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Esmaeilian N, Hoorelbeke K, Naderzadeh S, Koster EH. Associations between borderline personality disorder features, early maladaptive schemas, and schema modes: A network analysis in a nonclinical sample. Personality and Individual Differences 2022. [DOI: 10.1016/j.paid.2022.111674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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2
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Carlson JM, Fang L, Koster EH, Andrzejewski JA, Gilbertson H, Elwell KA, Zuidema TR. Neuroplastic changes in anterior cingulate cortex gray matter volume and functional connectivity following attention bias modification in high trait anxious individuals. Biol Psychol 2022; 172:108353. [DOI: 10.1016/j.biopsycho.2022.108353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 03/11/2022] [Accepted: 05/09/2022] [Indexed: 12/21/2022]
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Hoorelbeke K, Vervaeke J, Siegle GJ, Baeken C, Koster EH. Individual differences associated with treatment adherence and transfer effects following gamified web-based cognitive control training for repetitive negative thinking. Internet Interv 2022; 27:100507. [PMID: 35242588 PMCID: PMC8859013 DOI: 10.1016/j.invent.2022.100507] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 12/27/2022] Open
Abstract
Recent research suggests beneficial effects of cognitive control training (CCT) on repetitive negative thinking (RNT), a key risk factor for internalizing symptomatology. However, relatively little is known regarding predictors of adherence to internet-delivered CCT as well as moderators of treatment effects for this intervention. Answering these questions could improve efficiency of clinical implementation of CCT as an eHealth intervention. The current pre-registered single-arm trial set-out to address these questions using a web-based gamified CCT procedure based on the adaptive Paced Auditory Serial Addition Task. Participants (N = 382) entered the internet-based study, where we observed considerable drop-out during the assessment phase and the first training sessions. Emotional stability and resilience emerged as predictors for deciding not to commence the intervention. Drop-out throughout the course of CCT was explained by age, emotion regulation-, and personality factors. We used latent profile analysis, a probabilistic modeling approach, to identify clusters of participants (User Profiles) based on indicators of baseline cognitive- and emotional functioning, training progress, and user experience. We obtained three User Profiles, reflecting low-, moderate-, and high-risk status. Effortful control, emotion regulation, internalizing symptomatology, resilience, and emotional stability played a central role in these User Profiles. Interestingly, User Profile predicted training related cognitive gains, as well as effects of CCT on anxiety- and stress symptoms, and reappraisal. Our findings suggest that CCT is most effective for the moderate- and high-risk groups. In addition, the high-risk group would likely benefit from a more intensive training procedure or repeated administration of the training procedure over time to foster long-term retention of training related gains.
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Affiliation(s)
- Kristof Hoorelbeke
- Psychopathology and Affective Neuroscience (PAN) lab, Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium,Corresponding author at: Henri-Dunantlaan 2, 9000 Ghent, Belgium.
| | - Jasmien Vervaeke
- Psychopathology and Affective Neuroscience (PAN) lab, Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium,Imec-Mict-Ghent University, Ghent, Belgium
| | - Greg J. Siegle
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Chris Baeken
- Department of Head and Skin (UZGent), Ghent Experimental Psychiatry (GHEP) Lab, Ghent University, Ghent, Belgium,Department of Psychiatry (UZBrussel), Vrije Universiteit Brussel (VUB), Brussels, Belgium,Department of Electrical Engineering, Eindhoven University of Technology, the Netherlands
| | - Ernst H.W. Koster
- Psychopathology and Affective Neuroscience (PAN) lab, Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
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Faelens L, Hoorelbeke K, Cambier R, van Put J, Van de Putte E, De Raedt R, Koster EH. The relationship between Instagram use and indicators of mental health: A systematic review. Computers in Human Behavior Reports 2021. [DOI: 10.1016/j.chbr.2021.100121] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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Faelens L, Hoorelbeke K, Soenens B, Van Gaeveren K, De Marez L, De Raedt R, Koster EH. Social media use and well-being: A prospective experience-sampling study. Computers in Human Behavior 2021. [DOI: 10.1016/j.chb.2020.106510] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Sanchez-Lopez A, Koster EH, Van Put J, De Raedt R. Attentional disengagement from emotional information predicts future depression via changes in ruminative brooding: A five-month longitudinal eye-tracking study. Behav Res Ther 2019; 118:30-42. [DOI: 10.1016/j.brat.2019.03.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/15/2019] [Accepted: 03/24/2019] [Indexed: 11/28/2022]
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Van den Bergh N, Hoorelbeke K, De Raedt R, Koster EH. Remediation of depression-related cognitive impairment: cognitive control training as treatment augmentation. Expert Rev Neurother 2018; 18:907-913. [DOI: 10.1080/14737175.2018.1537783] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Nathan Van den Bergh
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Kristof Hoorelbeke
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Rudi De Raedt
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Ernst H.W. Koster
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
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Koster EH, Hoorelbeke K, Onraedt T, Owens M, Derakshan N. Cognitive control interventions for depression: A systematic review of findings from training studies. Clin Psychol Rev 2017; 53:79-92. [DOI: 10.1016/j.cpr.2017.02.002] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/17/2017] [Accepted: 02/26/2017] [Indexed: 12/26/2022]
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Vanderhasselt MA, Brose A, Koster EH, De Raedt R. Co-variation between stressful events and rumination predicts depressive symptoms: An eighteen months prospective design in undergraduates. Behav Res Ther 2016; 87:128-133. [DOI: 10.1016/j.brat.2016.09.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 08/30/2016] [Accepted: 09/06/2016] [Indexed: 11/25/2022]
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Abstract
There is increasing interest in spontaneous thought, namely task-unrelated or rest-related mental activity. Spontaneous thought is an umbrella term for processes like mindwandering, involuntary autobiographical memory, and daydreaming, with evidence elucidating adaptive and maladaptive consequences. In this theoretical framework, we propose that, apart from its positive functions, spontaneous thought is a precursor for cognitive vulnerability in individuals who are at-risk for mood disorders. Importantly, spontaneous thought mostly focuses on unattained goals and evaluates the discrepancy between current and desired status (Klinger, 1971, 2013a). In individuals who stably (i.e., trait negative affectivity) or transitorily (i.e., stress) experience negative emotions in reaction to goal-discrepancy, spontaneous thought fosters major cognitive vulnerabilities (e.g., rumination, hopelessness, low self-esteem, and cognitive reactivity) which, in turn, enhance depression. Furthermore, we also highlight preliminary links between spontaneous thought and bipolar disorder. The evidence for this framework is reviewed and we discuss theoretical and clinical implications of our proposal.
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Affiliation(s)
- Igor Marchetti
- Ghent University, Department of Experimental-Clinical and Health Psychology, Henri Dunantlaan 2, Ghent, B-9000, Belgium
| | - Ernst H.W. Koster
- Ghent University, Department of Experimental-Clinical and Health Psychology, Henri Dunantlaan 2, Ghent, B-9000, Belgium
| | - Eric Klinger
- University of Minnesota, Morris, Psychology Discipline, Division of Social Sciences, Morris, MN 56267, USA
| | - Lauren B. Alloy
- Temple University, Department of Psychology, Weiss Hall, 1701 N. 13th Street, Philadelphia, PA 19122, USA
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Everaert J, Grahek I, Koster EH. Individual differences in cognitive control over emotional material modulate cognitive biases linked to depressive symptoms. Cogn Emot 2016; 31:736-746. [DOI: 10.1080/02699931.2016.1144562] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Jonas Everaert
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Ivan Grahek
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Ernst H.W. Koster
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
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Waugh CE, Koster EH. A resilience framework for promoting stable remission from depression. Clin Psychol Rev 2015; 41:49-60. [DOI: 10.1016/j.cpr.2014.05.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 04/08/2014] [Accepted: 05/01/2014] [Indexed: 10/25/2022]
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Hoorelbeke K, Koster EH, Vanderhasselt MA, Callewaert S, Demeyer I. The influence of cognitive control training on stress reactivity and rumination in response to a lab stressor and naturalistic stress. Behav Res Ther 2015; 69:1-10. [DOI: 10.1016/j.brat.2015.03.010] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 12/01/2022]
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Baert S, Koster EH, De Raedt R. Modification of Information-Processing Biases in Emotional Disorders: Clinically Relevant Developments in Experimental Psychopathology. Int J Cogn Ther 2011. [DOI: 10.1521/ijct.2011.4.2.208] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Van Bockstaele B, Verschuere B, Koster EH, Tibboel H, De Houwer J, Crombez G. Differential predictive power of self report and implicit measures on behavioural and physiological fear responses to spiders. Int J Psychophysiol 2011; 79:166-74. [DOI: 10.1016/j.ijpsycho.2010.10.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 09/21/2010] [Accepted: 10/06/2010] [Indexed: 10/18/2022]
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Raes AK, Koster EH, Van Damme S, Fias W, De Raedt R. Aversive Conditioning under Conditions of Restricted Awareness: Effects on Spatial Cueing. Q J Exp Psychol (Hove) 2010; 63:2336-58. [DOI: 10.1080/17470218.2010.492995] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In the literature on aversive conditioning there is still debate on the role of awareness. According to some authors, affective learning can occur with or without contingency learning (dual-process model), whereas others argue that a single process produces both affective responses and contingency knowledge. Although many studies have investigated these models, the results to date are inconclusive. Based on a review of the literature, a new series of experiments was designed to examine aversive conditioning in the absence of contingency awareness. In the present study we examined the effects of subliminal aversive conditioning on a spatial cueing task. Awareness was stringently tested after conditioning. Three kinds of awareness were distinguished: contingency awareness (awareness of the CS−US contingencies, where CS is the conditioned stimulus, and US is the unconditioned stimulus), perceptual awareness (awareness of the perceptual differences between the CSs), and US expectancy (awareness of a threat feeling when confronted with the CS+, but not when confronted with the CS−). The results of three experiments demonstrated that responses on the spatial cueing task were modulated by subliminal aversive conditioning. Importantly, none of the participants was contingency aware or able to perceptually discriminate between the conditioned stimuli. However, in Experiment 3, only those participants showing some level of postconditioning expectancy awareness exhibited conditioning effects. These experiments suggest that subliminal aversive conditioning produces small but significant effects, which may be modulated by expectancy awareness.
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Affiliation(s)
| | | | | | - Wim Fias
- Ghent University, Ghent, Belgium
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Derakshan N, Salt M, Koster EH. Attentional control in dysphoria: An investigation using the antisaccade task. Biol Psychol 2009; 80:251-5. [DOI: 10.1016/j.biopsycho.2008.09.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 11/28/2022]
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Koster EH, Crescenzi C, den Hoedt W, Ensing K, de Jong GJ. Fibers coated with molecularly imprinted polymers for solid-phase microextraction. Anal Chem 2001; 73:3140-5. [PMID: 11467565 DOI: 10.1021/ac001331x] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The simplicity and flexibility of solid-phase microextraction have been combined with the selectivity of molecularly imprinted polymers (MIPs). Silica fibers were coated reproducible with a 75-microm layer of methacrylate polymer either nonimprinted or imprinted with clenbuterol to compare their extraction characteristics under various conditions. Although the template molecule could be removed effectively from the imprinted polymer, structural analogues of clenbuterol were used for evaluation. The influence of pH on the extractability of brombuterol was investigated. Extraction yields up to approximately 80% were obtained when both types of fibers were used to extract brombuterol from phosphate buffer (pH 7.0). In contrast, yields of about 75 and <5% were obtained when extraction was performed from acetonitrile with imprinted and nonimprinted polymers, respectively, which demonstrates the selectivity of the MIP-coated fiber. Time sorption profiles were measured for the extraction of brombuterol from buffer and acetonitrile at the 10 and 100 ng/mL level with both types of fibers in order to compare extraction characteristics. Equilibrium times of about 30 and 90 min were found for the extraction of brombuterol from acetonitrile and buffer, respectively. The MIP-coated fibers were capable of extracting five structural analogues of clenbuterol from both buffer and acetonitrile, which suggests that the amine alcohol part of these molecules is responsible for interaction with the imprinted polymer. To achieve selective extraction of brombuterol from human urine, MIP-coated fibers were washed with acetonitrile after the extraction. Clean extracts and yields of approximately 45% were obtained, demonstrating the suitability of MIP-coated fibers for the analysis of biological samples.
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Affiliation(s)
- E H Koster
- Department of Analytical Chemistry and Toxicology, University Centre for Pharmacy, Groningen, The Netherlands
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Theodoridis G, Koster EH, de Jong GJ. Solid-phase microextraction for the analysis of biological samples. J Chromatogr B Biomed Sci Appl 2000; 745:49-82. [PMID: 10997704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Solid-phase microextraction (SPME) has been introduced for the extraction of organic compounds from environmental samples. This relatively new extraction technique has now also gained a lot of interest in a broad field of analysis including food, biological and pharmaceutical samples. SPME has a number of advantages such as simplicity, low cost, compatibility with analytical systems, automation and the solvent-free extraction. The last few years, SPME has been combined with liquid chromatography and capillary electrophoresis, besides the generally used coupling to gas chromatography, and has been applied to various biological samples such as, e.g., urine, plasma and hair. The objective of the present paper is a survey of the application of SPME for the analysis of biological samples. Papers about the analysis of biologically active compounds are categorised and reviewed. The impact of SPME on various analytical fields (toxicological, forensic, clinical, biochemical, pharmaceutical, and natural products) is illustrated. The main features of SPME and its modes are briefly described and important aspects about its application for the determination of pharmaceuticals, drugs of abuse and compounds of clinical and toxicological interest are discussed. SPME is compared with other sample pretreatment techniques. The potential of SPME and its main advantages are demonstrated. Special attention is paid to new trends in applications of SPME in bioanalysis.
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Affiliation(s)
- G Theodoridis
- Department of Chemistry, Aristotle University of Thessaloniki, Greece
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20
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Abstract
Theoretical aspects of multiple solid-phase microextraction are described and the principle is illustrated with the extraction of lidocaine from aqueous solutions. With multiple extraction under non-equilibrium conditions considerably less time is required in order to obtain an extraction yield that is equal to that of one extraction at equilibrium. On the other side, the extraction yield can be increased if multiple extraction is performed with the same total time as is needed for one extraction at equilibrium time. The effect of multiple extraction is strongly dependent on the value of the partition constant and for practical use the length of the desorption time is important. A good agreement between theoretical and experimental data has been obtained. Chromatograms are presented showing the potential of multiple solid-phase microextraction.
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Affiliation(s)
- E H Koster
- Department of Analytical Chemistry and Toxicology, University Centre for Pharmacy, Groningen, The Netherlands
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Koster EH, Wemes C, Morsink JB, de Jong GJ. Determination of lidocaine in plasma by direct solid-phase microextraction combined with gas chromatography. J Chromatogr B Biomed Sci Appl 2000; 739:175-82. [PMID: 10744325 DOI: 10.1016/s0378-4347(99)00344-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Direct-immersion solid-phase microextraction (SPME) has been used to extract the local anesthetic lidocaine from human plasma. A simplified model shows the relationship between the total amount of drug in plasma and the amount of drug extracted. The model takes into account that the drug participates between the fiber, sample and proteins. Therefore the model can also be used to obtain a good approximation of the drug-protein binding. Extraction yields of lidocaine in plasma are <1%, and the protein binding of lidocaine was found to be about 74% at pH 9.5. A SPME method has been developed for the determination of the total amount of lidocaine in plasma. The protein binding was reduced by acidification and, subsequently, the sample was deproteinized with trichloroacetic acid. With a 100-microm polydimethylsiloxane-coated fiber and addition of sodium chloride to the sample an extraction yield of about 12% at equilibrium (45 min) has been obtained. The relative standard deviation of this method is <10%. A linear range was found from 25 to 2000 ng ml(-1) lidocaine in plasma (r=0.998) with a detection limit of 5 ng ml(-1) in plasma. An extraction yield of about 80% could be obtained after an overnight extraction by use of a 65-microm polydimethylsiloxane-divinylbenzene-coated fiber. If an extraction time of 10 min is used with this fiber, the same yield is obtained as with the single-phase fiber in 45 min. However, the drawback of this mixed-phase fiber is its much shorter lifetime.
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Affiliation(s)
- E H Koster
- University Centre for Pharmacy, Department of Analytical Chemistry and Toxicology, Groningen, The Netherlands
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22
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Reubsaet JL, Beijnen JH, Bult A, van der Houwen OA, Teeuwsen J, Koster EH, Underberg WJ. Degradation kinetics of antagonist [Arg6, D-Trp7,9, MePhe8]-substance P [6-11] in aqueous solutions. Anal Biochem 1995; 227:334-41. [PMID: 7573955 DOI: 10.1006/abio.1995.1289] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Antagonist [Arg6, D-Trp7,9, MePhe8]-substance P {6-11} was subjected to a systematic stability study in which kinetic parameters were obtained for the degradation of this hexapeptide under several well-defined conditions. The influences of pH, temperature, ionic strength, buffer concentration, and initial concentration of the peptide on the reaction rate constant, kobs, were investigated with a stability-indicating reversed-phase high-performance liquid chromatographic system. From the pH-log kobs degradation profile, obtained at 63 degrees C, it appears that antagonist [Arg6, D-Trp7,9, MePhe8]-substance P {6-11} shows its maximum stability around pH 4.2. The half-life at this pH and temperature is 150 days. In both the hydroxyl- and proton-catalyzed parts of the pH-log kobs degradation profile, the influence of temperature was investigated and Arrhenius plots were constructed. The activation energies in both parts were comparable; however, the frequency factor in the hydroxyl-catalyzed part was 3.3 x 10(4) times higher than in the proton-catalyzed part. Eyring analysis of the data reveals that in both acidic and alkaline media the overall degradation was endotherm (delta H++ as well as delta G++ positive between 273 and 373 degrees K) and the entropy was negative. Increasing ionic strengths in acidic media causes an increase in kobs, while in alkaline media the kobs decreases with increasing ionic strength. Increasing buffer concentrations of acetate, phosphate, and carbonate led to an increase of kobs values. Drug concentrations up to 1 mg/ml at pH 10.8 and constant temperature and ionic strength have no influence on the overall degradation rate. At higher concentrations, above 1 mg/ml, kobs decreases.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- J L Reubsaet
- Department of Pharmaceutical Analysis, Faculty of Pharmacy, Utrecht University, The Netherlands
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Reubsaet JL, Beijnen JH, Bult A, Teeuwsen J, Koster EH, Waterval JC, Underberg WJ. Reversed-phase high-performance liquid chromatography and capillary electrophoresis in the stability study of the neuropeptide growth factor antagonist [Arg6,D-Trp7,9,MePhe8]-substance P (6-11): a comparative study. Anal Biochem 1994; 220:98-102. [PMID: 7526736 DOI: 10.1006/abio.1994.1304] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Reversed-phase high-performance liquid chromatography and capillary zone electrophoresis are widely used in protein and peptide analysis. Degradation of the basic peptide [Arg6,D-Trp7,9,MePhe8]-substance P (6-11) (antagonist G) was monitored with reversed-phase high-performance liquid chromatography, free capillary zone electrophoresis, and capillary zone electrophoresis with a capillary cationic coating. Capillary zone electrophoresis with a dynamically coated capillary provided better separation between antagonist G and its degradation products (formed at pH/Hv 13) than high-performance liquid chromatography and free zone capillary electrophoresis. Rate constants of the alkaline degradation of antagonist G measured with reversed-phase high-performance liquid chromatography and capillary zone electrophoresis with a dynamic coated capillary wall are similar whereas the values measured with free zone capillary electrophoresis are lower. Rate constants for the degradation of antagonist G in acidic media are comparable for the three techniques. It is concluded that capillary zone electrophoresis using a dynamic coating with Fluorad is the most suited of the above-mentioned techniques in analyzing antagonist G and its degradation products.
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Affiliation(s)
- J L Reubsaet
- Department of Pharmaceutical Analysis, Faculty of Pharmacy, Utrecht University, The Netherlands
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