The purpose of this study was to test the hypothesis that adenosine is required to maintain arteriolar vasodilation distal to a severe coronary stenosis. Eight closed-chest conscious pigs were prepared by placing a 7.5-mm long stenosis (82% lumenal diameter reduction) in the proximal left anterior descending coronary artery. Regional myocardial blood flow (microsphere technique) was measured at...

Cultured leukemic T-lymphoblasts, incubated in the presence of inhibitors of adenosine deaminase, are exquisitely sensitive to growth inhibition by deoxyadenosine. An analogy between this phenomenon and human combined immunodeficiency disease associated with inborn adenosine deaminase deficiency and the use of inhibitors of adenosine deaminase in the management of T-cell acute lymphoblastic leu...

Adenosine deaminase (ADA) can aid in the diagnosis of tuberculous pleural effusions, but false-positive findings from lymphocytic effusions have been reported. The purpose of this study is to assess the ADA levels in nontuberculous lymphocytic pleural effusions (lymphocyte count > 50%) of different aetiologies. Altogether, 410 nontuberculous lymphocytic pleural fluid samples were consecutively ...

OBJECTIVE This study aims to evaluate the diagnostic efficacy of adenosine deaminase in tubercular effusions. METHODS This study was conducted at the Department of General Medicine and Cardiovascular and Thoracic Surgery, SKIMS, for a period of two years between November 2008 and November 2010. A total of 57 patients presenting with pleural effusions during the two-year study period, who pres...

Pre-mRNA editing involving the conversion of adenosine to inosine is mediated by adenosine deaminases that act on RNA (ADAR1 and ADAR2). ADARs contain multiple double-stranded RNA(dsRNA)-binding domains in addition to an adenosine deaminase domain. An adenosine deaminase acting on tRNAs, scTad1p (also known as scADAT1), cloned from Saccharomyces cerevisiae has a deaminase domain related to the ...

A B S T RA C T Incubation of isolated rat epididymal fat cells is associated with the accumulation of adenosine in the incubation medium. To more clearly define the effect of adenosine on lipolysis, isolated rat epididymal adipocytes were studied with the perifusion system. Various combinations of epinephrine, adenosine, and adenosine deaminase were perifused through the adipocytes. Exogenous a...

Regulatory T cells have an important role in immune suppression during HIV-1 infection. As regulatory T cells produce the immunomodulatory molecule adenosine, our aim here was to assess the potential of adenosine removal to revert the suppression of anti-HIV responses exerted by regulatory T cells. The experimental setup consisted of ex vivo cocultures of T and dendritic cells, to which adenosi...

A radioisotopic assay for adenosine deaminase (EC 3.5.4.4) is described together with its application in investigating the activity of the enzyme in rat cerebral cortex. Activity of the adenosine deaminase was determined to be 115nmol/min per g of tissue, measured in isoosmotic sucrose dispersions of the neocortex, and to be 170nmol/min per g of tissue after treatment with Triton X-100. The enz...

Objective: We have previously demonstrated that myocardium is capable of down-regulating its 0, requirements and thus avoiding ischaemia when 0, supply is limited. The present study tested the hypothesis that endogenous adenosine produced this protective response when 0, supply was decreased by moderate coronary hypoperfusion or moderate coronary hypoxaemia. Methods: In anaesthetised dogs, hear...