| 1. |
- Larsson, Elna-Marie, et al.
(författare)
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Magnetic resonance imaging and histopathology in dementia, clinically of frontotemporal type
- 2000
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Ingår i: Dementia and Geriatric Cognitive Disorders. - : S. Karger AG. - 1420-8008 .- 1421-9824. ; 11:3, s. 123-134
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Tidskriftsartikel (refereegranskat)abstract
- The magnetic resonance imaging (MRI) and computed tomography findings in 28 patients with the clinical diagnosis of frontotemporal dementia (FTD) were compared with the findings in a control group of 76 individuals without dementia or stroke. A pattern of frontal and temporal atrophy with predominantly frontal white matter changes was found in the FTD patients, and this was significantly different from the radiological findings in the control group. Six of the FTD patients have undergone autopsy. Histopathological evaluation showed a primary cortical degenerative disease (frontal lobe degeneration of non-Alzheimer type) in 3 of them, and primary white matter disorder, mainly frontal, of basically ischemic type (selective incomplete white matter infarction) in 3 of them. MRI could be a helpful tool to support the clinical diagnosis FTD, especially in young patients. MRI may also be helpful for the differentiation of a primary neurodegenerative from a mainly ischemic-vascular type of dementia.
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| 2. |
- Andersson, Anders, et al.
(författare)
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Hyperhomocysteinemia and changed plasma thiol redox status in chronic obstructive pulmonary disease
- 2001
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Ingår i: Clinical Chemistry and Laboratory Medicine. - 1434-6621. ; 39:3, s. 229-233
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Tidskriftsartikel (refereegranskat)abstract
- Reduced and total homocysteine, cysteine, glutathione and cysteinylglycine in plasma were investigated in 19 patients with chronic obstructive pulmonary disease and in 29 healthy subjects. The purpose was to examine the influence of pro-oxidant activity caused by the lung disease on the metabolism of homocysteine and other plasma thiols. We observed a decreased concentration of reduced glutathione and a decreased ratio of reduced/total glutathione in the patients compared to the healthy individuals, which supports the hypothesis of an association between free radicals and pathogenesis in some lung diseases. We also observed an increased total plasma homocysteine. The influence of a possible extracellular pro-oxidant activity on the concentration of total plasma homocysteine is discussed.
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| 3. |
- Andersson, Anders S, et al.
(författare)
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Vitamin supplementation normalizes total plasma homocysteine concentration but not plasma homocysteine redox status in patients with acute coronary syndromes and hyperhomocysteinemia.
- 2002
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Ingår i: Clinical Chemistry and Laboratory Medicine. - 1434-6621. ; 40:6, s. 554-558
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Tidskriftsartikel (refereegranskat)abstract
- Despite the growing evidence that elevated total homocysteine (tHcy) in plasma is a cardiovascular risk factor, the mechanism underlying the vascular injury is still unknown. Studies are difficult due to the fact that little is known about the formation of different homocysteine species in vivo. In the present study we have investigated the different fractions of tHcy in 21 patients with acute coronary syndromes and elevated concentration of plasma tHcy. A subgroup of the patients (n=16) was investigated before and after a 3 months study period with or without vitamin supplementation (folic acid 5 mg, pyridoxine 40 mg and cyanocobalamin 1 mg once daily). A major finding is that these patients had a lowered ratio (0.95%) between the concentration of reduced homocysteine (HcyH) and tHcy compared to controls (1.38%). A low ratio HcyH/tHcy in plasma in combination with elevated plasma tHcy concentrations might reflect increased oxidative activity or decreased reducing capacity in plasma from the patients. Another main finding in the present study is that, although vitamin supplementation of these patients normalized plasma tHcy, the ratio between HcyH and tHcy did not normalize. Since substantial evidence indicates that progression of arteriosclerosis is related to enhanced oxidant activity, the premature vascular disease associated with increased plasma tHcy concentration might be due to increased oxidative activity and the elevated plasma tHcy concentration may only reflect the increased oxidative stress.
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| 4. |
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| 5. |
- Geijer, Bo, et al.
(författare)
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Persistent high signal on diffusion-weighted MRI in the late stages of small cortical and lacunar ischaemic lesions
- 2001
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 43:2, s. 115-122
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Tidskriftsartikel (refereegranskat)abstract
- Diffusion-weighted imaging (DWI) is very sensitive to early brain infarcts. However, the late stages have been insufficiently studied. Infarcts in small vessel disease are often multiple and of different ages, and differentiation between new and old lesions might be difficult. We have therefore studied the change with time in DWI of small (< 3 ml) ischaemic lesions. We imaged 21 patients with an acute lacunar syndrome and a lesion visible on early DWI. They all had three MRI examinations 12-58 h (early), 7-16 and 54-144 days after the onset of stroke; 10 patients with high DWI signal on the third examination had a fourth examination 12-28 months after the stroke. MRI was performed at 1.5 T, using echo-planar DWI with 7 b-values from 0 to 1200 x 10(6) s/m2 and conventional T2-weighted imaging. After 7-16 days 18 of 21 lesions gave high signal on DWI, and 12/16 measurable lesions had a decreased apparent diffusion coefficient (ADC). After 54-144 days ten lesions still gave high DWI signal and two still had an ADC below normal. On the fourth examination there was no remaining high DWI signal and all ADC were higher than normal.
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| 6. |
- Geijer, Bo, et al.
(författare)
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The value of b required to avoid T2 shine-through from old lucunar infarcts in diffusion-weighted imaging
- 2001
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 1432-1920 .- 0028-3940. ; 43:7, s. 511-517
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Tidskriftsartikel (refereegranskat)abstract
- Multiple small infarcts of different ages are common in small-vessel disease. Diffusion-weighted imaging (DWI) is a powerful method for discriminating new from chronic lesions. This can be done on the diffusion-weighted images provided that b is sufficiently high. Our purpose was to determine that critical value of b. We reviewed DWI from a previous study of acute, mainly lacunar strokes, and selected 18 old lacunar infarcts, well defined on uncoded images with b 0 s/m2 (i. e., T2-weighted images) but invisible on DWI with b 1,200 x 10(6) s/m2. We used a 1.5 tesla imager and single-shot echo-planar technique. We had seven separate acquisitions with echo time 123 ms and b in steps between 0 and 1,200 x 10(6) s/m2. Two neuroradiologists blinded to the selection of lesions carried out two different lesion-detection procedures, thereby testing each lesion four times, giving a total of 72 tests of b values. The results were consistent, indicating a level for detection of 800 x 10(6) s/m2 in two tests, 400-600 x 10(6) s/m2 in 65 tests and at lower values in the remainder. For imagers up to 1.5 tesla, at long repetition times and an echo time up to 120 ms T2-shine through of old lacunar infarcts can be avoided using b of 1,000 x 10(6) s/m2.
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| 7. |
- Grip, Olof, et al.
(författare)
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Increased presence of cells containing transforming growth factor alpha (TGF-alpha) in ulcerative colitis, both during active inflammation and in remission
- 2000
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Ingår i: European Journal of Gastroenterology and Hepathology. - 1473-5687. ; 12:7, s. 761-766
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Patients with extensive and long-standing ulcerative colitis have an increased risk of developing colorectal cancer and sub-epithelial fibrosis. The polypeptide transforming growth factor alpha (TGF-alpha) has mitogenic effects and it is believed that local overproduction may result in tumour formation and fibrosis. DESIGN: In the present study, we correlated the presence of TGF-alpha in ulcerative colitis with the degree of inflammation and with dysplasia. METHODS: Sixty two patients were investigated, 46 with ulcerative colitis (16 with active inflammation and 20 in remission, 10 with dysplasia of the colon), and 16 controls with normal colonoscopy and without a history of colitis. There were no overlaps between the subgroups. Tissue sections from colonic biopsies were examined and TGF-alpha was detected by immunohistochemistry. TGF-alpha-containing cells were characterized by double-staining with antibodies to eosinophil cationic protein (ECP). An antibody (EG2) recognizing eosinophils with an activated phenotype was also used. RESULTS: The median number of TGF-alpha-containing cells in the mucosa was 24 per mm2 (inter-quartile range 10-51) in controls, 186 per mm2 (73-245) in ulcerative colitis with active inflammation, 76 per mm2 (52-198) in remission, and 130 per mm2 (66-203) in areas of dysplasia. Double-staining for TGF-alpha and ECP revealed that most of the TGF-alpha-containing cells were eosinophils, and most had an activated phenotype as judged by staining with EG2. CONCLUSIONS: The presence of TGF-alpha-containing cells in colonic mucosa is increased both in active inflammation and during remission in ulcerative colitis. Dysplasia is not associated with any significant increase in TGF-alpha-containing cells. The majority of TGF-alpha-containing cells are eosinophils with an activated phenotype. TGF-alpha released from these cells could be important for the development of complications seen in ulcerative colitis, such as cancer and fibrosis.
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| 8. |
- Gullman-Strand, Johan, et al.
(författare)
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Numerical and experimental study of separated flow in a plane asymmetric diffuser
- 2004
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Ingår i: International Journal of Heat and Fluid Flow. - : Elsevier BV. - 0142-727X .- 1879-2278. ; 25:3, s. 451-460
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Tidskriftsartikel (refereegranskat)abstract
- Computations of the turbulent flow through plane asymmetric diffusers for opening angles from 8degrees to 10degrees have been carried out with the explicit algebraic Reynolds stress model (EARSM) of Wallin and Johansson [J. Fluid Mech. 403 (2000) 89]. It is based on a two-equation platform in the form of a low-Re K - omega formulation, see e.g. Wilcox [Turbulence Modeling for CFD, DCW Industries Inc., 1993]. The flow has also been studied experimentally for the 8.5degrees opening angle using PIV and LDV. The models under-predict the size and magnitude of the recirculation zone. This is, at least partially, attributed to an over-estimation of the wall normal turbulence component in a region close to the diffuser inlet and to the use of damping functions in the near-wall region. By analyzing the balance between the production and dissipation of the turbulence kinetic energy we find that the predicted dissipation is too large. Hence, we can identify a need for improvement of the modeling the transport equation for the turbulence length-scale related quantity.
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| 9. |
- Hallström, Björn, et al.
(författare)
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Stroke in Lund-Orup, Sweden: improved long-term survival among elderly stroke patients.
- 2002
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Ingår i: Stroke: a journal of cerebral circulation. - 1524-4628. ; 33:6, s. 1624-1629
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Several studies report declining early stroke case fatality, but the findings are not consistent across geographic areas. Corresponding changes in long-term survival are less well documented. We recently reported increased stroke incidence among patients aged <75 years and stable incidence among older persons. We now report temporal trends for early and late case fatality among patients with stroke onset during 1983-1985 and 1993- 1995. METHODS: Patients living within the Lund-Orup, Sweden, hospital district and fulfilling the diagnostic criteria for first-ever stroke during 1983-1985 (n=998) and 1993-1995 (n=1318) were followed up concerning survival status at 28 days, 1 year, and 3 years. Age and sex adjustments were performed. The possible influence of Oxfordshire Community Stroke Project (OCSP) stroke subtypes on survival was also analyzed. RESULTS: Overall survival improved between the study periods (Cox proportional hazards regression: hazard ratio, 0.84; 95% confidence limits, 0.75 to 0.94; P=0.0019). The 28-day case fatality was 15% for stroke patients from both study periods. One-year case fatality was 31% for 1983-1985 patients and 27% for 1993-1995 patients. The corresponding figures at 3 years were 44% and 40%, respectively. In the group aged <75 years, there were no significant changes in overall survival, but survival improved significantly among patients aged > or = 75 years beyond 28 days after stroke onset. OCSP stroke subtype was an independent predictor of death (P<0.0001). CONCLUSIONS: The recently observed increase in stroke incidence among patients aged <75 years was not accompanied by changing survival in that age group. However, among patients aged > or =75 years, survival improved beyond 28 days after stroke. The causes of this change in survival are unknown but may be related to improved long-term care of elderly stroke patients.
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| 10. |
- Johansson, Arne V., et al.
(författare)
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Experimental tests of mean velocity distribution laws derived by lie group symmetry methods in turbulent boundary layers
- 2004
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Ingår i: IUTAM SYMPOSIUM ON REYNOLDS NUMBER SCALING IN TURBULENT FLOW. - 1402017758 ; , s. 257-264
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Konferensbidrag (refereegranskat)abstract
- New scaling laws for turbulent boundary layers recently derived (see Oberlack, 2001) using Lie group symmetry methods have been tested against experimental data from the KTH data-base for zero-pressure-gradient turbulent boundary layers. The most significant new law gives an exponential variation of the mean velocity defect in the outer (wake) region. It was shown to fit very well the experimental data over a large part of the boundary layer, from the outer part of the overlap region to about half the boundary layer thickness (delta(99)). A small modification of the innermost part of the log-layer is predicted by the same method, in the form of an additive constant within the log-function, and was confirmed by the experimental data.
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