132 A Novel Murine Model of Burn-Induced Platelet Dysfunction

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S88-S89
Author(s):  
Breanne H Gibson ◽  
Matthew T Duvernay ◽  
Stephen Gondek ◽  
Jonathan G Schoenecker
Keyword(s):  
Clinical Significance ◽  
Platelet Function ◽  
Murine Model ◽  
Molecular Mechanisms ◽  
Burn Injury ◽  
Platelet Dysfunction ◽  
Significant Difference ◽  
Platelet Signaling ◽  
Cellular Markers ◽  
And Function

Abstract Introduction Platelet dysfunction has been demonstrated as a part of burn induced coagulopathy (BIC), however, the etiology and clinical significance are unknown. Determining the etiology and clinical significance of BIC platelet dysfunction is difficult in humans due to heterogeneity of injuries and treatment. The goal of this study was to develop a murine model of BIC burn-induced platelet dysfunction to allow for high-throughput investigation of the mechanisms and the possible effects platelet dysfunction has on burn outcomes. Methods Using an established murine model of burn injury, we investigated plasma and cellular markers of BIC. Under adequate anesthesia and analgesia six-week-old C57BL6/J mice were administered a ~30% TBSA dorsal burn by scalding. Sham animals received identical preparation and resuscitation without the burn injury. Blood was collected at 6-, 24-, and 48-hours post-burn for measurement of platelet function, and plasma was isolated for protein measurements of coagulopathy (N=5 per group per time point). Results Like findings in humans, mice exhibited systemic markers of BIC (excess coagulation, fibrinolysis, and inflammation) within the first 6–24 hours post-burn. Platelets in whole blood were treated with platelet agonists ADP and PAR4-activating peptide (PAR4AP), and markers of platelet signaling and function (P-selectin expression and GpIIb/IIIa activation) were measured by flow cytometry. At 6 hours post-procedure, platelets from burn mice exhibited a slight, insignificant increase in markers of activation and response to stimulation compared with platelets from sham mice. At 24 hours post-burn, burn mice exhibited a significant decrease in platelet count (P< 0.02) and platelet function indicated by reduced GpIIb/IIIa activation (P< 0.01) and P-selectin expression (P< 0.05)in response to ADP and PAR4-AP compared with sham mice. Platelet function began to return at 48 hours post-burn with no significant difference between groups. Conclusions Platelet loss and dysfunction occur after burn injury, but the consequence of these effects is not well understood. The findings in this study are consistent across multiple experiments and resembled platelet dysfunction observed in different human traumatic injuries, validating the murine model as an inexpensive and efficient model of human injury in which to study platelet defects and the molecular mechanisms driving them.

Bleeding Time in Rats: A Comparison of Different Experimental Conditions

1982 ◽  
Vol 48 (01) ◽  
pp. 108-111 ◽  
Author(s):  
Elisabetta Dejana ◽  
Silvia Villa ◽  
Giovanni de Gaetano
Keyword(s):  
Platelet Function ◽  
Bleeding Time ◽  
Platelet Dysfunction ◽  
Experimental Conditions ◽  
Platelet Number ◽  
Coagulation Defects ◽  
Tail Tip ◽  
And Function ◽  
Storage Pool Disease ◽  
Type Of Anaesthesia

SummaryThe tail bleeding time (BT) in rats definitely varies according to the method applied. Of the various variables that may influence BT, we have evaluated the position (horizontal or vertical) of the tail, the environment (air or saline), the temperature (4°, 23° or 37° C) and the type of anaesthesia. Transection of the tail tip cannot be used to screen drugs active on platelet function since it is sensitive to coagulation defects. Template BT in contrast is not modified by heparin and is sensitive to defects of platelet number and function (“storage pool disease”, dipyridamole-like drugs, exogenous prostacyclin). In contrast the test fails to detect aspirin-induced platelet dysfunction. The evidence reported indicates that thromboxane A2-prostacyclin balance is not a factor regulating BT. Aspirin treatment however may be a precipitating factor when associated with other abnormalities of platelet function.Template BT is a valid screening test for platelet disorders and for antiplatelet drugs.

45 Unravelling the Unique Burn-induced Temporal Alterations in Adipose Tissue Metabolism

2020 ◽  
Vol 41 (Supplement_1) ◽  
pp. S30-S30
Author(s):  
Carly M Knuth ◽  
Chris Auger ◽  
Abdikarim Abdullahi ◽  
Marc G Jeschke
Keyword(s):  
Adipose Tissue ◽  
Murine Model ◽  
Burn Injury ◽  
Total Body Surface Area ◽  
Time Dependent ◽  
Metabolic Effects ◽  
Whole Body ◽  
Potential Contribution ◽  
Significant Difference ◽  
Tissue Browning

Abstract Introduction A severe burn elicits a systemic hypermetabolic response that substantially alters the function of multiple organs and contributes to increased morbidity and mortality. A consequence of hypermetabolism is the activation of UCP1-mediated browning of white adipose tissue (WAT), which may further facilitate the hypermetabolic response. In this study, we aimed to provide comprehensive characterization of the acute and long term pathophysiological responses to burns to determine the persistence of adipose tissue browning and its potential contribution to the hypermetabolic response. Methods Mice were subjected to either a 30% total body surface area (TBSA) scald burn or were denoted sham. Body weight and food intake were monitored throughout the duration of the study. Cohorts were sacrificed at 6hrs, 1, 3, 5, 7, 14, 30 and 60d post-burn and adipose tissue depots were harvested. Mitochondrial respiration, protein expression, and morphology in adipose tissues were assessed. Results Despite consuming considerably more food, the burn group lost significantly more weight throughout the duration of the study. We also detected increases in free fatty acids and interleukin-6, markers of whole-body lipolysis and inflammation, respectively. At the tissue level, eWAT mass significantly decreased over time, suggesting that this depot provides substrate to fuel the hypermetabolic response. This was further supported by a decrease in adipocyte area and an increase in lipolytic markers which remains significant up until 60d post-burn relative to sham. There were no significant difference in iWAT mass, however we detected significant increases in the protein content of UCP1, the master regulator of adipose tissue browning, as early as day 3 which persisted until day 60. This was corroborated by the presence of UCP1+ adipocytes. Conclusions Consistent with previous human studies, a burn injury elicits a dynamic response that cannot be simply characterized by a single timepoint. The alterations that occur in adipose tissue are depot-specific, time-dependent, and this notion likely extends to other metabolic tissues. Further, we demonstrate that in our 30% TBSA burn murine model, the effects of the hypermetabolic response persist for up to 60 days following initial injury. Applicability of Research to Practice Our data indicate the hypermetabolic response persists for up to 60 days, the equivalent of approximately 7 years in humans. This underscores the severity of adipose tissue browning and potentially provides an explanation as to how the hypermetabolic response persists even after the wound has healed. Moreover, providing a comprehensive map of the time-dependent changes in a murine model gives clinicians a better indication of the metabolic effects in a burn patient and will contribute to the development of effective, targeted treatments.

Early infection during burn-induced inflammatory response results in increased mortality and p38-mediated neutrophil dysfunction

2010 ◽  
Vol 299 (3) ◽  
pp. R918-R925 ◽  
Author(s):  
Samuel G. Adediran ◽  
Derrick J. Dauplaise ◽  
Kevin R. Kasten ◽  
Johannes Tschöp ◽  
Jonathan Dattilo ◽  
...  
Keyword(s):  
Oxidative Burst ◽  
Bacterial Infections ◽  
Burn Injury ◽  
Bacterial Load ◽  
Significant Difference ◽  
Scald Injury ◽  
Altered Immune Status ◽  
Direct Contrast ◽  
Intraperitoneal Infection ◽  
And Function

Following burn injury, the host is susceptible to bacterial infections normally cleared by healthy patients. We hypothesized that during the systemic immune response that follows scald injury, the host's altered immune status increases infection susceptibility. Using a murine model of scald injury under inhaled anesthesia followed by intraperitoneal infection, we observed increased neutrophil numbers and function at postburn day (PBD) 1 compared with sham-burned and PBD4 mice. Further, increased mortality, bacteremia, and serum IL-6 were observed in PBD1 mice after Pseudomonas aeruginosa (PA) infection compared with sham-burned and PBD4 mice infected with PA. To examine these disparate responses, we investigated neutrophils isolated at 5 and 24 h following PA infection from PBD1 and sham-burned mice. Five hours after infection, there was no significant difference in number of recruited neutrophils; however, neutrophils from injured mice had decreased activation, active-p38, and oxidative burst compared with sham-burned mice. In direct contrast, 24 h after infection, we observed increased numbers, active-p38, and oxidative burst of neutrophils from PBD1 mice. Finally, we demonstrated that in neutrophils isolated from PBD1 mice, the observed increase in oxidative burst was p38 dependent. Altogether, neutrophil activation and function from thermally injured mice are initially delayed and later exacerbated by a p38-dependent mechanism. This mechanism is likely key to the observed increase in bacterial load and mortality of PBD1 mice infected with PA.

scholarly journals Overview and Clinical Significance of Multiple Mutations in Individual Genes in Hepatocellular Carcinoma

2021 ◽  
Author(s):  
Taisuke Imamura ◽  
Yukiyasu Okamura ◽  
Keiichi Ohshima ◽  
Katsuhiko Uesaka ◽  
Teiichi Sugiura ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Clinical Significance ◽  
Independent Predictor ◽  
Single Mutation ◽  
Recurrence Free Survival ◽  
Wild Type ◽  
Free Survival ◽  
Significant Difference ◽  
And Function ◽  
Worse Prognosis

Abstract BackgroundMultiple mutations (MMs) within individual oncogenes have been newly characterized as a mechanism for promotion of carcinogenesis. We investigated the spectra of the MMs and the clinical significance in hepatocellular carcinoma (HCC). MethodsWhole-exome sequencing and gene expression profiling were performed in 223 surgically resected HCCs. ResultsMMs within individual genes was identified in 178 samples (79.8%, MMs tumors). All the remaining samples carried single mutation (20.2%, SM tumors). Mutations identified as MMs show different mutational patterns with higher functional impact compared with mutations identified as SM. Recurrence-free survival was significantly worse in the group with MMs tumors than the group with SM tumors (P = 0.012). MMs tumor was identified as an independent predictor for worse prognosis (hazard ratio, 1.72; 95%, P = 0.045). MMs were observed particularly in MUC16 (15% of samples with at least one mutation in the gene) and CTNNB1 (14%). Although there was no significant difference in MUC16 mRNA expression between MUC16 wild-type and MUC16 SM tumors, the expression in MUC16 MMs tumors was significantly enhanced compared with MUC16 SM tumors (P < 0.001). MMs in MUC16 were associated with viral hepatitis, higher tumor markers and vascular invasion. Recurrence-free survival was significantly worse in the MUC16 MMs group than the MUC16 SM group (P = 0.022); no significant difference was observed between the MUC16 SM group and MUC16 wild-type group (P = 0.324).ConclusionsMMs are relatively common driver events that selectively occur in specific oncogenes and function in tumor-promoting activity.

131 Burn-Induced Coagulopathy: Burn Patient Plasma Causes Platelet Dysfunction

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S88-S88
Author(s):  
Breanne H Gibson ◽  
Matthew T Duvernay ◽  
Stephen Gondek ◽  
Jonathan G Schoenecker
Keyword(s):  
Platelet Function ◽  
Wound Repair ◽  
Molecular Mechanisms ◽  
Morbidity And Mortality ◽  
Burn Patients ◽  
Platelet Dysfunction ◽  
Markers Of Inflammation ◽  
Vitro Effect ◽  
Burn Patient

Abstract Introduction Burn-induced coagulopathy (BIC) greatly increases the risk of thrombosis, leading to organ dysfunction and death. Although BIC is attributed to a multitude of factors including hemodilution, SIRS, and excess coagulation, the exact molecular mechanisms are elusive. Determination of these mechanisms is essential to develop new strategies aimed at reducing the morbidity and mortality of BIC as commonly used anticoagulants are ineffective at preventing the consequences of BIC. Platelet dysfunction, which has been associated with bleeding, thrombosis, poor wound repair, and susceptibility to infection, occurs in BIC, but the etiology of this phenomenon is unknown. Burn injuries provoke a dramatic increase in plasma levels of inflammatory, coagulation, and fibrinolytic factors, potentially altering the physiology of blood cells and platelets. Therefore, we hypothesized that burn patient plasma pathologically alters normal platelet function. Methods In this prospective study, plasma samples were collected from 32 adult patients with burns &gt;10% TBSA at a regional burn center. To assess the effects of burn plasma on platelet function, platelets isolated from healthy individuals were incubated with heparinized plasma from burn patients or control plasmas (N=15) for 2 hours. Following incubation, platelets were stimulated with various agonists, and markers of platelet activation (GPIIb/IIIa activation and P-selectin expression) were measured using flow cytometry. Results Platelets incubated with burn plasmas exhibited a reduction in response to stimulation compared with those incubated with control plasma. Both GPIIb/IIIa activation and P-selectin expression were affected, suggesting a defect in platelet signaling. This dysfunction did not strongly correlate with TBSA affected or modified Baux score but was significant when compared to healthy controls (P&lt; 0.05). However, measurement of markers of inflammation, coagulation, and fibrinolysis in burn plasmas revealed a significant correlation of both plasma D-dimer (P&lt; 0.02) and soluble P-selectin (P&lt; 0.05) with induced platelet dysfunction. This suggests circulating factors indicative of coagulation, fibrinolysis, and endothelial dysfunction may play a role in platelet dysfunction observed in BIC. Conclusions This study demonstrates an in vitro effect of burn patient plasma on platelet function, suggesting a possible benefit for resuscitation with FFP. BIC is a principal source of morbidity and mortality in burn patients, and current thromboprophylaxis for burn patients may not address critical elements of BIC. Future studies are required to optimize resuscitation and minimize the consequences of BIC.

scholarly journals Effect of Cardiopulmonary Bypass Machine on the Platelet Function Testing.

2020 ◽  
Author(s):  
Khalid A. AlSaleh ◽  
Rashed B. AlBakr ◽  
Turki B. AlBacker ◽  
Rakan AlNazer ◽  
Abdulkareem Almomen ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Platelet Function ◽  
Clinical Decision Making ◽  
Complete Blood Count ◽  
Artery Bypass ◽  
Postoperative Bleeding ◽  
Inverse Correlation ◽  
Platelet Dysfunction ◽  
Significant Difference

Abstract Background: Bleeding during coronary artery bypass surgery is a leading cause of mortality. Several factors have been associated with bleeding, platelet dysfunction being the most significant.Objective: to assess the effect of cardiopulmonary bypass machine (CPB) during cardiac surgery on platelet function using Platelet Function Analyzers (PFA-100), and Multiplate Electrode Aggregometry (MEA), and correlating that with a drop in Hemoglobin (Hb).Methods: Whole blood samples were collected preoperative and sixty minutes intraoperatively of different cardiac procedures utilizing (CPB) and tested for platelet function by PFA-100 and MEA. Complete blood count was measured using an automated hematology analyzer.Results: A significant difference was found between pre- and intraoperative ADP and EPI measurement in PFA-100, where preoperative PFA-ADP values displayed the ability to predict the intra-op drop in Hb (P–value 0.01, correlation coefficient 0.4699). At the same time, pre-op MEA- Ristocetin and TRAP showed an inverse correlation with an intra-op drop in Hb (-0.31 and -0.36). Conclusion: The current study reported significant changes in platelet dysfunction in cardiac surgeries with CPB, measured by two modalities PFA-100, and MEA. While PFA-100 and MEA both detected the changes in platelet dysfunction due to CPB, PFA-100 results were sensitive and positively predicted intra-op Hb drop as compared to MEA. There was a significant change in Hb one hour into the CPB, indicating that platelet transfusion might help decrease Intra- and postoperative bleeding independent of the platelet count as they are dysfunctional. PFA-100 results can be relied upon for distinction of high-risk cardiac surgery patients for bleeding and can be used for clinical decision making to improve patient outcome.

Platelet Suruival and Function in Rats with Enhanced Thrombotic Tendency

1985 ◽  
Vol 54 (04) ◽  
pp. 739-743 ◽  
Author(s):  
Federica Delaini ◽  
Elisabetta Dejana ◽  
Ine Reyers ◽  
Elisa Vicenzi ◽  
Germana De Bellis Vitti ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Nephrotic Syndrome ◽  
Platelet Function ◽  
Laboratory Tests ◽  
Thrombus Formation ◽  
The Other ◽  
Mean Survival Time ◽  
The Mean ◽  
And Function ◽  
Thrombotic Tendency

SummaryWe have investigated the relevance of some laboratory tests of platelet function in predicting conditions of thrombotic tendency. For this purpose, we studied platelet survival, platelet aggregation in response to different stimuli, TxB2 and 6-keto-PGFlα production in serum of rats bearing a nephrotic syndrome induced by adriamycin. These animals show a heavy predisposition to the development of both arterial and venous thrombosis. The mean survival time was normal in nephrotic rats in comparison to controls. As to aggregation tests, a lower aggregating response was found in ADR-treated rats using ADP or collagen as stimulating agents. With arachidonic acid (AA) we observed similar aggregating responses at lower A A concentrations, whereas at higher AA concentrations a significantly lower response was found in nephrotic rats, despite their higher TxB2 production. Also TxB2 and 6-keto-PGFlα levels in serum of nephrotic rats were significantly higher than in controls. No consistent differences were found in PGI2-activity generated by vessels of control or nephrotic rats.These data show that platelet function may appear normal or even impaired in rats with a markedly increased thrombotic tendency. On the other hand, the significance of high TxB2 levels in connection with mechanisms leading to thrombus formation remains a controversial issue.

Platelet Function in Experimentally Induced Pancreatitis in the Dog

1986 ◽  
Vol 55 (02) ◽  
pp. 197-200 ◽  
Author(s):  
R M Jacobs ◽  
R J Murtaugh ◽  
R H Fertel
Keyword(s):  
Platelet Function ◽  
Disseminated Intravascular Coagulation ◽  
Degradation Products ◽  
Plasma Concentrations ◽  
Adenosine Diphosphate ◽  
Intravascular Coagulation ◽  
Fibrin Degradation Products ◽  
Functional Defect ◽  
And Function ◽  
Experimentally Induced

SummaryEvidence suggests that changes in prostaglandins and disseminated intravascular coagulation accompany pancreatitis. Both may induce changes in platelet function. We wished to determine if experimentally induced pancreatitis in the dog was associated with altered platelet number and function, and whether there were concomitant changes in prostaglandins. Evidence for disseminated intravascular coagulation in the dogs with pancreatitis were red blood cell fragmentation, increased platelet turnover indicated by macro-platelets and the transient presence of fibrin degradation products in urine. There were no significant changes in platelet count. The platelets from dogs with pancreatitis showed a functional defect characterized by significantly decreased aggregation in response to adenosine diphosphate, arachidonic acid, and collagen. Release of adenosine triphosphate from platelets was reduced in collagen-stimulated aggregation. There were no changes in the plasma concentrations of thromboxane B2, 6-Keto-PGF1a, and PGE2. This defect may have been due to the generation of fibrin degradation products and platelet “exhaustion”.

A Mucin-Specific Protease Enables Molecular and Functional Analysis of Human Cancer-Associated Mucins

2018 ◽  
Author(s):  
Stacy A. Malaker ◽  
Kayvon Pedram ◽  
Michael J. Ferracane ◽  
Elliot C. Woods ◽  
Jessica Kramer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
High Resolution Mass Spectrometry ◽  
Human Cancer ◽  
Glycosylation Sites ◽  
Bacterial Protease ◽  
Specific Protease ◽  
To Come ◽  
And Function

<div> <div> <div> <p>Mucins are a class of highly O-glycosylated proteins that are ubiquitously expressed on cellular surfaces and are important for human health, especially in the context of carcinomas. However, the molecular mechanisms by which aberrant mucin structures lead to tumor progression and immune evasion have been slow to come to light, in part because methods for selective mucin degradation are lacking. Here we employ high resolution mass spectrometry, polymer synthesis, and computational peptide docking to demonstrate that a bacterial protease, called StcE, cleaves mucin domains by recognizing a discrete peptide-, glycan-, and secondary structure- based motif. We exploited StcE’s unique properties to map glycosylation sites and structures of purified and recombinant human mucins by mass spectrometry. As well, we found that StcE will digest cancer-associated mucins from cultured cells and from ovarian cancer patient-derived ascites fluid. Finally, using StcE we discovered that Siglec-7, a glyco-immune checkpoint receptor, specifically binds sialomucins as biological ligands, whereas the related Siglec-9 receptor does not. Mucin-specific proteolysis, as exemplified by StcE, is therefore a powerful tool for the study of glycoprotein structure and function and for deorphanizing mucin-binding receptors. </p> </div> </div> </div>

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