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- Blomstrand, Peter, et al.
(författare)
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Cardiovascular effects of dobutamine stress testing in women with suspected coronary artery disease
- 1996
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Ingår i: Heart. - : BMJ Publishing Group Ltd. - 1355-6037 .- 1468-201X. ; 75:5, s. 463-468
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To investigate the central and peripheral haemodynamic response to dobutamine stress testing in women with suspected ischaemic heart disease and to seek an explanation for the hypotension phenomenon. Design. 18 women aged 54-73 years were investigated with Doppler echocardiography and venous occlusion plethysmography during intravenous infusion of dobutamine 5-10 d after an episode of unstable angina. Results. An average peak dose of 33 (SD 9.7) μg/kg/min was given. Heart rate and cardiac output increased by 49% and 59%, respectively (P < 0.001). Total and leg peripheral vascular resistance decreased by 44% and 26%, respectively (P < 0.001). Four patients developed hypotension (decrease in systolic blood pressure > 10 mm Hg), one of whom had a paradoxical bradycardia and two a low increase in cardiac output. Patients with hypotension had a more pronounced decrease in total peripheral vascular resistance but a similar change in leg peripheral vascular resistance compared with patients without hypotension. Conclusions. Dobutamine infusion leads to marked peripheral vasodilatation and an increase in cardiac output. Some patients experience hypotension during the test for reasons which include paradoxical vasovagal reactions and diminished capacity for adequate increase in cardiac output. There is also a disparity between the pattern of total and leg peripheral vascular resistance in patients with hypotension which might reflect a baroreceptor mediated compensatory increase in vasoconstrictor tone of muscle vessels not matched in other vascular territories.
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| 2. |
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| 3. |
- Hill, Tobias, et al.
(författare)
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SPRIT : Identifying horizontal gene transfer in rooted phylogenetic trees
- 2010
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 10:1, s. 42-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Phylogenetic trees based on sequences from a set of taxa can be incongruent due to horizontal gene transfer (HGT). By identifying the HGT events, we can reconcile the gene trees and derive a taxon tree that adequately represents the species' evolutionary history. One HGT can be represented by a rooted Subtree Prune and Regraft (RSPR) operation and the number of RSPRs separating two trees corresponds to the minimum number of HGT events. Identifying the minimum number of RSPRs separating two trees is NP-hard, but the problem can be reduced to fixed parameter tractable. A number of heuristic and two exact approaches to identifying the minimum number of RSPRs have been proposed. This is the first implementation delivering an exact solution as well as the intermediate trees connecting the input trees. RESULTS: We present the SPR Identification Tool (SPRIT), a novel algorithm that solves the fixed parameter tractable minimum RSPR problem and its GPL licensed Java implementation. The algorithm can be used in two ways, exhaustive search that guarantees the minimum RSPR distance and a heuristic approach that guarantees finding a solution, but not necessarily the minimum one. We benchmarked SPRIT against other software in two different settings, small to medium sized trees i.e. five to one hundred taxa and large trees i.e. thousands of taxa. In the small to medium tree size setting with random artificial incongruence, SPRIT's heuristic mode outperforms the other software by always delivering a solution with a low overestimation of the RSPR distance. In the large tree setting SPRIT compares well to the alternatives when benchmarked on finding a minimum solution within a reasonable time. SPRIT presents both the minimum RSPR distance and the intermediate trees. CONCLUSIONS: When used in exhaustive search mode, SPRIT identifies the minimum number of RSPRs needed to reconcile two incongruent rooted trees. SPRIT also performs quick approximations of the minimum RSPR distance, which are comparable to, and often better than, purely heuristic solutions. Put together, SPRIT is an excellent tool for identification of HGT events and pinpointing which taxa have been involved in HGT.
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| 4. |
- Landtblom, Anne-Marie, 1953-, et al.
(författare)
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A case of Kleine-Levin syndrome examined with SPECT and neuropsychological testing
- 2002
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Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 105:4, s. 318-321
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Tidskriftsartikel (refereegranskat)abstract
- A case of Kleine-Levin syndrome with typical periodic hypersomnia and bulemia was diagnosed. On examination with single photo emission tomography (SPECT) (CERETEC«) during a relapse period and 2 weeks later there was marked cortical hypoperfusion of the frontal and temporal lobes, especially on the left side as well as in the right parietal lobe. Neuropsychological testing performed 1 week after a relapse showed a reduction in encoding to memory function of verbal learning indicating neocortical damage of the left fronto-temporal region. A follow-up 2 months later after the patient had spontaneously recovered showed only a slight left fronto-temporal disturbance. CT and MRI of the brain were normal although the MRI showed a large and asymmetric mamillary body. Neuropsychological testing 6 years after recovery showed pronounced reduction in short-time verbal and visual memory. Seven years after recovery SPECT demonstrated a normalized frontal perfusion but still a slight hypoperfusion in the left temporal lobe. Our results correlate to autopsy findings in two cases described previously.
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| 5. |
- Landtblom, Anne-Marie, 1953-, et al.
(författare)
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Short-term memory dysfunction in Kleine-Levin syndrome
- 2003
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Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 108:5, s. 363-367
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Tidskriftsartikel (refereegranskat)abstract
- Background - A previous investigation at our department of a young man with typical Kleine-Levin syndrome revealed short-term memory dysfunction as well as hypoperfusion of the temporal lobes on single photon emission tomography (SPECT) (CERETECR) examination, 6 and 7 years after recovery, suggesting long lasting or even permanent cerebral dysfunction. Patients and methods - We investigated four cases with classical adolescent Kleine-Levin syndrome characterized by hypersomnia and typical associated symptoms. We used neuropsychological testing and SPECT (CERETECR) of the brain. The results from the previous report related to above is included. Results - Examination with SPECT (CERETECR) during remission revealed hypoperfusion of the temporal lobes and fronto-temporal region in two of four cases. There were normal findings in two. Neuropsychological testing performed during remission showed reduction in the short-term memory capacity in all four cases. Conclusion - It is striking that all the cases investigated showed short-term memory dysfunction. One patient who had recovered from paroxysmal symptoms (hypersomnia attacks and bulimia) 6 years earlier showed progress in the short-term memory dysfunction. A pathologic condition in the temporal lobes may be suspected in Kleine-Levin syndrome.
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