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Biomedical subjects

N Blumberg

Publications and source records attributed to N Blumberg.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Platelet collection and transfusion using the fenwal CS-3000 cell separator.

A prototype model of the Fenwal CS-3000 Blood Cell Separator (Deerfield, IL) was studied for plateletpheresis in 63 donors and 5 transfusions in patients. Donor effects were consistent with platelet removal and mild hemodilution. The incidence of reactions (9 of 63) was low and all were mild "citrate" type. A two-hour collection yielded 4.0 +/- 0.72 x 10(11) platelets at an efficiency of 45 +/- 6.9 per cent. The product had little contamination with leukocytes (0.26 +/- 1.2 x 10(9) and red blood cells (hematocrit less than 1%). Morphology and pH were well preserved during 24 hours of storage. Four patients with uncomplicated aregenerative thrombocytopenia were transfused on five occasions, with a mean of 4.5 +/- 0.87 x 10(11) platelets resulting in a mean platelet count increment of 55,000/microliter and dramatic reduction in template bleeding times.

Blood Platelets↗
PubMedDate not supplied

Incidence of adverse reactions in blood donors taking antihypertensive medications.

A study was performed to determine whether donors taking antihypertensive medications other than "beta blocking agents" have an increased incidence of vasovagal reactions to blood donation. A total of 546 reactions were observed in 16,424 blood donors over a period of 3 months. First-time donors had a significantly higher frequency of reactions than repeat donors. Eighty-five percent of all donors were experienced donors and 96 percent of those taking antihypertensive medication were experienced donors. The reaction rate in repeat donors was not significantly different for those taking antihypertensive medication as compared with those not taking medication. Over 97% of all reactions were mild. The deferral of donors taking antihypertensive medication is not indicated when blood pressure is normal, symptoms are absent, and diuretics or similar agents are the only drugs used.

Antihypertensive Agents↗
PubMedDate not supplied

A technetium-99m red cell survival technique for in vivo compatibility testing.

A technique for labeling red cells with Technetium-99m was developed using in vitro reduction by stannous pyrophosphate. The use of Technetium-99m and Chromium-51 enabled simultaneous determination of 60-minute autologous and heterologous red cell survival using small aliquots. In vivo pretransfusion red cell compatibility in a patient with a panagglutinin was identical to that with 51Cr-labeled cells. Simultaneous testing of two heterologous donor units or testing multiple units in the course of a few days was also feasible. In nine studies (one patient and six healthy controls) no significant elution of the 99mTc was observed over 1 hour.

Aged↗
PubMedDate not supplied

A critical survey of fresh-frozen plasma use.

The use of 534 units of fresh-frozen plasma (FFP) during 160 transfusion episodes in 135 consecutive patients was reviewed. Only 27 percent of transfusions were indicated by a need for replacement of labile coagulation factors. Other uses included volume repletion (31%), intraoperative bleeding or massive transfusion without coagulopathy (19%), and miscellaneous indications unrelated to labile coagulation factors (23%). Data from other institutions and national sources support the hypothesis that much of the increase in FFP use over the last decade is related to decreases in whole blood availability rather than to use for labile coagulation factor replacement. The use of FFP and red cells as a substitute for, or in preference to, whole blood may have significant adverse implications in terms of the cost and safety of blood transfusion.

Blood Coagulation Disorders↗
PubMedDate not supplied

Neutralization of P blood group antibodies by synthetic solid-phase antigens.

P blood group system antibodies are encountered frequently in clinical transfusion practice. The authors describe an improved method for removing P antibodies from patient specimens without dilution. Solid-phase synthetic P antigens were used to neutralize serums containing P blood group system antibodies; 26 alloantibodies with specificity other than P were not inhibited. The synthetic P antigens are also used to characterize the heterogeneous immunochemical fine specificity of antibodies to P1 and P + P1 + Pk.

Adult↗
PubMedDate not supplied

A chloroquine elution technique for platelet serology.

The authors describe a prototype elution method employing chloroquine, a quinoline derivative, to elute IgG antibodies from the platelet surface. This chloroquine elution technique is relatively easy to perform and is effective in the removal of alloantibodies from the platelet surface. Eluted alloantibody was immunologically active once the chloroquine was removed from the eluate. The major advantage of this technique is that serologic testing of platelets after elution is possible, as 50 percent of the platelets remain after exposure to hypertonic acid chloroquine solution. Antigens on the platelet surface maintained their antigenicity subsequent to treatment, although measurable reductions in PIA1 reactivity occur. The elution technique was also successful in removing IgG from the platelet surface in patients with diseases involving elevated levels of platelet-associated IgG.

Binding Sites, Antibody↗
PubMedDate not supplied

The importance of ABH antigens in platelet crossmatching.

In the present study, the frequency with which ABH incompatibility could be detected in platelet crossmatches was determined. The effect of chloroquine elution on ABH antigens was also evaluated, and a technique was developed to remove IgG anti-A from group O plasma using a chemically synthesized human blood group A trisaccharide antigen covalently linked to crystalline silica (Synsorb-A). Group O plasmas were found to be incompatible with 52 percent of group A platelets and 17 percent of group B platelets (p less than 0.05). In contrast, anti-A from group B plasmas rarely produced a positive crossmatch, and no anti-B that reacted with platelets could be demonstrated in group A plasmas. IgG anti-A reactions with group A platelets were eliminated in 100 percent of the group O plasmas tested after treatment with the synthetic solid-phase immunoadsorption technique. Synsorb-A may be a useful adjunct to platelet serologic testing when group O sera need to be tested against A platelets. Group A platelets bound less anti-A after exposure to chloroquine, but only 17 percent of platelets became negative when crossmatched with group O plasma. It was concluded that increased IgG binding occurs in a majority of platelet crossmatches using a k-ELISA technique when group O recipients are tested against group A donors. These results offer a potential explanation for conflicting results in studies of transfusion results with ABH-incompatible platelets. Transfusions of group B platelets to incompatible recipients may be more likely to yield satisfactory increments than incompatible transfusions of group A platelets, but this remains to be proven. There appear to be significant differences between red cells and platelets in regard to serologic reactivity in the ABH system.

ABO Blood-Group System↗
PubMedDate not supplied

Infection or suspected infection after hip replacement surgery with autologous or homologous blood transfusions.

Homologous blood transfusions have been associated in both animals and humans with an increased risk of acute postoperative infectious complications. Eighty-four patients who underwent hip replacement surgery and were transfused with 2 or 3 units of blood were analyzed to determine whether those receiving homologous transfusions had different outcomes than those receiving autologous blood only. Only patients free of other risks for postoperative infection were studied. Those receiving homologous blood had a 32 percent (16/50) rate of proven or suspected infections, which was significantly higher than the 3 percent (1/34) rate in patients receiving autologous blood (p = 0.0029). Wound infections accounted for only a minority (6/17) of the proven or suspected infections, which suggests that nonsurgical factors contributed to these complications. The patients identified as being infected required significantly more antibiotic therapy (mean, 7.6 days) and lengthier hospital stays (mean, 15.5 days) than the patients who remained free of evidence of infection (means: 2.3 days of antibiotics and 12.3 days in the hospital) (p = 0.0001 for each variable). Other potential risk factors for infection, such as duration of surgical procedure, advanced patient age, amount of blood loss, type of anesthesia, surgeon performing the operation, use of a cemented versus porous-coat prosthesis, leukocytopenia, anemia, and underlying medical diagnosis, did not account for the differences in infection rates seen in those receiving homologous and autologous transfusions. These results confirm previous reports of an increased risk of postoperative infection in patients receiving homologous transfusions. Homologous transfusion may contribute to an increased risk of infection by immunologic modulation of the recipient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

A clinical and immunologic study of blood transfusion and postoperative bacterial infection in spinal surgery.

Allogeneic blood transfusion has been implicated as an independent risk factor for postoperative bacterial infection in clinical and animal studies. The association among transfusion, quantitative immunologic factors, and infection was examined in 102 patients undergoing 109 spinal fusion procedures. In 60 procedures, patients received autologous blood only; in 24 procedures, they received at least 1 unit of allogeneic blood, and in 25 procedures, they received no transfusions. Twenty-two patients developed bacterial infections, in 8 cases while in hospital and in 14 cases after discharge. Univariate analysis revealed that patients who received any allogeneic blood and those who received no allogeneic blood differed significantly in the rate of hospital-acquired infection (20.8 vs. 3.5%), length of stay (12.3 vs. 9.7 days), days of fever greater than or equal to 38 degrees C (4.0 vs. 2.9), days on antibiotics (3.9 vs. 2.5), duration of surgery (309 vs. 231 min), blood loss (1343 vs. 887 mL), surgeon, and postoperative drop in natural killer (NK) cells (-174 vs. -42/microL). Multivariate logistic and linear regressions revealed that the number of allogeneic units transfused was the only significant predictor of in-hospital infection (p = 0.016) or days on antibiotics and length of stay. None of the clinical, surgical, or transfusion variables was significantly associated with posthospital infection, although a significantly greater drop in NK cells had occurred in patients who developed infection (p = 0.0035). These data strongly implicate allogeneic transfusion as a risk factor for in-hospital postoperative bacterial infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗