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- Becker, K., et al.
(författare)
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Antibacterial activity of apramycin at acidic pH warrants wide therapeutic window in the treatment of complicated urinary tract infections and acute pyelonephritis
- 2021
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Ingår i: EBioMedicine. - : Elsevier B.V.. - 2352-3964. ; 73
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Tidskriftsartikel (refereegranskat)abstract
- Background: The clinical-stage drug candidate EBL-1003 (apramycin) represents a distinct new subclass of aminoglycoside antibiotics for the treatment of drug-resistant infections. It has demonstrated best-in-class coverage of resistant isolates, and preclinical efficacy in lung infection models. However, preclinical evidence for its utility in other disease indications has yet to be provided. Here we studied the therapeutic potential of EBL-1003 in the treatment of complicated urinary tract infection and acute pyelonephritis (cUTI/AP). Methods: A combination of data-base mining, antimicrobial susceptibility testing, time-kill experiments, and four murine infection models was used in a comprehensive assessment of the microbiological coverage and efficacy of EBL-1003 against Gram-negative uropathogens. The pharmacokinetics and renal toxicology of EBL-1003 in rats was studied to assess the therapeutic window of EBL-1003 in the treatment of cUTI/AP. Findings: EBL-1003 demonstrated broad-spectrum activity and rapid multi-log CFU reduction against a phenotypic variety of bacterial uropathogens including aminoglycoside-resistant clinical isolates. The basicity of amines in the apramycin molecule suggested a higher increase in positive charge at urinary pH when compared to gentamicin or amikacin, resulting in sustained drug uptake and bactericidal activity, and consequently in potent efficacy in mouse infection models. Renal pharmacokinetics, biomarkers for toxicity, and kidney histopathology in adult rats all indicated a significantly lower nephrotoxicity of EBL-1003 than of gentamicin. Interpretation: This study provides preclinical proof-of-concept for the efficacy of EBL-1003 in cUTI/AP. Similar efficacy but lower nephrotoxicity of EBL-1003 in comparison to gentamicin may thus translate into a higher safety margin and a wider therapeutic window in the treatment of cUTI/API. Funding: A full list of funding bodies that contributed to this study can be found in the Acknowledgements section. © 2021 The Author(s)
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| 2. |
- Erlandsson, Lena, et al.
(författare)
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Joining chain-expressing and -nonexpressing B cell populations in the mouse
- 2001
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 194:5, s. 557-570
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Tidskriftsartikel (refereegranskat)abstract
- The diphtheria toxin A chain (DTA) was gene targeted into the Joining chain (J chain) locus to create a mouse strain selecting against J chain-expressing cells, JDTA mice. Serum immunoglobulin (Ig)M and serum IgG were reduced six to eightfold, while serum IgA was elevated 14-fold in these mice. JDTA mice were immune competent although the serum Ig response compared with wild-type mice was reduced sixfold at day 14 but only fourfold at day 45 after immunization. Exchanging the DTA gene with a cDNA for c-myc resulted in mice with a distinct phenotype with increased Ig production and enhanced humoral immune responses. Analysis of single B cells stimulated by lipopolysaccharide in vitro using reverse transcription-polymerase chain reaction showed that J chain-nonexpressing B cells could be detected that had a secretory phenotype as determined by an abundance of transcript for secretory IgM. Finally, limiting dilution analysis of peripheral B cells showed that J chain expression was a clonal property already established in naive, peripheral B lymphocytes.
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