1
|
Fejfarová V, Jarošíková R, Antalová S, Husáková J, Wosková V, Beca P, Mrázek J, Tůma P, Polák J, Dubský M, Sojáková D, Lánská V, Petrlík M. Does PAD and microcirculation status impact the tissue availability of intravenously administered antibiotics in patients with infected diabetic foot? Results of the DFIATIM substudy. Front Endocrinol (Lausanne) 2024; 15:1326179. [PMID: 38774229 PMCID: PMC11106387 DOI: 10.3389/fendo.2024.1326179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Accepted: 04/16/2024] [Indexed: 05/24/2024] Open
Abstract
Aims/hypothesis The aim of this substudy (Eudra CT No:2019-001997-27)was to assess ATB availability in patients with infected diabetic foot ulcers(IDFUs)in the context of microcirculation and macrocirculation status. Methods For this substudy, we enrolled 23 patients with IDFU. Patients were treated with boluses of amoxicillin/clavulanic acid(AMC)(12patients) or ceftazidime(CTZ)(11patients). After induction of a steady ATB state, microdialysis was performed near the IDFU. Tissue fluid samples from the foot and blood samples from peripheral blood were taken within 6 hours. ATB potential efficacy was assessed by evaluating the maximum serum and tissue ATB concentrations(Cmax and Cmax-tissue)and the percentage of time the unbound drug tissue concentration exceeds the minimum inhibitory concentration (MIC)(≥100% tissue and ≥50%/60% tissue fT>MIC). Vascular status was assessed by triplex ultrasound, ankle-brachial and toe-brachial index tests, occlusive plethysmography comprising two arterial flow phases, and transcutaneous oxygen pressure(TcPO2). Results Following bolus administration, the Cmax of AMC was 91.8 ± 52.5 μgmL-1 and the Cmax-tissue of AMC was 7.25 ± 4.5 μgmL-1(P<0.001). The Cmax for CTZ was 186.8 ± 44.1 μgmL-1 and the Cmax-tissue of CTZ was 18.6 ± 7.4 μgmL-1(P<0.0001). Additionally, 67% of patients treated with AMC and 55% of those treated with CTZ achieved tissue fT>MIC levels exceeding 50% and 60%, respectively. We observed positive correlations between both Cmax-tissue and AUCtissue and arterial flow. Specifically, the correlation coefficient for the first phase was r=0.42; (P=0.045), and for the second phase, it was r=0.55(P=0.01)and r=0.5(P=0.021). Conclusions Bactericidal activity proved satisfactory in only half to two-thirds of patients with IDFUs, an outcome that appears to correlate primarily with arterial flow.
Collapse
Affiliation(s)
- Vladimíra Fejfarová
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Department of Internal Medicine, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Radka Jarošíková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Department of Internal Medicine, Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Simona Antalová
- Department of Clinical Pharmacy and Drug Information Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Jitka Husáková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Veronika Wosková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Pavol Beca
- Department of Clinical Pharmacy and Drug Information Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Jakub Mrázek
- Laboratory of Anaerobic Microbiology, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Prague, Czechia
| | - Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Polák
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Michal Dubský
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Dominika Sojáková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Věra Lánská
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Martin Petrlík
- Vascular and Internal Medicine Outpatient Clinic, Prague, Czechia
| |
Collapse
|
2
|
Fejfarová V, Jarošíková R, Polák J, Sommerová B, Husáková J, Wosková V, Dubský M, Tůma P. Microdialysis as a tool for antibiotic assessment in patients with diabetic foot: a review. Front Endocrinol (Lausanne) 2023; 14:1141086. [PMID: 37139338 PMCID: PMC10150051 DOI: 10.3389/fendo.2023.1141086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/17/2023] [Indexed: 05/05/2023] Open
Abstract
Diabetic foot is a serious late complication frequently caused by infection and ischaemia. Both require prompt and aggressive treatment to avoid lower limb amputation. The effectiveness of peripheral arterial disease therapy can be easily verified using triplex ultrasound, ankle-brachial/toe-brachial index examination, or transcutaneous oxygen pressure. However, the success of infection treatment is difficult to establish in patients with diabetic foot. Intravenous systemic antibiotics are recommended for the treatment of infectious complications in patients with moderate or serious stages of infection. Antibiotic therapy should be initiated promptly and aggressively to achieve sufficient serum and peripheral antibiotic concentrations. Antibiotic serum levels are easily evaluated by pharmacokinetic assessment. However, antibiotic concentrations in peripheral tissues, especially in diabetic foot, are not routinely detectable. This review describes microdialysis techniques that have shown promise in determining antibiotic levels in the surroundings of diabetic foot lesions.
Collapse
Affiliation(s)
- Vladimíra Fejfarová
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Second Faculty of Medicine, Charles University, Prague, Czechia
- *Correspondence: Vladimíra Fejfarová,
| | - Radka Jarošíková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
- Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Polák
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Blanka Sommerová
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague, Czechia
| | - Jitka Husáková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Veronika Wosková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Michal Dubský
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czechia
| | - Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague, Czechia
| |
Collapse
|
3
|
Tůma P. Monitoring of biologically active substances in clinical samples by capillary and microchip electrophoresis with contactless conductivity detection: A review. Anal Chim Acta 2022; 1225:340161. [DOI: 10.1016/j.aca.2022.340161] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/08/2022] [Accepted: 07/08/2022] [Indexed: 12/11/2022]
|
4
|
Tůma P, Jaček M, Sommerová B, Dlouhý P, Jarošíková R, Husáková J, Wosková V, Fejfarová V. Monitoring of amoxicilline and ceftazidime in the microdialysate of diabetic foot and serum by capillary electrophoresis with contactless conductivity detection. Electrophoresis 2022; 43:1129-1139. [PMID: 35072285 DOI: 10.1002/elps.202100366] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/17/2021] [Accepted: 12/23/2021] [Indexed: 11/11/2022]
Abstract
Determination of the broad-spectrum antibiotics amoxicilline (AMX) and ceftazidime (CTZ) in blood serum and microdialysates of the subcutaneous tissue of the lower limbs is performed using CE with contactless conductivity detection (C4 D). Baseline separation of AMX is achieved in 0.5 M acetic acid as the background electrolyte and separation of CTZ in 3.2 M acetic acid with addition of 13% v/v methanol. The CE-C4 D determination is performed in a 25 µm capillary with suppression of the EOF using INST-coating on an effective length of 18 cm and the attained migration time is 4.2 min for AMX and 4.4 min for CTZ. The analysis was performed using 20 µl of serum and 15 µl of microdialysate, treated by the addition of acetonitrile in a ratio of 1/3 v/v and the sample is injected into the capillary using the large volume sample stacking technique. The LOQ attained in the microdialysate is 148 ng/ml for AMX and 339 ng/ml for CTZ, and in serum 143 ng/ml for AMX and 318 ng/ml for CTZ. The CE-C4 D method is employed for monitoring the passage of AMX and CTZ from the blood circulatory system into the subcutaneous tissue at the sites of diabetic ulceration in patients suffering from diabetic foot syndrome and also for measuring the pharmacokinetics following intravenous application of bolus antibiotic doses.
Collapse
Affiliation(s)
- Petr Tůma
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague 10, Czech Republic
| | - Martin Jaček
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague 10, Czech Republic
| | - Blanka Sommerová
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague 10, Czech Republic
| | - Pavel Dlouhý
- Department of Hygiene, Third Faculty of Medicine, Charles University, Prague 10, Czech Republic
| | - Radka Jarošíková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague 4, Czech Republic
| | - Jitka Husáková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague 4, Czech Republic
| | - Veronika Wosková
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague 4, Czech Republic
| | - Vladimíra Fejfarová
- Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague 4, Czech Republic
| |
Collapse
|
5
|
Tůma P, Sommerová B, Daněček V. On-line coupling of capillary electrophoresis with microdialysis for determining saccharides in dairy products and honey. Food Chem 2020; 316:126362. [PMID: 32050115 DOI: 10.1016/j.foodchem.2020.126362] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/24/2019] [Accepted: 02/04/2020] [Indexed: 12/19/2022]
Abstract
Free sucrose, lactose, galactose, glucose and fructose were determined in yoghurts, milk and honey using on-line coupling of capillary electrophoresis with microdialysis. The dairy products were diluted 50-fold with 10 mmol/L NaOH and sampled using laboratory-made microdialysis probes. The microdialysate was brought to the entrance of the electrophoretic capillary and the coupling consisted in a polydimethylsiloxane (PDMS) cross connector working in the flow-gating interface regime. The electrophoretic analysis was performed in 50 mmol/L NaOH (pH 12.6) background electrolyte, where baseline separation of the five saccharides was achieved in 3.5 min. The LOQs varied in the range 2.3-7.3 mg/L, the number of separation plates varied between 176,000 plates/m for glucose to 326,000 plates/m for galactose and the relative standard deviation (RSD) for ten consecutive analyses of fruit yoghurt was 0.2% for the migration time and 4.4-7.6% for the peak area.
Collapse
Affiliation(s)
- Petr Tůma
- Charles University, Third Faculty of Medicine, Department of Hygiene, Ruská 87, 100 00 Prague 10, Czech Republic.
| | - Blanka Sommerová
- Charles University, Third Faculty of Medicine, Department of Hygiene, Ruská 87, 100 00 Prague 10, Czech Republic
| | - Václav Daněček
- Charles University, Third Faculty of Medicine, Department of Biophysics, Ruská 87, 100 00 Prague 10, Czech Republic
| |
Collapse
|
6
|
Hassani SA, Lendor S, Boyaci E, Pawliszyn J, Womelsdorf T. Multineuromodulator measurements across fronto-striatal network areas of the behaving macaque using solid-phase microextraction. J Neurophysiol 2019; 122:1649-1660. [PMID: 31433731 DOI: 10.1152/jn.00321.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Different neuromodulators rarely act independent from each other to modify neural processes but are instead coreleased, gated, or modulated. To understand this interdependence of neuromodulators and their collective influence on local circuits during different brain states, it is necessary to reliably extract local concentrations of multiple neuromodulators in vivo. Here we describe results using solid-phase microextraction (SPME), a method providing sensitive, multineuromodulator measurements. SPME is a sampling method that is coupled with mass spectrometry to quantify collected analytes. Reliable measurements of glutamate, dopamine, acetylcholine, and choline were made simultaneously within frontal cortex and striatum of two macaque monkeys (Macaca mulatta) during goal-directed behavior. We find glutamate concentrations several orders of magnitude higher than acetylcholine and dopamine in all brain regions. Dopamine was reliably detected in the striatum at tenfold higher concentrations than acetylcholine. Acetylcholine and choline concentrations were detected with high consistency across brain areas within monkeys and between monkeys. These findings illustrate that SPME microprobes provide a versatile novel tool to characterize multiple neuromodulators across different brain areas in vivo to understand the interdependence and covariation of neuromodulators during goal-directed behavior. Such data would be important to better distinguish between different behavioral states and characterize dysfunctional brain states that may be evident in psychiatric disorders.NEW & NOTEWORTHY Our paper reports a reliable and sensitive novel method for measuring the absolute concentrations of glutamate, acetylcholine, choline, dopamine, and serotonin in brain circuits in vivo. We show that this method reliably samples multiple neurochemicals in three brain areas simultaneously while nonhuman primates are engaged in goal-directed behavior. We further describe how the methodology we describe here may be used by electrophysiologists as a low-barrier-to-entry tool for measuring multiple neurochemicals.
Collapse
Affiliation(s)
- Seyed-Alireza Hassani
- Department of Psychology, Vanderbilt University, Nashville, Tennessee.,Department of Biology, Centre for Vision Research, York University, Toronto, Ontario, Canada
| | - Sofia Lendor
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada
| | - Ezel Boyaci
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada
| | - Janusz Pawliszyn
- Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada
| | - Thilo Womelsdorf
- Department of Psychology, Vanderbilt University, Nashville, Tennessee.,Department of Biology, Centre for Vision Research, York University, Toronto, Ontario, Canada
| |
Collapse
|
7
|
Bongaerts J, De Bundel D, Mangelings D, Smolders I, Vander Heyden Y, Van Eeckhaut A. Sensitive targeted methods for brain metabolomic studies in microdialysis samples. J Pharm Biomed Anal 2018; 161:192-205. [DOI: 10.1016/j.jpba.2018.08.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 08/20/2018] [Accepted: 08/21/2018] [Indexed: 02/06/2023]
|
8
|
Enrico P, Diana M. On the Accuracy of In Vivo Ethanol and Acetaldehyde Monitoring, a Key Tile in the Puzzle of Acetaldehyde as a Neuroactive Agent. Front Behav Neurosci 2017; 11:97. [PMID: 28611604 PMCID: PMC5447755 DOI: 10.3389/fnbeh.2017.00097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/09/2017] [Indexed: 11/18/2022] Open
Abstract
Over the last 20 years researchers have explored the postulated role of acetaldehyde (ACD) as a mediator of some of the actions of ethanol (EtOH) in the central nervous system (CNS). However, efforts have been hampered mainly by the difficulty of directly measuring in vivo EtOH and ACD levels in the CNS and thus, our knowledge is based on indirect evidences. Although technically challenging, the development of reliable methods for in vivo measurement of ACD and EtOH is of paramount importance to solve the “puzzle of acetaldehyde as a neuroactive agent.” In this short review we discuss the recent advances on brain EtOH pharmacokinetic and state-of-the-art available techniques that could be used for in vivo detect EtOH and ACD both non-invasively (magnetic resonance spectroscopy), and invasively (microdialysis and biosensors). Among the different in vivo sampling techniques described, particular emphasis is paid to the field of enzyme-based amperometric biosensors. Biosensors have gained much attention in recent years for their ability to online monitor biological signals in vivo, and several micro- and nano-structured devices have been successfully used for in vivo studies. Owing to their high temporal and spatial resolution, biosensors could provide the adequate technology for studying in vivo EtOH pharmacokinetic.
Collapse
Affiliation(s)
- Paolo Enrico
- Department of Biomedical Sciences, University of SassariSassari, Italy
| | - Marco Diana
- 'G. Minardi' Cognitive Neuroscience Laboratory, Department of Chemistry and Pharmacy, University of SassariSassari, Italy
| |
Collapse
|
9
|
Van Schoors J, Maes K, Van Wanseele Y, Broeckhoven K, Van Eeckhaut A. Miniaturized ultra-high performance liquid chromatography coupled to electrochemical detection: Investigation of system performance for neurochemical analysis. J Chromatogr A 2016; 1427:69-78. [DOI: 10.1016/j.chroma.2015.11.076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/19/2015] [Accepted: 11/24/2015] [Indexed: 01/03/2023]
|
10
|
Kao CY, Anderzhanova E, Asara JM, Wotjak CT, Turck CW. NextGen Brain Microdialysis: Applying Modern Metabolomics Technology to the Analysis of Extracellular Fluid in the Central Nervous System. MOLECULAR NEUROPSYCHIATRY 2015; 1:60-7. [PMID: 27602357 DOI: 10.1159/000381855] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 03/24/2015] [Indexed: 01/31/2023]
Abstract
Microdialysis is a powerful method for in vivo neurochemical analyses. It allows fluid sampling in a dynamic manner in specific brain regions over an extended period of time. A particular focus has been the neurochemical analysis of extracellular fluids to explore central nervous system functions. Brain microdialysis recovers neurotransmitters, low-molecular-weight neuromodulators and neuropeptides of special interest when studying behavior and drug effects. Other small molecules, such as central metabolites, are typically not assessed despite their potential to yield important information related to brain metabolism and activity in selected brain regions. We have implemented a liquid chromatography online mass spectrometry metabolomics platform for an expanded analysis of mouse brain microdialysates. The method is sensitive and delivers information for a far greater number of analytes than commonly used electrochemical and fluorescent detection or biochemical assays. The metabolomics platform was applied to the analysis of microdialysates in a foot shock-induced mouse model of posttraumatic stress disorder (PTSD). The rich metabolite data information was then used to delineate affected prefrontal molecular pathways that reflect individual susceptibility for developing PTSD-like symptoms. We demonstrate that hypothesis-free metabolomics can be adapted to the analysis of microdialysates for the discovery of small molecules with functional significance.
Collapse
Affiliation(s)
- Chi-Ya Kao
- Departments of Translational Research in Psychiatry, Munich, Germany; Graduate School of Systemic Neurosciences, Ludwig Maximilian University, Munich, Germany
| | - Elmira Anderzhanova
- Departments of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, Mass., USA; Department of Medicine, Harvard Medical School, Boston, Mass., USA
| | - Carsten T Wotjak
- Departments of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Christoph W Turck
- Departments of Translational Research in Psychiatry, Munich, Germany
| |
Collapse
|
11
|
Saylor RA, Lunte SM. A review of microdialysis coupled to microchip electrophoresis for monitoring biological events. J Chromatogr A 2015; 1382:48-64. [PMID: 25637011 DOI: 10.1016/j.chroma.2014.12.086] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/23/2014] [Accepted: 12/26/2014] [Indexed: 12/30/2022]
Abstract
Microdialysis is a powerful sampling technique that enables monitoring of dynamic processes in vitro and in vivo. The combination of microdialysis with chromatographic or electrophoretic methods with selective detection yields a "separation-based sensor" capable of monitoring multiple analytes in near real time. For monitoring biological events, analysis of microdialysis samples often requires techniques that are fast (<1 min), have low volume requirements (nL-pL), and, ideally, can be employed on-line. Microchip electrophoresis fulfills these requirements and also permits the possibility of integrating sample preparation and manipulation with detection strategies directly on-chip. Microdialysis coupled to microchip electrophoresis has been employed for monitoring biological events in vivo and in vitro. This review discusses technical considerations for coupling microdialysis sampling and microchip electrophoresis, including various interface designs, and current applications in the field.
Collapse
Affiliation(s)
- Rachel A Saylor
- Department of Chemistry, University of Kansas, Lawrence, KS 66045, USA; Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047, USA.
| | - Susan M Lunte
- Department of Chemistry, University of Kansas, Lawrence, KS 66045, USA; Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047, USA; Ralph N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, KS 66047, USA.
| |
Collapse
|
12
|
Anderzhanova E, Wotjak CT. Brain microdialysis and its applications in experimental neurochemistry. Cell Tissue Res 2014; 354:27-39. [PMID: 24022232 DOI: 10.1007/s00441-013-1709-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 07/19/2013] [Indexed: 12/20/2022]
Abstract
Abstract Microdialysis is one of the most powerful neurochemistry techniques, which allows the monitoring of changes in the extracellular content of endogenous and exogenous substances in the brain of living animals. The strength as well as wide applicability of this experimental approach are based on the bulk theory of brain neurotransmission. This methodological review introduces basic principles of chemical neurotransmission and emphasizes the difference in neurotransmission types.Clear understanding of their significance and degree of engagement in regulation of physiological processes is an ultimate prerequisite not only for choosing an appropriate method of monitoring for interneuronal communication via chemical messengers but also for accurate data interpretation. The focus on the processes of synthesis/metabolism, receptor interaction/neuronal signaling or the behavioral relevance of neurochemical events sculpts the experiment design. Brain microdialysis is an important method for examining changes in the content of any substances, irrespective of their origin, in living animals. This article compares contemporary approaches and techniques that are used for monitoring neurotransmission (including in vivo brain microdialysis, voltammetric methods, etc). We highlight practical aspects of microdialysis experiments in particular to those researchers who are seeking to increase the repertoire of their experimental techniques with brain microdialysis.
Collapse
|
13
|
Guihen E, Ho WL, Hogan AM, O’Connell ML, Leahy MJ, Ramsay B, O’Connor WT. Rapid quantification of histamine in human psoriatic plaques using microdialysis and ultra high performance liquid chromatography with fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 880:119-24. [DOI: 10.1016/j.jchromb.2011.11.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2011] [Revised: 11/15/2011] [Accepted: 11/18/2011] [Indexed: 01/04/2023]
|
14
|
Kang CM, Joo S, Bae JH, Kim YR, Kim Y, Chung TD. In-Channel Electrochemical Detection in the Middle of Microchannel under High Electric Field. Anal Chem 2011; 84:901-7. [DOI: 10.1021/ac2016322] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Chung Mu Kang
- Department of Chemistry, Seoul National University, Seoul 151-747, Korea
| | - Segyeong Joo
- Department of Medical Engineering,
Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea
| | - Je Hyun Bae
- Department of Chemistry, Seoul National University, Seoul 151-747, Korea
| | - Yang-Rae Kim
- Department of Chemistry, Seoul National University, Seoul 151-747, Korea
| | - Yongseong Kim
- Department
of Science Education, Kyungnam University, Masan 631-701, Korea
| | - Taek Dong Chung
- Department of Chemistry, Seoul National University, Seoul 151-747, Korea
| |
Collapse
|
15
|
|
16
|
The absolute quantification of endogenous levels of brain neuropeptides in vivo using LC-MS/MS. Bioanalysis 2011; 3:1271-85. [PMID: 21649502 DOI: 10.4155/bio.11.91] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Neuropeptides seem to play an important role when the CNS is challenged. In order to obtain better insights into the central peptidergic effects, it is essential to monitor their concentration in the brain. Quantification of neuropeptides in dialysates is challenging due to their low extracellular concentrations (low pM range), their low microdialysis efficiencies, the need for acceptable temporal resolution, the small sample volumes, the complexity of the matrix and the tendency of peptides to stick to glass and polymeric materials. The quantification of neuropeptides in dialysates therefore necessitates the use of very sensitive nano-LC-MS/MS methods. A number of LC-MS/MS and microdialysis parameters need to be optimized to achieve maximal sensitivity. The optimized and validated methods can be used to investigate the in vivo neuropeptide release during pathological conditions, in this way initiating new and immense challenges for the development of new drugs.
Collapse
|
17
|
Investigation of microdialysis sampling calibration approaches for lipophilic analytes: doxorubicin. J Pharm Biomed Anal 2010; 53:490-6. [PMID: 20605079 DOI: 10.1016/j.jpba.2010.05.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 05/19/2010] [Accepted: 05/24/2010] [Indexed: 11/23/2022]
Abstract
Microdialysis is an important sampling technique in many pharmacokinetics and pharmacological studies. Applying microdialysis to lipophilic analytes can be difficult as low extraction efficiencies are generally obtained with these types of analytes. In this investigation, the effects of applying microdialysis to the lipophilic compound, doxorubicin are discussed. Using varying concentrations of doxorubicin (DOX) from 1 to 20 microM, in vitro probe calibrations were performed by delivery, recovery and no-net flux. Any changes in the extraction efficiencies calculated were monitored through the addition of an internal standard, antipyrine. DOX was chosen as a representative lipophilic analyte because its red color could be visibly monitored on the probe. At higher concentrations the probe membrane became redder. For delivery experiments, the inlet of the probe was more highly colored than the outlet. The opposite was true for recovery experiments, in which the outlet was more highly colored than the inlet. It was observed that while antipyrine was well-behaved in these experiments, for DOX the extraction efficiency determined by recovery was not the same as the extraction efficiency determined by delivery (p<0.005, 0.05). It was further observed that for DOX the extraction efficiency determined by a no-net flux experiment was in good agreement with the value determined by delivery and not that determined by recovery. However, the only point in which no DOX was present in the perfusate was not on the no-net flux line. In addition, the transport of DOX across the microdialysis membrane was considerably slower than the transport of antipyrine.
Collapse
|
18
|
Guihen E, O'Connor WT. Capillary and microchip electrophoresis in microdialysis: recent applications. Electrophoresis 2010; 31:55-64. [PMID: 20039293 DOI: 10.1002/elps.200900467] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The theme of this review is to highlight the importance of microscale electrophoretic-based separation systems in microdialysis (microD). The ability of CE and MCE to yield very rapid and highly efficient separations using just nanolitre volumes of microdialysate samples will also be discussed. Recent advances in this area will be highlighted, by illustration of some exciting new applications while the need for further innovation will be covered. The first section briefly introduces the concept of microD sampling coupled with electrophoresis-based separation and the inherent advantages of this approach. The following section highlights some specific applications of CE separations in the detection of important biomarkers such as low-molecular-weight neurotransmitters, amino acids, and other molecules that are frequently encountered in microD. Various detection modes in CE are outlined and some of the advantages and drawbacks thereof are discussed. The last section introduces the concepts of micro-total analysis systems and the coupling of MCE and microD. Some of the latest innovations will be illustrated. The concluding section reflects on the future of this important chemical alliance between microD and CE/MCE.
Collapse
Affiliation(s)
- Elizabeth Guihen
- Graduate Entry Medical School and Materials and Surface Science Institute, University of Limerick, Limerick, Ireland.
| | | |
Collapse
|