Survival and recovery of apheresis platelets stored in a polyolefin container with high oxygen permeability.

BACKGROUND AND OBJECTIVES: Oxygen permeability is important in platelet storage media. We compared a new polyolefin container with enhanced oxygen permeability (PO-80; Kawasumi, Tokyo, Japan) to a widely used alternative (PL2410; Baxter Healthcare, Deerfield, IL, USA). MATERIALS AND METHODS: In vitro characteristics of paired platelet concentrates (PCs; mean 4.2 x 10(11)/250 ml plasma/bag) stored in PO-80 or PL2410 were assessed through 9 days of storage. In vivo recovery and survival of 7-day-old autologous PCs were assessed according to the Murphy method. RESULTS: Laboratory assessment of platelet quality favoured PO-80 during 9 days of storage with statistically significant differences in glucose consumption (2.75 vs. 4.93 mmol/10(12)/24 h in the interval 120-168 h), lactate generation (4.37 vs. 8.11 mmol/10(12)/24 h in the interval 120-168 h), pressure of oxygen (pO(2)) (59.3 vs. 38.1 mmHg at day 1), and HCO(3)(-) (14.7 vs. 13.4 mmol/l at day 1). Statistically significant differences were not seen in aggregation, hypotonic shock response or pH. In vivo assessment of autologous platelets stored 7 days in the PO-80 container revealed that recovery was 82.1% and survival was 81.0% of fresh control. Seven-day stored PCs in PO-80 were shown in vivo to be non-inferior to fresh platelets, with upper confidence limits (UCL(95)) in recovery and survival of stored PCs below the maximum acceptable difference (MAD); 15.3% UCL(95) < 20.4% MAD and 2.1 days UCL(95) < 2.1 days MAD. CONCLUSIONS: The in vitro characteristics of PCs stored in a highly oxygen-permeable container were stable at least 7 days. The in vivo study supports the suitability of PO-80 for 7-day platelet storage.

Helical volume CT and its clinical significance.

Helical Volume CT (HVCT) is an X-ray CT scanning technique in which the patient is scanned continuously while the couch-top is moved in the axial direction. It is performed using the Toshiba TCT-900S CT scanner jointly developed by the authors and Toshiba Corporation. This scanner features a large central opening, the inner surface of which is lined with a circular array of 2,304 detectors. The X-ray tube rotates outside the detector array at the rate of one revolution per second. Electrical power is supplied to the X-ray tube through a slip ring mechanism, permitting the X-ray to be continuously generated without any interscan delay. The X-ray tube and detectors move in a "nutate/rotate" pattern. The maximum scanning time is 30 seconds (equivalent to a single breath-hold). To improve image quality, the slice thickness can be selected to equal the distance over which the couch-top moves in one second. The clinical advantages of HVCT are as follows: (1) the examination time is significantly reduced (to minimize the patient's discomfort), (2) continuous data of anatomical structures can be obtained without artifacts due to respiratory motion, and (3) it is possible to obtain superior images for multiplanar reconstruction (MPR), cine-display, and three-dimensional reconstruction.