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Biomedical subjects

A A Waldman

Publications and source records attributed to A A Waldman.

18 recordsLinked to original sources
PubMed1985

Biochemistry of whole blood in poly(ethylene-co-ethylacrylate) experimental blood containers.

The biochemical status of whole blood stored in containers fabricated of ethylene ethylacrylate (EEA) film was monitored at several times during 4 weeks of storage at 4 degrees C. Fifteen biochemical indicators were studied to reflect on erythrocyte integrity, cellular metabolism, plasma protein stability, and microaggregate formation. Comparison to storage in polyvinyl chloride (PVC) containers was made by distributing aliquots from each unit of blood among the containers being compared. Whole blood in EEA developed significantly higher levels of plasma hemoglobin, erythrocyte osmotic fragility, and D-glycerate-2,3-diphosphate (2,3-DPG), and somewhat greater glucose utilization, lactate production, and pH. These biochemical differences were not of great magnitude and the data suggest that EEA containers are compatible with the storage of whole blood.

Acrylic Resins↗
PubMed1985

Stabilization of red blood cells by the plasticizer, diethylhexylphthalate.

The red blood cells of blood stored in containers made of polyvinylchloride (PVC) film are osmotically more stable and lose on average about 1/3 less hemoglobin than when blood is stored in another plastic [poly-(ethylene-co-ethyl acrylate); EEA]. The stability of uniform volumes of stored red blood cells varies directly with PVC surface area, whereas changes in EEA surface area have comparatively little or no effect. PVC contains high concentrations of the plasticizer, diethylhexylphthalate (DEHP), known to migrate into blood and to have a high potential for toxicity. To determine if DEHP could be the red cell stabilizing agent in PVC, whole blood was stored in containers made from EEA into which was incorporated varying amounts of DEHP. Incorporation of DEHP into EEA significantly reduced erythrocyte osmotic fragility (p = 0.01). The degree of reduced fragility correlated with the level of DEHP in the cell phase implicating DEHP in PVC containers as the stabilizing agent for red cells.

Acrylic Resins↗
PubMed1985

Granulocyte enriched buffy coat transfusions in neutropenic patients.

Twenty four courses of granulocyte enriched buffy coat transfusions were administered to 22 different infected neutropenic patients. Those patients who received an average of greater than or equal to 13 units per transfusion, which represented a mean of 1.02 X 10(10) granulocytes, had a survival rate of only 30% which was not significantly different from the 28.5% found among patients who received an average of less than or equal to 12 units per transfusion, which represented a mean of .63 X 10(10) granulocytes. In addition, no significant difference in survival rate was found between patients who received a course of greater than or equal to four transfusions and those who received a course of less than or equal to three transfusions. Finally, no significant difference in survival rate was found between patients with acute leukemia and those with other disorders or between patients with positive cultures and those whose cultures were negative. Given the poor clinical results associated with buffy coat transfusions, it is concluded that every effort should be made to recruit single leukapheresis donors for the support of infected neutropenic patients, rather than use granulocyte enriched buffy coats as they are presently produced.

Adult↗
PubMed1984

Strategies for detection of transfusion-transmitted viruses eluding identification by conventional serologic tests. II. Detection of host DNA in human plasmas with elevated alanine aminotransferase.

As a prelude to the development of nucleic acid probes specific for non-A, non-B hepatitis virus(es) (NANBV), plasmas with alanine aminotransferase levels greater than or equal to 110 IU were assayed for DNA by a radioimmunoassay. Approximately 50% of such plasmas are expected to contain NANBV. One-hundred and seventy-eight of 420 plasma samples tested (42.4%) contained sequestered DNA resistant to DNAse I. The DNA has a molecular weight of approximately equal to 0.8 to 1.4 X 10(6) daltons and hybridizes with a 32P-labeled human DNA probe. The DNA in plasma is mostly bound to IgM. The presence of host DNA will have to be taken into account in planning experiments aiming at the preparation of nucleic acid probes specific for NANBV using infected plasmas as source material. Such experiments will have to utilize recombinant DNA technology and will require the separation of bacterial colonies containing recombinant DNA with viral DNA sequences from colonies with human DNA inserts. The feasibility of this approach is demonstrated using plasma-containing hepatitis B virus.

Alanine Transaminase↗
PubMed1982

Transfusion of granulocyte rich buffy coats to neutropenic patients.

Granulocyte rich buffy coats were transfused to infected neutropenic patients when leukapheresis donors were not available. Efficacy of transfusions was evaluated from data supplied by hospitals administering them. Buffy coats separated from ACD blood contained a mean of 4.9 X 10(8) granulocytes. Fifty-seven patients received a course consisting of a mean of 3.8 transfusions. Of these, 27 received a mean of 17.5 units per transfusion and had a survival rate of 44.4%, which was not significantly different from the 50.0% found in 30 who received a mean of 11.1 units per transfusion. No significant difference in survival rate was found between 31 patients with acute leukemia and 26 with other disorders or 38 patients with positive and 19 with negative cultures. Finally, no significant difference in survival rate was noted between patients who received a course of greater than or equal to four transfusions or less than or equal to three transfusions in any of the above groups. Survival rates were less than those generally reported following similar courses of leukapheresis units. Buffy coat transfusions consisting of a mean of approximately 17.5 units as produced during this study have therefore been shown to be not generally beneficial. The increased survival seen in some studies utilizing leukapheresis products may relate in part to the larger number of granulocytes they contained. Greater benefit from buffy coat transfusions might result if the number of granulocytes infused were increased. Evaluation of possible efficacy associated with transfusions of increased numbers of buffy coat units further enriched with granulocytes may be justified when leukapheresis donors are not available.

Adult↗
PubMed1979

Human leukocyte interferon: production, purification to homogeneity, and initial characterization.

A method of fractionating proteins by high-performance liquid partition chromatography has been developed and used for isolation and purification to homogeneity of one of the species of human leukocyte interferon. The homogeneous interferon exhibited a sharp peak on high-performance liquid chromatography and a single narrow band on sodium dodecyl sulfate/polyacrylamide gel electrophoresis in the presence of 2-mercaptoethanol. Extraction of the gel gave a single sharp peak of antiviral activity coinciding with the protein band. The specific activity of pure interferon was found to be 2--4 X 10(8) units/mg, based on amino acid analysis. The molecular weight is 17,500--18,000.

Amino Acids↗
PubMed1978

Human leukocyte interferon purified to homogeneity.

One of the species of human interferon produced by incubation of leukocytes with Newcastle disease virus was purified to homogeneity. It exhibited one peak of activity coinciding with a single protein band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Humans↗
PubMed1975

Isolation of rabbit reticulocyte initiation factors by means of heparin bound to sepharose.

Passage of cell-free extracts of rabbit reticulocytes through heparin-Sepharose affinity columns results in the loss of the ability of the effluent to initiate protein synthesis. This is shown by the loss of response to added rabbit globin mRNA or to inhibitors of initiation of protein synthesis, such as heparin and aurin tricarboxylic acid, and by recovery of initiation activity by addition of protein retained and subsequently eluted from the columns. The effluent retains, however, the ability to elongate protein chains. Only 0.8% of the applied cell extract protein binds to heparin-Sepharose columns. This bound protein, which can be recovered by increasing the salt concentration of the eluting buffer, has initiation factor activity equal to that of a crude initiation factor preparation obtained from rabbit reticulocyte ribosomes by extraction with 0.5 M KCl. The protein patterns on polyacrylamide gels of the initiation factors prepared by either method are very similar and indicate a protein mixture, which may represent a complex. These data confirm that heparin interacts specifically with initiation factos, and indicate that heparin-Sepharose chromatography will simplify procedures for the preparation of initiation factors.

Animals↗