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Biomedical subjects

L I Friedman

Publications and source records attributed to L I Friedman.

At least 37 records · Page 2Linked to original sources
PubMed1989

Evaluation of technical and behavioral issues in predonation alanine aminotransferase testing.

To evaluate the technical and behavioral impact of predonation alanine aminotransferase (ALT) testing, one group of 2914 donors (Reflotron group) were tested with the Boehringer Mannheim Reflotron instrument; 3042 control group donors had no predonation test. Mobile blood collection sites in three regional blood centers were studied. More Reflotron group donors than control group donors thought that predonation testing did not add time and was a good idea. Both groups were equally satisfied with the donation process and indicated they would donate again even if testing added time. Comparison of the Reflotron and standard laboratory tests showed excellent correlation with low variability. The mean r value was 0.934, with a mean sensitivity of 94.4 percent and a specificity of 99.8 percent. The staff working with the Reflotron group found predonation testing easy to incorporate into donor screening. They observed that donors were pleased with testing and accepting of deferral counseling for elevated ALT. The control group staff was concerned that predonation testing would require more time and would have a negative effect on the donor return rate. This did not appear to be the case as judged by donor response and the 6-month return rates of 50 percent for Reflotron group and 54 percent for control group donors.

Alanine Transaminase↗
PubMed1986

Application of robotics in blood banking.

To demonstrate the feasibility of using robots in blood banking applications several prototype systems were developed. Activities associated with sample testing and component preparation were examined. In one project, a general-purpose laboratory robot (Zymate Laboratory Automation System, Zymark, Inc., Hopkinton, Mass.) was configured to prepare samples for microplate-based ABO/Rh testing. In a second project, this same robot was configured to carry out specific steps in evaluating bar-coded labels, as part of a quality control procedure. A fluid-handling robot (Sampler 505, Tecan AG, Hombrechtikon, Switzerland) was used to prepare the dilution of serum samples for the evaluation of an anti-HTLV-III test kit. It was then configured to aspirate, dilute and dispense samples for anti-HTLV-III and HBsAg testing. This robotic system is now in field trial. The use of large industrial robots for automating component production was also considered. The key element in this design was the development of a fixture that would hold the blood bag set during the balancing, centrifugation and expressing steps. However, a fixture which was capable of performing these operations and that was equivalent in size and adaptable to a standard centrifuge bucket could not be fabricated.

Antibodies, Viral↗
PubMed1986

A flow system for the study of shear forces upon cultured endothelial cells.

A parallel plate chamber in a flow system has been designed to study the effects of fluid shear stresses on cells. The system was applied to the study of cultured endothelial cells grown on cover slips which were accommodated in recessed wells in the base plate. Dye injection studies in the chamber indicated laminar flow over the cells. Shear rates measured over the cover slips by an electrochemical technique were found to be linear with flow rate. Laser doppler anemometry showed parabolic profiles between the plates. Endothelial cells subjected to flow showed a correlation between the time required for orientation and the magnitude of the shear stress.

Biomechanical Phenomena↗
PubMed1984

Automated determination of ABO/Rh in microplates.

A semi-automated system for determining the ABO group and Rh type of blood samples has been developed using a commercially available automated microplate (ELISA) reader and a microcomputer. Optimization of serologic, measurement and interpretation parameters was accomplished without significantly changing an existing manual procedure. The first pass noninterpretation rate of this system in the laboratory prior to field trials is 7.1%. A commercial system of this type should be cost-effective as a primary instrument for small to medium sized blood centers and transfusion services.

ABO Blood-Group System↗
PubMed1984

Enhanced production of human gamma-interferon in nylon column-fractionated cell cultures.

The production of human gamma-interferon (HuIFN-gamma) in unfractionated and nylon wool column-fractionated leukocyte cell cultures stimulated with PMA and PHA was investigated. Production was studied with normal and reduced autologous serum protein levels in 96-hr spinner cultures. A 10- to 15-fold enhancement of production and a 50-fold increase in specific activity of crude HuIFN-gamma was demonstrated in nylon column-fractionated/reduced serum cell cultures. Kinetic analysis revealed a production rate maximum within 6 hr of induction in unprocessed cell cultures, whereas production occurred at an essentially constant rate for 48 hr in fractionated cell cultures.

Blood Proteins↗
PubMed1983

Evaluation of membranes for plasmapheresis.

Commercial flat-sheet microporous membranes were evaluated for potential use in plasmapheresis with a specially designed filtration module. Significant differences in filtration rates were observed with different membranes. Saline filtration data were not useful in predicting the capacity of the membranes to filter plasma from whole blood. For all membranes studied, no rejection of plasma proteins was detected. No activation or deactivation of clotting factors was detected as a result of filtration. In addition, little or no hemolysis was caused by filtration with the various membranes. Saline, cell-free plasma, platelet-poor plasma, and whole blood were perfused over a track-etched membrane and the resulting filtration rates were compared. The cell-free plasma filtration rate decreased significantly with time, probably owing primarily to protein adsorption in the membrane pores. Cell-free plasma and saline filtration data were used to calculate an apparent adsorbed layer thickness in the membrane pores. Perfusion of platelet-poor plasma and whole blood resulted in time-dependent filtration rates that were much lower than those obtained when cell-free plasma was perfused. Results of the study support recent theoretical models that postulate that the rate-limiting process for blood filtration is the formation of a layer of blood cells (particle polarization) on the membrane surface.

Blood Coagulation↗
PubMed1982

Reducing the incidence of non-A,non-B post-transfusion hepatitis by testing donor blood for alanine aminotransferase: economic considerations.

Recent studies have established a relation between elevated alanine aminotransferase levels in donor blood and the incidence of non-A, non-B hepatitis in recipients of such blood. Routine testing of donor blood for alanine aminotransferase activity in order to reduce hepatitis is not currently supported, largely because the results of such testing are unknown. We assessed the potential economic benefits of screening donor blood for alanine aminotransferase as a means to reduce post-transfusion hepatitis. Benefits, defined as the expected costs of hepatitis potentially avoided, ranged from $898 to $31,629 per 1000 blood units collected. This wide range reflected lack of information about the natural history of non-A, non-B hepatitis. Costs were defined as the direct costs of testing and the indirect costs associated with loss of blood product, additional donor recruitment, and informing donors of their abnormal aminotransferase levels; costs ranged from $3,151 to $4,003 per 1000 units. Our results suggest that if prospective studies demonstrate that exclusion of blood with elevated aminotransferase levels decreases non-A, non-B hepatitis in recipients, the net economic impact may be positive. However, because of major uncertainties about the medical consequences of non-A, non-B hepatitis, the benefit estimates are so broad that they preclude a definitive policy decision.

Alanine Transaminase↗
PubMed1982

Production and recovery of human leukocyte-derived alpha interferon using a cascade filtration system.

The use of a cascade filtration system for production and recovery of human leukocyte-derived alpha interferon (HuIFN-alpha) has been investigated. Included in the investigation were mass transfer studies of HuIFN-alpha across ultrafiltration membranes, design and evaluation of a laboratory-scale production system and determination of IFN production kinetics in both batch and filtration systems. The cascade filtration system allows separation of interferon from leukocytes and virus during production with simultaneous concentration and complete recovery. Kinetic studies indicate that HuIFN-alpha production can be enhanced by appropriate timing of the filtration procedure. While the current study is concerned with HuIFN-alpha, it is expected that the techniques developed will be applicable to the production and recovery of both natural and recombinant IFNs and lymphokines in general.

Cell Survival↗
PubMed1981

Overview, history, evaluation and future developments of the AutoGrouper 16-C.

This paper presents an overview and history of the Technicon blood-grouping machine from the first single-channel AutoAnalyser of 1963 through to the new, fully automated AutoGrouper 16-C. The report includes an analysis of facts drawn from a detailed evaluation of the AutoGrouper 16-C including its installation, performance, reliability, simplicity of operation, detection of irregular antibodies, syphilis screening, use of reagents and a brief cost analysis.

ABO Blood-Group System↗
PubMed1975

A computerized national Blood Donor Deferral Register.

With blood given exclusively by volunteer donors, the American National Red Cross (ANRC) Blood Program aims to supply patients needing transfusion with blood products of the highest quality. The use of blood from volunteers, with its established greater safety, combined with laboratory testing to detect carriers of hepatitis B surface antigen (HB-SAg) and modern computer technology, creates an effective system to reduce the risk of post-transfusion hepatitis. The ANRC has devised a national Donor Deferral System, which is designed to minimize the transmission of hepatitis by blood and blood products.

Blood Banks↗