Paul Avery | PubMed Health

PubMed2006

Use of flow cytometry and monochlorobimane to quantitate intracellular glutathione concentrations in feline leukocytes.

Oxidative stress and abnormal glutathione metabolism is thought to play an important role in various diseases of cats. However, current assays for the reduced form of glutathione (GSH) are time-consuming and semi-quantitative and do not allow assessment of GSH concentrations in individual cell populations. Therefore, we developed a flow cytometric assay for rapid determination of intracellular GSH concentrations in feline blood leukocytes. The assay was based on the ability of the non-fluorescent substrate monochlorobimane (mBCl) to form fluorescent adducts with GSH in a reaction catalyzed by the enzyme glutathione-S-transferase. Using flow cytometry, we found that mBCl was sensitive and specific for intracellular detection of the reduced form of GSH in feline leukocytes. Intracellular GSH concentrations were also stable for at least 24h in EDTA preserved whole blood samples stored at 4 degrees C. Neutrophils and monocytes from normal cats had significantly higher intracellular concentrations of GSH than T cells and B cells. The effects of FIV infection on intracellular GSH concentrations in cats were assessed using flow cytometry. We found that neutrophils from FIV-infected cats had significantly increased GSH concentrations, whereas intracellular GSH concentrations were significantly decreased in CD4(+) and CD8(+) lymphocytes from FIV-infected cats, compared to age-matched control animals. We conclude that a flow cytometric assay based on mBCl may be used to accurately and rapidly assess the effects of various disease states and treatments on GSH concentration in cat leukocytes and to help assess intracellular oxidative stress.

Animals↗

PubMed2002

Data Grids: a new computational infrastructure for data-intensive science.

Twenty-first-century scientific and engineering enterprises are increasingly characterized by their geographic dispersion and their reliance on large data archives. These characteristics bring with them unique challenges. First, the increasing size and complexity of modern data collections require significant investments in information technologies to store, retrieve and analyse them. Second, the increased distribution of people and resources in these projects has made resource sharing and collaboration across significant geographic and organizational boundaries critical to their success. In this paper I explore how computing infrastructures based on Data Grids offer data-intensive enterprises a comprehensive, scalable framework for collaboration and resource sharing. A detailed example of a Data Grid framework is presented for a Large Hadron Collider experiment, where a hierarchical set of laboratory and university resources comprising petaflops of processing power and a multi-petabyte data archive must be efficiently used by a global collaboration. The experience gained with these new information systems, providing transparent managed access to massive distributed data collections, will be applicable to large-scale, data-intensive problems in a wide spectrum of scientific and engineering disciplines, and eventually in industry and commerce. Such systems will be needed in the coming decades as a central element of our information-based society.

Computer Communication Networks↗