Exploring the pharmacokinetics of phenoxymethylpenicillin (Penicillin-V) in adults: a healthy volunteer study

This healthy volunteer study aimed to explore Phenoxymethylpenicillin (Penicillin-V) pharmacokinetics (PK) to support the planning of large, dosing studies in adults. Volunteers were dosed with penicillin-V at steady state. Total and unbound penicillin-V serum concentration was determined and a base population PK model were fitted to the data

Theory of exciton-exciton correlation in nonlinear optical response

We present a systematic theory of Coulomb interaction effects in the nonlinear optical processes in semiconductors using a perturbation series in the exciting laser field. The third-order dynamical response consists of phase-space filling correction, mean-field exciton-exciton interaction, and two-exciton correlation effects expressed as a force-force correlation function. The theory provides a unified description of effects of bound and unbound biexcitons, including memory-effects beyond the Markovian approximation. Approximations for the correlation function are presented.Comment: RevTex, 35 pages, 10 PostScript figs, shorter version submitted to Physical Review

Immediate oral versus immediate topical versus delayed oral antibiotics for children with acute otitis media with discharge: the REST three-arm non-inferiority electronic platform-supported RCT

BACKGROUND: Acute otitis media is a painful infection of the middle ear that is commonly seen in children. In some children, the eardrum spontaneously bursts, discharging visible pus (otorrhoea) into the outer ear. OBJECTIVE: To compare the clinical effectiveness of immediate topical antibiotics or delayed oral antibiotics with the clinical effectiveness of immediate oral antibiotics in reducing symptom duration in children presenting to primary care with acute otitis media with discharge and the economic impact of the alternative strategies. DESIGN: This was a pragmatic, three-arm, individually randomised (stratified by age < 2 vs. ≥ 2 years), non-inferiority, open-label trial, with economic and qualitative evaluations, supported by a health-record-integrated electronic trial platform [TRANSFoRm (Translational Research and Patient Safety in Europe)] with an internal pilot. SETTING: A total of 44 English general practices. PARTICIPANTS: Children aged ≥ 12 months and < 16 years whose parents (or carers) were seeking medical care for unilateral otorrhoea (ear discharge) following recent-onset (≤ 7 days) acute otitis media. INTERVENTIONS: (1) Immediate ciprofloxacin (0.3%) solution, four drops given three times daily for 7 days, or (2) delayed 'dose-by-age' amoxicillin suspension given three times daily (clarithromycin twice daily if the child was penicillin allergic) for 7 days, with structured delaying advice. All parents were given standardised information regarding symptom management (paracetamol/ibuprofen/fluids) and advice to complete the course. COMPARATOR: Immediate 'dose-by-age' oral amoxicillin given three times daily (or clarithromycin given twice daily) for 7 days. Parents received standardised symptom management advice along with advice to complete the course. MAIN OUTCOME MEASURE: Time from randomisation to the first day on which all symptoms (pain, fever, being unwell, sleep disturbance, otorrhoea and episodes of distress/crying) were rated 'no' or 'very slight' problem (without need for analgesia). METHODS: Participants were recruited from routine primary care appointments. The planned sample size was 399 children. Follow-up used parent-completed validated symptom diaries. RESULTS: Delays in software deployment and configuration led to small recruitment numbers and trial closure at the end of the internal pilot. Twenty-two children (median age 5 years; 62% boys) were randomised: five, seven and 10 to immediate oral, delayed oral and immediate topical antibiotics, respectively. All children received prescriptions as randomised. Seven (32%) children fully adhered to the treatment as allocated. Symptom duration data were available for 17 (77%) children. The median (interquartile range) number of days until symptom resolution in the immediate oral, delayed oral and immediate topical antibiotic arms was 6 (4-9), 4 (3-7) and 4 (3-6), respectively. Comparative analyses were not conducted because of small numbers. There were no serious adverse events and six reports of new or worsening symptoms. Qualitative clinician interviews showed that the trial question was important. When the platform functioned as intended, it was liked. However, staff reported malfunctioning software for long periods, resulting in missed recruitment opportunities. Troubleshooting the software placed significant burdens on staff. LIMITATIONS: The over-riding weakness was the failure to recruit enough children. CONCLUSIONS: We were unable to answer the main research question because of a failure to reach the required sample size. Our experience of running an electronic platform-supported trial in primary care has highlighted challenges from which we have drawn recommendations for the National Institute for Health Research (NIHR) and the research community. These should be considered before such a platform is used again. TRIAL REGISTRATION: Current Controlled Trials ISRCTN12873692 and EudraCT 2017-003635-10. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 67. See the NIHR Journals Library website for further project information

Stratification of candidate genes for Parkinson's disease using weighted protein-protein interaction network analysis

Background: Genome wide association studies (GWAS) have helped identify large numbers of genetic loci that significantly associate with increased risk of developing diseases. However, translating genetic knowledge into understanding of the molecular mechanisms underpinning disease (i.e. disease-specific impacted biological processes) has to date proved to be a major challenge. This is primarily due to difficulties in confidently defining candidate genes at GWAS-risk loci. The goal of this study was to better characterize candidate genes within GWAS loci using a protein interactome based approach and with Parkinson’s disease (PD) data as a test case. // Results: We applied a recently developed Weighted Protein-Protein Interaction Network Analysis (WPPINA) pipeline as a means to define impacted biological processes, risk pathways and therein key functional players. We used previously established Mendelian forms of PD to identify seed proteins, and to construct a protein network for genetic Parkinson’s and carried out functional enrichment analyses. We isolated PD-specific processes indicating ‘mitochondria stressors mediated cell death’, ‘immune response and signaling’, and ‘waste disposal’ mediated through ‘autophagy’. Merging the resulting protein network with data from Parkinson’s GWAS we confirmed 10 candidate genes previously selected by pure proximity and were able to nominate 17 novel candidate genes for sporadic PD. // Conclusions: With this study, we were able to better characterize the underlying genetic and functional architecture of idiopathic PD, thus validating WPPINA as a robust pipeline for the in silico genetic and functional dissection of complex disorders

Facile access to a heterocyclic, sp3-rich chemical scaffold via a tandem condensation/intramolecular nitrone–alkene [3+2] cycloaddition strategy

A heterocyclic, sp3-rich chemical scaffold was synthesised in just 6 steps via a highly regio- and diastereo-selective tandem nitrone formation/intramolecular nitrone–alkene [3+2] cycloaddition reaction. A library of 543 lead-like compounds based on the scaffold core has been produced

Expedient synthesis of an atypical oxazolidinone compound library

In order to address the current downturn in the drug discovery pipeline, initiatives are being undertaken to synthesise screening libraries of sp3-rich, low molecular weight compounds. As part of the European Lead Factory initiative, the synthesis and derivatisation of a simple hexahydrooxazolo[5,4-c]pyridin-2(1H)-one bicyclic carbamate has been achieved. The synthetic route employed involved a telescoped hetero-Diels-Alder/[2,3]-sigmatropic rearrangement/cyclisation sequence to deliver the desired core scaffold containing two points for further diversification. When applied, this synthesis was found to be robust and scalable which allowed the production of a 155 compound library

Term Matrix: a novel Gene Ontology annotation quality control system based on ontology term co-annotation patterns.

Biological processes are accomplished by the coordinated action of gene products. Gene products often participate in multiple processes, and can therefore be annotated to multiple Gene Ontology (GO) terms. Nevertheless, processes that are functionally, temporally and/or spatially distant may have few gene products in common, and co-annotation to unrelated processes probably reflects errors in literature curation, ontology structure or automated annotation pipelines. We have developed an annotation quality control workflow that uses rules based on mutually exclusive processes to detect annotation errors, based on and validated by case studies including the three we present here: fission yeast protein-coding gene annotations over time; annotations for cohesin complex subunits in human and model species; and annotations using a selected set of GO biological process terms in human and five model species. For each case study, we reviewed available GO annotations, identified pairs of biological processes which are unlikely to be correctly co-annotated to the same gene products (e.g. amino acid metabolism and cytokinesis), and traced erroneous annotations to their sources. To date we have generated 107 quality control rules, and corrected 289 manual annotations in eukaryotes and over 52 700 automatically propagated annotations across all taxa

Structural and biochemical analysis of a unique phosphatase from Bdellovibrio bacteriovorus reveals its structural and functional relationship with the protein tyrosine phosphatase class of phytase

Bdellovibrio bacteriovorus is an unusual δ-proteobacterium that invades and preys on other Gram-negative bacteria and is of potential interest as a whole cell therapeutic against pathogens of man, animals and crops. PTPs (protein tyrosine phosphatases) are an important class of enzyme involved in desphosphorylating a variety of substrates, often with implications in cell signaling. The B. bacteriovorus open reading frame Bd1204 is predicted to encode a PTP of unknown function. Bd1204 is both structurally and mechanistically related to the PTP-like phytase (PTPLP) class of enzymes and possesses a number of unique properties not observed in any other PTPLPs characterized to date. Bd1204 does not display catalytic activity against some common protein tyrosine phosphatase substrates but is highly specific for hydrolysis of phosphomonoester bonds of inositol hexakisphosphate. The structure reveals that Bd1204 has the smallest and least electropositive active site of all characterized PTPLPs to date yet possesses a unique substrate specificity characterized by a strict preference for inositol hexakisphosphate. These two active site features are believed to be the most significant contributors to the specificity of phytate degrading enzymes. We speculate that Bd1204 may be involved in phosphate acquisition outside of prey