives: The aim of this study was to determine whether decreasing intestinal epithelial apoptosis in sepsis would alter mortality rates. The roles of the antiapoptotic protein Bcl-2 and the "executioner" protease caspase-3 in sepsis-induced gut cell death also were evaluated.

Design: Prospective, randomized, controlled trial.

Depletion of dendritic cells, but not macrophages, in patients with sepsis.

Dendritic cells (DCs) are a group of APCs that have an extraordinary capacity to interact with T and B cells and modulate their responses to invading pathogens. Although a number of defects in the immune system have been identified in sepsis, few studies have examined the effect of sepsis on DCs, which is the purpose of this study. In addition, this study investigated the effect of sepsis on macrophages, which are reported to undergo apoptosis, and MHC II expression, which has been noted to be decreased in sepsis.

Development of a novel nasal nicotine formulation comprising an optimal pulsatile and sustained plasma nicotine profile for smoking cessation.

A novel nasal formulation, in the form of a nicotine-Amberlite resin complex powder has been developed that provided an optimal combined pulsatile and sustained plasma nicotine profile for smoking cessation. The adsorption isotherms of nicotine hydrogen tartrate salt on two types of Amberlite resins (IRP69 and IR120) were evaluated and the subsequent in vitro release properties of nicotine from the nicotine-Amberlite complex powders were tested using a Franz diffusion cell. Amberlite IRP69 and Amberlite IR120 are similar cationic exchange materials with the same ion-exchange capacity but due to a smaller particle size range (10-150 microm) Amberlite IRP69 had a better flow property and a better adsorptive capacity than Amberlite IR120.

Gene expression profile of human bone marrow stromal cells: high-throughput expressed sequence tag sequencing analysis.

Human bone marrow stromal cells (HBMSC) are pluripotent cells with the potential to differentiate into osteoblasts, chondrocytes, myelosupportive stroma, and marrow adipocytes. We used high-throughput DNA sequencing analysis to generate 4258 single-pass sequencing reactions (known as expressed sequence tags, or ESTs) obtained from the 5' (97) and 3' (4161) ends of human cDNA clones from a HBMSC cDNA library. Our goal was to obtain tag sequences from the maximum number of possible genes and to deposit them in the publicly accessible database for ESTs (dbEST of the National Center for Biotechnology Information).

NADPH oxidase of neutrophils elevates o,o'-dityrosine cross-links in proteins and urine during inflammation.

Reactive intermediates generated by phagocytic white blood cells are of central importance in destroying microorganisms, but they may also damage normal tissue at sites of inflammation. To investigate the potential role of such oxidants in tissue injury, we used gas chromatography/mass spectrometry to quantify levels of o,o'-dityrosine in mouse peritoneal neutrophils and urine. In wild-type animals, neutrophils markedly increased their content of protein-bound dityrosine when they were activated in vivo.

Neutrophils employ the myeloperoxidase system to generate antimicrobial brominating and chlorinating oxidants during sepsis.

The myeloperoxidase system of neutrophils uses hydrogen peroxide and chloride to generate hypochlorous acid, a potent bactericidal oxidant in vitro. In a mouse model of polymicrobial sepsis, we observed that mice deficient in myeloperoxidase were more likely than wild-type mice to die from infection. Mass spectrometric analysis of peritoneal inflammatory fluid from septic wild-type mice detected elevated concentrations of 3-chlorotyrosine, a characteristic end product of the myeloperoxidase system.

Confocal fluorescent intravital microscopy of the murine spleen.

Intravital microscopy has provided many insights into cellular interactions in various secondary lymphoid tissues. Because this technique allows for the visualization of cellular movement in real-time, it has been very powerful. However, until now, it has been difficult to apply this technique to the spleen.

Pediatric floating elbow.

A retrospective review of 16 patients with floating elbow injuries over a 9-year period at a tertiary care children's hospital confirms that these injuries are associated with substantial swelling and the potential to develop compartment syndrome, particularly when circumferential cast immobilization is used. Among 10 patients in whom the forearm was treated with closed reduction and plaster immobilization, a compartment syndrome developed in 2, and 4 patients had incipient compartment syndrome that responded to splitting of the cast; 3 of these subsequently required remanipulation of the distal radius. One patient with compartment syndrome had Volkmann ischemic contracture.

Sepsis-induced apoptosis causes progressive profound depletion of B and CD4+ T lymphocytes in humans.

Patients with sepsis have impaired host defenses that contribute to the lethality of the disorder. Recent work implicates lymphocyte apoptosis as a potential factor in the immunosuppression of sepsis. If lymphocyte apoptosis is an important mechanism, specific subsets of lymphocytes may be more vulnerable.

Caspase inhibitors improve survival in sepsis: a critical role of the lymphocyte.

Sepsis induces lymphocyte apoptosis and prevention of lymphocyte death may improve the chances of surviving this disorder. We compared the efficacy of a selective caspase-3 inhibitor to a polycaspase inhibitor and to caspase-3-/- mice. Both inhibitors prevented lymphocyte apoptosis and improved survival.

Injury in the era of genomics.

The traditional approach to the study of biology employs small-scale experimentation that results in the description of a molecular sequence of known function or relevance. In the era of the genome the reverse is true, as large-scale cloning and gene sequencing come first, followed by the use of computational methods to systematically determine gene function and regulation. The overarching goal of this new approach is to translate the knowledge learned from a systematic, global analysis of genomic data into a complete understanding of biology.

Injection of iron compounds followed by induction of the stress response causes tissue injury and apoptosis.

To determine whether iron-laden tissue subsequently stimulated to produce the stress ("heat shock") response-sustained injury, hindlimbs of male ND4 mice were injected with iron salts, hemin, or hemoglobin. The stress response was induced with sodium arsenite or with heat. Ulcers appeared at the injection site.