Isolation of human conjunctival mast cells and epithelial cells: Tumor necrosis factor-alpha from mast cells affects intercellular adhesion molecule 1 expression on epithelial cells

PURPOSE. TO isolate and purify mast cells and epithelial cells from human cadaveric donor conjunctival tissue and to characterize interactions between these cell types in vitro. METHODS. Monodispersed cell suspensions obtained by enzymatic digestion of conjunctival tissue were applied to a single-density Percoll gradient. Epithelial cells obtained from the top layer of the gradient were cultured to confluence. Mast cells obtained from the pellet were equilibrated in culture medium and further purified using a two-step Percoll gradient. Using reverse transcriptionpolymerase chain reaction (RT-PCR), RNA from the purified mast cell preparation was probed for tumor necrosis factor-a (TNFa) message. Fluorescence activated cell sorting (FACS) analysis of intracellular immunostained mast cells was used to detect the TNFa protein. An examination for intercellular adhesion molecule 1 OCAM-1) on epithelial cells was performed after 24-hour incubations with either recombinant TNFa supernatants from calcium ionophore A23187 (Cal)-stimulated mast cells or appropriate controls using FACS analysis. RESULTS. Highly purified human conjunctival mast cells and epithelial cells (each >95%) were obtained from human cadaveric donor tissue. RT-PCR analysis of purified mast cell RNA revealed the expression of TNFa mRNA. An evaluation of mast cells for intracellular protein demonstrated positive staining for tryptase and TNFa. ICAM-1 was found on purified epithelial cells, and incubation of epithelial cell monolayers with supernatants from Cal-stimulated mast cells resulted in upregulation of this receptor. This upregulation was blocked by incubation with TNFa-neutralizing antibody. CONCLUSIONS. This work provides the methods for isolating and purifying mast cells and epithelial cells from human donor tissue and the opportunity for studying mechanisms of conjunctival inflammation by evaluating the interactions between these cells. (Invest Ophthalmol Vis Sci. 1998; 39:336-343) C onjunctival mast cells and their mediators are implicated, at least in part, in all types of allergic ocular disease. Human studies of allergic ocular disease, however, have primarily consisted of the study of pathologic biopsy specimens (demonstrating increased numbers of mast cells, eosinophils, and other inflammatory cells) and tear film evaluation for mediators and cellular infiltration

Portraying the nature of corruption: Using an explorative case-study design

What is the nature of corruption in Western democracies? To answer this research question, the authors study 10 Dutch corruption cases in depth, looking at confidential criminal files. The cases allow them to sketch a general profile of a corruption case. The authors offer nine propositions to portray the nature of corruption. They conclude that corruption usually takes place within enduring relationships, that the process of becoming corrupt can be characterized as a slippery slope, and that important motives for corruption, aside from material gain, include friendship or love, status, and the desire to impress others. The explorative multiple case study methodology helps to expand our understanding of the way in which officials become corrupt. © 2008 The American Society for Public Administration

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Energy Resolution Performance of the CMS Electromagnetic Calorimeter

The energy resolution performance of the CMS lead tungstate crystal electromagnetic calorimeter is presented. Measurements were made with an electron beam using a fully equipped supermodule of the calorimeter barrel. Results are given both for electrons incident on the centre of crystals and for electrons distributed uniformly over the calorimeter surface. The electron energy is reconstructed in matrices of 3 times 3 or 5 times 5 crystals centred on the crystal containing the maximum energy. Corrections for variations in the shower containment are applied in the case of uniform incidence. The resolution measured is consistent with the design goals

Advocacy and the Search for Truth in Management Scholarship: Can the Twain Ever Meet?

Scholars have long debated the merits of advocacy-based research versus research considered from the quest for objective truth. Building upon reflections from multiple sources, a set of 11 brief reflections on three posed questions are presented. Tsang concludes our discussion with additional insights on how moving beyond the “interestingness” advocacy will be beneficial to the continued professional development of the management discipline

Advocacy and the search for truth in management scholarship: can the twain ever meet?

Scholars have long debated the merits of advocacy-based research versus research considered from the quest for objective truth. Building upon reflections from multiple sources, a set of 11 brief reflections on three posed questions are presented. Tsang concludes our discussion with additional insights on how moving beyond the “interestingness” advocacy will be beneficial to the continued professional development of the management discipline