The clinical presentation of avoidant restrictive food intake disorder in children and adolescents is largely independent of sex, autism spectrum disorder and anxiety traits.

Background: Avoidant restrictive food intake disorder (ARFID) is a new eating disorder with a heterogeneous clinical presentation. It is unclear which patient characteristics contribute to its heterogeneity. Methods: To identify these patient characteristics, we performed symptom-level correlation and driver-level regression analyses in our cross-sectional study in up to 261 ARFID patients (51% female; median age = 12.7 years) who were assessed at the Maudsley Centre for Child and Adolescent Eating Disorders, London between November 2019 and July 2022. Findings: Symptoms across the three drivers 1) avoidance based on sensory characteristics of food; 2) apparent lack of interest in eating; and 3) concern about aversive consequences positively correlated with each other. Patients' anxiety traits showed the greatest positive correlations with symptoms of concern about aversive consequences of eating. Patient sex was not significantly associated with any of the three ARFID drivers. Patients with comorbid autism spectrum disorder (ASD; 28%) showed more food-related sensory sensitivities (RR = 1.26) and greater lack of interest in eating (RR = 1.18) than those of patients without ASD (49%). Interpretation: In our clinical sample, the ARFID drivers occurred together and did not show clinically meaningful differences between the sexes. ASD may accentuate food-related sensory sensitivities and lack of interest, but may not drive a completely different symptom presentation. ARFID is multi-faceted and heterogenous, requiring a comprehensive multidisciplinary assessment to sufficiently understand the drivers of the restrictive eating behaviour. Results need replication in larger samples with more statistical power. Funding: None.

Genome-wide assessment of the carriers involved in the cellular uptake of drugs: a model system in yeast.

BACKGROUND: The uptake of drugs into cells has traditionally been considered to be predominantly via passive diffusion through the bilayer portion of the cell membrane. The recent recognition that drug uptake is mostly carrier-mediated raises the question of which drugs use which carriers. RESULTS: To answer this, we have constructed a chemical genomics platform built upon the yeast gene deletion collection, using competition experiments in batch fermenters and robotic automation of cytotoxicity screens, including protection by 'natural' substrates. Using these, we tested 26 different drugs and identified the carriers required for 18 of the drugs to gain entry into yeast cells. CONCLUSIONS: As well as providing a useful platform technology, these results further substantiate the notion that the cellular uptake of pharmaceutical drugs normally occurs via carrier-mediated transport and indicates that establishing the identity and tissue distribution of such carriers should be a major consideration in the design of safe and effective drugs.

Yeast-based automated high-throughput screens to identify anti-parasitic lead compounds.

We have developed a robust, fully automated anti-parasitic drug-screening method that selects compounds specifically targeting parasite enzymes and not their host counterparts, thus allowing the early elimination of compounds with potential side effects. Our yeast system permits multiple parasite targets to be assayed in parallel owing to the strains' expression of different fluorescent proteins. A strain expressing the human target is included in the multiplexed screen to exclude compounds that do not discriminate between host and parasite enzymes. This form of assay has the advantages of using known targets and not requiring the in vitro culture of parasites. We performed automated screens for inhibitors of parasite dihydrofolate reductases, N-myristoyltransferases and phosphoglycerate kinases, finding specific inhibitors of parasite targets. We found that our 'hits' have significant structural similarities to compounds with in vitro anti-parasitic activity, validating our screens and suggesting targets for hits identified in parasite-based assays. Finally, we demonstrate a 60 per cent success rate for our hit compounds in killing or severely inhibiting the growth of Trypanosoma brucei, the causative agent of African sleeping sickness.