Browsing by Author "Sink, Carolyn A."
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- Canine Platelet Concentrates: An In Vitro Study to Effectively Provide a Source of Functional PlateletsSink, Carolyn A. (Virginia Tech, 2002-03-25)This study monitored the storage lesion of 15 units of canine platelet concentrates harvested by differential centrifugation. Canine platelet concentrates were stored at 20-24°C in a platelet rotator for a total of 9 days; the storage lesion of three second generation platelet storage containers was compared. The battery of in vitro tests used to monitor the storage lesion were selected from previous studies performed with human platelet concentrates separated by differential centrifugation. Based on these tests, canine platelet concentrates exhibited a storage lesion similar to human platelet concentrates. Metabolic analytes demonstrated decreasing pH, carbon dioxide, bicarbonate and glucose concentrations concurrent with increasing oxygen and lactate dehydrogenase activity over the 9-day period. Platelet structural changes were monitored by mean platelet volume, which began to increase on Day-5. Platelet function appeared to be compromised, as indicated by aggregation studies using collagen and adenosine diphosphate as agonists. Product sterility was maintained. There was no consensus of data supporting superior performance of one platelet storage container. This study indicates that canine platelet concentrates may be harvested by differential centrifugation of whole blood. In vitro studies utilizing three second-generation platelet storage bags support a previous study and concurs that canine platelet concentrates stored at 20-24°C using continuous agitation are viable for at least 5 days.
- Comparison of platelet counting technologies in equine platelet concentratesO'Shea, Caitlin Mary (Virginia Tech, 2014-04-16)Platelet rich plasma (PRP) is a popular autologous biological therapy used for the treatment of various equine ailments, including tendon and ligament injuries, osteoarthritis, and cutaneous wounds. A number of commercial products are available for producing PRP, each generating a slightly different product. Variations in platelet numbers and white blood cell (WBC) counts are believed to be the most critical variables, as they are directly related to concentrations of growth factors and inflammatory cytokines. Accurate documentation of platelet numbers is essential for prospective evaluation of clinical outcomes, but can be problematic in platelet concentrates depending on the counting method employed. The objectives of this study were to compare the performance of four platelet counting technologies in equine platelet concentrates and to evaluate the ability of the Magellan PRP system to concentrate equine platelets. We hypothesized that there would be no differences in platelet counts among the four counting technologies and that the Magellan system would generate platelet concentrations greater than 500,000/μL. Citrated whole blood was collected from 32 horses and platelet, WBC, and red blood cell concentrations were measured using a commercial hematology analyzer (Advia 2120) prior to preparation of PRP using the Magellan system. Platelets were quantified in individual identical aliquots of equine PRP produced by the Magellan system (n=32) using three different technologies: optical scatter (Advia 2120), impedance (CellDyn 3700), and hand count using direct microscopy (Thrombo-TIC). An immunofluorescent counting method was performed on a subset of 15 of the 32 samples using a mouse monoclonal anti-sheep antibody against integrin alpha αIIbβ₃ (anti-CD41/CD61) and a fluorescent secondary antibody. Measured platelet concentrations were compared using Passing and Bablok regression analyses and mixed model ANOVA. The Magellan PRP system yielded mean (± SD) platelet and WBC counts of 893,090 ± 226,610/μL and 35,806 ± 9,971/μL, respectively. Platelet counts generated by optical scatter were consistently higher than those generated by impedance. Systematic and proportional biases were observed between these two automated methods. No bias (systematic or proportional) was observed among any of the other counting methods. Despite the bias detected between the two automated systems, there were no significant differences on average among the four counting methods evaluated, based on the ANOVA. All four platelet counting methods tested are therefore suitable for quantifying platelets in equine PRP for clinical applications. The Magellan PRP system consistently generated desirably high platelet concentrations as well as higher than expected WBC concentrations. The high platelet concentrations served as a good test medium for the study; however, the concurrent high WBC counts may be undesirable for selected orthopedic applications.
- Tube centrifugation for processing platelet-rich plasma in the horseFontenot, Robin L. (Virginia Tech, 2012-04-18)Platelet-rich plasma (PRP) is a popular treatment for equine tendon and ligament injuries; however, commercial PRP systems are expensive. Development of a safe, inexpensive alternative would make PRP therapy more widely available to horse owners. The purpose of this study was to evaluate the quality and bacteriologic safety of PRP produced by three simple, inexpensive tube centrifugation methods and compare the results to a commercial system. Citrated blood collected from 26 normal horses was processed by four methods: blood collection tubes centrifuged at 1200 and 2000 x g, a 50ml conical tube, and a commercial system. Platelet and cell counts and mean platelet volume (MPV) in whole blood and PRP were determined using an automated hematology analyzer. Results were analyzed using mixed model ANOVA with post-hoc comparisons (MPV and fold change for RBC, WBC, and platelets) and binary logistic generalized estimating equations with horse as a blocking factor (absolute numbers of WBC, and platelets). Aerobic and anaerobic cultures were performed. Significance was set at p<0.05. Mean platelet concentrations ranged from 1.55 to 2.58 fold. The conical tube method produced the highest number of PRP samples with platelet concentrations of greater than 2.5-fold and within the clinically acceptable range of >250,000 platelets/?l. WBC counts were lowest using the commercial system and unacceptably high using the red top methods. The incidence of bacterial contamination was low (2.1%). Based on these results, the conical tube method may be a suitable alternative to commercial PRP systems in cases with budgetary constraints.