| 1. |
- Blind, Per-Jonas, et al.
(författare)
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Microdialysis in early detection of temporary pancreatic ischemia in a porcine model
- 2012
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Ingår i: European Surgical Research. - : S. Karger AG. - 0014-312X .- 1421-9921. ; 49:3-4, s. 113-120
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Tidskriftsartikel (refereegranskat)abstract
- Background: Ischemic injury to the pancreas occurs in various clinical conditions. A method for online monitoring of pathophysiological events in pancreatic parenchyma is missing. Aims: To assess the timing of microdialysis (MD) technique response on temporary changes in pancreatic perfusion, and to evaluate the relationship between MD data and systemic markers of anaerobic metabolism and inflammation. Methods: In anaesthetized normoventilated pigs, MD probes were placed in right (control) and left (ischemic) pancreatic lobes, respectively. Following the clamping of the vessels, ischemia was verified by tissue oxygen tension (PtiO2) measurements. Results: PtiO2 decreased within 20 min after the clamping of the vessels, already returning to baseline levels at the first sampling point after the removal of the clamp. MD lactate levels increased, whereas pyruvate and glucose levels decreased at 20 min after the induction of ischemia. These trends continued until the end of ischemia and returned to baseline following reperfusion. Serum lactate, amylase and tumor necrosis factor-alpha levels decreased throughout the protocol time. Conclusion: MD data were in concordance with changes in PtiO2, which is indicative of local anaerobic metabolism. MD allowed the detection of pathophysiological processes within the ischemic pancreas at a stage when no elevations of systemic markers of ischemia or inflammation were observed.
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| 2. |
- Abrahamsson, Pernilla, et al.
(författare)
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Surface microdialysis sampling : a new approach described in a liver ischaemia model
- 2012
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley-Blackwell. - 1475-0961 .- 1475-097X. ; 32:2, s. 99-105
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Barbu, Andreea, et al.
(författare)
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Blood flow in endogenous and transplanted pancreatic islets in anesthetized rats : Effects of lactate and pyruvate
- 2012
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Ingår i: Pancreas. - 0885-3177 .- 1536-4828. ; 41:8, s. 1263-1271
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The objective of this study was to evaluate the effects of exogenously administered lactate and pyruvate on blood perfusion in endogenous and transplanted islets. METHODS: Anesthetized Wistar-Furth rats were given lactate or pyruvate intravenously, and regional blood perfusion was studied 3 or 30 minutes later with a microsphere technique. Separate rats received a 30-minute infusion of pyruvate or lactate into the portal vein before blood flow measurements. We also administered these substances to islet-implanted rats 4 weeks after transplantation and measured graft blood flow with laser Doppler flowmetry. The expression of monocarboxylate transporter 1 and lactate dehydrogenase A was analyzed. RESULTS: The expression of monocarboxylate transporter 1 and lactate dehydrogenase A was markedly up-regulated in transplanted as compared with endogenous islets. Administration of pyruvate, but not lactate, increased mesenteric blood flow after 3 minutes. Pyruvate decreased mesenteric blood flow after 30 minutes, whereas lactate decreased only islet blood flow. These responses were absent in transplanted animals. A continuous intraportal infusion of lactate or pyruvate increased selectively islet blood flow but did not affect blood perfusion of transplanted islets. CONCLUSIONS: Lactate and pyruvate affect islet blood flow through effects mediated by interactions between the liver and the nervous system. Such a response can help adjust the release of islet hormones during excess substrate concentrations.
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| 4. |
- Broström, Anders, 1963-, et al.
(författare)
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Symptom profile of undiagnosed obstructive sleep apnoea in hypertensive outpatients in primary care : a structural equation model analysis
- 2012
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Ingår i: Quality in Primary Care. - London, United Kingdom : iMedPub Ltd.. - 1479-1072 .- 1479-1064. ; 20:4, s. 287-298
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundObstructive sleep apnoea (OSA) has been linked to hypertension in sleep clinic populations, but little is known about the symptom profile of undiagnosed OSA in hypertensive outpatients in primary care.AimTo explore characteristics associated with undiagnosed OSA in hypertensive primary care patients.MethodsCross-sectional design, including 411 consecutive patients (52% women), mean age 57.9 years (standard deviation [SD] 5.9 years), with diagnosed hypertension (blood pressure >140/90 mmHg) fromfour primary care centres. All subjects underwent a full-night, home-based, respiratory recording to establish the presence and severity of OSA. Clinical variables, medication and comorbidities, as well as data from self-rating scales regarding symptoms/characteristics, insomnia, excessive daytime sleepiness, depressive symptoms and health were collected during a clinical examination. Factor analyses and structural equation modelling (SEM) were used to explore the relationships between selfrated symptoms, clinical characteristics and objectively verified diagnosis of OSA.Main outcomeMeasures symptom profile of undiagnosed OSA (as measured by the Apnoea/ Hypopnoea Index [AHI]) in hypertensive outpatients in primary care.ResultsFifty-nine percent of the patients had an AHI _ 5/hour indicating OSA. An exploratory factor analysis based on 19 variables yielded a six-factor model (anthropometrics, blood pressure, OSA-related symptoms, comorbidity, health complaints and physical activity) explaining 58% of the variance. SEM analyses showed strong significant associations between anthropometrics (body mass index, neck circumference, waist circumference) (0.45), OSA-related symptoms (snoring, witnessed apnoeas, dry mouth) (0.47) and AHI. No direct effects of OSA on comorbidities, blood pressure, dyssomnia or self-rated health were observed.ConclusionOSA was highly prevalent and was directly associated with anthropometrics and OSArelated symptoms (snoring, witnessed apnoeas and dry mouth in the morning). When meeting patients with hypertension, these characteristics could be used by general practitioners to identify patients who are in need of referral to a sleep clinic for OSA evaluation.
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| 5. |
- Broström, Anders, 1963-, et al.
(författare)
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Undiagnosed obstructive sleep apnea in hypertensive outpatients in primary care : Associations with sleep complaints, depressive symptoms and global perceived health
- 2013
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Ingår i: Open Journal of Nursing. - : Scientific Research Publishing, Inc.. - 2162-5336 .- 2162-5344. ; 3:6, s. 445-452
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Tidskriftsartikel (refereegranskat)abstract
- Objective: 1) To describe the prevalence of undiagnosed obstructive sleep apnea (OSA) and depressive symptoms in hypertensive men and women below 65 years of age, and 2) to describe the association of OSA to subjective sleep complaints, depressive symptoms and global perceived health. Design: Cross-sectional design focusing on nursing care outcomes of obstructive sleep apnea. Setting: Four primary care health centres in Sweden. PATIENTS: 411 consecutive patients (52% women), mean age 57.9 years (SD 5.9 years), with diagnosed hypertension (BP > 140/90). Main Outcome Measures: Prevalence of OSA and depressive symptoms, and association of OSA to sleep complaints, depressive symptoms and global perceived health. RESULTS: Mild, moderate and severe OSA was seen among 29%, 16% and 14% of patients, respectively. Depressive symptoms were seen in 16% of the total group, with a higher prevalence among men, compared to women, 21% vs. 12%. No differences were found regarding blood pressure, estimated sleep need, sleep sufficiency index, insomnia symptoms, daytime sleepiness or depressive symptoms with respect to different degrees of OSA. Apnea-hypopnea index was significantly associated to perceived health after adjustment for gender and comorbidities, but when depressive symptoms and non-restorative sleep were added to the model, 33% of the variance in global perceived health was explained. Conclusion: OSA is highly prevalent among patients with hypertension in primary care and does together with sleep complaints and depressive symptoms have a negative impact on global perceived health. Hypertensive patients without subjective sleep complaints or depressive symptoms may still have OSA.
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| 6. |
- Christoffersson, Gustaf, et al.
(författare)
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Clinical and Experimental Pancreatic Islet Transplantation to Striated Muscle : Establishment of a Vascular System Similar to that in Native Islets
- 2010
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 59:10, s. 2569-2578
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Curing type 1 diabetes by transplanting pancreatic islets into the liver is associated with poor long-term outcome and graft failure at least partly due to inadequate graft revascularization. The aim of the current study was to evaluate striated muscle as a potential angiogenic site for islet transplantation. Research Design and Methods: The current study presents a new experimental model which is found applicable to clinical islet transplantation. Islets were implanted into striated muscle where after intra-islet vascular density and blood flow were visualized with intravital and confocal microscopy in mice, and by magnetic resonance imaging in three auto-transplanted pancreatectomized patients. Mice were rendered neutropenic by repeated injections of Gr-1 antibody and diabetes was induced by alloxan treatment. Results: Contrary to liver-engrafted islets, islets transplanted to mouse muscle were revascularized with vessel densities and blood flow entirely comparable to islets within intact pancreas. Initiation of islet revascularization at the muscular site was dependent on neutrophils, and the function of islets transplanted to muscle was proven by curing diabetic mice. The experimental data were confirmed in auto-transplanted patients where higher plasma volumes were measured in islets engrafted in forearm muscle compared to adjacent muscle tissue through high-resolution magnetic resonance imaging. Conclusions: This study presents a novel paradigm in islet transplantation whereby recruited neutrophils are crucial for the functionally restored intra-islet blood perfusion following transplantation to striated muscle under experimental and clinical situations.
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| 7. |
- Eriksson, Olof, et al.
(författare)
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The Positron Emission Tomography ligand [11C]5-Hydroxy-Tryptophan can be used as a surrogate marker for the human endocrine pancreas
- 2014
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 63:10, s. 3428-3437
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Tidskriftsartikel (refereegranskat)abstract
- In humans a well-developed serotonin system is localized to the pancreatic islets while being absent in exocrine pancreas. Assessment of pancreatic serotonin biosynthesis could therefore be used to estimate the human endocrine pancreas. Proof of concept was tested in a prospective clinical trial by comparisons of type 1 diabetic (T1D) patients, with extensive reduction of beta cells, with healthy volunteers (HV).C-peptide negative (i.e. insulin-deficient) T1D subjects (n=10) and HV (n=9) underwent dynamic Positron Emission Tomography with the radiolabeled serotonin precursor [(11)C]5-Hydroxy-Tryptophan ([(11)C]5-HTP).A significant accumulation of [(11)C]5-HTP was obtained in the pancreas of the HV, with large inter-individual variation. A substantial and highly significant reduction (66%) in the pancreatic uptake of [(11)C]5-HTP in T1D subjects was observed, and this was most evident in the corpus and caudal regions of the pancreas where beta-cells normally are the major constituent of the islets.[(11)C]5-HTP retention in the pancreas was reduced in T1D compared to non-diabetic subjects. Accumulation of [(11)C]5-HTP in the pancreas of both HV and subjects with T1D were in agreement with previously reported morphological observations on the beta cell volume implying that [(11)C]5-HTP retention is a useful non-invasive surrogate marker for the human endocrine pancreas.
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| 8. |
- Gustafsson, Ola, et al.
(författare)
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NOISE LEVEL IN RELATION TO ENERGY PERFORMANCE OF AIR-TO-AIR HEAT PUMPS
- 2011
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Ingår i: 10th international heat pump conference.
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Konferensbidrag (refereegranskat)abstract
- With increased use of air source heat pumps, a possible barrier for further market growth and customer acceptance is their noise level. The disturbance is both an issue for the owner of the heat pump and the neighbors since both the indoor and the outdoor units radiate sound. The purpose of this study is to create an understanding of the noise generation of air-to-air heat pumps and relate this to their energy performance. This knowledge is then to be used in continued work when describing the total disturbance of a heat pump.Two heat pumps, both of inverter type and with different noise performance were selected for measurements. Energy performance, in the form of Coefficient of Performance (COP), was evaluated at different operating conditions. Measurements of the sound power level were performed on both the outdoor and the indoor units. Results show that the sound level from the indoor units is independent of the outdoor conditions. The noise from the outdoor units varies with different climates and the variation is particularly large at part load conditions.
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| 9. |
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| 10. |
- Isaksson, Sofi, et al.
(författare)
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Detecting EGFR alterations in clinical specimens-pitfalls and necessities.
- 2013
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Ingår i: Virchows Archiv: an international journal of pathology. - : Springer Science and Business Media LLC. - 1432-2307. ; 463:6, s. 755-764
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the epidermal growth factor receptor (EGFR) status in early stage lung cancer in Southern Sweden, a population for which there are no previous reports on the EGFR mutation frequency. Three hundred fifty small cell lung cancers, adenocarcinomas (AC), squamous cell carcinomas (SqCC), and large cell carcinomas were analyzed using a combination of techniques for the analysis of protein expression, gene copy numbers, and mutations. Immunohistochemical (IHC) staining with antibodies for the EGFR mutations L858R and del E746-A750 revealed intratumoral heterogeneity and several discrepant cases when compared to mutation-specific polymerase chain reaction (PCR)-based analysis. The frequencies of these two mutations, when considering IHC staining with mutation-specific antibodies in a cohort of 298 cases and subsequent confirmation by PCR, were 10 % in AC and <2 % in SqCC. Furthermore, screening by sequencing of EGFR in a cohort of 52 lung AC and squamous carcinomas demonstrated a more diverse mutation spectrum, not covered by the mutation-specific antibodies. High expression of total EGFR protein was correlated to high gene copy numbers but did not reflect the mutational status of the tumors. We believe that the mutation spectra in a Southern Swedish population is too diverse to be covered by the mutation-specific antibodies, and we also raise some other issues regarding the use of the mutation-specific antibodies, for example concerning heterogeneous expression of the mutated protein, optimal antibody dilution, and discrepancies between staining results and PCR.
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