| 51. |
- Persson, M, et al.
(författare)
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Phase contrast MRI segmentation using multiple cues
- 2005
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Ingår i: SSBA Symposium on Image Analysis.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a method for three-dimensional (3D) segmentation of blood vessels, using a combination of velocity data and magnitude images obtained using phase contrast MRI. In addition to standard MRI images, phase contrast MRI gives velocity information for blood and tissue. The proposed method uses a variational formulation of the segmentation problem which combines different cues; velocity and magnitude. Experiments on phantom and clinical data support the proposed method.
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| 52. |
- Henriksson, Eva, et al.
(författare)
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Comparison of cisplatin sensitivity and the 18F fluoro-2-deoxy 2 glucose uptake with proliferation parameters and gene expression in squamous cell carcinoma cell lines of the head and neck
- 2009
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Ingår i: Journal of Experimental & Clinical Cancer Research. - : Springer Science and Business Media LLC. - 1756-9966. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- Background: The survival of patients with locally advanced head and neck cancer is still poor, with 5-year survival rates of 24-35%. The identification of prognostic and predictive markers at the molecular and cellular level could make it possible to find new therapeutic targets and provide "taylor made" treatments. Established cell lines of human squamous cell carcinoma (HNSCC) are valuable models for identifying such markers. The aim of this study was to establish and characterize a series of cell lines and to compare the cisplatin sensitivity and 18F fluoro-2 deoxy 2 glucose (18F-FDG) uptake of these cell lines with other cellular characteristics, such as proliferation parameters and TP53 and CCND1 status. Methods: Explant cultures of fresh tumour tissue were cultivated, and six new permanent cell lines were established from 18 HNSCC cases. Successfully grown cell lines were analysed regarding clinical parameters, histological grade, karyotype, DNA ploidy, and index and S-phase fraction (Spf). The cell lines were further characterized with regard to their uptake of 18F-FDG, their sensitivity to cisplatin, as measured by a viability test ( crystal violet), and their TP53 and CCND1 status, by fluorescence in situ hybridization (FISH), polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) with DNA sequencing and, for cyclin D1, by immunohistochemistry. Results: Patients with tumours that could be cultured in vitro had shorter disease-free periods and overall survival time than those whose tumours did not grow in vitro, when analysed with the Kaplan-Meier method and the log-rank test. Their tumours also showed more complex karyotypes than tumours from which cell lines could not be established. No correlation was found between TP53 or CCND1 status and 18F-FDG uptake or cisplatin sensitivity. However, there was an inverse correlation between tumour cell doubling time and 18F-FDG uptake. Conclusion: In vitro growth of HNSCC cells seem to be an independent prognostic factor, with cell lines being more readily established from aggressive tumours, a phenomenon more dependent on the molecular genetic characteristics of the tumour cells than on tumour location or TNM status.
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| 53. |
- Larsson, Elna-Marie, et al.
(författare)
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MR-undersökning av hjärnan vid 3 tesla. Högre magnetfältsstyrka ger bättre morfologisk och funktionell bild
- 2005
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Ingår i: Läkartidningen. - 0023-7205. ; 102:7, s. 3-460
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Tidskriftsartikel (refereegranskat)abstract
- 3T MRI offers improved morphological and functional studies of the brain compared with the more commonly used field strength 1.5T. Clinical 3T MRI of the brain is beneficial for high resolution morphological imaging, MR angiography, diffusion-MRI including diffusion tensor imaging, perfusion-MRI, functional MRI (fMRI), and MR spectroscopy. The performance is enhanced by the combination with powerful magnetic field gradients.
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| 54. |
- Burnand, B, et al.
(författare)
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Use, appropriateness, and diagnostic yield of screening colonoscopy: an international observational study (EPAGE)
- 2006
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Ingår i: Gastrointestinal Endoscopy. - : Elsevier BV. - 1097-6779 .- 0016-5107. ; 63:7, s. 1018-1026
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Tidskriftsartikel (refereegranskat)abstract
- Abstract in UndeterminedBackgroundScreening for colorectal cancer (CRC) has been shown to decrease mortality.ObjectiveTo examine determinants associated with having (1) a screening colonoscopy, (2) an appropriate indication for screening, and (3) a significant diagnosis at screening.DesignProspective observational study.SettingTwenty-one endoscopy centers from 11 countries.PatientsAsymptomatic patients who underwent a colonoscopy for the purpose of detecting CRC and who did not have a history of polyps or CRC, a lesion observed at a recent barium enema or sigmoidoscopy, or a recent positive fecal occult blood test.InterventionScreening colonoscopy.Main Outcome MeasurementsAppropriateness according to the European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE) criteria and significant diagnoses (cancer, adenomatous polyps, new diagnoses of inflammatory bowel disease, angiodysplasia).ResultsOf 5069 colonoscopies, 561 (11%) were performed for screening purposes. Patients were more likely to have a screening colonoscopy if they were aged 45 to 54 years (odds ratio [OR] 2.53, 95% confidence interval [CI] 1.60-3.99). Screening colonoscopies were appropriate, uncertain, and inappropriate in 26%, 60%, and 14% of cases, respectively. Eighty-one significant diagnoses were made, including 4 cancers. Significant diagnoses were more often made for uncertain/appropriate indications (OR 3.20, 95% CI 1.12-9.17) than for inappropriate indications.LimitationsAlthough data completeness was asked of all centers, it is possible that not all consecutive patients were included. Participating centers were a convenience sample and thus may not be representative.ConclusionsAbout 1 of 10 colonoscopies were performed for screening, preferentially in middle-aged individuals. A higher diagnostic yield in uncertain/appropriate indications suggests that the use of appropriateness criteria may enhance the efficient use of colonoscopy for screening.
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| 55. |
- Gujar, Sachin, et al.
(författare)
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Magnetic Resonance Spectroscopy.
- 2005
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Ingår i: Journal of Neuro-Ophthalmology. - 1070-8022. ; 25:3, s. 217-226
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Tidskriftsartikel (refereegranskat)
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| 56. |
- Hansson, Ola, et al.
(författare)
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Transcriptome and proteome analysis of soleus muscle of hormone-sensitive lipase-null mice
- 2005
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Ingår i: Journal of Lipid Research. - 1539-7262. ; 46:12, s. 2614-2623
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Tidskriftsartikel (refereegranskat)abstract
- Hormone-sensitive lipase (HSL), a key enzyme in fatty acid mobilization in adipocytes, has been demonstrated also in skeletal muscle. To gain further insight into the role and importance of HSL in skeletal muscle, a transcriptome analysis of soleus muscle of HSL-null mice was performed. A total of 161 transcripts were found to be differentially expressed. Increased mRNA levels of fructose-1,6-bisphosphatase, fructose-2,6-bisphosphatase, and phosphorylase kinase gamma 1A suggest a higher glycogen flux in soleus muscle of HSL-null mice. An observed increase in the utilization of glycogen stores supports this finding. Moreover, an increased amount of intramyocellular lipid droplets, observed by transmission electron microscopy, suggests decreased mobilization of lipid stores in HSL-null mice. To complement the transcriptome data, protein expression analysis was performed. Five spots were found to be differentially expressed: pyruvate dehydrogenase E1 alpha, creatine kinase (CK), ankyrin-repeat domain 2, glyceraldehyde-3-phosphate dehydrogenase, and one protein yet to be identified. The increased protein level of CK indicates creatine phosphate degradation to be of increased importance in HSL-null mice. The results of this study suggest that in the absence of HSL, a metabolic switch from reliance on lipid to carbohydrate energy substrates takes place, supporting an important role of HSL in soleus muscle lipid metabolism.
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| 57. |
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| 58. |
- Kullberg, Joel, et al.
(författare)
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Whole-body adipose tissue analysis: comparison of MRI, CT and dual energy X-ray absorptiometry.
- 2009
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Ingår i: The British journal of radiology. - : British Institute of Radiology. - 1748-880X .- 0007-1285. ; 82:974, s. 123-30
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to validate a recently proposed MRI-based T(1)-mapping method for analysis of whole-body adipose tissue (AT) using an established CT protocol as reference and to include results from dual energy X-ray absorptiometry (DEXA). 10 subjects, drawn from the Swedish Obese Subjects Sibling-pairs study, were examined using CT, MRI and DEXA. The CT analysis was based on 28 imaged slices. T(1) maps were calculated using contiguous MRI data from two different gradient echo sequences acquired using different flip angles. CT and MRI comparison was performed slice-wise and for the whole-body region. Fat weights were compared between all three modalities. Strong correlations (r > or = 0.977, p<0.0001) were found between MRI and CT whole-body and AT volumes. MRI visceral AT volume was underestimated by 0.79 +/- 0.75 l (p = 0.005), but total AT was not significantly different from that estimated by CT (MRI - CT = -0.61+/-1.17 l; p = 0.114). DEXA underestimated fat weights by 5.23 +/- 1.71 kg (p = 0.005) compared with CT. MRI underestimated whole-body volume by 2.03 +/- 1.61 l (p = 0.005) compared with CT. Weights estimated either by CT or by DEXA were not significantly different from weights measured using scales. In conclusion, strong correlations were found between whole-body AT results from CT, MRI-based T(1) mapping and DEXA. If the differences between the results from T(1)-mapping and CT-based analysis are accepted, the T(1)-mapping method allows fully automated post-processing of whole-body MRI data, allowing longitudinal whole-body studies that are also applicable for children and adolescents.
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| 59. |
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| 60. |
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