In vitro evaluation of hyperosmotic canine plasma suitable for infusion.

OBJECTIVE: To determine the characteristics of canine freeze-dried plasma (cFDP) as it is serially diluted with sterile water. DESIGN: In vitro experimental study. SETTING: Government blood and coagulation research laboratory. ANIMALS: cFDP from a commercial manufacturer. INTERVENTIONS: Ten units of cFDP were reconstituted to 100%, 90%, 80%, 70%, 60%, 50%, and 40% of the recommended volume with sterile water. The resultant solutions were analyzed for coagulation factor activity (factors II, V, VII, VIII, IX, X, and XII as well as antithrombin), fibrinogen concentration, prothrombin time, activated partial thromboplastin time, viscosity, osmolality, and kaolin-activated thromboelastography. MEASUREMENTS AND MAIN RESULTS: Viscosity, osmolality, and turbidity properties of plasma were increased in a reconstitution volume-dependent manner, with the 40% suggested volume generating approximately 2-fold increases in each. Similarly, factor activity levels and fibrinogen concentration increased by approximately 2-fold over this range in a concentration-dependent manner. Prothrombin time declined from 11.4 seconds at 100% volume to 10.9 seconds at 70% before increasing to 11.9 seconds at 40%. Activated partial thromboplastin time increased exponentially from 21.8 seconds at 100% rehydration to 100.0 seconds at 40%. R-time on TEG increased from 3.1 to 13.9 minutes at 50% rehydration, while alpha angle declined from 61.3° to 24.7° over the same range, and the maximum amplitude initially increased from 13.2 mm at 100% water to 18.6 mm at 70% water before dropping back down to 14.6 mm at 50% water. No clotting was observed with 40% rehydration. CONCLUSIONS: The creation of hyperosmotic plasma from cFDP appears feasible with preservation of concentrated coagulation factors, although there are some unexplained effects that happen to coagulation functions at the highest concentrations tested using only 40%-50% of recommended rehydration volume. Further studies are needed to evaluate the hyperosmotic product in vivo.

The impact of delivery by a fixed-wing, sling-launched unmanned aerial vehicle on the hematologic function of whole blood.

BACKGROUND: Unmanned aerial vehicles (UAVs) have been shown to shorten delivery times of medical products in health care, providing a potential answer to the question of prehospital resuscitation where blood and blood products are not readily available. While the capabilities and efficiencies of delivery via UAVs are already well established, the postdelivery viability and hemostatic function of whole blood has not been examined. METHODS: Whole blood units were sampled for a preflight control and loaded onto a fixed wing UAV. The UAVs flew in predetermined flight paths to either deliver via parachute drop or direct recovery after UAV capture by arresting gear. Postflight and preflight samples were assayed for coagulation function with thromboelastography, blood chemistry, and free hemoglobin to observe hemolysis. RESULTS: No significant differences in any metric were observed between the blood samples assayed preflight versus those flown and parachute dropped or those flown and recovered from the UAV. CONCLUSION: The use of UAVs for delivery of whole blood offers significant benefits for prehospital care. Further innovations in UAV and transportation technologies will expand on an already strong foundation. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Hemoglobin-Based Oxygen Carrier for the Reconstitution of Canine Freeze-Dried Plasma in an In Vitro Model of Resuscitation.

Military working dogs (MWDs) are force multipliers that are at risk for severe trauma when employed on the battlefield. When in severe hemorrhagic shock, MWDs require both oxygen- carrying capacity and replacement of vascular volume and coagulation factors. The objective of this study was to evaluate the hemostatic capacity of canine freeze-dried plasma (cFDP) with a Food and Drug Administration (FDA)-approved hemoglobin- based oxygen carrier (HBOC) in an in vitro model of resuscitation. Whole blood (WB) was collected from 10 MWDs, and these samples were diluted by 10%, 25%, or 40% with either cFDP (reconstituted with water), HBOC, cFDP (reconstituted with HBOC), or an equal volume of a 1:1 ratio of cFDP (reconstituted with water) and HBOC. Hemostatic parameters were minimally changed based on evaluation of prothrombin time, activated partial thromboplastin time, fibrinogen and thromboelastography at the 10% and 25% dilutions, and parameters consistent with a hypocoagulability were seen at dilutions of 40%. Based on the results of this study, additional research is warranted to determine if cFDP reconstituted with HBOC is a viable resuscitation product in canine trauma.

Coagulation function of never frozen liquid plasma stored for 40 days.

BACKGROUND: Never frozen liquid plasma (LP) has limited shelf life versus fresh frozen plasma (FFP) or plasma frozen within 24 h (PF24). Previous studies showed decreasing factor activities after Day (D)14 in thawed FFP but no differences between LP and FFP until D10. This study examined LP function through D40. STUDY DESIGN AND METHODS: FFP and PF24 were stored at -20°C until assaying. LP was assayed on D5 then stored (4°C) for testing through D40. A clinical coagulation analyzer measured Factor (F)V, FVIII, fibrinogen, prothrombin time (PT), and activated partial thromboplastin time (aPTT). Thromboelastography (TEG) and thrombogram measured functional coagulation. Ristocetin cofactor assay quantified von Willebrand factor (vWF) activity. Residual platelets were counted. RESULTS: FV/FVIII showed diminished activity over time in LP, while PT and aPTT both increased over time. LP vWF declined significantly by D7. Fibrinogen remained high through D40. Thrombin lagtime was delayed in LP but consistent to D40, while peak thrombin was significantly lower in LP but did not significantly decline over time. TEG R-time and angle remained constant. LP and PF24 (with residual platelets) had initially higher TEG maximum amplitudes (MA), but by D14 LP was similar to FFP. CONCLUSION: Despite significant declines in some factors in D40 LP, fibrinogen concentration and TEG MA were stable suggesting stored LP provides fibrinogen similarly to frozen plasmas even at D40. LP is easier to store and prepare for prehospital transfusion, important benefits when the alternative is crystalloid.

Effects of refrigerated storage on hemostatic stability of four canine plasma products.

OBJECTIVE: To assess clotting times, coagulation factor activities, sterility, and thromboelastographic parameters of liquid plasma (LP), thawed fresh frozen plasma (FFP-T), and 2 novel formulations of freeze-dried plasma (FDP) stored refrigerated over 35 days. SAMPLE: 6 units of canine LP and FFP-T from a commercial animal blood bank and 5 units each of 2 formulations of canine FDP. PROCEDURES: Prothrombin time; activated partial thromboplastin time; activities of coagulation factors II, V, VII, VIII, IX, X, XI, and XII; and thromboelastographic parameters were determined for each product on days 0 (baseline), 3, 7, 14, 21, 28, and 35. For each day, a sample of each product was also submitted for aerobic bacterial culture. RESULTS: Small changes in coagulation factor activities and mild increased time to initial clot formation in LP and FFP-T were noted over the 35-day storage period. Activities of factor VIII in FDP1 and factor XII in FDP2 were < 50% at baseline but varied throughout. Compared with FFP-T, time to initial clot formation was increased and clot strength was preserved or increased for the FDPs throughout the study. One FDP had decreased pH, compared with other products. No plasma product yielded bacterial growth. CONCLUSIONS AND CLINICAL RELEVANCE: Liquid plasma and FFP-T would be reasonable to use when stored refrigerated for up to 35 days. Both FDP products showed variability in coagulation factor activities. Studies investigating the usefulness of these plasma products (FDPs) in dogs and the variable days of refrigerated storage (all products) are warranted. (Am J Vet Res 2020;81:964-972).

Field-expedient thawing of fresh-frozen plasma.

INTRODUCTION: Frozen plasma is superior to crystalloids for hemorrhage resuscitation but remains logistically challenging in austere environments because of specialized clinical equipment for on-demand thawing. This research examines some ad hoc thawing techniques that have been implemented by military medical personnel. METHODS: Fresh-frozen plasma (FFP) units were thawed accordingly: using a slow cooker (three temperature settings) with preheated or room temperature water; affixing flameless ration heaters from meals ready-to-eat (MREs) to FFP and submerging in water; exposing FFP to electric kettle-boiled water; incubating with a sous vide immersion circulator; or using a clinical thawer (control). Hemostatic function, thrombin generation, factor activities, and essential chemistry were measured after thawing. RESULTS: Even at the highest temperatures, without preheated water the slow cooker doubled thawing time (62.5 min vs. control, 32.5 min; p < 0.0001), and the final temperature was 13.5°C versus 28.8°C in control (p < 0.01). When preheated, the slow cooker thawed in 31.3 minutes (p < 0.05), with a final temperature of 22.4°C. Kettle-boiled water thawed in 23.0 minutes with a final temperature of 25.1°C. The sous vide thawed in 28.1 minutes, with a final temperature of 20.2°C. MRE heaters were insufficient. Functional measures were similar in all conditions. DISCUSSION: In emergencies, protracted plasma thawing is unacceptable, and slower thawing methods also produced cryoprecipitate. Although no functional changes were observed with boiled water thawing, potential negative physiological impacts must be examined. Safe, controlled thawing can be obtained with the sous vide, although optimization requires further testing.

TEG PlateletMapping assay results may be misleading in the presence of cold stored platelets.

BACKGROUND: Viscoelastic tests (VETs) are used widely to monitor hemostasis in settings such as cardiac surgery. There has also been renewed interest in cold stored platelets (CSPs) to manage bleeding in this setting. CSPs are reported to have altered hemostatic properties compared to room temperature platelets (RTPs), including activation of GPIIb/IIIa. We investigated whether the functional differences between CSP and RTP affected the performance of the PlateletMapping VET on the TEG 5000 and 6s analyzer. METHOD: Platelet concentrates were divided equally into CSP (stored at 4°C ± 2°C) and RTP (stored at 22°C ± 2°C) fractions. Whole blood was treated to induce platelet dysfunction (WBIPD) by incubating with anti-platelet drugs (1.0 µM ticagrelor and 10 µM aspirin) or by simulating cardiopulmonary bypass. WBIPD samples were then mixed with 20% by volume of CSPs or RTPs to model platelet transfusion before analysis using the PlateletMapping VET. RESULTS: Addition of CSPs to WBIPD increased the PlateletMapping MAFIBRIN and MAADP parameters with the TEG 5000 analyzer (both p < 0.0001 compared to addition of buffer alone). This effect was not observed with RTPs. The differential effect of CSPs on the MAFIBRIN corrected after pre-incubation with the GPIIb/IIIa antagonist tirofiban and was quantitatively less with the PlateletMapping test for the TEG 6s analyzer which contains the GPIIb/IIa antagonist abciximab. DISCUSSION: The PlateletMapping MAFIBRIN and MAADP test results may be misleadingly high with CSPs, particularly with the TEG 5000 analyzer, most likely due to constitutive activation of GPIIb/IIIa on CSPs during storage. TEG PlateletMapping results should be interpreted with caution following CSP transfusion.

The effects of cell type and culture condition on the procoagulant activity of human mesenchymal stromal cell-derived extracellular vesicles.

BACKGROUND: Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) have great potential as a cell-free therapy in wound healing applications. Because EV populations are not equivalent, rigorous characterization is needed before clinical use. Although there has been much focus on their RNA composition and regenerative capabilities, relatively less is known regarding the effects of MSC cell type (adipose tissue [Ad-MSCs] or bone marrow [BM-MSCs]) and culture condition (monolayer or spheroid) on MSC-EV performance, including characteristics related to their ability to promote coagulation, which could determine EV safety if administered intravenously. METHODS: The successful isolation of EVs derived from Ad-MSCs or BM-MSCs cultured in either monolayer or spheroid cultures was confirmed by NanoSight (particle size distribution) and Western blot (surface marker expression). Extracellular vesicle surface expression of procoagulant molecules (tissue factor and phosphatidylserine) was evaluated by flow cytometry. Extracellular vesicle thrombogenicity was tested using calibrated thrombogram, and clotting parameters were assessed using thromboelastography and a flow-based adhesion model simulating blood flow over a collagen-expressing surface. RESULTS: The MSC cell type and culture condition did not impact EV size distribution. Extracellular vesicles from all groups expressed phosphatidylserine and tissue factor on their surfaces were functionally thrombogenic and tended to increase clotting rates compared to the negative control of serum-free media without EVs. On average, EVs did not form significantly larger or stronger clots than the negative control, regardless of cell source or culture condition. Additionally, EVs interfered with platelet adhesion in an in vitro flow-based assay. CONCLUSION: Adipose-derived EVs were more thrombogenic and expressed higher amounts of phosphatidylserine. Our findings suggest that, like intact MSCs, source variability among EVs is an important factor when considering EVs for potential therapeutic purposes. LEVEL OF EVIDENCE: Therapeutic care management, level II.

Freeze-dried plasma mitigates the dilution effects of a hemoglobin-based oxygen carrier (HBOC-201) in a model of resuscitation for hemorrhage and hemodilution.

BACKGROUND: Hemoglobin-based oxygen carriers (HBOCs) have proven useful for supplementing oxygen delivery when red cells are unavailable; however, HBOCs do not promote hemostasis. The need for prehospital bridges to blood transfusion informed this study which sought to determine the impact of HBOCs on coagulation, with or without cotransfusion of freeze-dried plasma (FDP). METHODS: Treatment was simulated in vitro by replacing whole blood volume (or whole blood prediluted with 25% plasmalyte A as a hemodilution model) with HBOC-201, FDP, or both at ratios of 10% to 50% of original volume. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, complete blood count, viscosity, thromboelastography (TEG), and platelet adhesion to collagen under flow were evaluated. Subsequently, tissue plasminogen activator was added to model hemorrhagic shock effects on fibrinolysis. RESULTS: Substituting blood with HBOC resulted in dose-dependent decreases in fibrinogen and cells, which lengthened PT (+61% at highest dose) and aPTT (+40% at highest dose) and produced TEG parameters consistent with dilutional coagulopathy. While substituting blood with FDP decreased cell counts accordingly, fibrinogen, PT, aPTT, and TEG parameters were not statistically changed. When HBOC and FDP were combined 1:1 for volume replacement, observed HBOC-only detriments were mitigated: PT and aPTT were increased by 17% and 11%, respectively, at the highest doses. In prediluted samples, similar trends were seen with exacerbated differences. Platelet adhesion to collagen was directly affected by hematocrit. Samples containing both HBOC and tissue plasminogen activator were highly susceptible to fibrinolysis. CONCLUSION: A dose equivalent to 1 unit to 2 units each of HBOC-201 and FDP had a modest impact on functional coagulation measures and is reasonable to consider for clinical study as a part of early transfusion intervention. Higher doses may impart hemodilution risks similar to resuscitation with crystalloid or other colloids in coagulation-compromised patients. Further study of HBOC effects on fibrinolysis is also indicated. STUDY TYPE: In vitro laboratory study.

Evaluation of a lyophilized platelet-derived hemostatic product.

BACKGROUND: Current limitations of platelet shelf life to 5 days have led to an increasingly greater demand for hemostatic agents with greater longevity. The objective of this study was to evaluate the function of a lyophilized platelet-derived hemostatic product (thrombosome [TS]) as a potential alternative to fresh platelets. METHODS: Platelets were collected from whole blood from healthy donors. TSs were reconstituted with water and added to various configurations of reassembled whole blood (platelets, plasma, and RBCs); measures included rotational thromboelastometry (ROTEM), optical aggregometry, mitochondrial function, calibrated automated thrombogram, collagen adhesion under flow (shear flow assay), and flow cytometry. RESULTS: In ROTEM, no differences were observed between maximum clot formation values for contact pathway activation thromboelastometry tests with TSs or platelet samples. Significantly decreased aggregation was observed in the TSs versus platelets (p < 0.001 for all agonists). Flow cytometry measures demonstrated significant decreases in glycoprotein Ib expression and increases in phosphatidylserine expression in the TS group (p < 0.01). The calibrated automated thrombogram assay was suggestive (lag time and peak thrombin) that the TSs might have some thrombogenic properties. Measurements of mitochondrial function revealed that TSs had no functional mitochondria. CONCLUSION: In this study, TSs were shown to have nonfunctional mitochondria. ROTEM measures revealed that the TSs had no impact on clot strength. Likewise, compared to platelets, the TSs displayed minimal aggregation, had significantly more phosphatidylserine (measure of activation status), but had the ability to adhere to a collagen surface under flow conditions and contribute to clot formation and induced greater thrombin generation.

Hemostatic characteristics of thawed, pooled cryoprecipitate stored for 35 days at refrigerated and room temperatures.

BACKGROUND: Cryoprecipitate's shelf life is limited due to concerns over decreased clotting factor activity and contamination with extended storage. Hemostatic characteristics of thawed cryoprecipitate stored up to 35 days at refrigerated and room temperatures were assessed. STUDY DESIGN AND METHODS: Pooled cryoprecipitate was thawed and aliquoted for storage at 1-6°C or 21-24°C. Samples were tested immediately after thawing and at 4 h, 24 h, 72 h, and weekly for 35 days. At each time point fibrinogen, factor VIII (FVIII), and von Willebrand factor (vWF) were assessed. Thrombin generation and rotational thromboelastometry (ROTEM) were also performed. Further, packed red cells, platelet concentrates, frozen plasma, and stored cryoprecipitate were combined (1:1:1:1) to simulate massive transfusion and analyzed by ROTEM. Day 35 samples were cultured for bacterial contamination. RESULTS: Precipitation was observed in refrigerated samples; however, these aggregates were easily resuspended upon warming in a 37°C water bath. No significant changes were observed in fibrinogen concentration or ROTEM at either temperature. FVIII and vWF declined significantly during storage. vWF, clot time, and thrombin generation were significantly better preserved with refrigeration. With simulated massive transfusion, fibrinogen function remained at or above the established range for whole blood at both storage temperatures. Bacterial contamination was not observed in cold stored or room temperature cryoprecipitate. CONCLUSION: The fibrinogen concentration and function of cryoprecipitate at extended storage durations are adequate for fibrinogen replacement in critical bleeding. These results support extension of the shelf life of cryoprecipitate when used for fibrinogen replacement.

Optimizing whole blood storage: hemostatic function of 35-day stored product in CPD, CP2D, and CPDA-1 anticoagulants.

BACKGROUND: Transitioning from whole blood (WB) to components developed from efforts to maximize donor yield. Components are advantageous for specific derangements, but treating hemorrhage with components requires significantly more volume to provide similar effects to WB. Because storage lesion and waste remain problematic, this study examined hemostatic function of refrigerated WB stored for 35 days in anticoagulants citrate-phosphate-dextrose-adenosine (CPDA-1), citrate-phosphate-dextrose (CPD), or citrate-phosphate-double dextrose (CP2D). METHODS: Refrigerated WB units from healthy donors were sampled over 35 days. Global hemostatic parameters were measured by thromboelastometry, thrombogram, platelet aggregometry, and platelet adhesion to collagen under shear conditions. The effects of transfusion filtration and mixing 35-day stored product with fresh WB were evaluated. RESULTS: Countable platelets declined as aggregation clusters appeared in microscopy. While gross platelet agonist-induced aggregation declined over time, normalization revealed aggregation responses in remaining platelets. Peak thrombin generation increased over time. Clot strength diminished over storage in tissue factor-activated samples (normalized by filtration of aggregates). Functional fibrinogen responses remained consistent throughout. Filtration was necessary to maintain consistent platelet adhesion to collagen beyond collection day. Few differences were observed between anticoagulants, and stored/fresh mixing studies normalized coagulation parameters. CONCLUSIONS: WB is easier to collect, store, and transfuse. WB provides platelets, an oft-neglected, critical resuscitation component, but their individual numbers decline as aggregates appear, resulting in diminished coagulation response. WB has better performance in these assays when examined at earlier time points, but expirations designated to specific anticoagulants appear arbitrary for hemostatic functionality, as little changes beyond 21 days regardless of anticoagulant.

Spray-dried plasma deficient in high-molecular-weight multimers of von Willebrand factor retains hemostatic properties.

BACKGROUND: Dried plasmas can overcome logistical barriers that prevent fresh frozen plasma (FFP) usage in acute resuscitation, but processing of these products can detrimentally alter the composition. Spray-dried plasma (SpDP) from single units is deficient in high-molecular-weight multimers of von Willebrand factor (vWF), a critical facilitator of platelet adhesion and thrombus formation. We hypothesized that converting high-molecular-weight multimers to smaller-molecular-weight multimers would retain vWF's capacity to mediate platelet adhesion. STUDY DESIGN AND METHODS: SpDP obtained from untreated FFP was reconstituted with glycine-hydrochloric acid (HCl) and glycine (20 mM:50 mM) or pretreated with glycine-HCl (20 mM) or glycine-glycine-HCl (20 mM:50 mM) and reconstituted with water. In vitro hemostatic potential of SpDPs versus FFP or FFP spiked with 70 mM of glycine was evaluated, leading to a more detailed in vitro study of glycine-HCl-glycine (20 mM:50 mM) pretreated SpDP. Plasmas were combined with RBCs and platelets to observe global coagulation response. RESULTS: While vWF-ristocetin cofactor activity is significantly decreased (-41.13%; p < .0001) in SpDP, a model of vWF-mediated platelet adhesion to collagen under flow showed enhanced function (+13%; p < .01). Fewer microparticles, particularly of platelet origin, were observed in SpDP versus FFP (p < .0001). Small but significant differences in thromboelastography results were observed, although SpDP and FFP were within normal ranges. CONCLUSION: Comparable coagulability was observed in FFP and SpDP. The apparent paradox between vWF-ristocetin cofactor assay and vWF-mediated platelet adhesion may be explained by the increase in smaller multimers of vWF in SpDP, producing different outcomes in these assays.

Cold storage of platelets in platelet additive solution: an in vitro comparison of two Food and Drug Administration-approved collection and storage systems.

BACKGROUND: Refrigeration of platelets (PLTs) in a PLT additive solution (PAS) reduces PLT activation compared to storage in plasma and preserves function for at least 15 days. Currently only two PASs are licensed by the Food and Drug Administration, each for use with only one apheresis platform. In this study, we compared the metabolic, functional, and activation status of PLTs collected on a Trima apheresis collection system and stored refrigerated in Isoplate (ISO) PAS to PLTs collected on an Amicus collection system and stored refrigerated in Intersol (INT) PAS. STUDY DESIGN AND METHODS: Apheresis PLTs (n = 4-7 donors) were collected on a Trima in ISO PAS or on an Amicus in INT PAS. PLTs were stored in a walk-in refrigerator (1-6°C) without agitation for long-term storage. Bags were assayed at Days 1, 5, 10, and 15 of storage. Measurements included PLT counts, pH, aggregation response, rotational thromboelastometry, and activation markers. RESULTS: Cold-stored Trima-collected PLTs in ISO were slightly more hemostatic than Amicus-collected PLTs in INT and displayed better adhesion to collagen under flow conditions. Amicus-collected PLTs in INT showed increased microaggregate formation on Days 5 and 10 and a significant decrease in PLT count over storage. Trima-collected PLTs in ISO displayed better clot strength than Amicus-collected PLTs in INT. CONCLUSION: Compared to cold-stored Amicus PLTs in INT, Trima PLTs in ISO display superior in vitro function and may be better suited for treatment of bleeding patients. Clinical studies are warranted to confirm these findings.

Functional stability of the TEG 6s hemostasis analyzer under stress.

BACKGROUND: Viscoelastic measurements of coagulation provide much needed information, including guidance for triage and insight into bleeding disorders. The current clinical standards for these devices are the thromboelastogram (TEG) 5000 and the rotational thromboelastometer (ROTEM) delta, but a new product, the TEG 6s, has recently come to market, designed to simplify the user experience, reduce the required blood volume, and conduct multiple assays simultaneously. This study compares the performance of these three devices and examines the resiliency of the TEG 6s under various stresses. METHODS: The variances of coagulation metrics obtained by the TEG 6s (prototype and production models), TEG 5000, and ROTEM delta were compared using manufacturers' reagents and citrate-collected blood from healthy donors. Variability between devices was examined, and their performances under various motion and temperature stresses were compared by placing one unit on a linear or orbital shaker, in the cold, or in the heat while a counterpart remained stationary at room temperature. RESULTS: Although most comparable parameters had low degrees of variance, there were small but significantly increased variances found in some ROTEM delta and TEG 5000 parameters versus comparable TEG 6s parameters. Orbital rotation of the TEG 6s had no effect on means of any parameter but resulted in increased variance of 2 parameters, but linear motion with sudden striking had no observed impact on results. Similarly, 7-day exposure to heat (45°C) or cold (4°C) only resulted in minor deviations within normal ranges of the TEG 6s. DISCUSSION: The TEG 6s provides several improvements over other coagulation analyzers: it is easier to use and robustly resilient against motion and temperature stresses. These features suggest that it may be capable of deployment not only in the clinical laboratory but also to a variety of austere settings. LEVEL OF EVIDENCE: Diagnostic test, level III.

Evaluation of adenosine, lidocaine, and magnesium for enhancement of platelet function during storage.

BACKGROUND: The combination of adenosine, lidocaine, and magnesium (Mg2+) (ALM) has demonstrated cardioprotective and resuscitative properties in models of cardiac arrest and hemorrhagic shock that are linked to reduction of metabolic demand. Platelets play a key role in resuscitation strategies for ATC but suffer from loss of function following storage in part owing to mitochondrial exhaustion. This study evaluates whether ALM also demonstrates protective properties in stored platelet preparations. METHODS: Platelets were tested at (baseline, Day 5, Day 10, and Day 15) at 22°C (room temperature) or 4°C in 100% plasma and platelet additive solution. Adenosine, lidocaine, and magnesium treatment or its individual components (A, L, M, or combinations) were added directly to the minibags at baseline for storage. Measurements consisted of blood gas and chemistry analyses, thromboelastography, impedance aggregometry, and flow cytometry. RESULTS: Blood gas and cell analysis, as well as flow cytometry measures, demonstrated only differences between temperature groups starting at Day 5 (p < 0.05) and no differences between treatment groups. Aggregation response to collagen (A only, M only, and ALM high dose) and thrombin receptor activation peptide (A + M, and ALM high dose) was significantly greater at Day 5 compared to respective 4°C (100% plasma) controls (p < 0.05). Thromboelastography analysis revealed significant preservation of all measures (reaction time, maximum amplitude, and angle) at Day 15 for 4°C-stored samples in 100% plasma in both controls (no ALM) and ALM treatment compared to room temperature (p < 0.05); no differences were observed between the ALM and control groups. CONCLUSIONS: The mechanism of ALM's protective effect remains unclear; key cellular functions may be required to provide protection. In this study, improvements in collagen and thrombin receptor activation peptide aggregation were seen when compared to 4°C-stored plasma samples although no improvements were seen when compared to 4°C-stored platelet additive solution platelets. LEVEL OF EVIDENCE: Therapeutic/care management, level II.

Volumetric control of whole blood collection in austere environments.

INTRODUCTION: Fresh whole blood transfusions are a powerful tool in prehospital care; however, the lack of equipment such as a scale in field situations frequently leads to collections being under- or overfilled, leading to complications for both patient and physician. This study describes two methods for simple, rapid control of collection bag volume: (1) a length of material to constrict the bag, and (2) folding/clamping the bag. METHOD: Whole blood collection bags were allowed to fill with saline via gravity. Paracord, zip-tie, beaded cable tie, or tourniquet was placed around the bag at circumferences of 6 to 8.75 inches. A hemostat was used to clamp folds of 1 to 1.5 inches. Several units were drawn during training exercises of the 75th Ranger Regiment with volume controlled by three methods: vision/touch estimation, constriction by paracord, and clamping with hemostat. RESULTS: Method validation in the Terumo 450-mL bag indicated that paracord, zip-tie, and beaded cable tie lengths of 6.5 inches or clamping 1.25 inches with a hemostat provided accurate filling. The volume variance was significantly lower when using the beaded cable tie. Saline filling time was approximately 2 minutes. With the Fenwal 450-mL bag, the beaded cable tie gave best results; even if incorrectly placed by one/two beads, the volume was still within limits. In training exercises, the use of the cord/clamp greatly reduced the variability; more bags were within limits. CONCLUSIONS: Both constricting and clamping allow for speed and consistency in blood collection. The use of common cord is appealing, but knot tying induces inevitable variability; a zip/cable tie is easier. Clamping was quicker but susceptible to high variance and bag rupturing. With proper methodological training, appropriate volumes can be obtained in any environment with minimal tools. LEVEL OF EVIDENCE: Therapeutic/care management study, level IV.

Pre-activated human mesenchymal stromal cells in combination with doxorubicin synergistically enhance tumor-suppressive activity in mice.

BACKGROUND AIMS: Previously, we showed that human mesenchymal stromal cells (hMSCs) were activated to express tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) upon TNF-α stimulation, induced cell death in triple-negative breast cancer (TNBC) MDA-MB-231 cells (MDA), and RNA released from apoptotic MDA further increased TRAIL expression in hMSCs. This feed-forward stimulation increased apoptosis in MDA cells. Here, we tested whether TRAIL-expressing hMSCs, in combination with a sub-toxic-dose of a chemotherapy drug doxorubicin, would overcome TRAIL resistance and create synergistic effects on targeting metastatic TNBC. METHODS: To optimize conditions for the combination treatment, we (i) selected an optimal condition to activate hMSCs for TRAIL expression, (ii) selected an optimal dose of doxorubicin treatment, (iii) examined underlying mechanisms in vitro and (iv) tested the efficacy of the optimized conditions in a xenograft mouse model of human breast cancer lung metastasis. RESULTS: The results showed that DNA fragments from apoptotic MDA triggered hMSCs to increase further TRAIL expression in an absent in melanoma 2 (AIM2)-dependent manner, and thus higher TRAIL-expressing hMSCs stimulated with synthetic DNA, poly(deoxyadenylic-deoxythymidylic) acid [poly(dA:dT)], more effectively suppressed tumor progression in vivo. Furthermore, activated hMSCs increased apoptosis in MDA cells when combined with a sub-toxic dose of doxorubicin, which was mediated by up-regulating TRAIL and Fas-related pathways. When we combined the optimized conditions, pre-activated hMSCs with poly (dA:dT) synergistically reduced tumor burden even with minimal doxorubicin treatment in a xenograft mouse model of human breast cancer lung metastasis. CONCLUSIONS: These results suggest that the treatment of hMSCs with a sub-toxic dose of doxorubicin can overcome TRAIL resistance and be a potential novel therapy for TNBC metastasis treatment.

A HA2-Fusion tag limits the endosomal release of its protein cargo despite causing endosomal lysis.

BACKGROUND: Protein transduction domains (PTDs) can be fused to a protein to render it cell-permeable. The delivery efficiencies of PTDs are, however, often poor because PTD-protein conjugates cannot escape from endosomes. A potential solution to this problem consists in adding HA2 analogs to the PTD-protein construct as these peptides can cause endosomal lysis upon acidification of the endosomal lumen. To date, however, the utility of HA2-based PTDs has not been clearly established. METHODS: We investigate the biophysical and cellular properties of the glutamate-rich HA2 analog E5 fused to the model protein TAT-mCherry. RESULTS: E5-TAT-mCherry causes the release of fluorescent dextrans trapped with the protein inside endosomes. Yet, E5-TAT-mCherry itself is not released in the cytosol of cells, indicating that the protein remained trapped inside endosomes even after endosomal lysis takes place. Cytosolic delivery of the protein could be achieved, however, by insertion of a disulfide bond between E5 and its cargo. CONCLUSIONS: These results show that E5 causes the retention of its fused protein inside endosomes even after lysis takes place. GENERAL SIGNIFICANCE: These data establish that HA2 analogs might not be useful PTDs unless cleavable linkers are engineered between PTD and protein cargo.

Attentional performance of (C57BL/6Jx129Sv)F2 mice in the five-choice serial reaction time task.

Impaired attention is evident in several neurological and psychiatric disorders. In the present study, attentional capabilities were measured in the operant five-choice serial reaction time task (5-CSRTT) in male (C57BL/6Jx129Sv)F2 hybrid (B6129F2) mice. Main aims were to validate and standardize the test in these mice: to setup procedures, measure potential beneficial effects of sub-chronic nicotine in degraded versions of the 5-CSRTT (by decreasing stimulus duration, inducing white noise and making the stimuli unpredictable) and study disruptive effects of additional administration of the muscarinic antagonist scopolamine. During the baseline pre-nicotine sessions, the B6129F2 mice attained a very good performance in the test (95% accuracy). As stimulus duration was reduced from 2 s to 1 s, response accuracy of the mice decreased. Mice treated with nicotine (0.16 mg/kg) attained significantly higher response accuracy and had a lower percentage of incorrect responses in comparison with the solvent-treated animals. No further beneficial effects of nicotine were found. Reduced response accuracy was also obtained when stimulus duration was reduced from 1 s to 0.5 s and when a variable intertrial interval was introduced. Noise interpolation between trials did not impair performance. Finally, scopolamine (0.16 mg/kg) disrupted attentional functioning. Although most studies have been performed in rats, these results add to the existing evidence that the 5-CSRTT can also be used to assess attentional performance in mice. This offers the opportunity to test transgenic and knockout mice with similar background as the B6129F2 as animal models of psychiatric and neurological diseases.