| 1. |
- Backteman, K, et al.
(författare)
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A rapid and reliable flow cytometric routine method for counting leucocytes in leucocyte-depleted platelet concentrates
- 2002
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Ingår i: Vox Sanguinis. - : Wiley. - 0042-9007 .- 1423-0410. ; 83:1, s. 29-34
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives: To ensure a proper quality control it is important to use a reliable method to count low numbers of leucocytes in leucocyte-reduced platelet concentrates (PCs). Materials and Methods: A modified flow cytometric method for counting low numbers of leucocytes, based on a reference population contained in tubes with an exact number of fluorescent beads and staining with propidium iodide was used. To increase the number of events, the original sample volume was increased. Results: There was a good correlation in the number of leucocytes (r = 0.99) between the modified flow cytometric method and microscopy of samples from unfiltered and expected numbers from serially diluted PCs. Samples from leucocyte-reduced PCs obtained by apheresis or filtered buffy coats showed no correlation between results from the modified flow cytometric method and microscopy (Nageotte). Conclusion: Counting by microscopy gave a lower number of leucocytes than the modified flow cytometric method when counting a low number of cells. However, analysis of the serially diluted PCs proved that the modified flow cytometric method was reliable and rapid, making it suitable for clinical routine use.
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| 2. |
- Berlin, Gösta, 1944-, et al.
(författare)
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Low-O2 affinity erythrocytes improve performance of ischemic myocardium
- 2002
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Ingår i: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 92:3, s. 1267-1276
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Tidskriftsartikel (refereegranskat)abstract
- O2 transport and O2 diffusion interact in providing O2 to tissue, but the extent to which diffusion may be critical in the heart is unclear. If O2 diffusion limits mitochondrial oxygenation, a change in blood O2 affinity at constant total O2 transport should alter cardiac O2 consumption (VO2) and function. To test this hypothesis, we perfused isolated isovolumically working rabbit hearts with erythrocytes at physiological blood-gas values and P50 (PO2 required to half-saturate hemoglobin) values at Ph of 7.4 of 17 ▒ 1 Torr (2,3-bisphosphoglycerate depletion) and 33 ▒ 5 Torr (inositol hexaphosphate incorporation). When perfused at 40 and 20% of normal coronary flow, mean VO2 decreased from the control value by 37 and 46% (P < 0.001), and function, expressed as cardiac work, decreased by 38 and 52%, respectively (P < 0.001). Perfusion at higher P50 during low-flow ischemia improved VO2 by 20% (P < 0.001) and function by 36% (P < 0.02). There was also modest improvement at basal flow (P < 0.02 and P < 0.002, respectively). The improvement in VO2 and function due to the P50 increase demonstrates the importance of O2 diffusion in this cardiac ischemia model.
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| 3. |
- Ernerudh, Jan, 1952-, et al.
(författare)
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Effect of photopheresis on lymphocyte population in children with newly diagnosed type 1 diabetes
- 2004
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Ingår i: Clinical and Diagnostic Laboratory Immunology. - 1071-412X. ; 11:5, s. 856-861
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Tidskriftsartikel (refereegranskat)abstract
- In recent years photopheresis has been claimed to be an effective form of immunomodulation. It has also been shown to have an effect on the disease process at the onset of type 1 diabetes. In a double-blind, placebo-controlled randomized study, we analyzed if the effect of photopheresis in children with newly diagnosed diabetes is related to changes in the balance of lymhocyte populations. We also analyzed if lymphocyte subsets were related to recent infection, mild or aggressive disease manifestations, heredity, or gender. Nineteen children received active treatment with photopheresis, while 21 children received sham pheresis (placebo group). No influence of a history of previous infection, heredity, or certain clinical parameters on lymphocyte subsets was found. At the onset of type 1 diabetes, girls showed a higher proportion and a larger number of T cells (CD3+) and T-helper cells (CD4+) and a higher proportion of naïve CD4 +CD45RA+ cells. In the placebo group, an increase in the number of subsets with the activated phenotype in both the CD4 (CD29 +) and the CD8 (CD11a+) compartments was noted during the course of the study. These changes did not occur in the photopheresis group. No relation between lymphocyte subsets and clinical outcome was found 1 year after the treatment with photopheresis. In conclusion, we found no major effect of photopheresis on lymphocyte populations in a group of children with newly diagnosed type 1 diabetes. However, in the placebo group the proportions of activated CD4 and CD8 cells increased over time. Since these changes did not occur in the actively treated group, our findings suggest that photopheresis may have some suppressive effects.
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| 4. |
- Ernerudh, Jan, 1952-, et al.
(författare)
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The use of cell products for treatment of autoimmune neuroinflammatory diseases
- 2002
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Ingår i: Current Medicinal Chemistry. - 0929-8673 .- 1875-533X. ; 9:16, s. 1497-1505
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Tidskriftsartikel (refereegranskat)abstract
- Cell products are live cells that are given to patients in order to replace or modify the function of missing or dysfunctional cells. Progress in technology and in the understanding of pathobiology may lead to the use of cell products in many areas. This review outlines the use of cell products in the treatment of autoimmune diseases, with focus on neuroinflammatory diseases like multiple sclerosis. Treatment of autoimmune diseases should be selective and specific in order to avoid serious side effects. To achieve this, T lymphocyte regulation has been in focus for several immunomodulatory regimens. One area of great interest is the use of T cell vaccination, when autologous attenuated auto-reactive T cells are given to patients in order to initiate a specific immune response to the pathogenic T cell populations. Phopheresis may be an immunomudulatory treatment related to T cell vaccination. Another promising area involves ex-vivo alteration of the cytokine profile of harmful auto-reactive T cells. This can be achieved by genetic manipulation or by certain cytokine stimulations. A subsequent adoptive cell transfer will, by homing mechanisms, lead to at site specific delivery of the cells, which will have a local down-regulatory effect on the inflammatory process. Although unsolved questions regarding doses, timing, optimal preparing conditions and mechanisms still remain, both T cell vaccination and adoptive transfer of ex-vivo manipulated cytokine secreting cells have proven successful for treatment of neuroinflammation in experimental models. T cell vaccination was shown to be feasible in patients with multiple sclerosis, however, otherwise the experience in humans so far is limited.
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| 5. |
- Ledent, Elisabeth, et al.
(författare)
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White Blood Cell Subsets in Buffy Coat-Derived Platelet Concentrates : The Effect of Pre- and Poststorage Filtration
- 2000
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Ingår i: Vox Sanguinis. - 0042-9007 .- 1423-0410. ; 79:4, s. 235-241
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives: Our objective was to study the effect of storage time on the filtration of platelet concentrates (PCs). We compared the total number of white blood cells (WBC), as well as the distribution of WBC subsets, in units filtered before and after storage.Materials and Methods: Buffy coat-derived PCs were filtered either fresh or after 5 days of storage, and total WBC were enumerated by flow cytometry. WBC subsets were analyzed by flow cytometry with three-color fluorescence.Results: The total number of white cells before filtration was significantly higher in fresh units compared with stored units, whereas in postfiltration samples the number of white cells was significantly lower in the fresh compared with the stored units. Although absolute numbers were significantly reduced, filtration also induced significant changes in the proportions of subsets in both fresh and stored units; the percentage of T cells was decreased, whereas the percentage of B cells and monocytes was increased after filtration.Conclusion: Our results suggest that prestorage WBC filtration of platelet concentrates is superior in reducing the absolute numbers of WBC. However, both pre- and poststorage WBC filtration significantly affect the proportions of WBC in the final product, decreasing the number of T cells while apparently increasing the proportion of MHC class II-positive cell populations.
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| 6. |
- Ludvigsson, Johnny, 1943-, et al.
(författare)
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Photopheresis at onset of type 1 diabetes : A randomised, double blind, placebo controlled trial
- 2001
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Ingår i: Archives of Disease in Childhood. - : BMJ. - 0003-9888 .- 1468-2044. ; 85:2, s. 149-154
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Tidskriftsartikel (refereegranskat)abstract
- Background - In recent years photopheresis, an extracorporeal form of photochemotherapy using psoralen and ultraviolet A irradiation of leucocytes, has been claimed to be an effective form of immunomodulation. Aim - To evaluate its effect in type 1 diabetes we performed a double blind, controlled study using placebo tablets and sham pheresis in the control group. Methods - A total of 49 children, aged 10-18 years of age at diagnosis of type 1 diabetes were included, 40 fulfilled the study and were followed for three years (19 received active treatment with photopheresis and 21 placebo treatment). Results - The actively treated children secreted significantly more C peptide in urine during follow up than control children. C peptide values in serum showed corresponding differences between the two groups. The insulin dose/kg body weight needed to achieve satisfactory HbA1c values was always lower in the photopheresis group, there was no difference between the groups regarding HbAlc values during follow up. The treatment was well accepted except for nausea (n = 3) and urticaria (n = 1) in the actively treated group. There were no differences regarding weight or height, or episodes of infection between the two groups during follow up. Conclusion - Photopheresis does have an effect in addition to its possible placebo effect, shown as a weak but significant effect on the disease process at the onset of type 1 diabetes, an effect still noted after three years of follow up.
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| 7. |
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| 8. |
- Palfi, Miodrag, 1954-, et al.
(författare)
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A randomized controlled trial of transfusion-related acute lung injury : Is plasma from multiparous blood donors dangerous?
- 2001
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Ingår i: Transfusion. - : Wiley. - 0041-1132 .- 1537-2995. ; 41:3, s. 317-322
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Transfusion-related acute lung injury (TRALI) and other posttransfusion reactions may be caused by granulocyte and/or HLA antibodies, which are often present in blood from multiparous donors. The purpose of this study was to compare the effects of plasma from multiparous donors with those of plasma from donors with no history of transfusion or pregnancy (control plasma) in a prospective, randomized, double-blind, crossover study. STUDY DESIGN AND METHODS: Intensive care patients, judged to need at least 2 units of plasma, were randomly assigned to receive a unit of control plasma and, 4 hours later, a plasma unit from a multiparous donor (=3 live births) or to receive the plasma units in opposite order. The patients were closely monitored, and body temperature, blood pressure, and heart rate were recorded. Blood samples for analysis of blood gases, TNFa, IL-1 receptor antagonist, soluble E selectin, and C3d complement factor were collected at least on four occasions (before and after the transfusion of each unit). RESULTS: Transfusion of plasma from multiparous donors was associated with significantly lower oxygen saturation and higher TNFa concentrations than transfusion of control plasma. The mean arterial pressure increased significantly after the transfusion of control plasma, whereas plasma from multiparous donors had no effect on it. Five posttransfusion reactions were observed in 100 patients, in four cases after the transfusion of plasma from multiparous donors. CONCLUSION: Plasma from multiparous blood donors may impair pulmonary function in intensive care unit patients.
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