OBJECTIVE: Few data exist on pediatric cardiopulmonary resuscitation (CPR) quality. This study is the first to evaluate actual in-hospital pediatric CPR. We hypothesized that with bedside CPR training and corrective feedback, CPR quality can approach American Heart Association (AHA) targets.

Secretion of tumor necrosis factor-α (TNF-α) by macrophages plays a predominant role in the development and progression of rheumatoid arthritis. We demonstrate that knockdown of TNF-α expression in systemic macrophages by intraperitoneal (i.p.) administration of chitosan/small interfering RNA (siRNA) nanoparticles in mice downregulates systemic and local inflammation. Chitosan nanoparticles containing an unmodified anti-TNF-α Dicer-substrate siRNA (DsiRNA) mediated TNF-α knockdown (~66%) in primary peritoneal macrophages in vitro. The presence of Cy3-labeled nanoparticles within peritoneal macrophages and specific TNF-α knockdown (~44%) with TNF-α siRNA after i.p. injection supports our therapeutic approach. Downregulation of TNF-α-induced inflammatory responses arrested joint swelling in collagen-induced arthritic (CIA) mice dosed i.p. with anti-TNF-α DsiRNA nanoparticles. The use of 2′-O-Me-modified DsiRNA resulted in the lowest arthritic scores and correlated with reduced type I interferon (IFN) activation in macrophages in vivo compared with unmodified DsiRNA. Histological analysis of joints revealed minimal cartilage destruction and inflammatory cell infiltration in anti-TNF-α-treated mice. The onset of arthritis could be delayed using a prophylactic dosing regime. This work demonstrates nanoparticle-mediated TNF-α knockdown in peritoneal macrophages as a method to reduce both local and systemic inflammation, thereby presenting a novel strategy for arthritis treatment.

Objective. We have previously described the location of tumor necrosis factor α (TNFα)–producing cells in synovial tissue and cartilage–pannus junction in rheumatoid arthritis (RA). To further understand the local actions of TNFα, we investigated the expression of TNF receptors (TNF‐R) on cells in the same compartments in patients with RA.Methods. The expression of both p55 TNF‐R and p75 TNF‐R was determined using alkaline phosphatase–conjugated mouse anti–alkaline phosphatase (APAAP) and double immunofluorescence staining techniques with monoclonal antibodies.Results. In RA synovial membrane, both p55 TNF‐R and p75 TNF‐R were detectable in up to 90% of the cells in the lining layer, and were demonstrated on cells in deeper layers of the membrane, including vascular endothelial cells. Cells in lymphoid aggregates expressed both TNF‐R, but with a predominant expression of p75 receptor. At the cartilage–pannus junction, the majority of pannus cells, especially those invading cartilage, expressed both the p55 and the p75 TNF‐R. Sequential section and double immunofluorescence staining showed that the TNF‐R–expressing cells were in the vicinity of TNFα‐containing cells, and some TNFα‐containing cells also expressed TNF‐R. TNF‐R–expressing cells were also detected in osteoarthritic and normal synovial tissue, but in smaller numbers and at a lower intensity.Conclusion. These results provide histologic evidence that both p55 TNF‐R and p75 TNF‐R are expressed by a variety of cell types in RA synovial tissue, reflecting the fact that a wide range of cells are potential targets for TNFα in this tissue. This study further supports the hypothesis that TNFα plays a major role in the pathogenesis of RA.

Using monoclonal antibodies and immunohistochemical techniques we have investigated the presence and distribution of interleukin-1α (IL-1α), type 1 IL-1 receptor (IL-1R1) and of interleukin-1 receptor antagonist (IL-1ra) in synovial tissue from 18 rheumatoid arthritis (RA) and eight osteoarthritis (OA) patients and in eight normal synovial tissue samples. IL-1α and IL-1R1 were found in all of the samples examined. In RA, there were a large number of synovial cells expressing IL-lα and IL-1Rl, with 85 and 90% positive cells in the lining layer, 45 and.80% in the interaggregate area, and 90% of the vascular endothelial cells. In the lymphoid aggregates, 20% of the cells contained IL-lα and 70% expressed IL-1R1. IL-1α and IL-1R1 expressing cells showed a similar distribution in OA synovial membrane, but there was a smaller number of positive cells in the deeper area; and the staining intensity was lower. In contrast to IL-1α and IL-1R1, IL-1ra was found only in 10/18 RA, 5/8 OA and 2/8 normal tissue samples. IL-1ra was detected in 35% of RA and 45% OA lining layer cells; 25% RA and 35% OA vascular endothelium; 10% RA and 15% OA interstitial cells and 30% cells in RA lymphoid aggregate. The staining intensity in both RA and OA tissues was comparably low. The presence of IL-1ra in RA and OA tissues was confirmed by Northern blot analysis for IL-1ra mRNA. At the RA cartilage/pannus junction, up to 90% of the pannus cells expressed IL-1α and IL-1R1, whereas IL-1ra was present in less than 10% of the cells. Some chondrocytes also expressed IL-1α and IL-1R1. In the normal cartilage/synovium junction fewer cells expressed IL-1α, IL-1R1 and IL-1ra. These results provide histological evidence that IL-1α, IL-1R1 and IL-1ra are present in the inflamed synovium, indicating that the IL-1 pathway is expressed and regulated within diseased joints.

Chlamydia trachomatis infection is associated with severe Fallopian tube tissue damage leading to tubal infertility and ectopic pregnancy. To explore the molecular mechanisms behind infection an ex vivo model was established from human Fallopian tubes and examined by scanning electron microscopy and immunohistochemistry. Extensive tissue destruction affecting especially ciliated cells was observed in C. trachomatis infected human Fallopian tube organ culture. Interleukin-1 (IL-1) produced by epithelial cells was detected after infection. Addition of IL-1 receptor antagonist (IL-1RA) completely eliminated tissue destruction induced by C. trachomatis. The anti-inflammatory cytokine IL-10 reduced the damaging effect of C. trachomatis infection, however, to a lesser extent than IL-1RA. Furthermore, IL-1 was found to induce IL-8, a neutrophil attractant, using a signal transduction pathway involving p38 MAP kinase. Consequently, IL-1 has the potential to generate a cellular infiltrate at the site of infection in vivo. Blocking the IL-1 receptors by IL-1RA eliminated tissue destruction and cytokine production. Hence, these studies show the importance of IL-1 in initiating the tissue destruction observed in the Fallopian tube following C. trachomatis infection. Because leukocytes are absent in the ex vivo model, this study strongly indicates that IL-1 is the initial proinflammatory cytokine activated by C. trachomatis infection.