| 1. |
- Fosse, Erik, et al.
(författare)
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Duraflo II coating of cardiopulmonary bypass circuits reduces complement activation, but does not affect the release of granulocyte enzymes : a European multicentre study
- 1997
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Ingår i: European Journal of Cardio-Thoracic Surgery. - 1010-7940 .- 1873-734X. ; 11:2, s. 320-327
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This study was carried out to: (a) compare complement and granulocyte activation during cardiac operations in patients operated with cardiopulmonary bypass coated with heparin by the Duraflo II method, with activation in patients operated with uncoated circuits; and (b) relate complement, and granulocyte activation to selected adverse effects. METHODS: In a multicentre study among Rikshospitalet, Ullevaal Hospital in Norway and Uppsala University Hospital in Sweden, plasma concentrations of the complement activation products C4b/iC4b/C4c (C4bc), C3b/iC3b/C3c (C3bc), the terminal SC5b-9 complement complex (TCC), and the granulocyte proteins myeloperoxidase and lactoferrin were assessed in two groups of patients undergoing aortocoronary bypass. Seventy-six patients underwent surgery operated with circuits coated by the Duraflo II heparin coating and 75 uncoated circuits. The same amount of systemic heparin was administered to all patients. RESULTS: In both groups a significant increase in C4bc was first seen by the end of operation, from 86.7 +/- 12.5 to 273.0 +/- 277.4 nM in controls and from 86.9 +/- 18.5 to 320.2 +/- 190.5 nM in the control group, confirming previous documentation that the classical pathway is not activated during CPB, but as a consequence of protamin administration. The formation of C4bc did not differ significantly between the two groups. In the uncoated group the C3bc concentration increased from 124.0 +/- 15.3 to a maximum of 1176.1 +/- 64.7 nM (P < 0.01) and in the coated group it increased from 129.8 +/- 16.1 to a maximum of 1019.4 +/- 54.9 nM (P < 0.01) during CPB. Summary values but not peak values differed significantly between the groups. In the uncoated group the TCC concentration increased from 0.52 +/- 0.03 to a maximum value of 8.09 +/- 0.57 AU/ml (P < 0.01) while in the coated group the TCC concentration increased from a baseline of 0.53 +/- 0.03 to a peak value of 5.2 +/- 0.24 AU/ml (P <0.01). The difference between the peak values was statistically significant (P = 0.00002). In both groups a significant increase in myeloperoxidase and lactoferrin release was observed by the end of operation. There was no difference in myeloperoxidase or lactoferrin release between the two groups. TCC levels were compared to the occurrence of perioperative infarction, development of lung or renal failure, postoperative bleeding, time on ventilator and days in hospital. Three patients developed perioperative infarction; the peak levels of TCC were significantly higher in these patients than in the 148 patients that did not develop infarction. The reduction in TCC formation in the heparin-coated group was not associated with differences in any of the other clinical parameters. Few adverse effects occurred in the study. The peak values of C3bc were higher in the patients needing inotropic support that in those who did not, the relevance of this finding remains uncertain. CONCLUSION: It is concluded that the Duraflo II heparin coating reduces complement activation, particularly TCC formation, during CPB, but not the release of specific neutrophil granule enzymes. No certain correlation was established between complement and granulocyte activation and clinical outcome.
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| 2. |
- Jensen, Kristin, et al.
(författare)
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Comparing five different iterative reconstruction algorithms for computed tomography in an ROC study
- 2014
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 24:12, s. 2989-3002
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to evaluate lesion conspicuity achieved with five different iterative reconstruction techniques from four CT vendors at three different dose levels. Comparisons were made of iterative algorithm and filtered back projection (FBP) among and within systems. An anthropomorphic liver phantom was examined with four CT systems, each from a different vendor. CTDIvol levels of 5 mGy, 10 mGy and 15 mGy were chosen. Images were reconstructed with FBP and the iterative algorithm on the system. Images were interpreted independently by four observers, and the areas under the ROC curve (AUCs) were calculated. Noise and contrast-to-noise ratios (CNR) were measured. One iterative algorithm increased AUC (0.79, 0.95, and 0.97) compared to FBP (0.70, 0.86, and 0.93) at all dose levels (p < 0.001 and p = 0.047). Another algorithm increased AUC from 0.78 with FBP to 0.84 (p = 0.007) at 5 mGy. Differences at 10 and 15 mGy were not significant (p-values: 0.084-0.883). Three algorithms showed no difference in AUC compared to FBP (p-values: 0.008-1.000). All of the algorithms decreased noise (10-71 %) and improved CNR. Only two algorithms improved lesion detection, even though noise reduction was shown with all algorithms. aEuro cent Iterative reconstruction algorithms affected lesion detection differently at different dose levels. aEuro cent One iterative algorithm improved lesion detectability compared to filtered back projection. aEuro cent Three algorithms did not significantly improve lesion detectability. aEuro cent One algorithm improved lesion detectability at the lowest dose level.
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| 3. |
- Jensen, Kristin, et al.
(författare)
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Evaluation of image quality for 7 iterative reconstruction algorithms in chest computed tomography imaging : A phantom study
- 2020
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Ingår i: Journal of Computer Assisted Tomography. - 0363-8715. ; 44:5, s. 673-680
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Tidskriftsartikel (refereegranskat)abstract
- Objectives This study aimed to evaluate the image quality of 7 iterative reconstruction (IR) algorithms in comparison to filtered back-projection (FBP) algorithm. Methods An anthropomorphic chest phantom was scanned on 4 computed tomography scanners and reconstructed with FBP and IR algorithms. Image quality of anatomical details - large/medium-sized pulmonary vessels, small pulmonary vessels, thoracic wall, and small and large lesions - was scored. Furthermore, general impression of noise, image contrast, and artifacts were evaluated. Visual grading regression was used to analyze the data. Standard deviations were measured, and the noise power spectrum was calculated. Results Iterative reconstruction algorithms showed significantly better results when compared with FBP for these criteria (regression coefficients/P values in parentheses): vessels (FIRST: -1.8/0.05, AIDR Enhanced: <-2.3/0.01, Veo: <-0.1/0.03, ADMIRE: <-2.1/0.04), lesions (FIRST: <-2.6/0.01, AIDR Enhanced: <-1.9/0.03, IMR1: <-2.7/0.01, Veo: <-2.4/0.02, ADMIRE: -2.3/0.02), image noise (FIRST: <-3.2/0.004, AIDR Enhanced: <-3.5/0.002, IMR1: <-6.1/0.001, iDose: <-2.3/0.02, Veo: <-3.4/0.002, ADMIRE: <-3.5/0.02), image contrast (FIRST: -2.3/0.01, AIDR Enhanced: -2.5/0.01, IMR1: -3.7/0.001, iDose: -2.1/0.02), and artifacts (FIRST: <-3.8/0.004, AIDR Enhanced: <-2.7/0.02, IMR1: <-2.6/0.02, iDose: -2.1/0.04, Veo: -2.6/0.02). The iDose algorithm was the only IR algorithm that maintained the noise frequencies. Conclusions Iterative reconstruction algorithms performed differently on all evaluated criteria, showing the importance of careful implementation of algorithms for diagnostic purposes.
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| 4. |
- Jensen, Kristin, et al.
(författare)
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Improved Liver Lesion Conspicuity With Iterative Reconstruction in Computed Tomography Imaging.
- 2016
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Ingår i: Current Problems in Diagnostic Radiology. - : Elsevier BV. - 0363-0188. ; 45:5, s. 291-296
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Forskningsöversikt (refereegranskat)abstract
- Studies on iterative reconstruction techniques on computed tomographic (CT) scanners show reduced noise and changed image texture. The purpose of this study was to address the possibility of dose reduction and improved conspicuity of lesions in a liver phantom for different iterative reconstruction algorithms. An anthropomorphic upper abdomen phantom, specially designed for receiver operating characteristic analysis was scanned with 2 different CT models from the same vendor, GE CT750 HD and GE Lightspeed VCT. Images were obtained at 3 dose levels, 5, 10, and 15mGy, and reconstructed with filtered back projection (FBP), and 2 different iterative reconstruction algorithms; adaptive statistical iterative reconstruction and Veo. Overall, 5 interpreters evaluated the images and receiver operating characteristic analysis was performed. Standard deviation and the contrast to noise ratio were measured. Veo image reconstruction resulted in larger area under curves compared with those adaptive statistical iterative reconstruction and FBP image reconstruction for given dose levels. For the CT750 HD, iterative reconstruction at the 10mGy dose level resulted in larger or similar area under curves compared with FBP at the 15mGy dose level (0.88-0.95 vs 0.90). This was not shown for the Lightspeed VCT (0.83-0.85 vs 0.92). The results in this study indicate that the possibility for radiation dose reduction using iterative reconstruction techniques depends on both reconstruction technique and the CT scanner model used.
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| 5. |
- Jensen, Kristin, et al.
(författare)
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Quantitative Measurements Versus Receiver Operating Characteristics and Visual Grading Regression in CT Images Reconstructed with Iterative Reconstruction : A Phantom Study
- 2018
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Ingår i: Academic Radiology. - : ELSEVIER SCIENCE INC. - 1076-6332 .- 1878-4046. ; 25:4, s. 509-518
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Tidskriftsartikel (refereegranskat)abstract
- Rationale and Objectives: This study aimed to evaluate the correlation of quantitative measurements with visual grading regression (VGR) and receiver operating characteristics (ROC) analysis in computed tomography (CT) images reconstructed with iterative reconstruction. Materials and Methods: CT scans on a liver phantom were performed on CT scanners from GE, Philips, and Toshiba at three dose levels. Images were reconstructed with filtered back projection (FBP) and hybrid iterative techniques (ASiR, iDose, and AIDR 3D of different strengths). Images were visually assessed by five readers using a four- and five-grade ordinal scale for liver low contrast lesions and for 10 image quality criteria. The results were analyzed with ROC and VGR. Standard deviation, signal-to-noise ratios, and contrast to-noise ratios were measured in the images. Results: All data were compared to FBP. The results of the quantitative measurements were improved for all algorithms. ROC analysis showed improved lesion detection with ASiR and AIDR and decreased lesion detection with iDose. VGR found improved noise properties for all algorithms, increased sharpness with iDose and AIDR, and decreased artifacts from the spine with AIDR, whereas iDose increased the artifacts from the spine. The contrast in the spine decreased with ASiR and iDose. Conclusions: Improved quantitative measurements in images reconstructed with iterative reconstruction compared to FBP are not equivalent to improved diagnostic image accuracy.
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| 6. |
- Johansson, Martin L, et al.
(författare)
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Integration between a percutaneous implant and the porcine small bowel.
- 2011
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Ingår i: Journal of biomedical materials research. Part B, Applied biomaterials. - : Wiley. - 1552-4981 .- 1552-4973. ; 98:1, s. 101-9
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Tidskriftsartikel (refereegranskat)abstract
- Inflammatory bowel diseases, cancer or trauma may require removal of all or part of the intestines, leaving the patient with a need to wear external stoma appliances for collection of bowel contents. By connecting the small bowel to a percutaneous port, equipped with a sealing lid, a fully continent and leak proof stoma can be created without a need for permanently wearing stoma appliance. The prerequisites for a connection between a permanent, transabdominal implant and a visceral organ are largely unexplored. Stoma ports made of titanium were implanted in the abdominal wall of domestic pigs and a branch of distal ileum was inserted through the ports. After being followed for 1-3 weeks, the ports were removed and subjected to histological evaluation to study the influence of their shape, structure, and position on the tissue response. Particular focus was attended to the attachment of the ileal serosal surface to the implants inner structure consisting of a titanium mesh. Macroscopic examination revealed fistulas and formation of abscesses in 4 of 11 the retrieved implants. Histological examination revealed regenerated and well-vascularized collagenous tissue around the mesh structure inside the implant. The integration was complete or partial for 10 of 11 ports. Despite various degrees of inflammation and tissue ingrowth, it was demonstrated for the first time that the serosal surface of ileum was firmly attached to the internal structure of the implant. These experiments provide a basis for optimization of the implant and surgical procedure before long-term functional animal experiments.
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| 7. |
- Johansson, Martin, et al.
(författare)
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The Healing Process of an Ileostomy to a Percutaneous Titanium Implant: a Short Term Experimental Study on animals
- 2008
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Ingår i: Abstract, 8th World Biomaterials Congress, Amsterdam, The Netherlands.
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Konferensbidrag (refereegranskat)abstract
- Introduction: Many diseases such as e.g. ulcerative colitis, colorectal cancer, familial adenomatous polyposis as well as bladder cancer often require surgery with removal of all or part of the intestines or urinary bladder with construction of an abdominal stoma. External stoma appliances or internal ileal pouches have to be used for collection of bowel contents and urine, respectively. It is hypothesized that by attachment of the intestine to a percutaneous implant, a fully continent stoma might be achieved. Such an attachment needs to be instantaneous, permanent and leakage free. As of today there is no implant or structure known to merge with intestine. The principal aim of the present study was to evaluate the tissue response to a newly designed implant. Apart from the healing process of the abdominal tissues to the implant surface, special focus was directed to the adherence of the ileal serosa to the inner surface of the implant. Conclusions: The present results demonstrate convincingly that the serosal side of the intestine may attach and merge with the internal structure of the implant. These studies provide a basis for optimization of the surgical procedure prior to long-term trials.
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| 8. |
- Klaastad, Øivind, et al.
(författare)
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A novel infraclavicular brachial plexus block : The lateral and sagittal technique, developed by magnetic resonance imaging studies
- 2004
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Ingår i: Anesthesia and Analgesia. - : Lippincott Williams & Wilkins. - 0003-2999 .- 1526-7598. ; 98:1, s. 252-256
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Tidskriftsartikel (refereegranskat)abstract
- A new infraclavicular brachial plexus block method has the patient supine with an adducted arm. The target is any of the three cords behind the pectoralis minor muscle. The point of needle insertion is the intersection between the clavicle and the coracoid process. The needle is advanced 0degrees-30degrees posterior, always strictly in the sagittal plane next to the coracoid process while abutting the antero-inferior edge of the clavicle. We tested the new method using magnetic resonance imaging (MRI) in 20 adult volunteers, without inserting a needle. Combining 2 simulated needle directions by 15degrees posterior and 0degrees in the images of the volunteers, at least one cord in 19 of 20 volunteers was contacted. This occurred within a needle depth of 6.5 cm. In the sagittal plane of the method the shortest depth to the pleura among all volunteers was 7.5 cm. The MRI study indicates that the new infraclavicular technique may be efficient in reaching a cord of the brachial plexus, often not demanding more than two needle directions. The risk of pneumothorax should be minimal because the needle is inserted no deeper than 6.5 cm. However, this needs to be confirmed by a clinical study.
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| 9. |
- Løvmo, Signe Dille, et al.
(författare)
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Intestinal health in Atlantic salmon post-smolt (Salmo salar) when fed low- and high HUFA diets
- 2022
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486. ; 557
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Tidskriftsartikel (refereegranskat)abstract
- It is well established that farmed Atlantic salmon (Salmo salar) need n3-highly unsaturated fatty acids (HUFA) in their diet to thrive and grow. However, the biological functions to the individual HUFAs may differ, implying that future supplementation could require fixed ratios for maximum benefit. The intestinal barrier is essential to fish health, and any disruption of the barrier can have detrimental effects. The current experiment was designed to examine the response of the intestinal hindgut when fed a low HUFA diet with 8.5 g/kg EPA + DHA (4.5% total fatty acid) or two high HUFA diets, with either high DHA (28.7 g/kg and 5.9% total fatty acid) or high EPA (25 g/kg and 14.2% total fatty acid). The diets were fed to Atlantic salmon post-smolt over 10 weeks and thereafter exposed to 3 weeks of chronic stress. After 10 weeks of feeding there were no differences in intestinal permeability and integrity, but intestinal morphology indicated increased intestinal health in the high EPA group. Gene expression also suggest that fish fed the high EPA diet had more regulation of pathways related to protein turnover compared to the high DHA fed fish. There was also indication of lower energy utilization in the low HUFA fed fish than high HUFA. Subjecting fish to 3 weeks of chronic stress led to a reduction in transepithelial resistance, increased ion flux and active L-lysine transport across the intestinal barrier in addition to a decrease in mucosal fold, enterocyte height and supranuclear vacuole density and an increase in thickness of the intestinal muscularis. After stress, the low HUFA group showed signs of inflammation with increased infiltration of MHCII positive cells. Gene expression also showed that low HUFA fed fish had a lower response to chronic stress compared to the high HUFA groups. Comparing fish fed either high DHA or EPA exposed to chronic stress showed few physical effects, but a lower density of supranuclear vacuoles and upregulation in immune-related gene expression indicate inflammation in the high DHA group.
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| 10. |
- Moen, Oddvar, et al.
(författare)
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Attenuation of changes in leukocyte surface markers and complement activation with heparin-coated cardiopulmonary bypass
- 1997
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Ingår i: Annals of Thoracic Surgery. - 0003-4975 .- 1552-6259. ; 63:1, s. 105-111
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The inflammatory response induced by cardiopulmonary bypass can result in severe organ dysfunction in some patients. This postperfusion response is caused mainly by contact between blood and the foreign surface of the cardiopulmonary bypass equipment and includes adhesion of leukocytes to vascular endothelium, which precedes a series of events that mediate inflammatory damage to tissues. METHODS: Low-risk patients accepted for coronary artery bypass grafting were randomized to operation with the cardiopulmonary bypass surface either completely heparin coated (Duraflo II) or uncoated. There were 12 patients in each group. Blood plasma sampled during cardiopulmonary bypass was analyzed for complement activation (C3bc and terminal SC5b-9 complement complex) and neutrophil activation (lactoferrin and myeloperoxidase). In addition, neutrophils, monocytes, and platelets were counted, and the expression of surface markers on the neutrophils and monocytes (complement receptor [CR] 1, CR3, CR4, and L-selectin) and on the platelets (P-selectin and CD41) was quantified with flow cytometry. RESULTS: Clinical and surgical results were similar in both groups. In the group with the heparin-coated surface, the formation of the terminal SC5b-9 complement complex was significantly reduced, and the counts of circulating leukocytes and platelets were significantly less reduced initially but were higher at the end of cardiopulmonary bypass compared with baseline. Also, the expression of CR1, CR3, and CR4 was significantly less upregulated and the L-selectin, significantly less downregulated on monocytes and neutrophils. CONCLUSIONS: We conclude that heparin coating reduces complement activation and attenuates the leukocyte integrin and selectin response that occurs when uncoated circuits are used.
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