351
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Shipkova M, Svinarov D. LC–MS/MS as a tool for TDM services: Where are we? Clin Biochem 2016; 49:1009-23. [DOI: 10.1016/j.clinbiochem.2016.05.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 04/23/2016] [Accepted: 05/01/2016] [Indexed: 12/23/2022]
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352
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Challenges for the in vivo quantification of brain neuropeptides using microdialysis sampling and LC-MS. Bioanalysis 2016; 8:1965-85. [PMID: 27554986 DOI: 10.4155/bio-2016-0119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In recent years, neuropeptides and their receptors have received an increased interest in neuropharmacological research. Although these molecules are considered relatively small compared with proteins, their in vivo quantification using microdialysis is more challenging than for small molecules. Low microdialysis recoveries, aspecific adsorption and the presence of various multiply charged precursor ions during ESI-MS/MS detection hampers the in vivo quantification of these low abundant biomolecules. Every step in the workflow, from sampling until analysis, has to be optimized to enable the sensitive analysis of these compounds in microdialysates.
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353
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Old dogs and new tricks in antimicrobial discovery. Curr Opin Microbiol 2016; 33:25-34. [PMID: 27262526 DOI: 10.1016/j.mib.2016.05.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 11/22/2022]
Abstract
The discovery of new antibiotics is crucial if we are to avoid a future in which simple infections once again lead to death. New antibiotics were traditionally discovered by analyzing extracts from cultured soil-derived microbes. However, in the last few years only a few new antibiotic classes have been identified using this method. Attempts to apply target-based screening approaches to antibiotic discovery have also proven to be unproductive. In this article, we describe how DNA sequencing and bioinformatic techniques are revolutionizing natural product discovery leading to new natural product antibiotics sourced from both cultivated and uncultivated microbes. New chemical structures are also being 'crowd sourced' from chemists around the world, and 'forgotten' antibiotics repositioned for clinical trials after chemical or biochemical modification of the original natural product. Collectively such approaches have the potential to revamp antibiotic lead discovery and re-invigorate the antibiotic pipeline.
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354
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Antunes MV, Charão MF, Linden R. Dried blood spots analysis with mass spectrometry: Potentials and pitfalls in therapeutic drug monitoring. Clin Biochem 2016; 49:1035-46. [PMID: 27179588 DOI: 10.1016/j.clinbiochem.2016.05.004] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/05/2016] [Accepted: 05/08/2016] [Indexed: 01/13/2023]
Abstract
Therapeutic drug monitoring (TDM) relays in the availability of specialized laboratory assays, usually available in reference centers that are not accessible to all patients. In this context, there is a growing interest in the use of dried blood spot (DBS) sampling, usually obtained from finger pricks, which allows simple and cost-effective logistics in many settings, particularly in Developing Countries. The use of DBS assays to estimate plasma concentrations is highly dependent on the hematocrit of the blood, as well as the particular characteristics of the measured analyte. DBS assays require specific validation assays, most of them are related to hematocrit effects. In the present manuscript, the application of mass spectrometric assays for determination of drugs for TDM purposes in the last ten years is reviewed, as well as the particular validation assays for new DBS methods.
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Affiliation(s)
- Marina Venzon Antunes
- Toxicological Analysis Laboratory, Instituto de Ciências da Saúde, Universidade Feevale, Novo Hamburgo, RS, Brazil
| | - Mariele Feiffer Charão
- Toxicological Analysis Laboratory, Instituto de Ciências da Saúde, Universidade Feevale, Novo Hamburgo, RS, Brazil
| | - Rafael Linden
- Toxicological Analysis Laboratory, Instituto de Ciências da Saúde, Universidade Feevale, Novo Hamburgo, RS, Brazil.
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355
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Quantitative bottom up analysis of infliximab in serum using protein A purification and integrated μLC-electrospray chip IonKey MS/MS technology. Bioanalysis 2016; 8:891-904. [DOI: 10.4155/bio-2015-0015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: TNO Triskelion has applied its general workflow for the development of quantitative LC–MS methods for proteins in biological matrices to the quantification of infliximab in rat serum using bottom up μLC–MS/MS. Results/methodology: The general workflow consists of sample purification, analyte processing and LC–MS analysis. In the development of a quantitative μLC–MS/MS method for infliximab in rat serum the analyte processing part and the LC–MS part were optimized, in order to meet the different sample requirements of μLC–MS as compared with UPLC–MS. Using the optimized μLC–MS/MS method the LOQ was 75 ng/ml. Conclusion: The present study showed that it is possible to gain sensitivity when going to smaller scale LC–MS (UPLC–MS to μLC–MS). Due to the combination of a modified sample preparation approach and the application of μLC–MS a lower LOQ could be achieved for infliximab compared with a previously developed UPLC–MS method.
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356
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Hoppentocht M, Akkerman OW, Hagedoorn P, Alffenaar JWC, van der Werf TS, Kerstjens HAM, Frijlink HW, de Boer AH. Tolerability and Pharmacokinetic Evaluation of Inhaled Dry Powder Tobramycin Free Base in Non-Cystic Fibrosis Bronchiectasis Patients. PLoS One 2016; 11:e0149768. [PMID: 26959239 PMCID: PMC4784940 DOI: 10.1371/journal.pone.0149768] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 02/03/2016] [Indexed: 12/01/2022] Open
Abstract
Rationale Bronchiectasis is a condition characterised by dilated and thick-walled bronchi. The presence of Pseudomonas aeruginosa in bronchiectasis is associated with a higher hospitalisation frequency and a reduced quality of life, requiring frequent and adequate treatment with antibiotics. Objectives To assess local tolerability and the pharmacokinetic parameters of inhaled excipient free dry powder tobramycin as free base administered with the Cyclops dry powder inhaler to participants with non-cystic fibrosis bronchiectasis. The free base and absence of excipients reduces the inhaled powder dose. Methods Eight participants in the study were trained in handling the device and inhaling correctly. During drug administration the inspiratory flow curve was recorded. Local tolerability was assessed by spirometry and recording adverse events. Serum samples were collected before, and 15, 30, 45, 60, 75, 90, 105, 120 min; 4, 8 and 12 h after inhalation. Results and Discussion Dry powder tobramycin base was well tolerated and mild tobramycin-related cough was reported only once. A good drug dose-serum concentration correlation was obtained. Relatively small inhaled volumes were computed from the recorded flow curves, resulting in presumably substantial deposition in the central airways—i.e., at the site of infection. Conclusions In this first study of inhaled dry powder tobramycin free base in non-cystic fibrosis bronchiectasis patients, the free base of tobramycin and the administration with the Cyclops dry powder device were well tolerated. Our data support further clinical studies to evaluate safety and efficacy of this compound in this population.
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Affiliation(s)
- Marcel Hoppentocht
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, Groningen, the Netherlands
- * E-mail:
| | - Onno W. Akkerman
- Department of Pulmonary Diseases and Tuberculosis, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Paul Hagedoorn
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, Groningen, the Netherlands
| | - Jan-Willem C. Alffenaar
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Tjip S. van der Werf
- Department of Pulmonary Diseases and Tuberculosis, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
- Department of Internal Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Huib A. M. Kerstjens
- Department of Pulmonary Diseases and Tuberculosis, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Henderik W. Frijlink
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, Groningen, the Netherlands
| | - Anne H. de Boer
- Department of Pharmaceutical Technology and Biopharmacy, University of Groningen, Groningen, the Netherlands
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357
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Saktiawati AMI, Sturkenboom MGG, Stienstra Y, Subronto YW, Sumardi, Kosterink JGW, van der Werf TS, Alffenaar JWC. Impact of food on the pharmacokinetics of first-line anti-TB drugs in treatment-naive TB patients: a randomized cross-over trial. J Antimicrob Chemother 2015; 71:703-10. [PMID: 26661397 DOI: 10.1093/jac/dkv394] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 10/22/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Concomitant food intake influences pharmacokinetics of first-line anti-TB drugs in healthy volunteers. However, in treatment-naive TB patients who are starting with drug treatment, data on the influence of food intake on the pharmacokinetics are absent. This study aimed to quantify the influence of food on the pharmacokinetics of isoniazid, rifampicin, ethambutol and pyrazinamide in TB patients starting anti-TB treatment. METHODS A prospective randomized cross-over pharmacokinetic study was conducted in treatment-naive adults with drug-susceptible TB. They received isoniazid, rifampicin and ethambutol intravenously and oral pyrazinamide on day 1, followed by oral administration of these drugs under fasted and fed conditions on two consecutive days. Primary outcome was the bioavailability while fasting and with concomitant food intake. This study was registered with clinicaltrials.gov identifier NCT02121314. RESULTS Twenty subjects completed the study protocol. Absolute bioavailability in the fasted state and the fed state was 93% and 78% for isoniazid, 87% and 71% for rifampicin and 87% and 82% for ethambutol. Food decreased absolute bioavailability of isoniazid and rifampicin by 15% and 16%, respectively. Pyrazinamide AUC0-24 was comparable for the fasted state (481 mg·h/L) and the fed state (468 mg·h/L). Food lowered the maximum concentrations of isoniazid, rifampicin and pyrazinamide by 42%, 22% and 10%, respectively. Time to maximum concentration was delayed for isoniazid, rifampicin and pyrazinamide. The pharmacokinetics of ethambutol were unaffected by food. CONCLUSIONS Food decreased absolute bioavailability and maximum concentration of isoniazid and rifampicin, but not of ethambutol or pyrazinamide, in treatment-naive TB patients. In patients prone to low drug exposure, this may further compromise treatment efficacy and increase the risk of acquired drug resistance.
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Affiliation(s)
- Antonia M I Saktiawati
- Department of Internal Medicine, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia Department of Pulmonary Diseases and Tuberculosis, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Marieke G G Sturkenboom
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Ymkje Stienstra
- Department of Internal Medicine/Infectious Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Yanri W Subronto
- Department of Internal Medicine, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Sumardi
- Department of Internal Medicine, Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Jos G W Kosterink
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands Section of Pharmacotherapy and Pharmaceutical Care, Department of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Tjip S van der Werf
- Department of Pulmonary Diseases and Tuberculosis, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands Department of Internal Medicine/Infectious Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan-Willem C Alffenaar
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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358
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Application of bacterial cytological profiling to crude natural product extracts reveals the antibacterial arsenal of Bacillus subtilis. J Antibiot (Tokyo) 2015; 69:353-61. [PMID: 26648120 DOI: 10.1038/ja.2015.116] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 09/01/2015] [Indexed: 11/09/2022]
Abstract
Although most clinically used antibiotics are derived from natural products, identifying new antibacterial molecules from natural product extracts is difficult due to the complexity of these extracts and the limited tools to correlate biological activity with specific molecules. Here, we show that bacterial cytological profiling (BCP) provides a rapid method for mechanism of action determination on plates and in complex natural product extracts and for activity-guided purification. We prepared an extract from Bacillus subtilis 3610 that killed the Escherichia coli lptD mutant and used BCP to observe two types of bioactivities in the unfractionated extract: inhibition of translation and permeablization of the cytoplasmic membrane. We used BCP to guide purification of the molecules responsible for each activity, identifying the translation inhibitors bacillaene and bacillaene B (glycosylated bacillaene) and demonstrating that two molecules contribute to cell permeabilitization, the bacteriocin subtilosin and the cyclic peptide sporulation killing factor. Our results suggest that bacillaene mediates translational arrest, and show that bacillaene B has a minimum inhibitory concentration 10 × higher than unmodified bacillaene. Finally, we show that BCP can be used to screen strains on an agar plate without the need for extract preparation, greatly saving time and improving throughput. Thus, BCP simplifies the isolation of novel natural products, by identifying strains, crude extracts and fractions with interesting bioactivities even when multiple activities are present, allowing investigators to focus labor-intensive steps on those with desired activities.
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359
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Enderle Y, Meid AD, Friedrich J, Grünig E, Wilkens H, Haefeli WE, Burhenne J. Dried Blood Spot Technique for the Monitoring of Ambrisentan, Bosentan, Sildenafil, and Tadalafil in Patients with Pulmonary Arterial Hypertension. Anal Chem 2015; 87:12112-20. [DOI: 10.1021/acs.analchem.5b03077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
| | | | | | - Ekkehard Grünig
- Centre
of Pulmonary Hypertension, Thoraxklinik, University of Heidelberg, Amalienstrasse 5, 69121 Heidelberg, Germany
| | - Heinrike Wilkens
- Department
of Pneumology, Allergology, and Environmental Medicine, University Hospital of Saarland, Kirrbergerstrasse, 66421 Homburg/Saar, Germany
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360
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A Novel Microbisporicin Producer Identified by Early Dereplication during Lantibiotic Screening. BIOMED RESEARCH INTERNATIONAL 2015; 2015:419383. [PMID: 26346738 PMCID: PMC4539421 DOI: 10.1155/2015/419383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 05/29/2015] [Accepted: 05/31/2015] [Indexed: 11/20/2022]
Abstract
With the increasing need of effective antibiotics against multi-drug resistant pathogens, lantibiotics are an attractive option of a new class of molecules. They are ribosomally synthetized and posttranslationally modified peptides possessing potent antimicrobial activity against aerobic and anaerobic Gram-positive pathogens, including those increasingly resistant to β-lactams and glycopeptides. Some of them (actagardine, mersacidin, planosporicin, and microbisporicin) inhibit cell wall biosynthesis in pathogens and their effect is not antagonized by vancomycin. Hereby, we apply an efficient strategy for lantibiotic screening to 240 members of a newly described genus of filamentous actinomycetes, named Actinoallomurus, that is considered a yet-poorly-exploited promising source for novel bioactive metabolites. By combining antimicrobial differential assay against Staphylococcus aureus and its L-form (also in the presence of a β-lactamase cocktail or Ac-Lys-D-alanyl-D-alanine tripeptide), with LC-UV-MS dereplication coupled with bioautography, a novel producer of the potent microbisporicin complex was rapidly identified. Under the commercial name of NAI-107, it is currently in late preclinical phase for the treatment of multi-drug resistant Gram-positive pathogens. To our knowledge, this is the first report on a lantibiotic produced by an Actinoallomurus sp. and on a microbisporicin producer not belonging to the Microbispora genus.
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