Biomedical subjects

G A Ludwig

Publications and source records attributed to G A Ludwig.

6 recordsLinked to original sources

PubMed1996

Providing leukocyte-reduced platelets using the CS-3000 PLUS.

Reducing leukocyte (WBC) contamination of platelet (PLT) concentrates diminishes some adverse effects associated with transfusions. To provide WBC-reduced PLTs, we initiated a program using bedside filtration. However, the inability to easily quantitate WBC removal and PLT loss at the bedside prompted us to perform filtration in the blood bank. To establish optimal methods, production of WBC-reduced PLTs using the CS-3000 PLUS was studied in three phases, during which technical modifications were made. During phase 1, prestorage WBC reduction was performed using the PALL LRF-10H filter, sterilely connected. WBC reduction was satisfactory, but PLT loss was excessive. During phase 2, the PLT-30 collection chamber and Fenwal Closed System Apheresis Kit with Integral Sepacell Leukocyte Reduction Filter were used. PLT yields were improved, but now WBC contamination was excessive. During phase 3, the interface offset was reduced from 10 to 6, and both PLT yields and WBC reduction were satisfactory. Using this final method (CS-3000 PLUS, PLT-30 collection chamber, integral filter and offset setting of 6), the mean PLT yield per unit is 4.29 x 10(11) (N = 1,146), and the mean WBC contamination is 0.50 x 10(6) (N = 32).

Blood Banks↗

PubMed1996

AS-1 red cells for neonatal transfusions: a randomized trial assessing donor exposure and safety.

BACKGROUND: Despite recent optimism about the use of erythropoietin therapy to treat the anemia of prematurity, very-low-birth-weight infants who are severely ill receive multiple red cell (RBC) transfusions. Many physicians transfuse relatively fresh RBCs to newborn infants, exposing them to multiple donors and possibly increasing their risk of acquiring transfusion-transmitted infections. STUDY DESIGN AND METHODS: A randomized, single-blind clinical trial was conducted to determine, as the primary endpoint, whether RBCs collected from one dedicated donor and stored for < or = 42 days in AS-1 storage media could safely supply all small-volume RBC transfusions (15 mL/kg/dose) needed by very-low-birth-weight infants (0.6-1.3 kg) during the first 84 days of life. Secondary endpoints were the assessment of the possible adverse clinical and biochemical effects of transfusing AS-1 RBCs stored for < or = 42 days. Control infants received identical nursery care, except they received fresh RBCs stored < or = 7 days in CPDA-1. RESULTS: Infants transfused with AS-1 RBCs were exposed to a mean of 1.6 donors,-compared with an exposure to 3.7 donors for infants given CPDA-1 RBCs (p < 0.05). Neither clinical transfusion reactions nor the results of multiple laboratory tests were significantly different in infants who received slow transfusions (15 mL/kg) of AS-1 RBCs stored for < or = 42 days and in infants who received the same volume of CPDA-1 RBCs stored < or = 7 days. CONCLUSION: AS-1 RBCs, usually from only one dedicated donor, can safely supply all RBCs needed by most very-low-birth-weight infants-a practice that decreases donor exposure and likely increases transfusion safety.

Adenine↗

PubMed1994

Concurrent comparison of the safety of paid cytapheresis and volunteer whole-blood donors.

BACKGROUND: Historically, paid blood donors were found to transmit hepatitis at higher rates than volunteers. In those older studies, paid donors frequently were recruited from prisons or slum areas--a finding consistent with the belief that monetary payment in itself did not necessarily lead to the high-risk status of commercial blood. Instead, it was the population base from which the donors were recruited that was important. STUDY DESIGN AND METHODS: Today, cytapheresis donors are in great demand. Because payment is one incentive that might entice donors to undertake the increased commitment of repeated cytapheresis donation, the results were studied of infectious disease history and laboratory testing performed concurrently in 917 volunteer whole-blood donors and 1240 paid cytapheresis donors, who were enrolled in distinct programs at the DeGowin Blood Center from October 7, 1987, through November 30, 1990. RESULTS: When first, repeat, and overall donations made by these donors were evaluated separately, paid cytapheresis donors were found to exhibit no increase in infectious disease history or test results beyond those of volunteer whole-blood donors. CONCLUSION: Thus, paid cytapheresis donors, when managed within a formal program, should not necessarily be presumed to be more dangerous than volunteers, from an infectious disease aspect. However, definitive proof of safety (comparison of transfusion-transmitted infection rates in two groups of patients receiving blood components exclusively from either paid cytapheresis or volunteer donors) was not pursued by long-term follow-up studies.

Blood Donors↗

PubMed1993

Comparison of plateletpheresis with a standard and an improved collection device.

A blood cell separator with a specialized separation chamber ([TNX-6]CS-3000 Plus) was developed for the collection of platelet concentrates with higher platelet yields and lower white cell contamination than obtained with the standard blood cell separator (CS-3000). To compare these devices, normal donors were scheduled for paired plateletpheresis procedures spaced 4 weeks apart, with one procedure using the CS-3000 Plus and the other using the CS-3000. Overall, the platelet yield per unit (mean +/- SEM) was 4.3 +/- 0.1 x 10(11) with the CS-3000 Plus versus 3.7 +/- 0.1 x 10(11) with the CS-3000 (p < 0.001), and the white cell contamination per unit (mean +/- SEM) with the former was 2.4 +/- 0.7 x 10(6) versus 84.1 +/- 21.1 x 10(6) with the latter (p < 0.001). The sequence of procedures (i.e., the order in which the devices were paired) was selected randomly, and similar results were found regardless of sequence. When donors with predonation platelet counts of > or = 200 x 10(9) per L (n = 21) were studied separately, 76 percent of the collections by the CS-3000 Plus contained > or = 4 x 10(11) platelets versus 34 percent of those by the CS-3000 (p < 0.01), and 93 percent of the collections by the former contained < 5 x 10(6) white cells (69% contained < 1 x 10(6)) versus 0 percent of those by the latter (p < 0.01). Thus, platelet collections with the TNX-6 chamber consistently demonstrated high platelet yields and strikingly low white cell contamination--qualities that justify converting standard devices to devices with a TNX-6 chamber.

Cell Separation↗

PubMed1991

Efficacy and safety of Fenwal CS-3000 plateletpheresis performed at a rapid donor blood flow rate: rapid plateletpheresis with Fenwal CS-3000.

Results of 3,214 plateletpheresis procedures, using the Fenwal CS-3000 cell separator, were reviewed to determine the effects on performance when the donor blood flow rate was increased by 30% (i.e., to 65 ml/min instead of 50 ml/min). Ninety-two percent (2,962 of 3,214) of procedures completed the rapid flow protocol, and results were compared with those reported by others using the more conventional blood flow rates of 32-55 ml/min. When the rapid flow procedure was used, mean platelet yields (4.07 x 10(11)) and leukocyte contamination (2.65 x 10(8)) were satisfactory, and major donor reactions were infrequent (0.6% of procedures). Thus, CS-3000 plateletpheresis can be performed at a relatively rapid, donor blood flow rate of 65 ml/min to shorten the procedure and make it more appealing to donors.

Blood Flow Velocity↗

PubMed1975

Binding of the sulfates of estradiol-17beta to human serum albumin and plasma.

The binding of the 3 estradiol-17beta sulfates in solutions of human serum albumin (HSA) and in plasma has been studied by the method of centrifugal ultrafiltration. HSA has one binding site for the 17-sulfate with association constants of about 10(5) to 10(6)M-1 at either 4 degrees or 37 degrees and several sites with association constants of 10(3) to 10(4) M-1. HSA has 3 groups of binding sites for estradiol-17beta disulfate, one binding site with association constants of about 10(6) M-1 at either 4 C or 37 C, about 2 binding sites with association constants of about 10(4)M-1 and several sites with association constants of about 10(3)M-1. The binding data of the 3-sulfate of estradiol-17beta are best interpreted by the postulate of the existence of a tetramer in addition to the monomer of the sulfate in solution. With this postulate, HSA has one binding site with an association constant of about 5-10(5)M-1 and seven binding sites with association constants of about 10(3)M-1 at either 4 C or 37 C. More than 99% of the 17-sulfate or the disulfate of estradiol-17beta is bound in plasma at 37 degrees, with all of the binding accounted for by HSA. The estradiol-17beta sulfates compete with one another for binding to HSA. Strong displacement has also been found by androgen sulfates and, less, by estrogen glucosiduronates.

Adult↗