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Muller Kobold AC, Kema IP, Dijck-Brouwer J, Koerts K, Weening M, Storteboom T, Kootstra-Ros JE, van Faassen M, Riphagen IJ. Pepsin pretreatment corrects underestimation of 25-hydroxyvitamin D measurement by an automated immunoassay in subjects with high vitamin D binding protein levels. Clin Chem Lab Med 2022; 60:e18-e20. [PMID: 34464525 DOI: 10.1515/cclm-2021-0722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/17/2021] [Indexed: 11/15/2022]
Affiliation(s)
- Anneke C Muller Kobold
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ido P Kema
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Janneke Dijck-Brouwer
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Karin Koerts
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Michiel Weening
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Twan Storteboom
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jenny E Kootstra-Ros
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Martijn van Faassen
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ineke J Riphagen
- Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Duflot M, Midelet G, Bourgau O, Buchmann K, Gay M. Optimization of tools for the detection and identification of Cryptocotyle metacercariae in fish: Digestion method and viability studies. J Fish Dis 2021; 44:1777-1784. [PMID: 34289140 PMCID: PMC9290975 DOI: 10.1111/jfd.13495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 06/13/2023]
Abstract
Some trematode metacercariae, including marine digeneans belonging to the genus Cryptocotyle, induce black spots in target tissues due to the attraction of fish host melanophores. To promote precise quantification of infection, the counting of black spots has to be confirmed by reliable quantification of metacercariae after tissue digestion. This process ensures the isolation of undamaged parasites for morphological and molecular identification. The aim of this work was to optimize the pepsin digestion protocol and to assess the duration of viability of Cryptocotyle metacercariae in fish post-mortem (pm). Four digestion protocols were compared by measuring the viability rate of metacercariae. The present study shows that the orbital digestion method was the least destructive for metacercariae and allowed better quantification of Cryptocotyle infection. Moreover, morphological identification seemed reliable up to 8 days pm for Cryptocotyle infection.
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Affiliation(s)
- Maureen Duflot
- ANSES, Laboratory for Food SafetyBoulogne‐sur‐MerFrance
- University of Littoral Côte d'OpaleBoulogne‐sur‐MerFrance
| | | | - Odile Bourgau
- ANSES, Laboratory for Food SafetyBoulogne‐sur‐MerFrance
| | - Kurt Buchmann
- Laboratory of Aquatic Pathobiology, Department of Veterinary and Animal Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Mélanie Gay
- ANSES, Laboratory for Food SafetyBoulogne‐sur‐MerFrance
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Stollberg KC, Schares G, Mayer-Scholl A, Hrushetska I, Diescher S, Johne A, Richter MH, Bier NS. Comparison of Direct and Indirect Toxoplasma gondii Detection and Genotyping in Game: Relationship and Challenges. Microorganisms 2021; 9:microorganisms9081663. [PMID: 34442742 PMCID: PMC8399173 DOI: 10.3390/microorganisms9081663] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/28/2021] [Accepted: 07/31/2021] [Indexed: 11/21/2022] Open
Abstract
The importance of game as a source of Toxoplasma gondii (T. gondii) infection in humans is largely unknown. New data on the presence of T. gondii in game hunted in the Federal State of Brandenburg, Germany, were obtained by direct and indirect detection (ELISA). DNA extracted either directly (5 g heart or foreleg muscle, DE) or after acid pepsin digestion (50 g heart, PD) or enriched by magnetic capture (50 g heart, MC) was examined by real-time PCR (qPCR). ELISA revealed seroprevalences of 20% in wild boar (Sus scrofa), 11% in roe deer (Capreolus capreolus) and 6% in red deer (Cervus elaphus). T. gondii DNA was detected by at least one direct detection method in 12% of wild boar, 6% of roe deer, 2% of fallow deer (Dama dama) and 2% of red deer. In both, positive wild boar and roe deer, T. gondii type II specific alleles were the most prevalent, as assessed by PCR-restriction fragment length polymorphism. The highest proportion of positive animals was detected by MC qPCR, followed by PD qPCR with a similar proportion of positive findings. Investigation of 50 g of heart muscle revealed a significantly higher proportion of positive qPCR results than analysis of 5 g (p = 0.048). An association between seropositivity and direct detection was evident in wild boar and roe deer (p < 0.001). Infectivity of T. gondii DNA–positive samples was confirmed by bioassay (4/4), providing evidence that game could represent a relevant source of viable T. gondii posing a risk for human infection.
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Affiliation(s)
- Kaya C. Stollberg
- German Federal Institute for Risk Assessment (BfR), Department for Safety in the Food Chain, 10589 Berlin, Germany;
| | - Gereon Schares
- National Reference Laboratory for Toxoplasmosis, Institute of Epidemiology, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, 17493 Greifswald, Insel Riems, Germany;
| | - Anne Mayer-Scholl
- German Federal Institute for Risk Assessment (BfR), Department for Biological Safety, 12277 Berlin, Germany; (A.M.-S.); (I.H.); (S.D.); (A.J.); (M.H.R.)
| | - Iryna Hrushetska
- German Federal Institute for Risk Assessment (BfR), Department for Biological Safety, 12277 Berlin, Germany; (A.M.-S.); (I.H.); (S.D.); (A.J.); (M.H.R.)
| | - Susanne Diescher
- German Federal Institute for Risk Assessment (BfR), Department for Biological Safety, 12277 Berlin, Germany; (A.M.-S.); (I.H.); (S.D.); (A.J.); (M.H.R.)
| | - Annette Johne
- German Federal Institute for Risk Assessment (BfR), Department for Biological Safety, 12277 Berlin, Germany; (A.M.-S.); (I.H.); (S.D.); (A.J.); (M.H.R.)
| | - Martin H. Richter
- German Federal Institute for Risk Assessment (BfR), Department for Biological Safety, 12277 Berlin, Germany; (A.M.-S.); (I.H.); (S.D.); (A.J.); (M.H.R.)
| | - Nadja S. Bier
- German Federal Institute for Risk Assessment (BfR), Department for Biological Safety, 12277 Berlin, Germany; (A.M.-S.); (I.H.); (S.D.); (A.J.); (M.H.R.)
- Correspondence:
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Rainer T, Eidelpes R, Tollinger M, Müller T. Microdroplet Mass Spectrometry Enables Extremely Accelerated Pepsin Digestion of Proteins. J Am Soc Mass Spectrom 2021; 32:1841-1845. [PMID: 34101451 PMCID: PMC8267842 DOI: 10.1021/jasms.1c00126] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In microdroplets, rates of chemical or biomolecular reactions can exceed those in the bulk phase by more than a million times. As electrospray ionization-based mass spectrometry (MS) involves the formation of charged microdroplets, reaction acceleration and online MS monitoring of reaction products can readily be performed at the same time. We investigated accelerated enzymatic reactions in microdroplets and focused on the proteolytic enzyme pepsin. Electrosonic spray ionization (ESSI) was utilized for developing the ultrarapid pepsin in-spray digestion of two different proteins, cytochrome c and RocC, at low pH values. The optimization of the protein digestion aimed at achieving maximum sequence coverage for the analyzed proteins. Furthermore, carefully designed control experiments allowed us to unambiguously prove that enzymatic protein cleavage almost exclusively occurs within the spray at a millisecond time scale and not prior to microdroplet generation.
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Liu J, Ronk M, Fujimori K, Lee H, Nashed-Samuel Y. Analysis of Silicone Oil in Prefilled Syringes and Biopharmaceutical Drug Products Using High-Performance Liquid Chromatography. AAPS PharmSciTech 2021; 22:75. [PMID: 33585996 DOI: 10.1208/s12249-021-01947-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/26/2021] [Indexed: 12/30/2022] Open
Abstract
As the packaging of choice for many therapeutic proteins, prefilled syringes have been widely used in biopharmaceutical industry as primary containers, where silicone oil is applied to ensure their proper functionality. Adequate lubrication from sufficient amount of silicone oil and its appropriate distribution across syringe barrels is crucial for successful administration of drug product (DP) from the prefilled syringes; however, silicone oil is also susceptible to leaching from the syringe surface into the formulation with the potential to interact with therapeutic proteins, which could lead to the formation of visible and sub-visible aggregates and/or particles that are potentially immunogenic. Accurate determination and careful control of silicone oil levels in both empty syringes and protein drug products are therefore critical in process development to ensure syringe functionality, drug product quality, and patient safety. On the other hand, analysis of silicone oil can be challenging especially when the analysis is performed on formulated protein drug products, where matrix effects could be significant. It is demonstrated in this study that silicone oil in empty syringes or formulated drug products can be extracted effectively using organic solvents and quantitatively determined using high-performance liquid chromatography (HPLC) coupled with a universal detector. It was also shown that direct extraction of silicone oil from formulated protein drug products can be very challenging, but pretreatment of the protein drug products with pepsin enzymatic digestion facilitated the extraction process, which enabled the analysis of silicone oil in the drug product at low ppm levels.
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Selis F, Focà G, Sandomenico A, Marra C, Di Mauro C, Saccani Jotti G, Scaramuzza S, Politano A, Sanna R, Ruvo M, Tonon G. Pegylated Trastuzumab Fragments Acquire an Increased in Vivo Stability but Show a Largely Reduced Affinity for the Target Antigen. Int J Mol Sci 2016; 17:491. [PMID: 27043557 DOI: 10.3390/ijms17040491] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 03/19/2016] [Accepted: 03/24/2016] [Indexed: 12/20/2022] Open
Abstract
PEGylation of biomolecules is a major approach to increase blood stream half-life, stability and solubility of biotherapeutics and to reduce their immunogenicity, aggregation potential and unspecific interactions with other proteins and tissues. Antibodies have generally long half-lives due to high molecular mass and stability toward proteases, however their size lowers to some extent their potential because of a reduced ability to penetrate tissues, especially those of tumor origin. Fab or otherwise engineered smaller fragments are an alternative but are less stable and are much less well retained in circulation. We have here investigated the effects of various PEGylations on the binding properties and in vivo half-life of Fab fragments derived from the enzymatic splitting of Trastuzumab. We find that PEGylation increases the half-life of the molecules but also strongly affects the ability to recognize the target antigen in a way that is dependent on the extent and position of the chemical modification. Data thus support the concept that polyethylene glycol (PEG) conjugation on Trastuzumab Fabs increases half-life but reduces their affinity and this is a fine balance, which must be carefully considered for the design of strategies based on the use of antibody fragments.
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Abstract
Cultures of human diploid fibroblasts were labeled with radioactive proline and glycine, and the precursor of collagen (procollagen) in cells and medium was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A covalently assembled molecule with the composition (pro alpha1)(2).pro alpha2 (approximate molecular weight, 360,000) appeared intracellularly soon after synthesis of the constituent chains, and could be detected in the medium after 60 min of labeling. The molecule was stabilized by disulfide bonds between cysteine residues in the amino-terminal procollagen peptide sequences of the three chains. Collagenase digested the molecule to peptides of 30,000 molecular weight or less. Limited digestion with pepsin excised nonhelical procollagen peptides, yielding native, triple-helical tropocollagen. Pulse-chase experiments indicated that a peptidase in the medium sequentially excised the nonhelical peptides from the molecule, generating tropocollagen molecules that aggregated as fibers in the cell layer. The excised, nonhelical procollagen peptides contained little or no proline or glycine. Intramolecular bonds of the lysyl aldehyde type were not detected in the secreted molecule, as reduction of the medium always resulted in quantitative recovery of free pro alpha chains in dodecyl sulfate-urea. Lysyl-derived, covalent bonds appeared to form between tropocollagen molecules aggregating in the cell layer. We suggest the term "pro-tropocollagen" for the assembled, secreted precursor of collagen.
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Abstract
Incubation of rat calvaria for short times in the presence of a labeled amino acid revealed the existence of a collagen fraction (procollagen) that functions as a biosynthetic precursor of collagen. Procollagen contains an alpha1-like chain (pre-alpha1) that elutes earlier from CM-cellulose than does rat-bone alpha1 and has a molecular weight, estimated by acrylamide gel electrophoresis, of 120,000. A time-dependent conversion of pre-alpha1 to alpha1 was demonstrated by incubation of calvaria for periods varying from 9 to 60 min and by a pulse-chase experiment. Limited cleavage of procollagen with pepsin resulted in a molecule with a chain resembling alpha1 in chromatographic properties, molecular weight, and relative hydroxyproline and proline contents. Thus, conversion of procollagen to collagen is likely to occur in vivo by a proteolytic mechanism. The additional peptide sequences in procollagen may serve to initiate chain association in triple-helix formation, to facilitate molecular transport, and to inhibit intracellular fibrogenesis.
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