Polyurethane foam (Bentley) micropore blood transfusion filter: filtration characteristics

Stored human blood of varying age was passed through polyurethane foam (Bentley) micropore blood transfusion filters. Passage through these filters resulted in decreased screen filtration pressure (SFP) of the blood and increased filter weights. Numerous microaggregates were removed and SFP returned to normal after filtration. Occlusion of the filter occurred after passage of only 2 units of whole blood. On the basis of this research, we conclude that polyurethane foam (Bentley) micropore blood transfusion filters are effective in removal of microaggregates from stored human blood. Because the filtering capacity is not great, it is recommended that when these filters are used during transfusion a new filter be used for each unit of blood administered.     

Jones' fractures and related fractures of the proximal fifth metatarsal

At least three fracture types occur in the proximal fifth metatarsal: the Jones' fracture, the proximal diaphysial stress fracture, and the tuberosity avulsion fracture. Each has distinct characteristics. The diaphysial stress fracture is commonly confused with the Jones' fracture, thereby obscuring vital differences in prognosis and treatment. Anatomical and biomechanical characteristics, as well as vascular studies of the proximal portion of the fifth metatarsal, are discussed in an attempt to better understand their diverse healing potentials. Guidelines for treatment are controversial, and must frequently be individualized. Although surgical intervention for certain proximal fifth metatarsal fracture types may speed recovery time, most fractures heal with immobilization. Treatment of displaced, intra-articular fractures, delayed unions, and nonunions usually requires operative methods.