| 1. |
- Mobarrez, Fariborz, et al.
(författare)
-
A multicolor flow cytometric assay for measurement of platelet-derived microparticles
- 2010
-
Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848 .- 1879-2472. ; 125:3, s. e110-e116
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Flow cytometry (FCM) is the most commonly used method for detection of platelet-derived microparticles (PDMPs), but it is poorly standardized and mainly used for “bedside” analyses in fresh samples. If PDMPs could be analyzed in previously frozen samples it would increase the usefulness of the method. However, cell membrane fragments from contaminating cells created during freezing/thawing may cause artifacts and disturb measurements. Materials and Methods: PDMPs were labeled with monoclonal antibodies directed against CD42a and CD62P, or CD42a and CD142. The PDMP gate was determined using forward scatter (FSC) and CD42a expression. The mean fluorescence intensities (MFIs) of CD62P or CD142 positive particles were translated into MESF-values (Molecules of Equivalent Soluble Fluorochrome) using a standard curve. FITC-labeled phalloidin (which binds to intracellular actin) was used to detect destroyed cells/cell fragments. Results: Phalloidin-positive particles were significantly more common in supernatants of frozen/thawed platelet rich and platelet poor plasma samples compared with supernatants of platelet free plasma. Highspeed centrifugation was then used to obtain PDMP samples with low contamination of cell fragments. Electron microscopy showed that these samples contained numerous round stained particles with cellular membranes of a size of 100-700 nm. Reproducibility experiments using plasma samples from healthy individuals showed that the coefficients of variation (CVs) of MESF values of CD62P and CD142 (both intra- and interassay) were <10%, and the variation between two cytometers in two different laboratories was <5%. We also found that PDMP expression of CD142 (i.e. tissue factor [TF]) and CD62P (i.e P-selectin) was around two times higher in samples from type 1-diabetes patients compared with those from healthy controls (p<0.001). Conclusions: The use of MESF values to quantify PDMP expression of P-selectin and TF yields reproducible data and enables comparison of data between laboratories. If high-speed centrifugation is performed, contamination of cell fragments is low in frozen/thawed samples. (C) 2009 Elsevier Ltd. All rights reserved.
|
|
| 2. |
- Torffvit, Ole, et al.
(författare)
-
Increased Urine IgM and IgG2 Levels, Indicating Decreased Glomerular Size Selectivity, Are Not Affected by Dalteparin Therapy in Patients with Type 2 Diabetes
- 2012
-
Ingår i: Biochemistry Research International. - : Hindawi Limited. - 2090-2247 .- 2090-2255. ; 2012, s. 480529-
-
Tidskriftsartikel (refereegranskat)abstract
- Fifty-four type 2 diabetic patients with neuroischemic foot ulcers were randomised to treatment with 5000 IU of dalteparin, (n = 28), or physiological saline, (n = 26), once daily until ulcer healing or for a maximum of 6 months. Thirty-three patients had normo-, 15 micro-, and 6 macroalbuminuria. The urinary levels of IgM and IgG2 were elevated in 47 and 50 patients, respectively. Elevated urinary levels of IgM and IgG2 indicate decreased glomerular size selectivity. Urine IgM levels were associated with IGF-1/IGFBP-1 and IGFBP-1 levels. Dalteparin treatment increased urinary levels of glycosaminoglycans (P < 0.001) and serum IGFBP-1 (P < 0.05) while no significant effects were seen in any of the other studied parameters. In conclusion, dalteparin therapy in patients with type 2 diabetes had no effects on urinary levels of albumin, IgM, or IgG2 despite significantly increased glycosaminoglycans in urine. Elevated urinary levels of IgM and IgG2 might be more sensitive markers of renal disease than albuminuria in patients with type 2 diabetes and antihypertensive therapy.
|
|
