Dry platelets with the Dideco Excel apparatus.

Dry platelets are required to prevent hemolytic and nonhemolytic febrile reactions after transfusion to ABO mismatched recipients, to reduce the risk of HLA immunization and to prevent allergic or anaphylactic reactions. Previously we have shown that the collection of single donor platelets almost free of plasma is possible with different cell separators. With the systems we described for the CS 3000+/Amicus and AS 104-204 apparatuses collection of dry platelets implies their resuspension in non plasma solutions after opening the circuit. With the new system developed by Dideco for the Excel apparatus this moreover is no longer required since the platelet bag can be connected to the resuspending medium through a dedicated line with an antibacterial filter. Platelets are collected cyclically and the resuspending solution is added when the procedure is over. In this study 53 collections were evaluated, 21 of which were erythrothrombocytapheresis. In 60-65 min 4.21 of anticoagulated blood (1/12) were processed with platelet collection automatically done after 6-700 ml cycles. The platelet yield averaged 4.67 +/- 0.7 x 10(11), with a platelet efficiency per minute of 7.18 +/- 0.9 x 10(9). The WBC contamination averaged 2.6 +/- 0.7 x 10(5) and contamination did not exceed 0.87 x 10(6). The quality of platelets was satisfactory as measured by aggregation, morphology score, and CD 62 membrane glycoprotein externalization. These results were comparable to those obtained with three other Excel apparatuses used in the conventional way to collect platelets resuspended in plasma or with the Amicus used to collect dry platelets using an open system.

Paediatric reference values for urinary catecholamine metabolites evaluated by high performance liquid chromatography and electrochemical detection.

The majority of the published reference range data on catecholamines excretion by healthy children is incomplete and often contradictory (1). We assayed in the urines of 127 healthy children the values of the catecholamines (norepinephrine, epinephrine, dopamine) and their methylated metabolites (normetanephrine, metanephrine, 3-methoxytyramine) for the determination of paediatric reference ranges. Data were expressed as micrograms/24 h, mumol/24 h and mmol/mol creatinine. An isocratic HPLC procedure by ion-pair reversed phase chromatography on a C18 column, using a single mobile phase containing formic acid, acetonitrile, diethylamine and octane sulphonic acid (ion pairing agent), permitted the separate assay of the various fractions of total catecholamines. The relations between each biogenic amine and age were studied and reference values were determined as a function of age.