Biomedical subjects

J H Wolff

Publications and source records attributed to J H Wolff.

3 recordsLinked to original sources

PubMedDate not supplied

The effect of hydroxyethyl starch on in vitro platelet and granulocyte function.

The effect of hydroxyethyl starch (HES) on granulocyte and platelet functions was assessed. No alteration of granulocyte viability, morphology, phagocytic ability, or bactericidal capacity was detected after incubation with 6 per cent HES at 25 C for two hours. Platelet morphology, size distribution, aggregation, nucleotide and serotonin release, and platelet factor-3 availability were also unchanged after exposure to HES. It is concluded that HES has no adverse effect on cell function and appears to be a suitable adjuvant agent for blood cell component collection.

Blood Bactericidal Activity↗

PubMedDate not supplied

Frozen autologous platelets in the supportive care of patients with leukemia.

Multiple units of platelet concentrate obtained by intensive plateletpheresis of patients with leukemia in remission were pooled and frozen using 4 to 5 per cent dimethylsulfoxide and retransfused during periods of thrombocytopenia. Plateletpheresis was well tolerated by all donors and an average platelet yield per unit of 0.99 X 10(11) (n = 155) was obtained. The results of 107 transfusions to 36 patients are presented. An average of 32.4 per cent of the platelets were lost during the freeze-thaw process. Freezing loss was lowest at a freezing rate of one degree C per minute, at a lower final concentration of platelets, and when polyolefin bags were used. The mean corrected posttransfusion count increment was 6,400/mul (range 600-19,000 xm2/10(11) platelets transfused). In vivo results did not correlate with freezing rate but were statistically significantly better at lower platelet (approximately 0.16 X 10(11) platelets/10 ml) concentrations. Eleven patients, including some who were refractory to random donor platelets were supported entirely with autologous platelets during reinduction therapy for leukemia. When administered prophylactically the autologous platelets seemed to prevent hemorrhage during periods of thromobocytopenia although in most patients bleeding times were not corrected posttransfusion. This study demonstrates that frozen autologous platelets can be used in the supportive care of thrombocytopenic patients. Further technical improvements are necessary before platelet freezing becomes practical for widespread use.

Blood Cell Count↗

PubMedDate not supplied

A standardized technique for efficient platelet and leukocyte collection using the Model 30 Blood Processor.

The Model 30 Blood Processor is a safe and simple means of harvesting blood cell components. Presently cell collection depends on a visual assessment by the operator of the indistinct boundaries of cell fractions. To determine when each cell component could best be harvested, serial samples were taken from the output port at fixed intervals anf the results of counts and differentials were graphed and tabulated. Studies in normal donors were done using acid-citrate-dextrose (ACD), 2 per cent sodium citrate in 6 per cent hydroxyethyl starch (HES), or heparin as anticoagulants. There was considerable overlap between the latter part of the platelet band, the leukocyte band and the rising hematocrit with all three anticoagulants. Normally functional lymphocytes could be harvested efficiently (approximately 80%) using ACD or heparin. Platelets could be harvested from ACD very efficiently (approximately 90%). Granulocytes could not be harvested from ACD (less than 10%) since they were dispersed in the red blood cell (RBC) layer. Using HES, granulocytes could be harvested efficiently (approximately 70%) by extending collection into the RBC layer. Based on these data, a standard technique for cell collection has been devised. The flow rate is slowed to 20 ml/min and collection is carried 30 ml (90 seconds at a rate of 20 ml/min) for platelets. The RBC loss is approximately 6 to 8 and 2 to 3 ml/pass respectively. These studies indicate that the Model 30 is a highly efficient apparatus for blood cell separation, but the volume of blood processed is limited by the intermittent blood flow.

Blood Cell Count↗