| 51. |
- Nilsson, Sven, et al.
(författare)
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Calcified leiomyosarcoma simulating uterine myoma in a patient with long-standing anaemia
- 1991
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Ingår i: Upsala Journal of Medical Sciences. - 0300-9734 .- 2000-1967. ; 96:2, s. 141-147
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Tidskriftsartikel (refereegranskat)abstract
- A case of small bowel leiomyosarcoma in a 75-year-old woman is reviewed. The patient had an unexplained anaemia with occult blood in the faeces for at least 15 years. The value of different radiological investigations in patients with suspected gastrointestinal bleeding is discussed. The possible significance of calcifications visible on plain abdominal films is emphasized.
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| 52. |
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| 53. |
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| 54. |
- Nordeman, Patrik, et al.
(författare)
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C-11 and F-18 Radiolabeling of Tetra- and Pentathiophenes as PET-Ligands for Amyloid Protein Aggregates
- 2016
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Ingår i: ACS Medicinal Chemistry Letters. - : American Chemical Society (ACS). - 1948-5875. ; 7:4, s. 368-373
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Tidskriftsartikel (refereegranskat)abstract
- Three oligothiophenes were evaluated as PET ligands for the study of local and systemic amyloidosis ex vivo using tissue from patients with amyloid deposits and in vivo using healthy animals and PET-CT. The ex vivo binding studies revealed that all three labeled compounds bound specifically to human amyloid deposits. Specific binding was found in the heart, kidney, liver, and spleen. To verify the specificity of the oligothiophenes toward amyloid deposits, tissue sections with amyloid pathology were stained using the fluorescence exhibited by the compounds and evaluated with multiphoton microscopy. Furthermore, a in vivo monkey PET-CT study showed very low uptake in the brain, pancreas, and heart of the healthy animal indicating low nonspecific binding to healthy tissue. The biological evaluations indicated that this is a promising group of compounds for the visualization of systemic and localized amyloidosis.
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| 55. |
- Puschmann, Andreas, et al.
(författare)
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A Swedish family with de novo alpha-synuclein A53T mutation: Evidence for early cortical dysfunction.
- 2009
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Ingår i: Parkinsonism & Related Disorders. - : Elsevier BV. - 1873-5126 .- 1353-8020. ; 15, s. 627-632
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Tidskriftsartikel (refereegranskat)abstract
- A de novo alpha-synuclein A53T (p.Ala53 Th; c.209G > A) mutation has been identified in a Swedish family with autosomal dominant Parkinson's disease (PD). Two affected individuals had early-onset (before 31 and 40 years), severe levodopa-responsive PD with prominent dysphasia, dysarthria, and cognitive decline. Longitudinal clinical follow-up, EEG, SPECT and CSF biomarker examinations suggested an underlying encephalopathy with cortical involvement. The mutated allele (c.209A) was present within a haplotype different from that shared among mutation carriers in the Italian (Contursi) and the Greek-American Family H kindreds. One unaffected family member carried the mutation haplotype without the c.209A mutation, strongly suggesting its de novo occurrence within this family. Furthermore, a novel mutation c.488G > A (p.Arg163His; R163H) in the presenilin-2 (PSEN2) gene was detected, but was not associated with disease state.
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| 56. |
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| 57. |
- Romlin, Birgitta S, et al.
(författare)
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Intraoperative thromboelastometry is associated with reduced transfusion prevalence in pediatric cardiac surgery.
- 2011
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Ingår i: Anesthesia and analgesia. - 1526-7598. ; 112:1, s. 30-6
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Tidskriftsartikel (refereegranskat)abstract
- Background: The majority of pediatric cardiac surgery patients receive blood transfusions. We hypothesized that the routine use of intraoperative thromboelastometry to guide transfusion decisions would reduce the overall proportion of patients receiving transfusions in pediatric cardiac surgery. Methods: One hundred pediatric cardiac surgery patients were included in the study. Fifty patients (study group) were prospectively included and compared with 50 procedure- and age-matched control patients (control group). In the study group, thromboelastometry, performed during cardiopulmonary bypass, guided intraoperative transfusions. Intraoperative and postoperative transfusions of packed red blood cells, fresh frozen plasma, platelets, and fibrinogen concentrates, and postoperative blood loss and hemoglobin levels were compared between the 2 groups. Results: The proportion of patients receiving any intraoperative or postoperative transfusion of packed red blood cells, fresh frozen plasma, platelets, or fibrinogen concentrates was significantly lower in the study group than in the control group (32 of 50 [64%] vs 46 of 50 [92%], respectively; P < 0.001). Significantly fewer patients in the study group received transfusions of packed red blood cells (58% vs 78%, P = 0.032) and plasma (14% vs 78%, P < 0.001), whereas more patients in the study group received transfusions of platelets (38% vs 12%, P = 0.002) and fibrinogen concentrates (16% vs 2%, P = 0.015). Neither postoperative blood loss nor postoperative hemoglobin levels differed significantly between the study group and the control group. Conclusions: The results suggest that routine use of intraoperative thromboelastometry in pediatric cardiac surgery to guide transfusions is associated with a reduced proportion of patients receiving transfusions and an altered transfusion pattern.
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| 58. |
- Roos, Håkan, et al.
(författare)
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Air bubble release and flow-induced forces in stent grafts
- 2017
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Ingår i: Engineering Health.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background: Stent grafts are used to treat aortic aneurysms, as a minimal invasive alternative to open surgery. The aorta is accessed via percutaneous punctures in the groins and insertion of guide wires. A stent graft is advanced over the guide wire and deployed in the desired position, using x-ray fluoroscopic guidance. The procedure significantly reduces short-term morbidity and mortality compared to open repair, but has a higher rate of late complications and re-interventions. Two possible complications are: release of air bubbles during thoracic stent graft deployment may lead to cerebral embolization and immediate stroke, and long-term migration due to flow-induced forces may lead to leakage into the aneurysm sack and remaining risk of aortic rupture. Objectives: Stent grafts are compressed in a long, soft and thin delivery catheter. Once the stent graft is in position, the surgeon withdraws the catheter, allowing the self-expanding stent graft to expand radially to the artery wall, or to a previously inserted stent graft. The stent graft is kept in place by the expansion force of the over-sized stent, and in some cases by anchoring hooks. Despite a strict preparation procedure, there is a risk that air is trapped in the compressed stent graft and released into the aorta during deployment. The present work describes two of our studies. In the first experimental study we measure the total amount of air released by two different brands of thoracic stent grafts and investigate the size and origin of the air bubbles. In the second experimental and numerical study angulated iliac limbs stent grafts are mounted in a pulsatile flow model to determine the flow-induced displacement forces under a variety of conditions.Methods: The air release measurements and visualizations are performed by inserting and deploying stent grafts in a closed water-filled container. A high-resolution and high-speed camera is used to capture the air release process, and the total amount of air collected in the container is measured. An experimental pulsatile flow model, with conditions similar to aortic in vivo conditions, is used to measure the proximal and distal displacement forces of iliac stent grafts under different angulations, pulsation frequencies, pressures, and configurations (tapered, tubular, bellbottom). Fluid-structure interaction simulations are used to determine the forces numerically.Results: We found that air is released during deployment of thoracic stent grafts and that the largest bubbles come from the proximal end. There is a significant difference between the two brands of stent grafts that have been investigated. The flow-induced forces are under some conditions comparable to the forces required to extract the iliac limb stent grafts. Both the forces and the graft movements increase with angulation and with perfusion pressure, but not with stroke rate. The distal displacement forces are particularly large for the bellbottom configuration. The origin of the forces is mainly the pressure, while the contributions of shear force and flow redirection are insignificant. The flexibility of the stent graft material reduces the forces (by 15% under the conditions in the numerical simulations in the present work).Conclusions: New packing and/or preparation procedures should be developed to reduce the amount of air released during deployment of thoracic stent grafts. Improved anchoring of the distal ends of stent grafts should be considered.References[1] Displacement Forces in Iliac Landing Zones and Stent Graft Interconnections in Endovascular Aortic Repair: An Experimental Study. Roos H, Ghaffari M, Falkenberg M, Chernoray V, Jeppsson A, Nilsson H.European Journal of Vascular and Endovascular Surgery 2014:47(3):262-267.
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| 59. |
- Roos, Håkan, 1967, et al.
(författare)
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Displacement Forces in Iliac Landing Zones and Stent Graft Interconnections in Endovascular Aortic Repair: An Experimental Study
- 2014
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884 .- 1532-2165. ; 47:3, s. 262-267
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Stent graft migration influences the long-term durability of endovascular aortic repair. Flow-induced displacement forces acting on the attachment zones may contribute to migration. Proximal fixation of aortic stent grafts has been improved by using hooks, while distal fixation and stent graft interconnections depend on self-expansion forces only. We hypothesized that flow-induced displacement forces would be significant at the distal end, and would correlate with graft movements. Methods: As part of an experimental study, an iliac limb stent graft was inserted in a pulsatile flow model similar to aortic invivo conditions, and fixed-mounted at its proximal and distal ends to strain gauge load cells. Peak displacement forces at both ends and pulsatile graft movement were recorded at different graft angulations (0-90°), perfusion pressures (145/80, 170/90, or 195/100mmHg), and stroke frequencies (60-100b.p.m.). Results: Flow-induced forces were of the same magnitude at the proximal and distal end of the stent graft (peak 1.8N). Both the forces and graft movement increased with angulation and perfusion pressure, but not with stroke rate. Graft movement reached a maximum of 0.29±0.01mm per stroke despite fixed ends. There were strong correlations between proximal and distal displacement forces (r=0.97, p<.001), and between displacement forces and graft movement (r=0.98, p<.001). Conclusions: Pulsatile flow through a tubular untapered stent graft causes forces of similar magnitude at both ends and induces pulsatile graft movements in its unsupported mid-section. Peak forces are close to those previously reported to be required to extract a stent graft. The forces and movements increase with increasing graft angulation and perfusion pressure. Improved anchoring of the distal end of stent grafts may be considered. © 2013 European Society for Vascular Surgery.
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| 60. |
- Roos, Håkan, 1967, et al.
(författare)
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Displacement Forces in Stent Grafts: Influence of Diameter Variation and Curvature Asymmetry
- 2016
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884 .- 1532-2165. ; 52:2, s. 150-156
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Long-term durability after endovascular aortic repair is influenced by stent graft migration causing types I and III endoleaks. Flow induced displacement forces have been shown to have the potential to cause migration. In this study, the influence of the distal diameter of iliac limb stent grafts and the shape of graft curvature on flow induced displacement forces, were investigated. Methods: In an experimental pulsatile flow model mimicking aortic conditions in vivo, flow induced displacement forces at the proximal and distal ends of iliac limb stent grafts were studied at different angles (0-90 degrees) and perfusion pressures (145/80, 170/90, 195/100 mmHg). Bell-bottomed, tapered, and non-tapered stent grafts and also asymmetric stent graft curvatures at 90 bend were studied. Measurements of graft movement were performed at all studied angulations and graft shapes. Results: For all stent graft diameters, flow induced displacement forces increased with higher pressure and increased stent graft angulation. Forces in the bell-bottom graft were considerably higher than in tapered and non-tapered grafts, with a markedly elevated peak force at the distal end (proximal end, 2.3 +/- 0.06 N and distal end, 6.9 +/- 0.05 N compared with 1.7 +/- 0.08 N and 1.6 +/- 0.08 N in non-tapered grafts; p <.001 both). Peak forces in tapered and non-tapered grafts were not significantly different between the proximal and distal end. In asymmetric stent graft curvatures, a significant increase in displacement forces was observed in the attachment zone that was closest to the stent graft bend. Graft movement increased with greater displacement forces. Conclusion: Flow induced displacement forces in iliac limb stent grafts are significant and are influenced by distal stent graft diameter and the shape of the graft curvature. The displacement forces are particularly high at the large distal end of bell-bottom grafts. Wide iliac arteries treated with bell-bottom stent grafts may require more vigilant surveillance and improved stent graft fixation.
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