| 1. |
- Adrian, Katrin, 1966, et al.
(författare)
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Cytokine release during long-term extracorporeal circulation in an experimental model.
- 1998
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Ingår i: Artificial organs. - 0160-564X. ; 22:10, s. 859-63
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to determine the degree of leukocyte activation, as measured by cytokine release, in circulating blood during experimental extracorporeal circulation. Complete in vitro extracorporeal membrane oxygenation (ECMO) circuits were used, and 9 experiments were performed. Whole blood stored at 37 degrees C was used as the control. Blood samples were withdrawn before the start of perfusion and at 24 h of perfusion. Statistically significant releases of interleukin (IL)-1beta, IL-8, and IL-1 receptor antagonist were observed in the perfusion circuits compared to both the control blood and baseline values. Also, increases in plasma tumor necrosis factor (TNF)alpha and IL-6 were seen after 24 h of perfusion although these changes did not reach statistical significance. These results indicate that extracorporeal circulation induced leukocyte activation and cytokine release. These reactions might, as an additional trauma, deteriorate the situation in an already severely ill patient. A search for methods to counteract this untoward activation seems warranted.
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| 2. |
- Adrian, Katrin, 1966, et al.
(författare)
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The effect of albumin priming solution on platelet activation during experimental long-term perfusion.
- 1998
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Ingår i: Perfusion. - 0267-6591. ; 13:3, s. 187-91
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to evaluate the effect of albumin priming on platelet consumption and activation during long-term perfusion. Two identical in vitro extracorporeal membrane oxygenation circuits were used; one was primed with Ringer's solution containing human serum albumin, the other with Ringer's solution only. Fresh heparinized human blood was pooled, divided between the two systems and circulated for 24 h at 37 degrees C. Platelet count, plasma concentration of betathromboglobulin (BTG), platelet membrane density of glycoprotein (GP) Ib and of GPIIb/IIIa were assayed before the start and at 0.5, 1, 3, 12 and 24 h of perfusion. In total, seven experiments were performed. We found that during the first hour of perfusion, slightly higher platelet counts (p = 0.058) and lower BTG values (p = 0.0005) were observed in the circuits primed with albumin, compared to the control circuits. No statistically significant differences were observed for the platelet membrane expression of GPIb and GPIIb/IIIa. We conclude that albumin priming appears to transiently prevent platelet consumption and activation during long-term perfusion.
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| 3. |
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| 4. |
- Andreasson, Björn, et al.
(författare)
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The measurement of venous haematocrit in patients with polycythaemia vera.
- 1999
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Ingår i: Journal of internal medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 246:3, s. 293-7
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: In clinical practice, patients with polycythaemia vera (PV) are monitored by measurement of venous packed cell volume (PCV). However, whereas treatment recommendations are still based upon studies in which the results were obtained with the centrifuged microhaematocrit, currently in most instances automated blood cell counters are used to calculate PCV. In a group of patients with polycythaemia we therefore compared the results obtained by the microhaematocrit method with PCV calculated by haematology analysers. DESIGN: The study was carried out on a prospective basis. Duplicate venous blood samples were collected. The centrifuged microhaemotocrit was obtained by using an IEC Micro-MB Centrifuge. Depending on different routine methods used in the participating hospitals, the blood cell counter PCV was calculated using Coulter STKS, Bayer Technicon H2 or H3. SETTING: Patients were included from four Swedish university hospitals: Akademiska (Uppsala), Huddinge and Karolinska (Stockholm) and Sahlgrenska (Göteborg). SUBJECTS: Seventy-four patients with PV and 10 patients with secondary polycythaemia were included and a total of 150 duplicate blood samples were analysed from these subjects. RESULTS: In the 150 measurements the mean blood cell counter calculated PCV was 0.448 +/- 0.037; the mean for centrifuged microhaematocrit was 0.467 +/- 0. 037 and the difference between means was highly significant (P = 6.8 x 10-25). The means for centrifuged haematocrit and calculated PCV differed significantly in the groups of PV patients treated with phlebotomy only, hydroxyurea or radiophosphorous (P < 0.0001, respectively). In PV patients treated with alpha-interferon and in patients with secondary polycythaemia the difference in means did not reach statistical significance (P = 0.07 and P = 0.13, respectively). The groups of patients with MCV <80 fL and >/=80 fL both presented significant differences between means for calculated PCV and centrifuged haematocrit. CONCLUSIONS: If PV patients are monitored with blood cell counter calculated PCV it appears that the therapeutic goal should be to maintain the calculated PCV below 0.43, provided the local differences in calculated PCV and centrifuged haematocrit are of the same magnitude as in this study.
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| 5. |
- Carneskog, Jan, et al.
(författare)
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Assessment of spleen size using gamma camera scintigraphy in newly diagnosed patients with essential thrombocythaemia and polycythaemia vera.
- 1996
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Ingår i: European journal of haematology. - 0902-4441. ; 56:3, s. 158-62
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Tidskriftsartikel (refereegranskat)abstract
- By using gamma camera imaging the spleen size was assessed in 18 consecutive patients with essential thrombocythaemia (ET) and in 18 consecutive patients with polycythaemia vera (PV). All ET and PV patients were newly diagnosed and had not received any myelosuppressive therapy prior to study. The spleen areas in both posterior and left lateral projections were determined. Eighteen consecutive patients with idiopathic thrombocytopenic purpura (ITP) served as a control group since by definition they do not present with splenic enlargement; in these latter subjects the mean posterior and left lateral splenic areas were almost identical (48 +/- 15 and 47 +/- 17 cm2, respectively). In comparison with this control group patients with ET and PC had significantly larger spleens. In both ET and in PV patients the left lateral spleen scan area exceeded the posterior one. Patients with PV had larger splenic areas in both projections than did patients with ET, but the differences were not statistically significant. Compared to the ITP patients it was found that at least 50% of the ET patients and at least 61% of the PV patients at diagnosis presented with splenomegaly.
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| 6. |
- Carneskog, Jan, et al.
(författare)
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Plasma erythropoietin by high-detectability immunoradiometric assay in untreated and treated patients with polycythaemia vera and essential thrombocythaemia.
- 1998
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Ingår i: European journal of haematology. - 0902-4441. ; 60:5, s. 278-82
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Tidskriftsartikel (refereegranskat)abstract
- By using an immunoradiometric method with a stated detection limit of < or =1 IU/l (stated normal reference limit in adults 3.7-16 IU/l) we determined EDTA-plasma erythropoietin (EPO) in 58 patients with polycythaemia vera (PV) and 49 patients with essential thrombocythaemia (ET). At the time of blood sampling, 20 of the PV patients were newly diagnosed and untreated, 23 were treated by phlebotomy only, and 30 also received myelosuppressive treatment (with 32P, hydroxyurea or alpha-interferon). Of the ET patients 24 were untreated and 28 received myelosuppressive therapy. For comparison plasma EPO was also determined in 10 patients with pseudopolycythaemia (PP). In this latter group the results for plasma EPO agreed well with the cited normal reference limits. The majority of untreated PV patients (12/20) had undetectable plasma EPO concentration, and the remainder all had values below the lower normal reference limit. Plasma EPO in PV was not significantly influenced by phlebotomy therapy. Twelve of the 24 untreated ET patients (50%) had plasma EPO values below the reference interval (undetectable in 2 patients). The mean EPO concentration was significantly lower in PV patients receiving phlebotomy therapy than in patients with untreated ET. In the total material of PV and ET treated with myelosuppressive agents the PV patients showed significantly lower values for EPO concentration than did patients with ET. The present results support the view that EPO measurements by high-detectability methods are diagnostically useful and should be included in the panel of new criteria for the diagnosis of PV.
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| 7. |
- Carneskog, Jan, et al.
(författare)
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The red cell mass, plasma erythropoietin and spleen size in apparent polycythaemia.
- 1999
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Ingår i: European journal of haematology. - 0902-4441. ; 62:1, s. 43-8
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Tidskriftsartikel (refereegranskat)abstract
- It has been shown previously that measurement of the spleen size and plasma erythropoietin (EPO) concentration are valuable adjuncts in the diagnostic work-up of patients with polycythaemia vera. The aim of the present work was to evaluate their value in the assessment of apparent polycythaemia (AP). Therefore, over a 24-month period we routinely performed bone marrow biopsies, measurement of red cell mass (RCM) and plasma volume (PV), spleen size determination by gamma camera scintigraphy and determination of the plasma EPO concentration in consecutive patients referred to us because of elevated values for packed cell volume (>0.48 in females and >0.51 in males). After having excluded patients with clonal and secondary polycythaemias we were left with 38 patients (27 males and 11 females) with AP. In all of them the measured RCM was within normal range, i.e. <36 ml/kg for males and <32 ml/kg for females. The subjects were characterized by moderate increase in RCM and a concomitant moderate decrease in PV. Thus, as an average the measured RCM exceeded the predicted values by 14% in males and by 12% in females; conversely, as compared to the predicted values the average measured value for PV was reduced by 17% in males and by 8% in females. The average RCM for males was 29+/-3 ml/kg; the corresponding figure for females was 23+/-4 ml/kg. It was shown that 86% of the subjects had plasma EPO concentrations within the control range; the remaining had values slightly above or below the control range. The mean posterior spleen scan area was 57+/-16 cm2 and mean left lateral area 57+/-17 cm2; the reference value for spleen scan area (for both projections) is 57+/-12 cm2. Of the patients 35/38 (92%) had a spleen scan area within the mean+2SD for controls and 38 subjects (100%) had values within the mean+3SD. It is concluded that measurement of plasma EPO and a careful assessment of the spleen size should always be considered in the evaluation of patients with elevated values for venous packed cell volume.
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| 8. |
- Forsberg, B, et al.
(författare)
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The platelet-specific alloantigen PlA1 (HPA-1a): a comparison of flow cytometric immunophenotyping and genotyping using polymerase chain reaction and restriction fragment length polymorphism in a Swedish blood donor population.
- 1995
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Ingår i: Transfusion. - 0041-1132. ; 35:3, s. 241-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is an increasing interest in the development of rapid and reliable techniques for platelet alloantigen typing. STUDY DESIGN AND METHODS: By use of standardized flow cytometry and a specific human alloantiserum, 236 Swedish blood donors were immunophenotyped for the platelet-specific alloantigen, PlA1 (HPA-1a). RESULTS: Ten individuals (4.2%) had low fluorescence intensities and were considered PlA1-negative (HPA-1a-negative); all of them also demonstrated a PlA2/PlA2 (HPA-1b/1b) genotype in a polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) assay of the underlying DNA polymorphism. The remaining population had clear positive fluorescence and was regarded as PlA1-positive (HPA-1a-positive). The fluorescence distribution histogram among PlA1-positive (HPA-1a-positive) individuals was dome-shaped, and those individuals who were homozygous for PlA1 (HPA-1a) could not be distinguished from those who were heterozygous. This finding was further substantiated by PCR-RFLP analysis of the PlA1/PlA2 (HPA-1a/1b) genotype; a heterozygous genotype was found among those having a medium fluorescence intensity as well as among those having a strong fluorescence intensity. CONCLUSION: Flow cytometry is a valuable tool for large-scale detection of PlA1 (HPA-1a). However, flow cytometry based on only one antiserum cannot distinguish between homozygous and heterozygous carriers of PlA1 (HPA-1a). For zygosity testing and when platelets are difficult to obtain, the PCR-RFLP technique is the assay of choice.
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| 9. |
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| 10. |
- Hou, M, et al.
(författare)
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Antibodies against platelet GPIb/IX, GPIIb/IIIa, and other platelet antigens in chronic idiopathic thrombocytopenic purpura.
- 1995
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Ingår i: European journal of haematology. - 0902-4441. ; 55:5, s. 307-14
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Tidskriftsartikel (refereegranskat)abstract
- Antibodies involved in the pathogenesis of chronic idiopathic thrombocytopenic purpura (ITP) react most frequently with platelet glycoprotein (GP) Ib/IX and GPIIb/IIIa. However, uncertainty as to the specificity, frequency, and clinical significance of such antibodies still remains. By using a modified antigen-capture ELISA (MACE), an immunoprecipitation assay, and an immunoblot assay, sera from 60 patients with chronic ITP were analyzed. GP-specific antibodies were found in 50% (30/60) of the patients, with 14 patients having antibodies directed solely to GPIIb/IIIa, 8 holding antibodies specific only for GPIb/IX, and 8 possessing antibodies against both antigens. Serum antibodies were more frequently (p < 0.01) detected in either active and/or non-splenectomized ITP patients. Moreover, in patients displaying antibodies against GPIb/IX, significantly (p < 0.05) lower platelet counts were observed. Using the immunoblot assay, antibodies specific for a 30 kD platelet antigen were detected in 12 of 60 patients. This antigen could not be immunoprecipitated from surface labelled platelet membranes, indicating an intracellular location. We conclude that in chronic ITP, (1) the frequency of anti-GPIIb/IIIa antibodies is close to that of anti-GPIb/IX antibodies, (2) anti-GP antibodies are more likely to be detected in patients with an active disease status and, (3) a 30 kD internal platelet protein is another frequent antigen.
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