Drug repurposing for rare: progress and opportunities for the rare disease community.

Repurposing is one of the key opportunities to address the unmet rare diseases therapeutic need. Based on cases of drug repurposing in small population conditions, and previous work in drug repurposing, we analyzed the most important lessons learned, such as the sharing of clinical observations, reaching out to regulatory scientific advice at an early stage, and public-private collaboration. In addition, current upcoming trends in the field of drug repurposing in rare diseases were analyzed, including the role these trends could play in the rare diseases' ecosystem. Specifically, we cover the opportunities of innovation platforms, the use of real-world data, the use of artificial intelligence, regulatory initiatives in repurposing, and patient engagement throughout the repurposing project. The outcomes from these emerging activities will help progress the field of drug repurposing for the benefit of patients, public health and medicines development.

A metagenomic analysis for combination therapy of multiple classes of antibiotics on the prevention of the spread of antibiotic-resistant genes.

Antibiotics used systemically to treat infections may have off-target effects on the gut microbiome, potentially resulting in the emergence of drug-resistant bacteria or selection of pathogenic species. These organisms may present a risk to the host and spread to the environment with a risk of transmission in the community. To investigate the risk of emergent antibiotic resistance in the gut microbiome following systemic treatment with antibiotics, this metagenomic analysis project used next-generation sequencing, a custom-built metagenomics pipeline, and differential abundance analysis to study the effect of antibiotics (ampicillin, ciprofloxacin, and fosfomycin) in monotherapy and different combinations at high and low doses, to determine the effect on resistome and taxonomic composition in the gut of Balb/c mice. The results showed that low-dose monotherapy treatments showed little change in microbiome composition but did show an increase in expression of many antibiotic-resistant genes (ARGs) posttreatment. Dual combination treatments allowed the emergence of some conditionally pathogenic bacteria and some increase in the abundance of ARGs despite a general decrease in microbiota diversity. Triple combination treatment was the most successful in inhibiting emergence of relevant opportunistic pathogens and completely suppressed all ARGs after 72 h of treatment. The relative abundances of mobile genetic elements that can enhance transmission of antibiotic resistance either decreased or remained the same for combination therapy while increasing for low-dose monotherapy. Combination therapy prevented the emergence of ARGs and decreased bacterial diversity, while low-dose monotherapy treatment increased ARGs and did not greatly change bacterial diversity.

Fosfomycin for Non-Urinary Tract Infections: a systematic review.

Introduction: Although fosfomycin is currently approved for treating urinary tract infections, it is increasingly being used as salvage therapy for various infectious syndromes outside the urinary tract. This systematic review evaluates clinical and microbiological cure rates in patients with bacterial infections not restricted to the urinary tract where fosfomycin was used off-label. Materials and Methods: Articles from two databases (Pubmed and Scopus) were reviewed. The dosage, route, and duration of fosfomycin therapy along with the details of adjunctive antimicrobial agents were noted. The final outcomes captured were clinical or microbiological cures. Results: A total of 649 articles, not including duplicates, were selected for the title and abstract screening. After title and abstract screening, 102 articles were kept for full-text screening. Of the 102 articles, 23 studies (n=1227 patients) were kept in the final analysis. Of the 1227 patients, 301 (25%) received fosfomycin as monotherapy, and the remaining 926 75%) received fosfomycin in combination with at least one other antimicrobial agent. Most of the patients received intravenous fosfomycin (n=1046, 85%). Staphylococcus spp and Enterobacteriaceae were the most common organisms. The pooled clinical and microbiological cure rates were 75% and 84%, respectively. Conclusion: Fosfomycin has moderate clinical success in patients with non-urinary tract infections, especially when used with other antimicrobials. Due to the paucity of randomized controlled trials, fosfomycin's use should be limited to situations where no alternatives are supported by better clinical evidence.

Diagnostic capacities and treatment practices on implantation mycoses: Results from the 2022 WHO global online survey.

Between January and March 2022, WHO conducted a global online survey to collect data on diagnostic capacities and treatment practices in different settings for four implantation mycoses: eumycetoma, actinomycetoma, cutaneous sporotrichosis and chromoblastomycosis. The survey investigated the type of diagnostic methods available in countries at various health system levels (tertiary, secondary, primary level) and the medicines used to treat implantation mycoses, with a view to understanding the level of drug repurposing for treatment of these diseases. 142 respondents from 47 countries, including all continents, contributed data: 60% were from middle-income countries, with 59% working at the tertiary level of the health system and 30% at the secondary level. The results presented in this article provide information on the current diagnostic capacity and treatment trends for both pharmacological and non-pharmacological interventions. In addition, the survey provides insight on refractory case rates, as well as other challenges, such as availability and affordability of medicines, especially in middle-income countries. Although the study has limitations, the survey-collected data confirms that drug repurposing is occurring for all four surveyed implantation mycoses. The implementation of an openly accessible global and/or a national treatment registry for implantation mycoses could contribute to address the gaps in epidemiological information and collect valuable observational data to inform treatment guidelines and clinical research.

Evaluation of a Sequential Antibiotic Treatment Regimen of Ampicillin, Ciprofloxacin and Fosfomycin against Escherichia coli CFT073 in the Hollow Fiber Infection Model Compared with Simultaneous Combination Treatment.

OBJECTIVE: Employ the hollow fiber infection model (HFIM) to study sequential antibiotic administration (ampicillin, ciprofloxacin and fosfomycin) using human pharmacokinetic profiles to measure changes in the rate of antibiotic resistance development and compare this to simultaneous combination therapy with the same antibiotic combinations. METHODS: Escherichia coli CFT073, a clinical uropathogenic strain, was exposed individually to clinically relevant pharmacokinetic concentrations of ampicillin on day 1, ciprofloxacin on day 2 and fosfomycin on day 3. This sequence was continued for 10 days in the HFIM. Bacterial samples were collected at different time points to enumerate total and resistant bacterial populations. The results were compared with the simultaneous combination therapy previously studied. RESULTS: Sequential antibiotic treatment (ampicillin-ciprofloxacin-fosfomycin sequence) resulted in the early emergence of single and multi-antibiotic-resistant subpopulations, while the simultaneous treatment regimen significantly delayed or prevented the emergence of resistant subpopulations. CONCLUSION: Sequential administration of these antibiotic monotherapies did not significantly delay the emergence of resistant subpopulations compared to simultaneous treatment with combinations of the same antibiotics. Further studies are warranted to evaluate different sequences of the same antibiotics in delaying emergent resistance.

Reproductive character displacement and potential underlying drivers in a species-rich and florally diverse lineage of tropical angiosperms (Ruellia; Acanthaceae).

Reproductive character displacement is a pattern whereby sympatric lineages diverge more in reproductive character morphology than allopatric lineages. This pattern has been observed in many plant species, but comparably few have sought to disentangle underlying mechanisms. Here, in a diverse lineage of Neotropical plants (Ruellia; Acanthaceae), we present evidence of reproductive character displacement in a macroevolutionary framework (i.e., among species) and document mechanistic underpinnings. In a series of interspecific hand pollinations in a controlled glasshouse environment, we found that crosses between species that differed more in overall flower size, particularly in style length, were significantly less likely to produce viable seeds. Further, species pairs that failed to set seed were more likely to have sympatric distributions in nature. Competition for pollinators and reinforcement to avoid costly interspecific mating could both result in these patterns and are not mutually exclusive processes. Our results add to growing evidence that reproductive character displacement contributes to exceptional floral diversity of angiosperms.

Effect of drug combinations on the kinetics of antibiotic resistance emergence in Escherichia coli CFT073 using an in vitro hollow-fibre infection model.

Antibiotic resistance is one of the major threats to public health today. To address this problem requires an urgent comprehensive approach. Strategic and multitargeted combination therapy has been increasingly used clinically to treat bacterial infections. The hollow-fibre infection model (HFIM) is a well-controlled in vitro bioreactor system that is increasingly being used in the assessment of resistance emergence with monotherapies and combination antibiotic therapies. In this study, the HFIM was evaluated as a reliable in vitro method to quantitatively and reproducibly analyse the emergence of antibiotic resistance using ampicillin, fosfomycin and ciprofloxacin and their simultaneous combinations against Escherichia coli CFT073, a clinical uropathogenic strain. Bacteria were exposed to clinically relevant pharmacokinetic (PK) concentrations of the drugs for 10 days. Drug and bacterial samples were collected at different time points for PK analysis and to enumerate total and resistant bacterial populations, respectively. The results demonstrated that double or triple combinations significantly delayed the emergence of resistant E. coli CFT073 subpopulations. These findings suggest that strategic combinations of antimicrobials may play a role in controlling the emergence of resistance during treatment. Further animal and human trials will be needed to confirm this and to ensure that there is no adverse impact on the host microbiome or unexpected toxicity. The HFIM system could potentially be used to identify clinically relevant combination dosing regimens for use in a clinical trial evaluating the appearance of resistance to antibacterial drugs.

Evolutionary and ecological drivers of plant flavonoids across a large latitudinal gradient.

Flavonoids are important secondary metabolites that play an integral role in protecting plants against UV radiation and other forms of environmental stress. Given widespread impacts of environmental effects associated with latitude on a multitude of biological systems and a well-documented increase in solar radiation towards the equator, plant flavonoid production is expected to increase as a response to factors associated with decreasing latitude. Using data from a Neotropical genus (Ruellia) that spans an exceptionally broad latitudinal gradient, we tested a hypothesis of a positive latitudinal gradient in flavonoid concentration and assessed other factors that influence flavonoid production including habitat type (xeric vs. wet), altitude, phylogenetic relatedness, and pleiotropic effects. Two flavones with peak absorbance in ultraviolet wavelengths, apigenin and luteolin, were detected across all species. Transcriptome data confirm high expression of the gene required for flavone biosynthesis, flavone synthase (FNS). Contrary to our prediction, data revealed a positive correlation between flavone concentration and higher latitudes. Further, we recovered strong impacts of xeric habitat, pleiotropy, and phylogenetic relatedness on flavone concentrations. This study documents a complex interplay of ecological, historical, phylogenetic relatedness, and pleiotropic factors driving plant flavonoid production.

Retention of Vaginal Breech Delivery Skills Taught in Simulation.

OBJECTIVE: The optimal frequency of conducting simulation training for high-acuity, low-frequency events in obstetrics and gynaecology residency programs is unknown. This study evaluated retention over time of vaginal breech delivery skills taught in simulation, by comparing junior and senior residents. In addition, the residents' subjective comfort level to perform this skill clinically was assessed. METHODS: This prospective cohort study included 22 obstetrics and gynaecology residents in a Canadian residency training program. Digital recordings were completed for pre-training, immediate post-training, and delayed (10-26 weeks later) post-training intervals of a vaginal breech delivery simulation, with skill assessment by a blinded observer using a binary checklist. Residents also completed questionnaires to assess their subjective comfort level at each interval. RESULTS: Junior and senior residents had significant improvements in vaginal breech delivery skills from the pre-training assessment to both the immediate post-training assessment (junior, P <0.001; senior, P <0.001) and the delayed post-training assessment (P <0.001 and P = 0.001, respectively). There was a significant decline in skills between the immediate and delayed post-training sessions for junior and senior residents (P = 0.003 and P <0.001, respectively). Both junior and senior residents gained more comfort immediately after the training (P <0.001 and P <0.001, respectively), without a significant change between immediate post-training and delayed post-training comfort levels (P = 0.19 and P = 0.11, respectively). CONCLUSION: Residents retained vaginal breech delivery skills taught in simulation 10-26 weeks later, although a decline in skills occurred over this time period. Comfort level was positively affected and retained. These results will aid in determining the frequency of simulation teaching for high-acuity, low-frequency events in a residency simulation curriculum.

Biological removal of nitrate by an oil reservoir culture capable of autotrophic and heterotrophic activities: kinetic evaluation and modeling of heterotrophic process.

Kinetics of heterotrophic denitrification was investigated using an oil reservoir culture with the ability to function under both autotrophic and heterotrophic conditions. In the batch system nitrate at concentrations up to 30 mM did not influence the kinetics but with 50mM slower growth and removal rates were observed. A kinetic model, representing the denitrification as reduction of nitrate to nitrite, and subsequent reduction of nitrite to nitrous oxides and nitrogen gas was developed. The value of various kinetic coefficients, including maximum specific growth rate, saturation constant, yield and activation energy for nitrate and nitrite reductions were determined by fitting the experimental data into the developed model. In continuous bioreactors operated with 10 or 30 mM nitrate, complete removal of nitrate (no residual nitrite) and linear dependency between nitrate loading and removal rates were observed for loading rates up to 0.21 and 0.58 mM h(-1), respectively. The highest removal rates of 0.31 and 0.94 mM h(-1) observed at loading rates of 0.42 mM h(-1) and 1.26 mM h(-1), with corresponding removal percentages of nitrate and total nitrogen being 75.4, 54.4%, and 74.4 and 17.9%, respectively. Developed kinetic model predicted the performance of the continuous bioreactors with accuracy.

Injuries and unattended home exits in persons with dementia: a 12-month prospective study.

Persons with dementia are at particular risk for injuries and unattended home exits. The purposes of this study were to prospectively describe the characteristics and determine the hazard rates of unattended home exits and injuries. A total of 9 times over 12 months, data were collected from 53 caregivers of persons with dementia about persons with dementia unattended home exits or injuries. A total of 24% of persons with dementia had at least 1 unattended exit; 4 participants exited multiple times. Men and younger persons with dementia were significantly more likely to exit than women or older individuals. A total of 30% of persons with dementia sustained injuries in 29 separate incidents; all but 3 injuries were caused by falls, and 38% of injuries resulted in nursing home placement. The hazard rate of untoward events was high, at approximately 1 unattended exit and 1 fall per person-year. For all persons with dementia living in the community, health care plans should include specific interventions to prevent these untoward events.