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Dirk de Korte

Publications and source records attributed to Dirk de Korte.

5 recordsLinked to original sources

Effects of skin disinfection method, deviation bag, and bacterial screening on clinical safety of platelet transfusions in the Netherlands.

BACKGROUND: Bacterial contamination of blood products is a great hazard for development of fatal transfusion reactions. Bacterial screening of platelet concentrates (PC) by aerobic and anaerobic culturing (BacT/ALERT, bioMérieux) was introduced in the Netherlands in October 2001. STUDY DESIGN AND METHODS: In November 2002, a nationwide, uniform skin cleansing method was introduced with a double-swab disinfection with 70 percent isopropyl alcohol. One location routinely used an integrated diversion bag to collect the first 20 to 30 mL. RESULTS: Over the calendar years 2002 and 2003, in total 113,093 PCs derived from pooled buffy coats were screened. After introduction of the new disinfection method, 0.85 percent were initially positive. This was a small reduction compared to the previous disinfection methods under which 0.95 percent were initially positive. The location with use of the diversion bag showed a significantly lower frequency of bacterial contamination, with 0.50 percent before and 0.37 percent after introduction of 70 percent isopropyl alcohol. In addition 8000 apheresis PCs were also screened, showing 24 initially positive samples (0.30%). CONCLUSION: The use of the diversion bag and, to a lesser extent, the use of double swabs with 70 percent isopropyl alcohol, led to a reduction of contamination. As expected, predominant contamination with resident skin bacteria was reduced. The combination of diversion bag and new disinfection led to a frequency of initial positive results for pooled five-donor PCs, which is similar to that of single-donor apheresis PCs. Furthermore, the bacterial detection system and associated product recall procedures have been shown to be effective in preventing transfusion of contaminated PCs and/or related red cells, especially for rapidly growing bacteria.

2-Propanol↗

The mitochondrial membrane potential in human platelets: a sensitive parameter for platelet quality.

BACKGROUND: Deterioration of platelet (PLT) quality during storage is accompanied by an increase in lactate production, indicating a decrease in mitochondrial function. In this study, the optimal conditions under which the fluorescent dye JC-1 can be used to detect changes in mitochondrial function in PLTs were established. STUDY DESIGN AND METHODS: PLTs were incubated at 37 degrees C in synthetic medium under various conditions of JC-1 loading. In the presence of a high membrane potential, this dye accumulates in the mitochondria with a concomitant increase in red fluorescence. After JC-1 loading, the ratio of red (FL2) to green (FL1) fluorescence was determined by flow cytometry. RESULTS: The FL2-to-FL1 ratio of PLTs (3 x 10(7)/mL, loaded with 0.5 micromol/L JC-1) amounted to about 5 in 1-day-old PLTs. At higher dye concentrations, the FL2-to-FL1 ratio was significantly lower, suggesting uncoupling by the dye itself. Plasma concentrations above 3 percent significantly affected the JC-1 signal. The FL2-to-FL1 ratio showed a dose-dependent decrease to an uncoupler of oxidative phosphorylation or to inhibition of the respiratory chain. JC-1-loaded PLTs showed a clear decrease in FL2-to-FL1 ratio after prolonged storage or upon ultraviolet (UV) illumination. Only after UV treatment did changes in JC-1 signal correlate with changes in CD62P expression. CONCLUSION: The FL2-to-F1 ratio of PLTs loaded with JC-1 is a reliable and sensitive indicator of the mitochondrial membrane potential, provided that the proper experimental conditions have been applied.

Blood Platelets↗

Evaluation of platelet mitochondria integrity after treatment with Mirasol pathogen reduction technology.

BACKGROUND: Previous studies showed that Mirasol (Navigant Biotechnologies, Inc.) pathogen reduction technology (PRT) treatment resulted in an increase in platelet (PLT) glucose consumption and lactate production rates and decrease in pH in media during PLT storage. Increased glycolytic flux could result from damage to mitochondria and/or increased ATP consumption. STUDY DESIGN AND METHODS: PLT concentrates were collected by standard automated blood component collection system (Trima, Gambro BCT) procedure on Day 0 and treated with Mirasol PRT treatment on Day 1. PLT mitochondrial transmembrane potential was evaluated by staining PLTs with JC-1 followed by flow cytometry analysis. Mitochondrial enzymatic activity was measured by the MTT assay. ATP content and pH were also quantified. The values for these measurements were compared among control, untreated, and pathogen reduction technology (PRT)-treated PLTs during PLT storage for up to 7 days. RESULTS: No significant changes were found in pH, JC-1 signal, MTT activity, and ATP content of the PLTs immediately after PRT treatment. The treated PLTs exhibited a moderate but significantly accelerated decrease in pH and lower ATP content after 7-day storage when compared to control PLTs. Neither the JC-1 assay nor the MTT assay, however, showed a significant difference between control and treated PLTs during PLT storage. CONCLUSIONS: There is no evidence from these studies that Mirasol PRT treatment alters PLT mitochondrial structural and functional integrity immediately after treatment and during PLT storage. An increased demand for ATP may be the driving force for observed increases in both the glycolytic flux and the oxidative metabolism observed in treated PLTs.

Adenosine Triphosphate↗

Laser-assisted optical rotational cell analyzer measurements reveal early changes in human RBC deformability induced by photodynamic treatment.

BACKGROUND: The ability to deform is important for circulating RBCs in vivo, and earlier studies showed that this property can objectively be measured in vitro by the LORCA. In this study it was investigated whether photodynamic treatment of human RBCs (meant to inactivate contaminating pathogens) affects deformability. STUDY DESIGN AND METHODS: WBC-reduced RBC suspensions (30% Hct) were treated with 1,9-dimethylmethylene blue (DMMB) and red light. Changes in deformability were analyzed by LORCA measurements, in which elongation of the cells is measured at increasing shear stress. The effect of DMMB concentration and light dose was determined as well as the interfering effect of two scavengers of reactive oxygen species, that is, dipyridamole and Trolox. RESULTS: Photodynamic treatment with DMMB resulted in clear changes in RBC deformability. Deformability changes occurred before onset of hemolysis. Under relatively mild treatment conditions, especially deformability at low shear stress was decreased, whereas deformability changes at high shear stress only occurred under harsher treatment conditions. Inclusion of dipyridamole and/or Trolox primarily prevented deformability changes at high shear stress. CONCLUSION: LORCA measurements can effectively be used to detect changes in deformability that are induced by photodynamic treatment of human RBCs. A change in deformability represents an early marker of RBC damage under these conditions.

Antioxidants↗

Sephadex-based cell-affinity adsorbents: preparation and performance.

Sephadex was derivatized consecutively with Staphylococcus Protein A (SpA) and cell-specific antibodies, and the binding of cells to the resulting material was examined. For comparison, cell binding to commercially obtained SpA-Sepharose was determined. Sephadex G-10, carboxylated by reaction with glycine and activated subsequently with 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide/N-hydroxysuccinimide (NHS), was allowed to react with SpA. Coupling of SpA to NHS-activated glycine-Sephadex appeared to be complete (immobilization capacity, approximately 300 microg of protein/ml of packed gel) when incubation was carried out at pH 4.0, in buffer of low ionic strength. However, incubation at higher pH values (> or = 6.5) led to poor coupling yields. After incubation with rabbit anti-(human red cell) antiserum, and upon mixing with human red blood cells, SpA-glycine-Sephadex G-10 could bind up to 5 x 10(8) red cells/ml of gel. Cell binding increased when the amount of antiserum, added to SpA-glycine-Sephadex G-10 for preparing the affinity gel, was increased from 0.5 to 5 microl/ml of gel. Compared with this, SpA-Sepharose CL 4B had to be incubated with much larger amounts of antiserum (100-700 microl/ml of gel) in order to obtain cell-affinity adsorbent. One obvious advantage of the approach described here is that relatively small amounts of SpA and antisera are needed for preparing cell-affinity media.

Adsorption↗