Virucidal activity of essential oils from aromatic plants of San Luis, Argentina.

Essential oils obtained from eight aromatic plants of San Luis Province, Argentina, were screened for virucidal activity against herpes simplex virus type 1 (HSV-1), Junin virus (JUNV) and dengue virus type 2 (DEN-2). The most potent inhibition was observed with the essential oil of Lippia junelliana and Lippia turbinata against JUNV with virucidal concentration 50% (VC(50)) values in the range 14-20 ppm, whereas Aloysia gratissima, Heterotheca latifolia and Tessaria absinthioides inhibited JUNV in the range 52-90 ppm. The virucidal activity was time- and temperature-dependent. The essential oils of A. gratissima, Artemisia douglasiana, Eupatorium patens and T. absinthioides inactivated HSV-1 at 65-125 ppm. However, only A. douglasiana and E. patens had any discernible effect on DEN-2 infectivity with VC(50) values of 60 and 150 ppm, respectively.

Cryopreservation of human platelets using 6% dimethyl sulfoxide and storage at -80 degrees C. Effects of 2 years of frozen storage at -80 degrees C and transportation in dry ice.

Platelet studies were done in healthy male volunteers and in thrombocytopenic patients. Some of the platelets used in the study were isolated by mechanical apheresis using either the Haemonetics blood processor 30, the IBM blood processor 2997 or the Fenwal CS-3000 blood processor before freezing. Other platelets were isolated from individual units of whole blood and pooled before freezing. The platelets were frozen with a 6% cryoprotectant (DMSO) in a polyvinylchloride (PVC) plastic bag or a polyolefin plastic bag at -80 degrees C in a mechanical freezer and stored for as long as 3 years. Some of the frozen platelets were transported in dry ice in polystyrene foam containers to determine whether they would be adversely affected by such treatment. Platelet recovery after freezing, thawing and washing was about 75%. In the healthy male volunteers, in vivo recovery of autologous platelets 1-2 h after transfusion was about 33%, and the life span was about 8 days. In the thrombocytopenic patients, in vivo recovery values were 50% of those from fresh platelets. The transfusion of previously frozen washed platelets reduced clinical bleeding in the thrombocytopenic patients with bleeding. There was no evidence of quality deterioration in platelets after storage at -80 degrees C for at least 2 years, as determined from in vivo recovery and in vivo survival values, nor was there any adverse effect as a result of shipment of the frozen platelets in dry ice in polystyrene foam containers from one facility to another.