| 1. |
- Brill, Margreke J. E., et al.
(författare)
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Semi-mechanistic pharmacokinetic-pharmacodynamic modelling of antibiotic drug combinations
- 2018
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Ingår i: Clinical Microbiology and Infection. - : Elsevier BV. - 1198-743X .- 1469-0691. ; 24:7, s. 697-706
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Forskningsöversikt (refereegranskat)abstract
- Background: Deriving suitable dosing regimens for antibiotic combination therapy poses several challenges as the drug interaction can be highly complex, the traditional pharmacokinetic-pharmacodynamic (PKPD) index methodology cannot be applied straightforwardly, and exploring all possible dose combinations is unfeasible. Therefore, semi-mechanistic PKPD models developed based on in vitro single and combination experiments can be valuable to suggest suitable combination dosing regimens. Aims: To outline how the interaction between two antibiotics has been characterized in semi-mechanistic PKPD models. We also explain how such models can be applied to support dosing regimens and design future studies. Sources: PubMed search for published semi-mechanistic PKPD models of antibiotic drug combinations. Content: Thirteen publications were identified where ten had applied subpopulation synergy to characterize the combined effect, i.e. independent killing rates for each drug and bacterial subpopulation. We report the various types of interaction functions that have been used to describe the combined drug effects and that characterized potential deviations from additivity under the PKPD model. Simulations from the models had commonly been performed to compare single versus combined dosing regimens and/or to propose improved dosing regimens.
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| 2. |
- Kristan, Matej, et al.
(författare)
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The Ninth Visual Object Tracking VOT2021 Challenge Results
- 2021
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Ingår i: 2021 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW 2021). - : IEEE COMPUTER SOC. - 9781665401913 ; , s. 2711-2738
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2021 is the ninth annual tracker benchmarking activity organized by the VOT initiative. Results of 71 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in recent years. The VOT2021 challenge was composed of four sub-challenges focusing on different tracking domains: (i) VOT-ST2021 challenge focused on short-term tracking in RGB, (ii) VOT-RT2021 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2021 focused on long-term tracking, namely coping with target disappearance and reappearance and (iv) VOT-RGBD2021 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2021 dataset was refreshed, while VOT-RGBD2021 introduces a training dataset and sequestered dataset for winner identification. The source code for most of the trackers, the datasets, the evaluation kit and the results along with the source code for most trackers are publicly available at the challenge website(1).
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| 3. |
- Lu, Qianqian, et al.
(författare)
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Ebselen, a multi-target compound : its effects on biological processes and diseases
- 2021
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Ingår i: Expert Reviews in Molecular Medicine. - : Cambridge University Press. - 1462-3994. ; 23
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Forskningsöversikt (refereegranskat)abstract
- Ebselen is a well-known synthetic compound mimicking glutathione peroxidase (GPx), which catalyses some vital reactions that protect against oxidative damage. Based on a large number of in vivo and in vitro studies, various mechanisms have been proposed to explain its actions on multiple targets. It targets thiol-related compounds, including cysteine, glutathione, and thiol proteins (e.g., thioredoxin and thioredoxin reductase). Owing to this, ebselen is a unique multifunctional agent with important effects on inflammation, apoptosis, oxidative stress, cell differentiation, immune regulation and neurodegenerative disease, with anti-microbial, detoxifying and anti-tumour activity. This review summarises the current understanding of the multiple biological processes and molecules targeted by ebselen, and its pharmacological applications.
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| 4. |
- Olsson, Anna, et al.
(författare)
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Synergy of polymyxin B and minocycline against KPC-3- and OXA-48-producing Klebsiella pneumoniae in dynamic time-kill experiments : agreement with in silico predictions.
- 2023
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Ingår i: Journal of Antimicrobial Chemotherapy. - 0305-7453 .- 1460-2091.
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Combination therapy is often used for carbapenem-resistant Gram-negative bacteria. We previously demonstrated synergy of polymyxin B and minocycline against carbapenem-resistant Klebsiella pneumoniae in static time-kill experiments and developed an in silico pharmacokinetic/pharmacodynamic (PK/PD) model. The present study assessed the synergistic potential of this antibiotic combination in dynamic experiments.METHODS: Two clinical K. pneumoniae isolates producing KPC-3 and OXA-48 (polymyxin B MICs 0.5 and 8 mg/L, and minocycline MICs 1 and 8 mg/L, respectively) were included. Activities of the single drugs and the combination were assessed in 72 h dynamic time-kill experiments mimicking patient pharmacokinetics. Population analysis was performed every 12 h using plates containing antibiotics at 4× and 8× MIC. WGS was applied to reveal resistance genes and mutations.RESULTS: The combination showed synergistic and bactericidal effects against the KPC-3-producing strain from 12 h onwards. Subpopulations with decreased susceptibility to polymyxin B were frequently detected after single-drug exposures but not with the combination. Against the OXA-48-producing strain, synergy was observed between 4 and 8 h and was followed by regrowth. Subpopulations with decreased susceptibility to polymyxin B and minocycline were detected throughout experiments. For both strains, the observed antibacterial activities showed overall agreement with the in silico predictions.CONCLUSIONS: Polymyxin B and minocycline in combination showed synergistic effects, mainly against the KPC-3-producing K. pneumoniae. The agreement between the experimental results and in silico predictions supports the use of PK/PD models based on static time-kill data to predict the activity of antibiotic combinations at dynamic drug concentrations.
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| 5. |
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| 6. |
- Zhao, Chenyan, et al.
(författare)
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Combination of polymyxin B and minocycline against multidrug-resistant Klebsiella pneumoniae : interaction quantified by pharmacokinetic/pharmacodynamic modelling from in vitro data
- 2020
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Ingår i: International Journal of Antimicrobial Agents. - : ELSEVIER. - 0924-8579 .- 1872-7913. ; 55:6
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Tidskriftsartikel (refereegranskat)abstract
- Lack of effective treatment for multidrug-resistant Klebsiella pneumoniae (MDR-Kp) necessitates finding and optimising combination therapies of old antibiotics. The aims of this study were to quantify the combined effect of polymyxin B and minocycline by building an in silico semi-mechanistic pharmacokinetic/pharmacodynamic (PKPD) model and to predict bacterial kinetics when exposed to the drugs alone and in combination at clinically achievable unbound drug concentration-time profiles. A clinical K. pneumoniae strain resistant to polymyxin B [minimum inhibitory concentration (MIC) = 16 mg/L] and minocycline (MIC = 16 mg/L) was selected for extensive in vitro static time-kill experiments. The strain was exposed to concentrations of 0.0625-48 ? MIC, with seven samples taken per experiment for viable counts during 0-28 h. These observations allowed the development of the PKPD model. The final PKPD model included drug-induced adaptive resistance for both drugs. Both the minocycline-induced bacterial killing and resistance onset rate constants were increased when polymyxin B was co-administered, whereas polymyxin B parameters were unaffected. Predictions at clinically used dosages from the developed PKPD model showed no or limited antibacterial effect with monotherapy, whilst combination therapy kept bacteria below the starting inoculum for 20 h at high dosages [polymyxin B 2.5 mg/kg + 1.5 mg/kg every 12 h (q12h); minocycline 400 mg + 200 mg q12h, loading + maintenance doses]. This study suggests that polymyxin B and minocycline in combination may be of clinical benefit in the treatment of infections by MDR-Kp and for isolates that are non-susceptible to either drug alone. (C) 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)
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| 7. |
- Zhao, Chenyan, et al.
(författare)
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Population pharmacokinetics of apramycin from first-in-human plasma and urine data to support prediction of efficacious dose
- 2022
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Ingår i: Journal of Antimicrobial Chemotherapy. - : Oxford University Press (OUP). - 0305-7453 .- 1460-2091. ; 77:10, s. 2718-2728
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Tidskriftsartikel (refereegranskat)abstract
- Background Apramycin is under development for human use as EBL-1003, a crystalline free base of apramycin, in face of increasing incidence of multidrug-resistant bacteria. Both toxicity and cross-resistance, commonly seen for other aminoglycosides, appear relatively low owing to its distinct chemical structure. Objectives To perform a population pharmacokinetic (PPK) analysis and predict an efficacious dose based on data from a first-in-human Phase I trial. Methods The drug was administered intravenously over 30 min in five ascending-dose groups ranging from 0.3 to 30 mg/kg. Plasma and urine samples were collected from 30 healthy volunteers. PPK model development was performed stepwise and the final model was used for PTA analysis. Results A mammillary four-compartment PPK model, with linear elimination and a renal fractional excretion of 90%, described the data. Apramycin clearance was proportional to the absolute estimated glomerular filtration rate (eGFR). All fixed effect parameters were allometrically scaled to total body weight (TBW). Clearance and steady-state volume of distribution were estimated to 5.5 L/h and 16 L, respectively, for a typical individual with absolute eGFR of 124 mL/min and TBW of 70 kg. PTA analyses demonstrated that the anticipated efficacious dose (30 mg/kg daily, 30 min intravenous infusion) reaches a probability of 96.4% for a free AUC/MIC target of 40, given an MIC of 8 mg/L, in a virtual Phase II patient population with an absolute eGFR extrapolated to 80 mL/min. Conclusions The results support further Phase II clinical trials with apramycin at an anticipated efficacious dose of 30 mg/kg once daily.
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| 8. |
- Zhao, Chenyan, et al.
(författare)
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Quantifying combined effects of colistin and ciprofloxacin against Escherichia coli in an in silico pharmacokinetic-pharmacodynamic model
- 2024
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Co-administering a low dose of colistin (CST) with ciprofloxacin (CIP) may improve the antibacterial effect against resistant Escherichia coli, offering an acceptable benefit-risk balance. This study aimed to quantify the interaction between ciprofloxacin and colistin in an in silico pharmacokinetic-pharmacodynamic model from in vitro static time-kill experiments (using strains with minimum inhibitory concentrations, MICCIP 0.023–1 mg/L and MICCST 0.5–0.75 mg/L). It was also sought to demonstrate an approach of simulating concentrations at the site of infection with population pharmacokinetic and whole-body physiologically based pharmacokinetic models to explore the clinical value of the combination when facing more resistant strains (using extrapolated strains with lower susceptibility). The combined effect in the final model was described as the sum of individual drug effects with a change in drug potency: for ciprofloxacin, concentration at half maximum killing rate (EC50) in combination was 160% of the EC50 in monodrug experiments, while for colistin, the change in EC50 was strain-dependent from 54.1% to 119%. The benefit of co-administrating a lower-than-commonly-administrated colistin dose with ciprofloxacin in terms of drug effect in comparison to either monotherapy was predicted in simulated bloodstream infections and pyelonephritis. The study illustrates the value of pharmacokinetic-pharmacodynamic modelling and simulation in streamlining rational development of antibiotic combinations.
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| 9. |
- Zhao, Chenyan
(författare)
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Quantifying effects of antimicrobial drug combinations by modelling and simulation
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Antibiotic resistance is becoming an accelerating issue, both in the treatment of nosocomial infections and for public health in general. There is a pressing need for innovative methods to understand how available antibiotics could be combined to overcome and limit the emergence of resistance. Pharmacokinetic-pharmacodynamic (PKPD) modelling and simulation (M&S) is a promising tool in quantitatively characterising longitudinal antibiotic drug effects, especially in exploring antibiotic combinations where the concentration ratios of the component drugs, their interactions and relative contributions to the combined drug effects change over time. This thesis aimed to develop approaches to quantify the effects of antibiotic combinations on gram-negative bacteria by PKPD M&S. Pre-clinical data for antibiotics alone and in combination, including in vitro static and dynamic time-kill data and in vivo murine thigh infection data, were quantitatively described by semi-mechanistic PKPD models, as exemplified in the thesis by the combination of colistin and ciprofloxacin against four Escherichia coli strains and by the combination of polymyxin B and minocycline against two Klebsiella pneumoniae strains. The developed PKPD models showed good translational ability, as demonstrated by bridging across strains, predicting in vitro drug effects under dynamic settings, integrating all available in vitro and in vivo data, and quantifying the discrepancy between the in vitro and in vivo settings. These developed models were used to explore the therapeutic potential of the combinations. The value of adding low dosages of colistin (thus low toxicity) to ciprofloxacin treatment for E. coli strains with decreased susceptibility, and of combining polymyxin B and minocycline against K. pneumoniae when either drug alone has a limited antibacterial effect, was shown. In addition, a methodological framework was developed to quantify antibiotic effects from time-lapse microscopic images, exemplified by meropenem-exposed Pseudomonas aeruginosa and ertapenem-exposed E. coli. The framework could be extended to the antibiotic combinations in the future. To conclude, this thesis illustrated how semi-mechanistic PKPD M&S could be leveraged to evaluate the effects of antibiotic combinations quantitatively and to understand the antibiotic-bacteria interaction. As a future perspective, in a world where the rational use of antibiotic combinations is important to overcome and minimise resistance, semi-mechanistic PKPD M&S approaches could be applied to streamline the development and use of antibiotic drug combinations.
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