Methylxanthines, including caffeine and theophylline, are among the most widely consumed stimulant drugs in the world. These effects are mediated primarily via blockade of adenosine receptors. Xanthine analogs with improved properties have been developed as potential treatments for diseases such as Parkinson's disease. Here we report the structures of a thermostabilized adenosine A(2A) receptor in complex with the xanthines xanthine amine congener and caffeine, as well as the A(2A) selective inverse agonist ZM241385. The receptor is crystallized in the inactive state conformation as defined by the presence of a salt bridge known as the ionic lock. The complete third intracellular loop, responsible for G protein coupling, is visible consisting of extended helices 5 and 6. The structures provide new insight into the features that define the ligand binding pocket of the adenosine receptor for ligands of diverse chemotypes as well as the cytoplasmic regions that interact with signal transduction proteins.

Potent, ligand efficient, selective, and orally efficacious 1,2,4-triazine derivatives have been identified using structure based drug design approaches as antagonists of the adenosine A2A receptor. The X-ray crystal structures of compounds 4e and 4g bound to the GPCR illustrate that the molecules bind deeply inside the orthosteric binding cavity. In vivo pharmacokinetic and efficacy data for compound 4k are presented, demonstrating the potential of this series of compounds for the treatment of Parkinson’s disease.

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In 1994, an outbreak of Enterobacter sakazakii infections occurred in a neonatal intensive care unit in France from 5 May to 11 July. During the outbreak, 13 neonates were infected with E. sakazakii, resulting in 3 deaths. In addition, four symptomless neonates were colonized by E. sakazakii. The strains were subjected to 16S rRNA gene sequence analysis, genotyped using pulsed-field gel electrophoresis, and phenotyped for a range of enzyme activities. E. sakazakii was isolated from various anatomical sites, reconstituted formula, and an unopened can of powdered infant formula. A fourth neonate died from septic shock, attributed to E. sakazakii infection, during this period. However, 16S rRNA gene sequence analysis revealed that the organism was Enterobacter cloacae. There were three pulsotypes of E. sakazakii associated with infected neonates, and three neonates were infected by more than one genotype. One genotype matched isolates from unused prepared formula and unfinished formula. However, no pulsotypes matched the E. sakazakii strain recovered from an unopened can of powdered infant formula. One pulsotype was associated with the three fatal cases, and two of these isolates had extended-spectrum ␤-lactamase activity. It is possible that E. sakazakii strains differ in their pathogenicities, as shown by the range of symptoms associated with each pulsotype.Enterobacter sakazakii is an opportunistic pathogen associated with the ingestion of reconstituted infant formula and is a rare cause of neonatal meningitis, necrotizing enterocolitis (NEC), and sepsis (9, 10, 11, 23). Such cases often occur among low-birth-weight preterm neonates, who are generally more susceptible to gram-negative bacterial sepsis and endotoxemia associated with NEC (1, 26). The International Commission on Microbiological Specifications for Foods (14) has ranked E. sakazakii as a "severe hazard for restricted populations, life-threatening or substantial chronic sequelae or long duration." A number of reported E. sakazakii outbreaks have been attributed to contaminated reconstituted infant formula (4,7,13,18,31). Bowen and Braden (4) reviewed 46 cases of invasive E. sakazakii infections and showed a link between symptoms and birth weight but did not consider cases of NEC.The virulence of E. sakazakii has been studied by Pagotto et al. (23) and Mange et al. (21), who showed the presence of enterotoxins and adhesion to brain cells, respectively. Townsend et al. demonstrated the translocation of E. sakazakii and other intestinal bacteria across the rat intestinal wall in response to the presence of lipopolysaccharide (28). They also demonstrated that E. sakazakii causes chronic-patterned inflammation in the neonatal rat brain, invades capillary endothelial brain cells, is taken up by macrophages, and induces anti-inflammatory cytokine (interleukin-10) expression in vitro and in vivo at various levels according to strain (29). However, these publications did not report the individual case details associated with the isolates under study. Therefor...

Virtual screening was performed against experimentally enabled homology models of the adenosine A2A receptor, identifying a diverse range of ligand efficient antagonists (hit rate 9%). By use of ligand docking and Biophysical Mapping (BPM), hits 1 and 5 were optimized to potent and selective lead molecules (11–13 from 5, pKI = 7.5–8.5, 13- to >100-fold selective versus adenosine A1; 14–16 from 1, pKI = 7.9–9.0, 19- to 59-fold selective).