35 research outputs found

    Pharmacodynamics of the Orotomides against Aspergillus fumigatus: New Opportunities for Treatment of Multidrug-Resistant Fungal Disease.

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    F901318 is an antifungal agent with a novel mechanism of action and potent activity against Aspergillus spp. An understanding of the pharmacodynamics (PD) of F901318 is required for selection of effective regimens for study in phase II and III clinical trials. Neutropenic murine and rabbit models of invasive pulmonary aspergillosis were used. The primary PD endpoint was serum galactomannan. The relationships between drug exposure and the impacts of dose fractionation on galactomannan, survival, and histopathology were determined. The results were benchmarked against a clinically relevant exposure of posaconazole. In the murine model, administration of a total daily dose of 24 mg/kg of body weight produced consistently better responses with increasingly fractionated regimens. The ratio of the minimum total plasma concentration/MIC (Cmin/MIC) was the PD index that best linked drug exposure with observed effect. An average Cmin (mg/liter) and Cmin/MIC of 0.3 and 9.1, respectively, resulted in antifungal effects equivalent to the effect of posaconazole at the upper boundary of its expected human exposures. This pattern was confirmed in a rabbit model, where Cmin and Cmin/MIC targets of 0.1 and 3.3, respectively, produced effects previously reported for expected human exposures of isavuconazole. These targets were independent of triazole susceptibility. The pattern of maximal effect evident with these drug exposure targets was also apparent when survival and histopathological clearance were used as study endpoints. F901318 exhibits time-dependent antifungal activity. The PD targets can now be used to select regimens for phase II and III clinical trials.IMPORTANCE Invasive fungal infections are common and often lethal. There are relatively few antifungal agents licensed for clinical use. Antifungal drug toxicity and the emergence of drug resistance make the treatment of these infections very challenging. F901318 is the first in a new class of antifungal agents called the orotomides. This class has a novel mechanism of action that involves the inhibition of the fungal enzyme dihydroorotate dehydrogenase. F901318 is being developed for clinical use. A deep understanding of the relationship between dosages, drug concentrations in the body, and the antifungal effect is fundamental to the identification of the regimens to administer to patients with invasive fungal infections. This study provides the necessary information to ensure that the right dose of F901318 is used the first time. Such an approach considerably reduces the risks in drug development programs and ensures that patients with few therapeutic options can receive potentially life-saving antifungal therapy at the earliest opportunity

    F901318 represents a novel class of antifungal drug that inhibits dihydroorotate dehydrogenase

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    There is an important medical need for new antifungal agents with novel mechanisms of action to treat the increasing number of patients with life-threatening systemic fungal disease and to overcome the growing problem of resistance to current therapies. F901318, the leading representative of a novel class of drug, the orotomides, is an antifungal drug in clinical development that demonstrates excellent potency against a broad range of dimorphic and filamentous fungi. In vitro susceptibility testing of F901318 against more than 100 strains from the four main pathogenic Aspergillus spp. revealed minimal inhibitory concentrations of ≀0.06 ”g/mL—greater potency than the leading antifungal classes. An investigation into the mechanism of action of F901318 found that it acts via inhibition of the pyrimidine biosynthesis enzyme dihydroorotate dehydrogenase (DHODH) in a fungal-specific manner. Homology modeling of Aspergillus fumigatus DHODH has identified a predicted binding mode of the inhibitor and important interacting amino acid residues. In a murine pulmonary model of aspergillosis, F901318 displays in vivo efficacy against a strain of A. fumigatus sensitive to the azole class of antifungals and a strain displaying an azole-resistant phenotype. F901318 is currently in late Phase 1 clinical trials, offering hope that the antifungal armamentarium can be expanded to include a class of agent with a mechanism of action distinct from currently marketed antifungals

    Experimental Models of Short Courses of Liposomal Amphotericin B for Induction Therapy for Cryptococcal Meningitis.

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    Cryptococcal meningoencephalitis is a rapidly lethal infection in immunocompromised patients. Induction regimens are usually administered for 2-weeks. The shortest effective period of induction therapy with liposomal amphotericin B (LAmB) is unknown. The pharmacodynamics of LAmB were studied in murine and rabbit models of cryptococcal meningoencephalitis. The concentrations of LAmB in plasma and brain of mice were measured using HPLC. Histopathological changes were determined. The penetration of LAmB into the brain was determined by immunohistochemistry using an antibody directed to amphotericin B. A dose-dependent decline in fungal burden was observed in the brain of mice with near-maximal efficacy achieved with LAmB 10-20 mg/kg/day. The terminal elimination half-life in brain was 133 hours. The pharmacodynamics of a single dose of 20 mg/kg was the same as 20 mg/kg/day administered for 2 weeks. Changes in quantitative counts were reflected by histopathological changes in the brain. Three doses of LAmB 5 mg/kg/day in rabbits were required to achieve fungicidal activity in cerebrospinal fluid (cumulative AUC 2500 mg.h/L). Amphotericin B was visible in the intra- and perivascular spaces, leptomeninges and choroid plexus. The prolonged mean residence time of amphotericin B in the brain suggest abbreviated induction regimens of LAmB are possible for cryptococcal meningoencephalitis

    The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

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    Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

    Genetic Surfing, Not Allopatric Divergence, Explains Spatial Sorting Of Mitochondrial Haplotypes In Venomous Coralsnakes

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    Strong spatial sorting of genetic variation in contiguous populations is often explained by local adaptation or secondary contact following allopatric divergence. A third explanation, spatial sorting by stochastic effects of range expansion, has been considered less often though theoretical models suggest it should be widespread, if ephemeral. In a study designed to delimit species within a clade of venomous coralsnakes, we identified an unusual pattern within the Texas coral snake (Micrurus tener): strong spatial sorting of divergent mitochondrial (mtDNA) lineages over a portion of its range, but weak sorting of these lineages elsewhere. We tested three alternative hypotheses to explain this pattern-local adaptation, secondary contact following allopatric divergence, and range expansion. Collectively, near panmixia of nuclear DNA, the signal of range expansion associated sampling drift, expansion origins in the Gulf Coast of Mexico, and species distribution modeling suggest that the spatial sorting of divergent mtDNA lineages within M. tener has resulted from genetic surfing of standing mtDNA variation-not local adaptation or allopatric divergence. Our findings highlight the potential for the stochastic effects of recent range expansion to mislead estimations of population divergence made from mtDNA, which may be exacerbated in systems with low vagility, ancestral mtDNA polymorphism, and male-biased dispersal

    Knowledge translation : radiographers compared to other healthcare professionals

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    Objectives: This narrative review examines the current status of evidence-based practice and knowledge translation in diagnostic radiography. It explores knowledge translation efforts in the allied health professions aimed at systematically implementing evidence-based practice and suggests ways that these may be applied within diagnostic radiography. Key findings: Knowledge translation in diagnostic radiography is in its infancy with numerous examples of key findings of rigorous studies not implemented in practice. Utilising frameworks, models and theories to systematically translate knowledge into evidence-based practice has been shown to be effective in other allied health professions. Whilst few studies in diagnostic radiography report utilising these systematic approaches to implementing evidence-based practice, those that do, show promising results. Attitudes towards evidence-based practice within diagnostic radiography are becoming more positive and it is important to use this positive shift in attitudes to create real evidence-based change in the profession. Conclusion: The potential benefits of systematically translating knowledge into evidence-based practice in diagnostic radiography are wide reaching with positive implications for our patients, the profession and wider community. Leaders at all levels of radiography must work towards implementing evidence-based practice in their daily work. Implications for practice: Systematic approaches to knowledge translation should be adopted and reported in diagnostic radiography in order to more effectively translate knowledge into evidence-based practice

    Amikacin Combined with Fosfomycin for Treatment of Neonatal Sepsis in the Setting of Highly Prevalent Antimicrobial Resistance

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    Antimicrobial resistance (particularly through extended-spectrum ÎČ-lactamase and aminoglycoside-modifying enzyme production) in neonatal sepsis is a global problem, particularly in low- and middle-income countries, with significant mortality rates. High rates of resistance are reported for the current WHO-recommended first-line antibiotic regimen for neonatal sepsis, i.e., ampicillin and gentamicin. We assessed the utility of fosfomycin and amikacin as a potential alternative regimen to be used in settings of increasingly prevalent antimicrobial resistance. The combination was studied in a 16-arm dose-ranged hollow-fiber infection model (HFIM) experiment. The combination of amikacin and fosfomycin enhanced bactericidal activity and prevented the emergence of resistance, compared to monotherapy with either antibiotic. Modeling of the experimental quantitative outputs and data from checkerboard assays indicated synergy. We further assessed the combination regimen at clinically relevant doses in the HFIM with nine Enterobacterales strains with high fosfomycin and amikacin MICs and demonstrated successful kill to sterilization for 6/9 strains. From these data, we propose a novel combination breakpoint threshold for microbiological success for this antimicrobial combination against Enterobacterales strains, i.e., MICF × MICA 99% probability of pharmacodynamic success for strains with MICs below this threshold. We conclude that the combination of fosfomycin with amikacin is a viable regimen for the empirical treatment of neonatal sepsis and is suitable for further clinical assessment in a randomized controlled trial

    Fildelning och upphovsrÀtten i Finland

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    Detta lÀrdomsprov Àr gjort för att ge en bild av hur fildelningen och upphovsrÀtten ser ut i Finland idag. I teoridelen gÄr jag in pÄ hur EU pÄverkar Finland med nya direktiv och metoder för att kÀmpa mot piratism. Jag beskriver Àven upphovsrÀttens historia och utveckling samt tar upp olika tekniker och programvaror som anvÀnds inom fildelning. Orsaken till att jag valde detta Àmne som lÀrdomsprov Àr för att Àmnet fÄtt sÄ stor uppmÀrksamhet i medier under de senaste tio Ären. Nuförtiden har de flesta tillgÄng till snabba nÀtverk och mÄnga sysslar med illegal fildelning för att det Àr sÄ enkelt, snabbt och riskfritt, men ocksÄ för att dagens ungdom krÀver att nytt material genast skall finnas till hands. Till sist gÄr jag igenom hur upphovsrÀtten ser ut idag och hur musik och filmbranschen pÄverkas av lÄngsamma lagförÀndringar. LÀrdomsprovet innehÄller en undersökning i form av enkÀt som 28 personer svarade pÄ. Resultatet gav samma svar som de flesta andra liknande undersökningar pÄ nÀtet gav. Slutledningen av undersökningen var att illegal fildelning Àr vanligt Ànnu idag men att lagliga alternativ har lyckats vÀnda pÄ spelet och fÄtt mÀnniskor att vÀlja lagliga alternativ pÄ grund av lÀttillgÀnglighet av material.This thesis is done to provide a picture of what file sharing and copyright laws looks like in Finland today. In the theoretical part I go into how the EU affects Finland, with new directives and the methods in the fight against piracy. I will go a bit into the history of copyright and the development of it. I will also discuss various techniques and software used in file sharing. The reason for choosing to study this topic is that the substance has received so much attention in the media over the 10 last years. Nowadays, most people have access to fast networks and many are engaged in illegal file sharing because it is so simple, quick and safe. But also because the youth today requires that new material are immediately to be available. Finally, I go through how copyright law is today, and how the music and film industry is affected by the slow legislative changes. The thesis includes a study in form of a questionnaire that 28 people responded to. The result gave the same answer as most other similar studies online have given. The conclusion of the study was that illegal file sharing is common even today but the legal options have managed to turn the tables and led people to choose the legal option because of the easy availability of materials
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