No abstract is provided for this article.
No abstract is provided for this article.
Intracoronary near infrared spectroscopy (NIRS), incorporated in the True Vessel Characterization (TVC) Imaging System™, is a novel method for the identification and quantification of lipid composition in coronary plaques. The main advantage of NIRS over other plaque characterisation methods is its ability to directly identify chemical composition - the primary use of spectroscopy for other applications. NIRS by itself does not display structures, but a combination device with co-registered intravascular ultrasound (IVUS) has been developed to give simultaneous and complementary structural and compositional information. Identification of lipid core plaque with NIRS hypothetically has the potential to optimise the length of vessel to stent and to lead to effective utilisation of embolic protection devices in the native coronaries, identifying the exact location of lipid-core lesions at high risk of distal embolisation. The NIRS-IVUS device also has promise in the identification of vulnerable plaque, which may lead to strategies to prevent future coronary events.
Background: The bile duct injury found in patients with biliary atresia (BA) is associated with a lymphocytic and monocytic inflammatory response with localized production of Th1 cytokines. Immunohistochemistry studies have shown that cholangiocytes express surface markers found on antigen presenting cells (APCs) including MHC class II and co-stimulatory molecules (CD80, CD86, CD40). Furthermore, Lazaridis et al have described a "reactive cholangiocyte phenotype" found in cholangiopathies including BA, where cholangiocytes are capable of expressing APC surface markers and producing various cytokines. Hypothesis: Cholangiocytes in BA are competent APCs, contributing to persistent T-cell mediated inflammation and bile duct injury. To test this hypothesis, the Rhesus rotavirus (RRV)-induced murine model of BA was utilized. Methods: Cholangiocyte surface expression of APC molecules was performed by FACS analysis on both a murine cholangiocyte cell line and cholangiocytes isolated ex vivo from normal mouse livers. Additional FACS analysis to determine changes in APC marker expression was performed on cholangiocytes subjected to RRV infection or co-cultured with Th1 cytokines. Results: APC surface markers (MHC classes I & II, CD40, CD80, CD86) were present on murine cholangiocytes. RRV infection of the cholangiocyte cell line increased expression of MHC II, CD80, and CD40 and co-culture with cytokines markedly increased expression of MHC I, and minimally increased expression of CD80 and CD86. Conclusions: Murine cholangiocytes possess the key surface markers necessary for antigen presentation. RRV infection and co-culture with cytokines increased APC marker expression. Future experiments will focus on the functional ability of cholangiocytes to present antigen and the role of cholangiocytes as effector cells capable of inflammatory cytokine production.
Human eosinophils may be prepared from blood taken from normal, atopic, asthmatic, or hypereosinophilic donors. Eosinophils are purified from buffy coat cells on metrizamide or Percoll density gradients. The interaction between platelet-activating factor (PAF) and eosinophils may be of relevance in allergic diseases, PAF may be one of the mediators that play a role in selective accumulation of eosinophils in the airways and may be involved in their activation. PAF is potently chemotactic for human eosinophils in vitro and has a greater effect on eosinophils than neutrophils. G-Proteins are involved in coupling surface receptors to second messenger systems. G-proteins are also involved in eosinophil degranulation and a novel G-protein associated with exocytosis. Corticosteroids are the most effective anti-inflammatory drugs used in the treatment of asthma and they reduce airway hyper-responsiveness. Corticosteroids reduce the numbers of circulating eosinophils and inhaled steroids reduce the number of hypodense eosinophils in the circulation of asthmatics.