Publications by authors named "David J Nicholls"

Article Synopsis
  • * The Cambridge COVID-19 Testing Centre (CCTC) was established in April 2020 through partnerships with AstraZeneca, GlaxoSmithKline, and the University of Cambridge, aiming for a testing capacity of 22,000 tests per day.
  • * The CCTC enhanced laboratory processes using internal metrics and new technologies, such as Heat Inactivation of samples and a Direct to PCR protocol, which improved efficiency and eliminated the RNA extraction step.
View Article and Find Full Text PDF

In 2011, AstraZeneca embarked on a major revision of its research and development (R&D) strategy with the aim of improving R&D productivity, which was below industry averages in 2005-2010. A cornerstone of the revised strategy was to focus decision-making on five technical determinants (the right target, right tissue, right safety, right patient and right commercial potential). In this article, we describe the progress made using this '5R framework' in the hope that our experience could be useful to other companies tackling R&D productivity issues.

View Article and Find Full Text PDF

In normal physiologic responses to injury and infection, inflammatory cells enter tissue and sites of inflammation through a chemotactic process regulated by several families of proteins, including inflammatory chemokines, a family of small inducible cytokines. In neutrophils, chemokines chemokine (CXC motif) ligand 1 (CXCL1) and CXCL8 are potent chemoattractants and activate G protein-coupled receptors CXC chemokine receptor 1 (CXCR1) and CXCR2. Several small-molecule antagonists of CXCR2 have been developed to inhibit the inflammatory responses mediated by this receptor.

View Article and Find Full Text PDF
Article Synopsis
  • - AZD9708 is an experimental drug being studied by AstraZeneca for treating respiratory diseases through inhalation, and it has been noted to have long-acting effects on β2-adrenergic receptors.
  • - In toxicology studies with rats, the drug caused a rise in micronucleated immature erythrocytes, but no genetic damage was found in other tests, leading to the hypothesis that the effects were from overstimulation of β2 receptors rather than direct DNA damage.
  • - Further experiments with repeated doses showed that this overstimulation could lead to tolerance, indicated by decreased effects on certain biomarkers and a resolution of the initial micronucleus response, supporting the idea that the changes are related to physiological effects rather than genotoxic
View Article and Find Full Text PDF

By careful analysis of experimental X-ray ligand crystallographic protein data across several inhibitor series we have discovered a novel, potent and selective series of iNOS inhibitors exemplified by compound 8.

View Article and Find Full Text PDF

Background And Purpose: Beta(2)-adrenoceptor agonists (beta(2)-agonists) are important bronchodilators used in the treatment of asthma and chronic obstructive pulmonary disease. At the molecular level, beta(2)-adrenergic agonist stimulation induces desensitization of the beta(2)-adrenoceptor. In this study, we have examined the relationships between initial effect and subsequent reduction of responsiveness to restimulation for a panel of beta(2)-agonists in cellular and in vitro tissue models.

View Article and Find Full Text PDF

Nitric oxide synthase (NOS) enzymes synthesize nitric oxide, a signal for vasodilatation and neurotransmission at low concentrations and a defensive cytotoxin at higher concentrations. The high active site conservation among all three NOS isozymes hinders the design of selective NOS inhibitors to treat inflammation, arthritis, stroke, septic shock and cancer. Our crystal structures and mutagenesis results identified an isozyme-specific induced-fit binding mode linking a cascade of conformational changes to a new specificity pocket.

View Article and Find Full Text PDF

The chemokine receptors CXCR1 and CXCR2 are G-protein-coupled receptors (GPCRs) implicated in mediating cellular functions associated with the inflammatory response. Potent CXCR2 receptor antagonists have been discovered, some of which have recently entered clinical development. The aim of this study was to identify key amino acid residue differences between CXCR1 and CXCR2 that influence the relative antagonism by two compounds that have markedly different chemical structures.

View Article and Find Full Text PDF

4-Methylaminopyridine (4-MAP) (5) is a potent but nonselective nitric oxide synthase (NOS) inhibitor. While simple N-methylation in this series results in poor activity, more elaborate N-substitution such as with 4-piperidine carbamate or amide results in potent and selective inducible NOS inhibition. Evidently, a flipping of the pyridine ring between these new inhibitors allows the piperidine to interact with different residues and confer excellent selectivity.

View Article and Find Full Text PDF

The discovery of a novel class of nitric oxide synthase (NOS) inhibitors, 2-substituted 1,2-dihydro-4-quinazolinamines, and the related 4'-aminospiro[piperidine-4,2'(1'H)-quinazolin]-4'-amines is described. Members of both series exhibit nanomolar potency and high selectivity for the inducible isoform of the enzyme (i-NOS) relative to the constitutive isoforms in vitro. Efficacy in acute and chronic animal models of inflammatory disease following oral administration has also been demonstrated using these compounds.

View Article and Find Full Text PDF