Correction of the hemostatic defects in Von Willebrand's disease.
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Adult↗
Biomedical subjects
H A Perkins
Publications and source records attributed to H A Perkins.
Effect of polyvinyl pyrrolidone on plasma coagulation factors.
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Blood Coagulation↗
Measurement of calcium ion levels during massive transfusion of citrated blood.
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Animals↗
Platelet loss on exposure of citrated blood to various foreign surfaces.
Citrated whole blood was rotated in tubes or closed loops of tubing and the percentage of platelets lost on exposure to the surface of the container was noted. Platelet loss in the presence of uncoated glass surfaces (mean loss 31%) was significantly less than in the presence of glass siliconed with two different reagents (82% and 86%). Platelets adhered to siliconed glass but not to uncoated glass. Other inert surfaces also resulted in a high degree of platelet loss: Teflon 90 per cent, silicone rubber 85 per cent, Parawax 84 per cent, polysytrene 82 per cent, polyethylene 79 per cent, polypropylene 60 per cent, and polycarbonate 58 per cent. One lot of polyvinyl chloride transfusion grade tubing resulted in only 2 per cent loss of platelets, but other lots varied between 35 and 84 per cent. Loss of platelets on exposure to the surface of plastic containers may have to be considered when evaluating new materials for preparation of blood components.
Acrylates↗
Comparison of HL-A typing with NIH trays and the NIH technique with typing by the fluorochromasia cytotoxicity assay.
A comparison of HL-A phenotypes determined with plates containing predispensed typing sera supplied by the NIH Serum Bank with phenotypes determined by the fluorochromasia cytotoxicity assay using local reagents showed that the NIH plates (as dispensed in 1972) had an insufficient number and variety of typing sera. Using NIH trays, it was difficult to detect HL-A9 and W19, both of which specificities are now known to have subtypes. The NIH trays also appeared to detect more HL-A antigens than were consistent with the current theory of two segregant series, each expressing a maximum of two antigens. The excess antigens could not be comparatively evaluated in view of the small number of sera defining each. With the NIH technique, it was impossible to interpret the reactions if the preparation had too many dead cells. A high proportion of dead cells was occasionally noted when lymphocytes had been previously frozen or obtained from lymph nodes. When the NIH and fluorochromasia techniques were compared using the same antisera and fresh lymphocytes, they proved equivalent in sensitivity.
Cytotoxicity Tests, Immunologic↗
Letter: Anti-IgA in blood donors.
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Anaphylaxis↗
HLA antigens in plasma protein fraction and albumin.
Renal allograft survival is signficantly worse than average in recipients who have never had blood transfusions. It has been speculated that this might be explained by the fact that patients on chronic dialysis often received plasma protein fraction (PPF) instead of blood and that HLA antigens from serum were likely to present in PPF. We have examined four different lots of both PPF and albumin for the presence of HLA antigens. Using the microlymphocytotoxicity technique, each lot was tested for the ability to neutralize ten different antisera containing antibodies against well-defined HLA antigens. In every case, no inhibition was observed--even when the ratio of blood derivative to antiserum was as high as 256:1. These results suggest that if PPF and albumin do contain HLA antigens, they are present at levels too low to be detected by the cytotoxicity test routinely used in HLA typing.
Blood Proteins↗
The natural history of alloimmunization to platelets.
Sixty-three patients have provided evidence that platelets are highly immunogenic even in recipients of potentially immunosuppressive therapy for malignant diseases. Approximately 70 per cent of patients who receive repeated transfusions of platelets from random donors over a prolonged period can be expected to develop lymphocytotoxic antibodies. Antibodies became detectable in one patient ten days after his first exposure to HLA antigens in the form of platelet concentrates, and as early as four days in two patients with prior exposure to HLA antigens. In the most heavily immunized patients, the presence of antibody correlated with poor increments of platelets after transfusion. Patients with prior exposure to HLA antigens are more likely to have antibodies resulting in poor platelet survival. On the other hand, 30 per cent of recipients of repeated platelet transfusions show no tendency to form cytotoxic antibodies.
Adolescent↗
Transient bacteremia after dental procedures and other minor manipulations.
The devastating transfusion reaction that can occur after the infusion of blood contaminated with bacteria has prompted blood banks to adopt practices designed to minimize the possibility of bacterial contamination. There are four recognized sources of contamination of blood collected for transfusion: 1) prior contamination of the bag or the anticoagulant solution; 2) airborne contamination of the needle; 3) inadequate skin preparation including coring of the skin; and 4) bacteremia in the donor. The use of plastic collection bags and specially designed needles, and the recognition of the importance of aseptic technique have drastically reduced the incidence of serious transfusion reactions due to contamination. The history obtained from the donor prior to phlebotomy also eliminates many donors who could have bacteria in their blood at the time of donation. Improved collection techniques and the deferral of potential high risk donors have made serious reactions from contaminated blood a rare occurrance.
Blood Donors↗
Fibrinogen in cryoprecipitate and its relationship to factor VIII (AHF) levels.
Very little has been published to indicate the quantity of fibrinogen in cryoprecipitates. We assayed 88 preparations from five blood banks for factor VIII(AHF) and fibrinogen to assess whether the AHF assay can predict the fibrinogen content. Cryoprecipitate was considered to be consistent with FDA standards with 80 units of factor VIII/bag (40% yield from 200 ml plasma). Fibrinogen was considered adequate if 200 mg were recovered (40% yield, 200 ml plasma, normal range 150--350 mg/dl). The mean AHF was 145 units/bag and fibrinogen. In 64/88 bags, the fibrinogen and AHF were concordant, but in 24/88 bags the results were discordant. Although it appears safe to conclude that a bag of cryoprecipitate will average 250 mg fibrinogen, adequate control may require separate assays for fibrinogen.
Chemical Precipitation↗
Enzyme-linked antiglobulin test: an accurate and simple method to quantify red cell antibodies.
An enzyme-linked antiglobulin test was used to quantify the amount of IgG antibodies on red blood cells. Erythrocytes were sensitized with various blood group antibodies, washed, incubated with antiglobulin conjugated with alkaline phosphatase, washed, substrate was added and the optical density of the product was measured. This optical density was linearly proportional to the concentration of red blood cell antibodies incubated with the cells. The assay was easy to perform, had a standard deviation of 7 per cent on replicated assays, and was more sensitive than the manual antiglobulin test.
Antibodies↗
Red cell antibodies and low ionic strength: a study with enzyme-linked antiglobulin test.
Alloantibody uptake on red blood cells was quantified with an accurate and reproducible enzyme-linked antiglobulin test. The uptake of anti-D, anti-Fy2 and anti-JK3 was markedly accelerated by low ionic strength salt solution (LISS) with a final ionic strength of 0.05 M. Near maximum uptake occurred within ten minutes at room temperature which corresponded to 60 minutes in saline at 37 C. Papain treatment of red blood cells increased the amount of anti-D bound, and there was no difference whether or not the papain-treated cells were suspended in LISS. In contrast, the uptake of IgG anti-A and anti-Leb was not accelerated by LISS, nor did LISS increase the rate of binding of antiblogulin to IgG antibody-coated red blood cells. We suggest this may be explained by the fact that the ABH and Lewis antigens (as well as bound IgG antibodies) extend beyond the "ionic cloud" surrounding the red blood cell. Antibody binding in the presence of albumin was approximately the same as in saline; but if the albumin was first dialyzed against LISS, the reaction was markedly accelerated and the final antibody uptake somewhat higher than in LISS alone.
Animals↗
Plasma in platelet concentrates.
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Blood Coagulation Factors↗
M and N specific hemagglutinins of human erythrocytes stored in glucose solutions.
Alloagglutinins of M and N specificites with unique characteristics found in normal sera are described. Specific M or N agglutination by these sera occurred only when erythrocytes had been exposed to glucose-containing solutions. Conversion to the form of MN recognized by these sera required incubation of the cells in 1 to 2% glucose buffered to physiological or alkaline pH and was dependent on time and temperature of exposure, occurring in hours at 37 C and in days at 4 C. The sera appeared to be detecting an antigenic structure in which interaction between glucose and the amino group of the N-terminal amino acid of the MN receptor has produced a new specificity, analogous to the action of formaldehyde on N receptors and the resulting N-like structure detected by sera from hemodialysis patients.
Absorption↗
Deformability of stored red blood cells. Relationship to degree of packing.
An ektacytometer was used to measure red blood cell deformability during blood storage for 42 days at different degrees of cell packing in citrate-phosphate-dextrose preservative. Observed changes in deformability were studied in relationship to red blood cell adenosine triphosphate (ATP) levels, lipid content, osmotic fragility, and hematocrit during storage. Decrease in whole cell deformability as measured in isotonic medium did not occur until cellular ATP levels were reduced to less than 30 percent of initial values. The rate of deformability loss during storage increased with increased degrees of cell packing because of more rapid substrate depletion. The loss in isotonic deformability was further magnified when deformability measurements were carried out in hypotonic media, suggesting that a reduction in surface area-to-volume ratio was the dominant cause of the reduced deformability of stored red blood cells. Marked spherocytosis, decreased membrane lipid content and increased osmotic fragility confirmed loss of membrane surface area during storage. The significantly higher rate of deformability loss observed in packed red blood cells suggests that careful control of storage hematocrit may be necessary to avoid loss of cellular deformability and possibly posttransfusion viability.
Adenosine Triphosphate↗
Lewis incompatibility.
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Blood Group Incompatibility↗
Experience with 11,916 designated donors.
From June, 1984, through December, 1985, Irwin Memorial Blood Bank drew 11,916 designated donors. The original protocol, filled with barriers that the donors and patients had to follow, was changed to an open protocol that was easy to follow. Patients wanted to participate in the program regardless of the obstacles so we removed them, making it easier for the patients and donors as well as the staff at the blood bank. 3063 designated donors were compared to 3201 homologous and 3439 first-time, non-designated donors. The three groups did not differ in any of the comparisons, deferral rate, age, sex, race, blood type, and test results. We conclude that these designated donations were no safer but no less safe than donations not designated.
Blood Banks↗
Specificity of enzyme immunoassay for hepatitis B core antibody used in screening blood donors.
Hepatitis B core antibody (anti-HBc) is currently tested by a competitive inhibition enzyme immunoassay (EIA), using recombinant DNA-produced core antigen. We have used the anti-HBc assay in routine screening of voluntary blood donors in San Francisco. The detection rate of anti-HBc was 2.08 percent. The specificity of the antibody test was established by an absorption method using purified HBc antigen (HBcAg) produced by recombinant DNA technology and covalently coupled to Sepharose 4B. Bovine serum albumin was used in the preparation of a control conjugate. The absorption test demonstrated that out of 98 anti-HBc-positive specimens, 97 could be specifically neutralized. Only one specimen was indeterminate. The absorption test was particularly useful in confirming the specificity of EIA in eight specimens inconsistently positive for anti-HBc. We conclude that the current EIA for anti-HBc is highly specific and we are of the opinion that it could be used as a rational basis for donor deferral since it gives evidence of active or previous HBV infection.
Blood Donors↗