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Biomedical subjects

C A Schiffer

Publications and source records attributed to C A Schiffer.

At least 19 recordsLinked to original sources
PubMed1979

Increased leukocyte alkaline phosphatase activity following transfusion of leukocytes from a patient with chronic myelogenous leukemia.

Neutrophils from a patient with chronic myelogenous leukemia and typically low leukocyte alkaline phosphatase (LAP) activity markedly increased in LAP content following transfusion to and circulation in an infected neutropenic recipient. Incubation of the recipient's serum and plasma with normal neutrophils failed to alter their LAP activity. This observation suggests that LAP activity is inducible by as yet unknown "environmental" factors, and possible mechanisms for this are discussed.

Adult↗
PubMed1979

Alloimmunization following prophylactic granulocyte transfusion.

Nineteen noninfected adults receiving initial induction chemotherapy for acute nonlymphocytic leukemia (ANLL) were randomized to receive either prophylactic granulocyte transfusion or platelet transfusion alone on an alternate-day schedule. An average of 11 granulocyte transfusions (range 3--19) were administered/patient with a mean dose of 11.5 X 10(9) granulocytes/transfusion. The groups were identical with respect to age, sex, number of days on study, granulocytopenic days, percent of days receiving systemic antibiotics, febrile days, complete remission rate, and incidence of minor infection. Significant transfusion reactions were much increased in the granulocyte transfusion group (7/10 versus 1/9 in controls) and were associated with the development of lymphocytotoxic antibodies (7/10 versus 4/9 controls), refractoriness to platelet transfusion, repeated fevers, and a pulmonary infiltrate in one patient. Alloimmunization to granulocytes occurred as early as the second week in some patients complicating platelet support during induction and maintenance. No severe infections occurred in the granulocyte transfusion group while three fungal infections occurred in the controls. The high rate of alloimmunization suggests that histocompatibility considerations indicate that prophylactic granulocyte transfusion should not be routine therapy and should be studied only in investigational settings.

Acute Disease↗
PubMed1979

Successful transfusion of platelets cryopreserved for more than 3 years.

To determine the duration of storage for cryopreserved platelets, 14 transfusions of random-donor, pooled platelets, stored in the vapor phase of liquid nitrogen for a mean period of 1157 days (range 1060-1240), were analyzed. Twelve of these transfusions were compared in a paired fashion with fresh, random-donor, pooled platelets given within a few days to the same thrombocytopenic recipients. Platelets had been frozen using 5% dimethylsulfoxide as a cryoprotective agent either at a controlled rate of -1 degrees C/min to -80 degrees C or by simply placing them in the vapor phase (-120 degrees C) of a liquid nitrogen freezer. The mean freeze-thaw loss for the 14 transfusions was 22%, and the mean corrected 1-hr increment in platelet count was 12,600/microliter. In the 12 paired observations, the mean corrected 1-hr increment for frozen platelets was 11,800/microliter and 25,900 for fresh platelets, giving a frozen/fresh recovery of 46%. Random donor platelets can be cryopreserved by these methods for greater than 3 yr with satisfactory post-transfusion increments. This suggests that a reservoir of frozen platelets, either random-donor for emergency transfusion or of known HLA-type for transfusion to alloimmunized patients, can be established and stored for at least 3 yr.

Blood Platelets↗
PubMed1978

Frozen autologous platelet transfusion for patients with leukemia.

Platelets were removed from 25 patients with leukemia during remission and were frozen for subsequent transfusion. With 5 per cent dimethyl sulfoxide as a cryoprotective agent, we froze 3 to 5 units of pooled platelet concentrate by simply placing the platelets in the vapor phase of a liquid nitrogen freezer. Ninety-one transfusions of platelets stored for 13 to 400 days were administered. The mean freeze-thaw loss was 13 percent, and the corrected one-hour increment in platelet count was 13,700 per microliter, corresponding to a recovery of 53 per cent of the predicted value. In many patients most or all of the transfusion requirements were met with frozen platelets. Our results indicate that frozen platelets can circulate and function hemostatically. Autologous frozen platelets are of particular value in the management of alloimmunized patients and have become an integral part of our transfusion support program.

Adult↗
PubMed1975

Transient neutropenia induced by transfusion of blood exposed to nylon fiber filters.

During the course of granulocyte collection by continuous-flow filtration leukopheresis, an abrupt fall in neutrophil count was noted (mean decrease 77%, range 64%-95%). Neutropenia occurred within 5 min of return of blood exposed to the nylon fiber filters and lasted less than 30 min. Saline exposed to the fibers, withdrawal and reinfusion of whole blood, and heparin did not cause neutropenia. Heparinized blood passed by gravity through isolated filters and reinfused immediately also induced neutropenia (mean decrease 64% +/- 8%, range 11%-19%). Blood anticoagulated with ACD (decrease 19.5% +/- 6%, range 6%-56%), heparinized plasma (N = 10, decrease 15% +/- 3%, range 3%-29%) and platelet-rich plasma exposed to the filters failed to produce neutropenia. 91% +/- 2% of the neutrophils adhered to the fibers using heparinized blood as compared to 21% +/- 5% using ACD (p less than 0.001). All donors were asymptomatic during the infusions. These results suggest that during neutrophil adherence a substance is released which produces profound, transient neutropenia perhaps by inducing margination of cells.

Agranulocytosis↗
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

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↗
PubMedDate not supplied

The effect of dexamethasone on platelet function.

To assess the effects of dexamethasone on platelet function, aggregation studies were performed on nine healthy adults before and after ingestion of a single dose of dexamethasone 10 mg, and on six patients receiving daily dexamethasone. Bleeding times were done on 14 volunteers before and after a similar drug dose. Platelet aggregation by ADP, epinephrine and collagen was unchanged after dexamethasone in the healthy subjects and aggregation curves in the patient group were comparable to the normals. Bleeding times were moderatley prolonged in women (from 284 +/- 58 seconds to 389 +/- 114 seconds) but not in men. This prolongation was much less pronounced than that which occurs with low doses of aspirin and no subject experienced delayed bleeding. Dexamethasone in single high doses probably does not cuase a clinically important effect on platelet function.

Blood Platelets↗