Characterisation of small molecule ligands 4CMTB and 2CTAP as modulators of human FFA2 receptor signalling.

Short chain fatty acids (SCFAs) are protective against inflammatory diseases. Free fatty acid receptor 2 (FFA2), is a target of SCFAs however, their selectivity for FFA2 over other FFA receptors is limited. This study aimed to functionally characterise 2-(4-chlorophenyl)-3-methyl-N-(thiazole-2-yl)butanamide (4CMTB) and 4-((4-(2-chlorophenyl)thiazole-2-yl)amino)-4oxo-3-phenylbutanoic acid (2CTAP), and their enantiomers, in modulating FFA2 activity. The racemic mixture (R/S) and its constituents (R-) and (S-) 4CMTB or 2CTAP were used to stimulate human (h)FFA2 in the absence or presence of acetate. Calcium ions (Ca2+), phosphorylated extracellular signal-regulated kinase 1 and 2 (pERK1/2) and cyclic adenosine monophosphate (cAMP) were measured. R/S-4CMTB is a functionally selective ago-allosteric ligand that enhances Ca2+ response to acetate. Both R/S-4CMTB and S-4CMTB are more potent activators of pERK1/2 and inhibitors of forskolin-induced cAMP than acetate. S-4CMTB increased neutrophil infiltration in intestinal ischemia reperfusion injury (IRI). 2CTAP inhibited constitutive Ca2+ levels, antagonised acetate-induced pERK1/2 and prevented damage following IRI. This study characterises enantiomers of functionally selective ligands for FFA2 in cells stably expressing hFFA2. It highlights the novel roles of selective FFA2 enantiomers 4CMTB and 2CTAP on Ca2+, pERK1/2 and cAMP and their roles as allosteric modulators which, may assist in efforts to design novel therapeutic agents for FFA2-driven inflammatory diseases.

Opioid analgesic use in Australia and The Netherlands: a cross-country comparison.

Background Increasing use of opioid analgesics (OA) has been reported worldwide. Objective To compare the use of OA in two countries in order to better understand these trends. Setting Outpatient settings in Australia and The Netherlands. Method We analysed publicly available government data on outpatient OA dispensing over 15 years (2000-2014). We compared dispensing trends for specific OA and explored medical (national clinical guidelines), contextual and policy-related factors to explain differences in use between the two countries. Main outcome measure OA prescribing in Australia and The Netherlands, absolute volume of use, preferred types of opioids and changes over time. Results The average annual increase in OA prescribing was 10% in Australia and 8% in The Netherlands between 2000 and 2014. In 2014, the total use of OA was 10.0 daily defined doses (DDD)/1000 population/day in Australia and 9.4 DDD/1000 population/day in The Netherlands. In Australia, the most commonly prescribed opioids were oxycodone and tramadol, compared to fentanyl and tramadol in The Netherlands. We found differences in prescribing guidelines, culture of prescribing and regulatory frameworks that could explain some of the observed differences. Conclusion OA prescribing has increased remarkably in both countries between 2000 and 2014 but the types of prescribed OA vary. Differences in national evidence-based guidelines influenced the types of OA used. Prescribing culture as well as regulatory policies and costs, may also contribute to the different patterns of OA use.

Oligonucleotide and polymer functionalized nanoparticles for amplification-free detection of DNA.

Sensitive and quantitative nucleic acid testing from complex biological samples is now an important component of clinical diagnostics. Whereas nucleic acid amplification represents the gold standard, its utility in resource-limited and point-of-care settings can be problematic due to assay interferants, assay time, engineering constraints, and costs associated with both wetware and hardware. In contrast, amplification-free nucleic acid testing can circumvent these limitations by enabling direct target hybridization within complex sample matrices. In this work, we grew random copolymer brushes from the surface of silica-coated magnetic nanoparticles using azide-modified and hydroxyl oligo ethylene glycol methacrylate (OEGMA) monomers. The azide-functionalized polymer brush was first conjugated, via copper-catalyzed azide/alkyne cycloaddition (CuAAC), with herpes simplex virus (HSV)-specific oligonucleotides and then with alkyne-substituted polyethylene glycol to eliminate all residual azide groups. Our methodology enabled control over brush thickness and probe density and enabled multiple consecutive coupling reactions on the particle grafted brush. Brush- and probe-modified particles were then combined in a 20 min hybridization with fluorescent polystyrene nanoparticles modified with HSV-specific reporter probes. Following magnetic capture and washing, the particles were analyzed with an aggregate fluorescence measurement, which yielded a limit of detection of 6 pM in buffer and 60 pM in 50% fetal bovine serum. Adoption of brush- and probe-modified particles into a particle counting assay will result in the development of diagnostic assays with significant improvements in sensitivity.

Structure aided design of chimeric antibiotics.

The rise of antibiotic resistance is of great clinical concern. One approach to reducing the development of resistance is to co-administer two or more antibiotics with different modes of action. However, it can be difficult to control the distribution and pharmacokinetics of two drugs to ensure both concentrations remain within the range of therapeutic efficacy whilst avoiding adverse effects. Hybrid drugs, where two drugs are linked together with a flexible linker, have been explored, but the resultant large, flexible molecules can have poor bioavailability. We have developed a chimeric approach using click chemistry where the pharmacophores of two drugs are overlapped into a single smaller, more drug-like molecule. Design and selection of compounds were assisted by in silico structural docking. We prepared a series of compounds that include candidates showing activity against the targets of both trimethoprim; dihydrofolate reductase, and ciprofloxacin; DNA gyrase and topoisomerase IV. The resultant triazole containing molecules show modest, but broad spectrum activities against drug sensitive and resistant Gram-negative and Gram-positive bacteria, with no observable cytotoxicity.

Synthesis of essramycin and comparison of its antibacterial activity.

The triazolopyrimidine natural product essramycin (1) was synthesized without the use of protecting groups via a two-step reaction scheme involving a 3-amino-1,2,4-triazole intermediate, and its structure was unequivocally determined. However, in contrast to the natural product, the synthetic essramycin (1) did not display any antibacterial activity.