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Åberg, Anna-Maja
Alternative names
Publications (10 of 18) Show all publications
Abrahamsson, P., Johansson, G., Åberg, A.-M., Winsö, O. & Blind, P. J. (2016). Outcome of microdialysis sampling on liver surface and parenchyma. Journal of Surgical Research, 200(2), 480-487
Open this publication in new window or tab >>Outcome of microdialysis sampling on liver surface and parenchyma
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2016 (English)In: Journal of Surgical Research, ISSN 0022-4804, E-ISSN 1095-8673, Vol. 200, no 2, p. 480-487Article in journal (Refereed) Published
Abstract [en]

Background: To investigate whether surface microdialysis (μD) sampling in probes covered by a plastic film, as compared to noncovered and to intraparenchymatous probes, would increase the technique's sensitivity for pathophysiologic events occurring in a liver ischemia-reperfusion model. Placement of μD probes in the parenchyma of an organ, as is conventionally done, may cause adverse effects, e.g., bleeding, possibly influencing outcome.

Methods: A transient ischemia-reperfusion model of the liver was used in six anesthetized normoventilated pigs. μD probes were placed in the parenchyma and on the liver surface. Surface probes were either left uncovered or were covered by plastic film.

Results: Lactate and glucose levels were significantly higher in plastic film covered probes than in uncovered surface probes throughout the ischemic period. Glycerol levels were significantly higher in plastic film covered probes than in uncovered surface probes at 30 and 45 min into ischemia.

Conclusions: Covering the μD probe increases the sensibility of the μD–technique in monitoring an ischemic insult and reperfusion in the liver. These findings confirm that the principle of surface μD works, possibly replacing need of intraparenchymatous placement of μD probes. Surface μD seemingly allows, noninvasively from an organ's surface, via the extracellular compartment, assessment of intracellular metabolic events. The finding that covered surface μD probes allows detection of local metabolic changes earlier than do intraparenchymatous probes, merit further investigation focusing on μD probe design.

Keywords
Microdialysis, Liver, Ischemia, Reperfusion, Surface probe, Metabolism
National Category
Physiology Biomedical Laboratory Science/Technology Surgery
Identifiers
urn:nbn:se:umu:diva-112153 (URN)10.1016/j.jss.2015.09.009 (DOI)000366841500010 ()26505659 (PubMedID)
Available from: 2015-12-03 Created: 2015-12-03 Last updated: 2018-06-07Bibliographically approved
Waldenström, A., Ronquist, G., Åberg, A.-M., Ahlstrom, K., Hauck, P., Abrahamsson, P., . . . Haney, M. F. (2012). Ischaemic preconditioning reduces myocardial calcium overload in coronary-occluded pig hearts shown by continuous in vivo assessment using microdialysis. Clinical Physiology and Functional Imaging, 32(2), 133-138
Open this publication in new window or tab >>Ischaemic preconditioning reduces myocardial calcium overload in coronary-occluded pig hearts shown by continuous in vivo assessment using microdialysis
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2012 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 32, no 2, p. 133-138Article in journal (Refereed) Published
Abstract [en]

During ischaemia, ATP depletion leads to insufficient fuelling for Na+/K+ ATPase, decreased electrochemical potential and increased influx of calcium ions. This study demonstrated a means to assess the effects of ischaemic preconditioning (IP) on the free intracellular Ca2+ pool during prolonged ischaemia. In a porcine myocardial ischaemia model, microdialysis (MD) was used for sampling of metabolic and injury markers in IP and non-IP (control) groups. 45Ca2+ was delivered in microperfusate locally to ischaemic myocardium, with distribution and uptake assessed by 45Ca2+ recovery in microdialysate. Cardiomyocytes in vitro were exposed to a Ca2+ ionophore and tested for 45Ca2+ uptake. An accentuated myocardial calcium ion influx (observed as an increased microdialysate 45Ca2+ recovery in the extracellular milieu) was noted in control pigs compared with IP pigs during ischaemia. Suspended cardiomyocytes preincubated with a Ca2+ ionophore to increase the intracellular calcium ion pool and subsequently incubated with 45Ca2+, displayed lower 45Ca2+ uptake in cells compared with control cells not exposed to the ionophore, corroborating the idea of a strong relationship between degree of intracellular calcium overload and microdialysate 45Ca2+ recovery. The ischaemic insult was differentially verified by metabolic and injury markers. We introduce an in vivo method for serial assessment of myocardial calcium overload during ischaemia, using a MD technique and 45Ca2+ inclusion. IP leads to relatively less calcium overload as assessed by this new method, and we interpret this to mean that reduction in calcium overload is an important part of the IP protective effect.

Place, publisher, year, edition, pages
Malden, MA: Wiley-Blackwell, 2012
Keywords
calcium, calcium overload, microdialysis, myocardial ischaemia, porcine
National Category
Physiology
Identifiers
urn:nbn:se:umu:diva-52838 (URN)10.1111/j.1475-097X.2011.01067.x (DOI)000299734400009 ()
Available from: 2012-03-05 Created: 2012-03-05 Last updated: 2018-06-08Bibliographically approved
Abrahamsson, P., Åberg, A.-M., Winsö, O., Johansson, G., Haney, M. & Blind, P.-J. (2012). Surface microdialysis sampling: a new approach described in a liver ischaemia model. Clinical Physiology and Functional Imaging, 32(2), 99-105
Open this publication in new window or tab >>Surface microdialysis sampling: a new approach described in a liver ischaemia model
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2012 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 32, no 2, p. 99-105Article in journal (Refereed) Published
Abstract [en]

We recently have shown that samples from microdialysis (MD) probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces. In 13 anesthetized pigs, transient liver ischaemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface and two in parenchyma were perfused with a flow rate of 1 mu l per min (n = 13). An identical set-up was used for probes with a flow rate of 2 mu l per min (n = 9). Samples were collected for every 15-min period during 60 min of baseline, 45 min of ischaemia and 60 min of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present study. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and those on parenchyma. No significant differences in relative changes in lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischaemia or reperfusion with a flow rate of 1 mu l per min. MD sampling applied on the liver surface is a new application area for the MD technique and may be used to monitor liver metabolism during both physiological and pathophysiological conditions.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2012
Keywords
ischaemia, liver, metabolism, microdialysis, surface probe
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-52839 (URN)10.1111/j.1475-097X.2011.01061.x (DOI)000299734400004 ()
Available from: 2012-03-06 Created: 2012-03-05 Last updated: 2018-06-08Bibliographically approved
Abrahamsson, P., Åberg, A.-M., Johansson, G., Winsö, O., Waldenström, A. & Haney, M. (2011). Detection of myocardial ischaemia using surface microdialysis on the beating heart. Clinical Physiology and Functional Imaging, 31(3), 175-181
Open this publication in new window or tab >>Detection of myocardial ischaemia using surface microdialysis on the beating heart
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2011 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 31, no 3, p. 175-181Article in journal (Refereed) Published
Abstract [en]

Microdialysis (MD) can be used to study metabolism of the beating heart. We investigated whether microdialysis results obtained from epicardial (surface) sampling reflect acute changes in the same way as myocardial sampling from within the substance of the ventricular wall. In anaesthetized open-thorax pigs a coronary snare was placed. One microdialysis probe was placed with the sampling membrane intramyocardially (myocardial), and a second probe was placed with the sampling membrane epicardially (surface), both in the area which was made ischaemic. Ten minutes collection intervals were used for microdialysis samples. Samples from 19 pigs were analysed for lactate, glucose, pyruvate and glycerol during equilibration, baseline, ischaemia and reperfusion periods. For both probes (surface and myocardial), a total of 475 paired simultaneous samples were analysed. Results from analyses showed no differences in relative changes for glucose, lactate and glycerol during baseline, ischaemia and reperfusion. Surface microdialysis sampling is a new application of the microdialysis technique that shows promise and should be further studied.

Keywords
epicardium; heart; ischaemia; metabolism; microdialysis; myocardium
National Category
Physiology
Identifiers
urn:nbn:se:umu:diva-39564 (URN)10.1111/j.1475-097X.2010.00995.x (DOI)21091606 (PubMedID)
Available from: 2011-02-01 Created: 2011-02-01 Last updated: 2018-06-08Bibliographically approved
Ahlström, K., Biber, B., Åberg, A.-M., Abrahamsson, P., Johansson, G., Ronquist, G., . . . Haney, M. F. (2011). Exogenous carbon monoxide does not affect cell membrane energy availability assessed by sarcolemmal calcium fluxes during myocardial ischaemia-reperfusion in the pig. European Journal of Anaesthesiology, 28(5), 356-362
Open this publication in new window or tab >>Exogenous carbon monoxide does not affect cell membrane energy availability assessed by sarcolemmal calcium fluxes during myocardial ischaemia-reperfusion in the pig
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2011 (English)In: European Journal of Anaesthesiology, ISSN 0265-0215, E-ISSN 1365-2346, Vol. 28, no 5, p. 356-362Article in journal (Refereed) Published
Abstract [en]

Carbon monoxide is thought to be cytoprotective and may hold therapeutic promise for mitigating ischaemic injury. The purpose of this study was to test low-dose carbon monoxide for protective effects in a porcine model of acute myocardial ischaemia and reperfusion.In acute open-thorax experiments in anaesthetised pigs, pretreatment with low-dose carbon monoxide (5% increase in carboxyhaemoglobin) was conducted for 120 min before localised ischaemia (45 min) and reperfusion (60 min) was performed using a coronary snare. Metabolic and injury markers were collected by microdialysis sampling in the ventricular wall. Recovery of radio-marked calcium delivered locally by microperfusate was measured to assess carbon monoxide treatment effects during ischaemia/reperfusion on the intracellular calcium pool.Coronary occlusion and ischaemia/reperfusion were analysed for 16 animals (eight in each group). Changes in glucose, lactate and pyruvate from the ischaemic area were observed during ischaemia and reperfusion interventions, though there was no difference between carbon monoxide-treated and control groups during ischaemia or reperfusion. Similar results were observed for glycerol and microdialysate Ca recovery.These findings show that a relatively low and clinically relevant dose of carbon monoxide did not seem to provide acute protection as indicated by metabolic, energy-related and injury markers in a porcine myocardial ischaemia/reperfusion experimental model. We conclude that protective effects of carbon monoxide related to ischaemia/reperfusion either require higher doses of carbon monoxide or occur later after reperfusion than the immediate time frame studied here. More study is needed to characterise the mechanism and time frame of carbon monoxide-related cytoprotection.

Keywords
calcium, carbon monoxide, myocardial ischaemia, preconditioning, reperfusion, swine
National Category
Anesthesiology and Intensive Care
Identifiers
urn:nbn:se:umu:diva-37169 (URN)10.1097/EJA.0b013e32833eab96 (DOI)000289459200011 ()20811288 (PubMedID)1365-2346 (Electronic) 0265-0215 (Linking) (ISBN)
Available from: 2010-10-25 Created: 2010-10-21 Last updated: 2018-06-08Bibliographically approved
Åberg, A.-M., Ahlström, K., Abrahamsson, P., Waldenström, A., Ronquist, G., Hauck, P., . . . Haney, M. (2010). Ischaemic pre-conditioning means an increased adenosine metabolism with decreased glycolytic flow in ischaemic pig myocardium. Acta Anaesthesiologica Scandinavica, 54(10), 1257-1264
Open this publication in new window or tab >>Ischaemic pre-conditioning means an increased adenosine metabolism with decreased glycolytic flow in ischaemic pig myocardium
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2010 (English)In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 54, no 10, p. 1257-1264Article in journal (Refereed) Published
Abstract [en]

This association between increased adenosine turnover and decreased glycolytic flow during prolonged ischaemia in response to IP can possibly be explained by the competitive effect for the metabolites from both glucose and adenosine metabolism for entering glycolysis. We conclude that this study provides support for an energy-metabolic explanation for the protective mechanisms of IP.

Identifiers
urn:nbn:se:umu:diva-39664 (URN)10.1111/j.1399-6576.2010.02312.x (DOI)21039347 (PubMedID)
Available from: 2011-02-03 Created: 2011-02-03 Last updated: 2018-06-08Bibliographically approved
Åberg, A.-M., Nilsson Sojka, B., Winsö, O., Abrahamsson, P., Johansson, G. & Larsson, J. E. (2009). Carbon monoxide concentration in donated blood: relation to cigarette smoking and other sources. Transfusion, 49(2), 347-353
Open this publication in new window or tab >>Carbon monoxide concentration in donated blood: relation to cigarette smoking and other sources
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2009 (English)In: Transfusion, ISSN 0041-1132, E-ISSN 1537-2995, Vol. 49, no 2, p. 347-353Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Carbon monoxide (CO) is normally present in the human body due to endogenous production of CO. CO can also be inhaled by exposure to external sources such as cigarette smoke, car exhaust, and fire. The purpose of this study was to investigate CO concentrations in blood from 410 blood donors at the blood center in Umea, Sweden. To further evaluate the effects of cigarette smoking on CO concentrations, the elimination time for CO was examined in six volunteer smokers after a smoked cigarette. STUDY DESIGN AND METHODS: Blood samples from whole blood donors were obtained during the blood center's routine operation. In connection with blood donations, demographic and behavioral data were collected from the donors. The CO concentration was determined using gas chromatography. RESULTS: The majority of blood donors had approximately the same CO concentration (mean, 84.5 micromol/L). In 6 percent of the samples, the concentrations were higher than 130 micromol per L. The highest CO concentration was 561 micromol per L. The main source for these high CO concentrations appeared to be cigarette smoking. In the volunteer smokers, the elimination time after a smoked cigarette varied significantly, with elimination half-lives from 4.7 to 8.4 hours. CONCLUSION: These results show that blood bank red blood cell bags may have CO concentrations above the physiologic level. The time interval between cigarette smoking and blood donation seems to be a particularly important factor for elevated CO concentrations.

Identifiers
urn:nbn:se:umu:diva-2756 (URN)10.1111/j.1537-2995.2008.01951.x (DOI)18980621 (PubMedID)
Available from: 2007-11-09 Created: 2007-11-09 Last updated: 2018-06-09Bibliographically approved
Åberg, A., Ronquist, G., Haney, M. & Waldenström, A. (2009). Effects of some modulators on purine nucleoside phosphorylase activity in myocardial tissue.. Scand J Clin Lab Invest
Open this publication in new window or tab >>Effects of some modulators on purine nucleoside phosphorylase activity in myocardial tissue.
2009 (English)In: Scand J Clin Lab InvestArticle in journal (Refereed) Published
Abstract [en]

Abstract Purine nucleoside phosphorylase (PNP) in mammalian tissue is an enzyme responsible for formation of purine bases in DNA. It is also believed that PNP is crucial under energy-deprived conditions for the cell to metabolise adenosine during ATP degradation. This work describes a new method for determination of PNP activity in myocardial tissue using a commercially available substrate, 2-amino-6-mercapto-7-methylpurine riboside (MESG). The method involves the photometric assessment of the reaction between PNP (extracted from myocardial tissue) and MESG. Quantification as well as temperature- and pH-dependency for myocardial PNP activity is described. Also, the effect of some modulators has been studied. We have established the presence of PNP activity in pig myocardial tissue. Further, the results indicate a pH tolerance under slightly acid conditions and a calcium ion dependence of the enzyme.

Identifiers
urn:nbn:se:umu:diva-31400 (URN)1502-7686 (ISBN)
Available from: 2010-02-10 Created: 2010-02-10 Last updated: 2018-06-08
Ahlström, K., Biber, B., Åberg, A., Waldenström, A., Ronquist, G., Abrahamsson, P., . . . Haney, M. (2009). Metabolic responses in ischemic myocardium after inhalation of carbon monoxide. Acta Anaesthesiologica Scandinavica, 53(8), 1036-1042
Open this publication in new window or tab >>Metabolic responses in ischemic myocardium after inhalation of carbon monoxide
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2009 (English)In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 53, no 8, p. 1036-1042Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: To clarify the mechanisms of carbon monoxide (CO) tissue-protective effects, we studied energy metabolism in an animal model of acute coronary occlusion and pre-treatment with CO. METHODS: In anesthetized pigs, a coronary snare and microdialysis probes were placed. CO (carboxyhemoglobin 5%) was inhaled for 200 min in test animals, followed by 40 min of coronary occlusion. Microdialysate was analyzed for lactate and glucose, and myocardial tissue samples were analyzed for adenosine tri-phosphate, adenosine di-phosphate, and adenosine mono-phosphate. RESULTS: Lactate during coronary occlusion was approximately half as high in CO pre-treated animals and glucose levels decreased to a much lesser degree during ischemia. Energy charge was no different between groups. CONCLUSIONS: CO in the low-doses tested in this model results in a more favorable energy metabolic condition in that glycolysis is decreased in spite of maintained energy charge. Further work is warranted to clarify the possible mechanistic role of energy metabolism for CO protection.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:umu:diva-30732 (URN)10.1111/j.1399-6576.2009.01992.x (DOI)19426237 (PubMedID)
Available from: 2010-01-14 Created: 2010-01-14 Last updated: 2018-06-08Bibliographically approved
Åberg, A. M. (2008). Carbon monoxide in biological systems: an experimental and clinical study. Acta Anaesthesiol Scand, 52(5), 716-7
Open this publication in new window or tab >>Carbon monoxide in biological systems: an experimental and clinical study
2008 (English)In: Acta Anaesthesiol Scand, Vol. 52, no 5, p. 716-7Article in journal (Refereed) Published
Keywords
Animals, Blood Donors, Carbon Monoxide/*metabolism, Cytokines/blood, Humans, Inflammation/blood, Swine
Identifiers
urn:nbn:se:umu:diva-31394 (URN)1399-6576 (Electronic) (ISBN)
Note
Aberg, Anna-Maja England Acta anaesthesiologica Scandinavica Acta Anaesthesiol Scand. 2008 May;52(5):716-7.Available from: 2010-02-10 Created: 2010-02-10 Last updated: 2018-06-08
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