Principal component analysis of a swine injury model identifies multiple phenotypes in trauma

BACKGROUND

Trauma is the third leading cause of death in the United States and the primary cause of death for people between the ages of 1 year and 44 years. In addition to tissue damage, trauma may also activate an inflammatory state known as trauma-induced coagulopathy (TIC) that is associated with clotting malfunctions, acidemia, and end-organ dysfunction. Prior work has also demonstrated benefit to acknowledging the type and severity of endothelial injury, coagulation derangements, and systemic inflammation in the management of trauma patients. This study builds upon prior work by combining laboratory, metabolic, and clinical metrics into an analysis of trauma phenotypes, evolution of phenotypes over time after trauma, and significance of trauma phenotype on mortality.

METHODS

Seventy 3-month-old female Yorkshire crossbred swine were randomized to injury and resuscitation groups. Principal component analysis (PCA) of longitudinal swine TEG data (Reaction time, Alpha-Angle, Maximum Amplitude, and Clot Lysis at 30 minutes), pH, lactate, and MAP was completed in R at baseline, 1 hour postinjury, 3 hours postinjury, 6 hours postinjury, and 12 hours postinjury. Subjects were compared by principal component factor scores to assess differences in survival, injury severity, and treatment group.

RESULTS

Among injured animals, three phenotypes were observed at each time point. Five phenotypes were associated with differences in survival, and of these, four were associated with differences in injury severity. Phenotype alignment was not significantly different by treatment group.

CONCLUSION

This application of PCA to a set of coagulation, hemodynamic, and organ perfusion variables has identified multiple evolving phenotypes after trauma. Some of these phenotypes may correlate with injury severity and may have implications for survival. Next steps include validating these findings over greater numbers of subjects and exploring other machine-learning techniques for phenotype identification.

LEVEL OF EVIDENCE

Level IV, Therapeutic/Care Management.

Pilot study of frozen platelet extracellular vesicles as a therapeutic agent in hemorrhagic shock in rats

BACKGROUND

Hemorrhage accounts for the most preventable deaths after trauma. Resuscitation is guided by studies that demonstrate improved outcomes in patients receiving whole blood or balanced administration of blood products. Platelets present a logistical challenge due to short shelf life and need for refrigeration. Platelet-derived extracellular vesicles (PEVs) are a possible platelet alternative. Platelet-derived extracellular vesicles are secreted from platelets, have hemostatic effects and mitigate inflammation and vascular injury, similar to platelets. This pilot study aimed to elucidate the therapeutic effects of PEVs in a rat model of uncontrolled hemorrhage.

METHODS

Male rats were anesthetized and femoral vessels cannulated. Vital signs (MAP, HR, and RR) were monitored. Electrolytes, lactate and ABG were obtained at baseline, 1-hour and 3-hours post injury. Laparotomy was performed, 50% of the middle hepatic lobe excised and the abdomen packed with gauze. Rats received 2 mL PEVs or lactated Ringers (LR) over 6 minutes immediately after injury. Peritoneal blood loss was quantified using preweighed gauze at 5 minutes, 15 minutes, 30 minutes, 45 minutes, and 60 minutes. Laparotomy was closed 1-hour postinjury. Animals were monitored for 3 hours postinjury then euthanized. Generalized Linear Mixed Effects models were performed to assess effects of treatment and time on lactate and MAP.

RESULTS

Twenty-one rats were included (11 LR, 10 PEV). Overall blood loss was between 6 mL and 10 mL and not significantly different between groups. There was a 36% mortality rate in the LR group and 0% mortality in the PEV group ( p = 0.03). The LR group had significantly higher lactates at 1 hour ( p = 0.025). At 15 minutes, 45 minutes, 60 minutes, and 180 minutes, the MAP of the PEV group was significantly higher than the LR group.

CONCLUSION

Early studies are encouraging regarding the potential use of PEVs in uncontrolled hemorrhagic shock based on improved survival and hemodynamics.

Insights from CTTACC: immune system reset by cellular therapies for chronic illness after trauma, infection, and burn

BACKGROUND AIMS

In this paper, we present a review of several selected talks presented at the CTTACC conference (Cellular Therapies in Trauma and Critical Care) held in Scottsdale, AZ in May 2023. This conference review highlights the potential for cellular therapies to "reset" the dysregulated immune response and restore physiologic functions to normal. Improvements in medical care systems and technology have increasingly saved lives after major traumatic events. However, many of these patients have complicated post-traumatic sequelae, ranging from short-term multi-organ failure to chronic critical illness.

METHODS/RESULTS

Patients with chronic critical illness have been found to have dysregulated immune responses. These abnormal and harmful immune responses persist for years after the initial insult and can potentially be mitigated by treatment with cellular therapies.

CONCLUSIONS

The sessions emphasized the need for more research and clinical trials with cellular therapies for the treatment of a multitude of chronic illnesses: post-trauma, radiation injury, COVID-19, burns, traumatic brain injury (TBI) and other chronic infections.

The injured monocyte: The link to chronic critical illness and mortality following injury

BACKGROUND

This study aimed to understand the altered innate immune response in severely injured patients leading to chronic critical illness (CCI). Specifically, it focused on characterizing the monocyte populations and their correlation with CCI development and long-term complications.

METHODS

Over a 3-year period, we monitored patients with severe injuries for up to 1-year postinjury. Chronic critical illness was defined as an ICU stay exceeding 14 days with persistent organ failure. Blood samples were collected on Days 1 and 5 for monocyte phenotypic expression analysis using cytometry by time flight. The monocyte subpopulations studied were classical (CL), intermediate (INT), and nonclassical (NC), along with cell surface receptor expression and activation.

RESULTS

Out of 80 enrolled patients, 26 (32.5%) developed CCI. Patients with CCI had more severe injuries (Injury Severity Score, 32.4 + 5.2 vs. 29.6 + 4.1, p = 0.01) and received a higher number of red blood cells (8.9 + 4.1 vs. 4.7 + 3.8 units, p < 0.01) compared with those without CCI. In patients with CCI, the NC monocytes were significantly reduced by over twofold early, and significantly increased later, compared with those without CCI. Moreover, significant changes in intracellular cytokine expression and cell receptors were observed within each monocyte subpopulation in patients with CCI, indicating an increased proinflammatory phenotype but decreased phagocytic capacity and antigen presentation. The development of CCI and the presence of this unique monocyte phenotype were associated with a significantly increased risk of infection, discharge to a long-term care facility, and 1-year mortality of 27%.

CONCLUSION

Development of CCI following severe injury is associated with significant long-term morbidity and unacceptably high mortality. The altered NC phenotype with reduced phagocytic capacity and antigen presentation in patients developing CCI after severe injury is appears partially responsible. Early identification of this unique phenotype may help predict and treat patients at risk for CCI, leading to improved outcomes.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Local manufacturing processes contribute to variability in human mesenchymal stromal cell expansion while growth media supplements contribute to variability in gene expression and cell function: a Biomedical Excellence for Safer Transfusion (BEST) collaborative study

BACKGROUND AIMS

Culture-derived mesenchymal stromal cells (MSCs) exhibit variable characteristics when manufactured using different methods, source material and culture media. The purpose of this multicenter study was to assess the impact on MSC expansion, gene expression and other characteristics when different laboratories expanded MSCs from cultures initiated with bone marrow-MSC aliquots derived from the same donor source material yet with different growth media.

METHODS

Eight centers expanded MSCs using four human platelet lysate (HPL) and one fetal bovine serum (FBS) products as media supplements. The expanded cells were taken through two passages then assessed for cell count, viability, doubling time, immunophenotype, cell function, immunosuppression and gene expression. Results were analyzed by growth media and by center.

RESULTS

Center methodologies varied by their local seeding density, feeding regimen, inoculation density, base media and other growth media features (antibiotics, glutamine, serum). Doubling times were more dependent on center than on media supplements. Two centers had appropriate immunophenotyping showing all MSC cultures were positive for CD105, CD73, CD90 and negative for CD34, CD45, CD14, HLA-DR. MSCs cultured in media supplemented with FBS compared with HPL featured greater T-cell inhibition potential. Gene expression analysis showed greater impact of the type of media supplement (HPL versus FBS) than the manufacturing center. Specifically, nine genes were decreased in expression and six increased when combining the four HPL-grown MSCs versus FBS (false discovery rate [FDR] <0.01), however, without significant difference between different sources of HPL (FDR <0.01).

CONCLUSIONS

Local manufacturing process plays a critical role in MSC expansion while growth media may influence function and gene expression. All HPL and FBS products supported cell growth.

Immediate use cryoprecipitate products provide lasting organ protection in a rodent model of trauma/hemorrhagic shock and prolonged hypotensive resuscitation

BACKGROUND

Cryoprecipitate (CP) can augment hemostasis after hemorrhagic shock (HS). Similar to fresh frozen plasma (FFP), CP may provide short-term endothelial protection. We tested a new 5-day postthaw CP (5-day pathogen-reduced cryoprecipitate [5PRC]) and lyophilized pathogen-reduced cryoprecipitate (LPRC) to overcome challenges of early administration and hypothesized that 5PRC and LPRC would provide lasting organ protection in a rodent model of HS.

METHODS

Mice underwent trauma/HS (laparotomy then HS), mean arterial pressure (MAP) 35 × 90 minutes, and then 6 hours of hypotensive resuscitation (MAP, 55-60 mm Hg) with lactated Ringer's solution (LR), FFP, CP, 5PRC, or LPRC and compared with shams. Animals were followed for 72 hours. Organs and blood were collected. Data are presented as mean ± SD and analysis of variance with Bonferroni post hoc.

RESULTS

Mean arterial pressure was comparable between experimental groups at baseline, preresuscitation, and 6 hours per protocol. However, volume needed to resuscitate to target MAP over 6 hours was less than half for CP, 5PRC, LPRC, and FFP compared with LR, suggesting that CP products can serve as effective resuscitative agents. Mean arterial pressure at 72 hours was also significantly higher in the CP, 5PRC, and FFP groups compared with LR. Resuscitation with CP, 5PRC, and LPRC provided lasting protection from gut injury and enhanced syndecan immunostaining comparable with FFP, while LR mice demonstrated persistent organ dysfunction. Sustained endothelial protection was demonstrated by lessened lung permeability, while cystatin C was an indicator of kidney function, and liver aspartate aminotransferase and alanine transaminase returned to sham levels in all groups.

CONCLUSION

Cryoprecipitate products can provide lasting organ protection comparable with FFP in a sustained rodent model of trauma/HS and hypotensive resuscitation. The availability of 5PRC and LPRC will allow for investigation into the immediate use of cryoprecipitate for severely injured patients. As lyophilized products such as cryoprecipitate become available clinically, their use has important implications for prehospital, rural, and battlefield usage.

Early lyophilized cryoprecipitate enhances the ADAMTS13/VWF ratio to reduce systemic endotheliopathy and lessen lung injury in a mouse multiple-trauma hemorrhage model

BACKGROUND

Recent studies in severely injured patients suggest an important role of von Willebrand Factor (VWF) and ADAMTS13 in the endotheliopathy of trauma (EoT). We hypothesized that the early use of cryoprecipitate would be effective as an endothelial protector by supplementing physiologic VWF and ADAMTS13 to reverse the EoT. We tested a pathogen-reduced lyophilized cryoprecipitate (LPRC) that could expedite the early administration of cryoprecipitate in the battlefield.

METHODS

A mouse multiple-trauma model with uncontrolled hemorrhage (UCH) from liver injury was utilized followed by hypotensive resuscitation (mean arterial pressure, 55-60) × 3 hours with lactated Ringer's (LR), fresh frozen plasma (FFP), conventional pathogen-reduced cryoprecipitate (CC), and LPRC. Blood was collected for measurement of syndecan-1, VWF, and ADAMTS13 by ELISA. Lungs were stained for histopathologic injury and syndecan-1 and bronchial alveolar lavage (BAL) fluid harvested for protein as an indicator of permeability. Statistical analysis was by ANOVA followed by Bonferroni correction.

RESULTS

Following multiple trauma and UCH, blood loss was similar across groups. Mean volume of resuscitation was higher in the LR group compared with the other resuscitation groups. Lung histopathologic injury, syndecan-1 immunostaining and BAL protein were higher with LR compared with resuscitation with FFP and CC, while LPRC further reduced BAL compared with FFP and CC. The ADAMTS13/VWF ratio was significantly lower in LR but improved with FFP and CC, comparable to shams while LPRC further increased this ratio.

CONCLUSION

The protective effects of CC and LPRC were comparable to FFP in ameliorating the EoT in our murine multiple trauma and UCH model. Lyophilized cryoprecipitate may also provide additional benefit by enhancing the ADAMTS13/VWF ratio. These data provide evidence of the safety and efficacy of LPRC and warrants further investigation for its potential application in military settings once approved for human administration.

Biomarkers of endothelial cell dysfunction persist beyond resuscitation in patients with hemorrhagic shock

BACKGROUND

It has been shown that microRNA-19b (miR-19b) binds to and degrades syndecan-1 after hemorrhagic shock (HS) and contributes to endothelial dysfunction in vitro and in vivo. The objective of the current study was to assess longitudinal changes in miR-19b and syndecan-1 in HS patients.

METHODS

Blood samples from HS patients (blood pressure <90 mm Hg and ≥2 U blood) were collected upon admission, completion of hemostasis, and after 24 hours for miR-19b (quantitative reverse transcription PCR) and syndecan-1 (enzyme-linked immunosorbent assay) and compared with controls and minimally injured (Injury Severity Score, ≤9). Inflammatory cytokines were measured (Luminex [Thermo Fisher, Waltham, MA]). Correlations between syndecan-1, miR-19b, inflammatory markers, and patient outcomes were performed. Logistic regression models were developed for outcomes.

RESULTS

Thirty-four HS patients were studied: age, 46 (19-89) years; male, 82%; penetrating, 35%; Injury Severity Score, 24 ± 10; and blood products at 24 hours, 21 ± 19 U. MicroRNA-19b was increased upon arrival and further increased over time: 4.6 → 6.7 → 24.1-fold change compared with 0.1 and 1.2 for minimally injured patients and controls, respectively. Syndecan-1 was increased to 42.6 → 50 → 51.5 ng/mL over time compared with 14.7 and 23.5 for minimally injured and controls, respectively. Values for both biomarkers remained significantly increased through 24 hours and were associated with a persistent increase in inflammatory cytokines. Admission syndecan-1 significantly predicted mortality, coagulopathy, and massive transfusion.

CONCLUSION

We have shown for the first time that miR-19b and syndecan-1 were biomarkers for endothelial dysfunction independent of resuscitation. MicroRNA-19b did not demonstrate a strong correlation with syndecan-1 nor outcomes. Admission syndecan-1, however, remains a strong prognostic marker, but its elevation over time suggests a versatile role following HS that requires further investigation.

LEVEL OF EVIDENCE

Prognostic/Epidemiological; Level II.

Lyophilized plasma resuscitation downregulates inflammatory gene expression in a mouse model of sepsis

BACKGROUND

Plasma resuscitation may improve outcomes by targeting endotheliopathy induced by severe sepsis or septic shock. Given the logistical constraints of using fresh frozen plasma in military settings or areas with prolonged prehospital care, dried products such as lyophilized plasma (LP) have been developed. We hypothesized that resuscitation with LP would decrease lung injury, inflammation, and mortality in a mouse sepsis model.

METHODS

Adult male C57BL/6J mice received an intraperitoneal injection of cecal slurry. Twenty-two hours later, the mice were anesthetized, the femoral artery was cannulated, and the mice were randomized to receive resuscitation with LP (10 mL/kg) or lactated Ringer's (LR; 30 mL/kg) for 1 hour. At 48-hours post-cecal slurry injection, bronchoalveolar lavage fluid was collected, the lungs were harvested, and plasma was obtained. Mortality and bronchoalveolar lavage total protein concentration (as an indicator of permeability) were compared between groups. The lungs were analyzed for histopathology and inflammatory gene expression using NanoString, and the plasma was analyzed for biomarkers of inflammation and endothelial function.

RESULTS

There was no significant difference in short-term mortality between LR and LP mice, 38% versus 47%, respectively ( p = 0.62). Bronchoalveolar lavage protein levels were similar among mice resuscitated with LR or LP, and there was a lack of significant histopathologic lung injury in all groups. However, LP resuscitation resulted in downregulation of pulmonary inflammatory genes, including signaling pathways such as Janus kinase-signal transducer and activator of transcription and nuclear factor κB, and a circulating inflammatory biomarker profile similar to sham animals.

CONCLUSION

Resuscitation with LP did not improve mortality or reduce permeability or injury in this model compared with LR. However, LP downregulated pulmonary inflammatory gene signaling and may also reduce circulating biomarkers of inflammation. Future studies should evaluate LP resuscitation in combination with antibiotics and other therapeutics to determine whether the anti-inflammatory effects of LP may improve outcomes in sepsis.

FFP maintains normal coagulation while Kcentra induces a hypercoagulable state in a porcine model of pulmonary contusion and hemorrhagic shock

BACKGROUND

Moderate injury can lead to a coagulopathy. Fresh frozen plasma (FFP) corrects coagulopathy by means of a balanced array of clotting factors. We sought to compare the late effects of FFP and a prothrombin complex concentrate (PCC) on the coagulopathy of trauma using a porcine model of pulmonary contusion (PC) and hemorrhagic shock (HS) designed to evaluate the organ protective effects of these treatments.

METHODS

Female Yorkshire swine (40-50 kg) were randomized to receive PC + HS or control (instrumented and uninjured). A blunt PC was created using a captive bolt gun. To induce HS, a liver crush injury was performed. Eighty minutes after injury, swine were treated with 25 U·kg-1 PCC, 1 U FFP, or 50 mL lactated Ringer's vehicle in a blinded manner. Arterial blood samples were drawn every 6 hours. Swine were euthanized 48 hours postinjury. Data were analyzed by Pearson χ2, analysis of variance and Kruskal-Wallis tests with Tukey's or Mann-Whitney U tests for post hoc analysis.

RESULTS

Twenty-seven swine received PC + HS, 3 groups of 9 per group received PCC, FFP, or vehicle. Nine were noninjured controls. When compared with control, PC + HS swine had significantly shortened R time at 6 hours, 36 hours, and 42 hours, decreased LY30 at 12 hours, shortened K time at 30 hours and reduced α angle at 42 hours. PC + HS swine showed significant differences between treatment groups in K and α angle at 3 hours, LY30 at 12 hours and 18 hours, and MA at 12 hours, 18 hours, and 30 hours. Post hoc analysis was significant for higher α angle in PCC versus vehicle at 3 hours, higher MA in vehicle versus PCC at 12 hours and 18 hours, and higher LY30 in PCC versus vehicle at 18 hours (p < 0.012) with no significant differences between FFP and vehicle.

CONCLUSION

Severe injury with HS induced a coagulopathy in swine. While FFP maintained normal coagulation following injury, PCC induced more rapid initial clot propagation in injured animals.

Mesenchymal stem cell extracellular vesicles mitigate vascular permeability and injury in the small intestine and lung in a mouse model of hemorrhagic shock and trauma

BACKGROUND

Hemorrhagic shock and trauma (HS/T)-induced gut injury may play a critical role in the development of multi-organ failure. Novel therapies that target gut injury and vascular permeability early after HS/T could have substantial impacts on trauma patients. In this study, we investigate the therapeutic potential of human mesenchymal stem cells (MSCs) and MSC-derived extracellular vesicles (MSC EVs) in vivo in HS/T in mice and in vitro in Caco-2 human intestinal epithelial cells.

METHODS

In vivo, using a mouse model of HS/T, vascular permeability to a 10-kDa dextran dye and histopathologic injury in the small intestine and lungs were measured among mice. Groups were (1) sham, (2) HS/T + lactated Ringer's (LR), (3) HS/T + MSCs, and (4) HS/T + MSC EVs. In vitro, Caco-2 cell monolayer integrity was evaluated by an epithelial cell impedance assay. Caco-2 cells were pretreated with control media, MSC conditioned media (CM), or MSC EVs, then challenged with hydrogen peroxide (H2O2).

RESULTS

In vivo, both MSCs and MSC EVs significantly reduced vascular permeability in the small intestine (fluorescence units: sham, 456 ± 88; LR, 1067 ± 295; MSC, 765 ± 258; MSC EV, 715 ± 200) and lung (sham, 297 ± 155; LR, 791 ± 331; MSC, 331 ± 172; MSC EV, 303 ± 88). Histopathologic injury in the small intestine and lung was also attenuated by MSCs and MSC EVs. In vitro, MSC CM but not MSC EVs attenuated the increased permeability among Caco-2 cell monolayers challenged with H2O2.

CONCLUSION

Mesenchymal stem cell EVs recapitulate the effects of MSCs in reducing vascular permeability and injury in the small intestine and lungs in vivo, suggesting MSC EVs may be a potential cell-free therapy targeting multi-organ dysfunction in HS/T. This is the first study to demonstrate that MSC EVs improve both gut and lung injury in an animal model of HS/T.

Targeting repair of the vascular endothelium and glycocalyx after traumatic injury with plasma and platelet resuscitation

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Endothelial glycocalyx shedding is a key instigator of the endotheliopathy of trauma.

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Plasma and platelet transfusions preserve vascular integrity in pre-clinical models.

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However, platelets may be less effective than plasma in preserving the glycocalyx.

Severely injured patients with hemorrhagic shock can develop endothelial dysfunction, systemic inflammation, and coagulation disturbances collectively known as the endotheliopathy of trauma (EOT). Shedding of the endothelial glycocalyx occurs early after injury, contributes to breakdown of the vascular barrier, and plays a critical role in the pathogenesis of multiple organ dysfunction, leading to poor outcomes in trauma patients. In this review we discuss (i) the pathophysiology of endothelial glycocalyx and vascular barrier breakdown following hemorrhagic shock and trauma, and (ii) the role of plasma and platelet transfusion in maintaining the glycocalyx and vascular endothelial integrity.

Standardization in Quantitative Imaging: A Multicenter Comparison of Radiomic Features from Different Software Packages on Digital Reference Objects and Patient Data Sets

Radiomic features are being increasingly studied for clinical applications. We aimed to assess the agreement among radiomic features when computed by several groups by using different software packages under very tightly controlled conditions, which included standardized feature definitions and common image data sets. Ten sites (9 from the NCI's Quantitative Imaging Network] positron emission tomography–computed tomography working group plus one site from outside that group) participated in this project. Nine common quantitative imaging features were selected for comparison including features that describe morphology, intensity, shape, and texture. The common image data sets were: three 3D digital reference objects (DROs) and 10 patient image scans from the Lung Image Database Consortium data set using a specific lesion in each scan. Each object (DRO or lesion) was accompanied by an already-defined volume of interest, from which the features were calculated. Feature values for each object (DRO or lesion) were reported. The coefficient of variation (CV), expressed as a percentage, was calculated across software packages for each feature on each object. Thirteen sets of results were obtained for the DROs and patient data sets. Five of the 9 features showed excellent agreement with CV < 1%; 1 feature had moderate agreement (CV < 10%), and 3 features had larger variations (CV ≥ 10%) even after attempts at harmonization of feature calculations. This work highlights the value of feature definition standardization as well as the need to further clarify definitions for some features.

Cryoprecipitate attenuates the endotheliopathy of trauma in mice subjected to hemorrhagic shock and trauma

BACKGROUND

Plasma has been shown to mitigate the endotheliopathy of trauma. Protection of the endothelium may be due in part to fibrinogen and other plasma-derived proteins found in cryoprecipitate; however, the exact mechanisms remain unknown. Clinical trials are underway investigating early cryoprecipitate administration in trauma. In this study, we hypothesize that cryoprecipitate will inhibit endothelial cell (EC) permeability in vitro and will replicate the ability of plasma to attenuate pulmonary vascular permeability and inflammation induced by hemorrhagic shock and trauma (HS/T) in mice.

METHODS

In vitro, barrier permeability of ECs subjected to thrombin challenge was measured by transendothelial electrical resistance. In vivo, using an established mouse model of HS/T, we compared pulmonary vascular permeability among mice resuscitated with (1) lactated Ringer's solution (LR), (2) fresh frozen plasma (FFP), or (3) cryoprecipitate. Lung tissue from the mice in all groups was analyzed for markers of vascular integrity, inflammation, and inflammatory gene expression via NanoString messenger RNA quantification.

RESULTS

Cryoprecipitate attenuates EC permeability and EC junctional compromise induced by thrombin in vitro in a dose-dependent fashion. In vivo, resuscitation of HS/T mice with either FFP or cryoprecipitate attenuates pulmonary vascular permeability (sham, 297 ± 155; LR, 848 ± 331; FFP, 379 ± 275; cryoprecipitate, 405 ± 207; p < 0.01, sham vs. LR; p < 0.01, LR vs. FFP; and p < 0.05, LR vs. cryoprecipitate). Lungs from cryoprecipitate- and FFP-treated mice demonstrate decreased lung injury, decreased infiltration of neutrophils and activation of macrophages, and preserved pericyte-endothelial interaction compared with LR-treated mice. Gene analysis of lung tissue from cryoprecipitate- and FFP-treated mice demonstrates decreased inflammatory gene expression, in particular, IL-1β and NLRP3, compared with LR-treated mice.

CONCLUSION

Our data suggest that cryoprecipitate attenuates the endotheliopathy of trauma in HS/T similar to FFP. Further investigation is warranted on active components and their mechanisms of action.

Constraints and challenges in convalescent plasma collection amidst the Covid 19 pandemic- strategies and recommendations to overcome these

Background

COVID 19 is an acute respiratory disease caused by infection by the virus SARS-COV-2 and has been declared as a pandemic whose specific treatment is still not established. One of the options in the treatment is Convalescent plasma (CP) therapy when there is presence of required amount of neutralizing antibodies in the plasma of recovered COVID patients. Our objective was to analyze the challenges and the constraints encountered in motivation of COVID 19 recovered persons to come for the screening procedures and to convince the selected persons to come for Plasma donation voluntarily.

Material & methods

The present retrospective observational study was conducted for a period of five and half months. Out of 1515 number of persons contacted telephonically for Plasma donation, 1291 persons came for screening of whom 1028 persons were eligible for donation, 263 cases were deferred and 966 persons finally donated.

Results

Maximum number of acceptance cases were from males-(98.7%). Of the accepted cases, (41.73%) were from the 18-30 years’ age group. 33.94% were from blood group ‘O’ Rh D positive giving maximum contribution from any blood group. 38.3% of the accepted cases had resolution of all COVID symptoms within time period of 28-40 days. Maximum number of accepted individuals (39.75%) had suffered from multiple symptoms followed by 39.02% of asymptomatic persons. Highest number of Plasma donation was contributed by Odisha Government Police personnel (51.56%).

Discussion

In this global ongoing pandemic, the “Fear Factor of contracting the disease” has acted as a major challenge in motivating and convincing a COVID recovered patient for plasma donation. The challenge before the medical professionals was to motivate, educate and convince the potential donors and the society about the likely benefits of convalescent plasma. This could be finally overcome with the help of positive orientation through social and conventional media as well as mass appeal from government side on the benefits of plasma therapy in saving lives in the present pandemic.

Evidence-Based and Clinically Relevant Outcomes for Hemorrhage Control Trauma Trials

OBJECTIVE

To address the clinical and regulatory challenges of optimal primary endpoints for bleeding patients by developing consensus-based recommendations for primary clinical outcomes for pivotal trials in patients within 6 categories of significant bleeding, (1) traumatic injury, (2) intracranial hemorrhage, (3) cardiac surgery, (4) gastrointestinal hemorrhage, (5) inherited bleeding disorders, and (6) hypoproliferative thrombocytopenia.

BACKGROUND

A standardized primary outcome in clinical trials evaluating hemostatic products and strategies for the treatment of clinically significant bleeding will facilitate the conduct, interpretation, and translation into clinical practice of hemostasis research and support alignment among funders, investigators, clinicians, and regulators.

METHODS

An international panel of experts was convened by the National Heart Lung and Blood Institute and the United States Department of Defense on September 23 and 24, 2019. For patients suffering hemorrhagic shock, the 26 trauma working-group members met for almost a year, utilizing biweekly phone conferences and then an in-person meeting, evaluating the strengths and weaknesses of previous high quality studies. The selection of the recommended primary outcome was guided by goals of patient-centeredness, expected or demonstrated sensitivity to beneficial treatment effects, biologic plausibility, clinical and logistical feasibility, and broad applicability.

CONCLUSIONS

For patients suffering hemorrhagic shock, and especially from truncal hemorrhage, the recommended primary outcome was 3 to 6-hour all-cause mortality, chosen to coincide with the physiology of hemorrhagic death and to avoid bias from competing risks. Particular attention was recommended to injury and treatment time, as well as robust assessments of multiple safety related outcomes.

Freeze-dried platelets promote clot formation, attenuate endothelial cell permeability, and decrease pulmonary vascular leak in a murine model of hemorrhagic shock

BACKGROUND

Hemorrhagic shock (HS) and trauma induce endothelial barrier compromise, inflammation, and aberrant clotting. We have shown that fresh human platelets (Plts) and Plt extracellular vesicles mitigate vascular leak in murine models of injury. Here, we investigate the potential of freeze-dried platelets (FDPlts) to attenuate pulmonary vascular permeability, decrease inflammation, and promote clotting in a murine model of HS.

METHODS

Human FDPlts were characterized using in vitro assays of Plt marker expression, aggregation, coagulation, and endothelial cell permeability. An intravital model of vascular injury in the mouse cremaster muscle was used to assess the ability of FDPlts to incorporate into clots. Mouse groups subjected to controlled hemorrhage for 90 minutes were (1) lactated Ringer solution (LR), (2) FDPlts, (3) fresh human Plts, (4) murine whole blood (WB), and (5) shams (only instrumented). Hemorrhagic shock mouse endpoints included coagulation, pulmonary vascular permeability, and lung injury.

RESULTS

Freeze-dried Plts expressed Plt-specific markers and retained functionality similar to fresh Plts. In in vitro assays of Plt aggregation, differences were noted. In vivo, FDPlts and Plts were found to incorporate into clots in postcapillary venules in the mouse cremaster muscle. Hemorrhagic shock mice resuscitated with LR displayed increased pulmonary vascular permeability compared with sham (sham, 686.6 ± 359.7; shock-LR, 2,637 ± 954.7; p = 0.001), and treatment with FDPlts or WB attenuated permeability compared with shock: shock-FDPlts, 1,328 ± 462.6 (p = 0.05), and shock-WB, 1,024 ± 370.5 (p = 0.0108). However, human Plts (Days 1-3) did not attenuate vascular leak in HS mice compared with shock-LR (shock-Plts, 3,601 ± 1,581; p = 0.33).

CONCLUSION

FDPlts contribute to clot formation similar to fresh human Plts. FDPlts also attenuated vascular permeability in vitro and in vivo. Mouse WB resuscitation but not fresh human Plts attenuated vascular permeability after HS. These data suggest that the effect of FDPlts may be a suitable alternative to fresh Plts in modulating hemostasis and the endotheliopathy associated with injury.

Human Mesenchymal Stromal Cell (MSC) Characteristics Vary Among Laboratories When Manufactured From the Same Source Material: A Report by the Cellular Therapy Team of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative

Background

Culture-derived mesenchymal stromal cells (MSCs) exhibit variable characteristics when manufactured using different methods and different source materials. The purpose of this study was to assess the impact on MSC characteristics when different laboratories propagated MSCs from cultures initiated with BM aliquots derived from the same donor source material.

Methods and Methods

Five aliquots from each of three different BM donors were distributed to five independent laboratories. Three laboratories plated whole BM and two laboratories a mononuclear BM cell fraction. Four laboratories cultured in media supplemented with fetal bovine serum (FBS) and one laboratory used human platelet lysate (hPL). Initial cell seeding densities (i.e., P0) ranged from 19.7 × 10³/cm²–282 × 10³/cm² and for second seeding (i.e., P1) 0.05 × 10³–5.1 × 10³ cells/cm². Post-thawed MSCs from each laboratory were analyzed for cell viability, immunophenotype, tri-lineage differentiation, fibroblast colony-forming units (CFU-F), gene expression, and immunosuppressive activity.

Results

Transit times from BM collection to receipt by laboratories located in the United States ranged from 16.0–30.0 h and from 41.5–71.5 h for a laboratory in Asia. Post-thaw culture derived MSCs rom BM #1, #2, and #3 exhibited viabilities that ranged from 74–92%, 61–96%, and 23–90%, respectively. CFU activity from BM #1, #2, and #3 per 200 MSCs plated averaged 45.1 ± 21.4, 49.3 ± 26.8 and 14.9 ± 13.3, respectively. No substantial differences were observed in immunophenotype, and immunosuppressive activities. Global gene expression profiles of MSCs revealed transcriptome differences due to different inter-laboratory methods and to donor source material with the center effects showing greater molecular differences than source material.

Conclusion

Functional and molecular differences exist among MSCs produced by different centers even when the same BM starting material is used to initiate cultures. These results indicated that manufacturing of MSCs by five independent centers contributed more to MSC variability than did the source material of the BM used in this study. Thus, emphasizing the importance of establishing worldwide standards to propagate MSCs for clinical use.

Aggressive treatment of acute kidney injury and hyperkalemia improves survival in a combat relevant trauma model in swine

INTRODUCTION

Our swine model of pulmonary contusion (PC) and hemorrhagic shock (HS) was initially complicated by renal failure, hyperkalemia, and premature death. To study the effects of novel therapies on organ failure, improved survival was necessary requiring the design of an aggressive treatment regimen.

METHODS

Anesthetized swine sustained either PC or PC with grade V liver injury to induce HS (PC + HS). After injury, animals were resuscitated followed by either standard care (SC) with maintenance intravenous fluids (IVF) and treatment at potassium level of 6.0 mmol/L (n = 7; 3 PC, 4 PC + HS) or aggressive care (AC) with increased initial IVF, early and frequent potassium monitoring, and treatment at potassium level of 5.0 mmol/L (n = 15, 8 PC, 7 PC + HS). Hyperkalemia was treated with calcium, insulin, and glucose in both groups.

RESULTS

Survival to 48 h was achieved in 13/15 (87%) in the AC group and 2/7 (29%) in the SC group (p = 0.014). Compared to SC, AC improved median survival (48 vs. 18 h, p = 0.008) and lowered potassium (5.0 vs. 7.5 mmol/L), creatinine (2.4 vs. 4.0 mg/dL), BUN (27.5 vs. 39.0 mg/dL), and lactate (0.97 vs. 3.57 mmol/L) at the last observed time-point prior to death. For PC + HS animals, survival to 48 h was achieved in 6/7 in the AC group and 0/4 in the SC group with an improved median survival in the AC group (48 vs. 18 h, p = 0.011) DISCUSSION: Aggressive and early hyperkalemia treatment prolongs survival while reducing kidney injury and potassium levels in a combat relevant injury model in swine.

Comparative analysis of PHAs production by Bacillus megaterium OUAT 016 under submerged and solid-state fermentation

In view of risk coupled with synthetic polymer waste, there is an imperative need to explore biodegradable polymer. On account of that, six PHAs producing bacteria were isolated from mangrove forest and affilated to the genera Bacillus & Pseudomonas from morpho-physiological characterizations. Among which the potent PHAs producer was identified as Bacillus megaterium OUAT 016 by 16S rDNA sequencing and in-silico analysis. This research addressed a comparative account on PHAs production by submerged and solid-state fermentation pertaining to different downstream processing. Here, we established higher PHAs production by solid-state fermentation through sonication and mono-solvent extraction. Using modified MSM media under optimized conditions, 49.5% & 57.7% of PHAs were produced in submerged and 34.1% & 62.0% in solid-state fermentation process. Extracted PHAs was identified as a valuable polymer PHB-co-PHV and its crystallinity & thermostability nature was validated by FTIR, ¹H NMR and XRD. The melting (Tm) and thermal degradation temperature (Td) of PHB-co-PHV was 166 °C and 273 °C as depicted from DTA. Moreover, FE-SEM and SPM surface imaging indicated biodegradable nature, while FACS assay confirmed cytocompatibility of PHB-co-PHV.

Is all plasma created equal? A pilot study of the effect of interdonor variability

BACKGROUND

Clinical benefits of plasma as an adjunct for treatment of hemorrhagic shock (HS) have been well established. However, its use is not without risk. Little is understood regarding the clinical implications of plasma variability. We hypothesized there to be interdonor variability in plasma that would impact endothelial and organ function postinjury.

METHODS

Pulmonary endothelial cells (ECs) were incubated with plasma from 24 random donors, and transendothelial electrical resistance was measured. Plasma units with a more or less protective effect on reducing EC permeability were selected for testing in vivo. Syndecan-1 and cytokines were measured. Mice underwent laparotomy and then HS followed by resuscitation with the selected plasma units and were compared with mice receiving no resuscitation and shams. Lung tissue was sectioned and stained for myeloperoxidase and pulmonary syndecan-1 and scored for lung histopathologic injury.

RESULTS

Plasma from 24 donors revealed variability in the reversal of EC monolayer hyperpermeability; transendothelial electrical resistance for the more protective plasma was significantly higher than that for the less protective plasma (0.801 ± 0.022 vs. 0.744 ± 0.035; p = 0.002). Syndecan-1 was also markedly increased in the less protective compared with the more protective plasma (38427 ± 1257 vs. 231 ± 172 pg/mL, p < 0.001), while cytokines varied. In vivo, the more protective plasma mitigated lung histopathologic injury compared with the less protective plasma (1.56 ± 0.27 vs. 2.33 ± 0.47, respectively; p = 0.005). Similarly, myeloperoxidase was significantly reduced in the more protective compared with the less protective plasma group (2.590 ± 0.559 vs. 6.045 ± 1.885; p = 0.02). Lastly, pulmonary syndecan-1 immunostaining was significantly increased in the more protective compared with the less protective plasma group (20.909 ± 8.202 vs. 9.325 ± 3.412; p = 0.018).

CONCLUSION

These data demonstrate significant interdonor variability in plasma that can adversely influence the protective effects of plasma-based resuscitation on HS-induced lung injury. This may have important implications for patient safety and clinical outcomes.

Platelet-derived- Extracellular Vesicles Promote Hemostasis and Prevent the Development of Hemorrhagic Shock

Every year more than 500,000 deaths are attributed to trauma worldwide and severe hemorrhage is present in most of them. Transfused platelets have been shown to improve survival in trauma patients, although its mechanism is only partially known. Platelet derived-extracellular vesicles (PEVs) are small vesicles released from platelets upon activation and/or mechanical stimulation and many of the benefits attributed to platelets could be mediated through PEVs. Based on the available literature, we hypothesized that transfusion of human PEVs would promote hemostasis, reduce blood loss and attenuate the progression to hemorrhagic shock following severe trauma. In this study, platelet units from four different donors were centrifuged to separate platelets and PEVs. The pellets were washed to obtain plasma-free platelets to use in the rodent model. The supernatant was subjected to tangential flow filtration for isolation and purification of PEVs. PEVs were assessed by total count and particle size distribution by Nanoparticle Tracking Analysis (NTA) and characterized for cells of origin and expression of EV specific-surface and cytosolic markers by flow cytometry. The coagulation profile from PEVs was assessed by calibrated automated thrombography (CAT) and thromboelastography (TEG). A rat model of uncontrolled hemorrhage was used to compare the therapeutic effects of 8.7 × 10⁸ fresh platelets (FPLT group, n = 8), 7.8 × 10⁹ PEVs (PEV group, n = 8) or Vehicle (Control, n = 16) following severe trauma. The obtained pool of PEVs from 4 donors had a mean size of 101 ± 47 nm and expressed the platelet-specific surface marker CD41 and the EV specific markers CD9, CD61, CD63, CD81 and HSP90. All PEV isolates demonstrated a dose-dependent increase in the rate and amount of thrombin generated and overall clot strength. In vivo experiments demonstrated a 24% reduction in abdominal blood loss following liver trauma in the PEVs group when compared with the control group (9.9 ± 0.4 vs. 7.5 ± 0.5 mL, p < 0.001>). The PEV group also exhibited improved outcomes in blood pressure, lactate level, base excess and plasma protein concentration compared to the Control group. Fresh platelets failed to improve these endpoints when compared to Controls. Altogether, these results indicate that human PEVs provide pro-hemostatic support following uncontrolled bleeding. As an additional therapeutic effect, PEVs improve the outcome following severe trauma by maintaining hemodynamic stability and attenuating the development of ischemia, base deficit, and cardiovascular shock.

Gaps in the knowledge of human platelet lysate as a cell culture supplement for cell therapy: a joint publication from the AABB and the International Society for Cell & Gene Therapy

Fetal bovine serum (FBS) is used as a growth supplement in a wide range of cell culture applications for cell-based research and therapy. However, as a xenogenic product, FBS can potentially transmit prions and adventitious viruses as well as induce undesirable immunologic reactions. In addition, the use of bovine fetuses for FBS production raises concerns as society looks for ways to replace animal testing and reduce the use of animal products for scientific purposes, in particular for the manufacture of clinical products intended for human use. Until chemically defined media are available for these purposes, human platelet lysate (hPL) has been introduced as an attractive alternative for replacing FBS as a cell culture supplement. hPL is a human product that can be produced from outdated platelets avoiding ethical, medical and animal welfare concerns. An increasing number of studies demonstrate that hPL can promote cell growth similarly or even better than FBS in specific cell types. Due to increasing interest in hPL, the AABB and the International Society of Cell Therapy (ISCT) established a joint working group to address its potential. With this article, we aim to present an overview of hPL, identifying the gaps in information on how hPL is produced and tested and the barriers to its translational use in the production of clinical-grade cell therapy products.

Regulation of endothelial cell permeability by platelet-derived extracellular vesicles

BACKGROUND

Platelet (Plt)-derived extracellular vesicles (Plt-EVs) have hemostatic properties similar to Plts. In addition to hemostasis, Plts also function to stabilize the vasculature and maintain endothelial cell (EC) barrier integrity. We hypothesized that Plt-EVs would inhibit vascular EC permeability, similar to fresh Plts. To investigate this hypothesis, we used in vitro and in vivo models of vascular endothelial compromise and bleeding.

METHODS

In the vitro model, Plt-EVs were isolated by ultracentrifugation and characterized for Plt markers and particle size distribution. Effects of Plts and Plt-EVs on endothelial barrier function were assessed by transendothelial electrical resistance measurements and histological analysis of endothelial junction proteins. Hemostatic potential of Plt-EVs and Plts was assessed by multiple electrode Plt aggregometry. Using an in vivo model, the effects of Plts and Plt-EVs on vascular permeability and bleeding were assessed in non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice by an established Miles assay of vascular permeability and a tail snip bleeding assay.

RESULTS

In the in vitro model, Plt-EVs displayed exosomal size distribution and expressed Plt-specific surface markers. Platelets and Plt-EVs decreased EC permeability and restored EC junctions after thrombin challenge. Multiplate aggregometry revealed that Plt-EVs enhanced thrombin receptor-activating peptide-mediated aggregation of whole blood, whereas Plts enhanced thrombin receptor-activating peptide-, arachidonic acid-, collagen-, and adenosine diphosphate-mediated aggregation. In the in vivo model, Plt-EVs are equivalent to Plts in attenuating vascular endothelial growth factor (VEGF)-A-induced vascular permeability and uncontrolled blood loss in a tail snip hemorrhage model.

CONCLUSION

Our study is the first to report that Plt-EVs might provide a feasible product for transfusion in trauma patients to attenuate bleeding, inhibit vascular permeability, and mitigate the endotheliopathy of trauma.

Bone marrow donor selection and characterization of MSCs is critical for pre-clinical and clinical cell dose production

Background

Cell based therapies, such as bone marrow derived mesenchymal stem cells (BM-MSCs; also known as mesenchymal stromal cells), are currently under investigation for a number of disease applications. The current challenge facing the field is maintaining the consistency and quality of cells especially for cell dose production for pre-clinical testing and clinical trials. Here we determine how BM-donor variability and thus the derived MSCs factor into selection of the optimal primary cell lineage for cell production and testing in a pre-clinical swine model of trauma induced acute respiratory distress syndrome.

Methods

We harvested bone marrow and generated three different primary BM-MSCs from Yorkshire swine. Cells from these three donors were characterized based on (a) phenotype (morphology, differentiation capacity and flow cytometry), (b) in vitro growth kinetics and metabolic activity, and (c) functional analysis based on inhibition of lung endothelial cell permeability.

Results

Cells from each swine donor exhibited varied morphology, growth rate, and doubling times. All expressed the same magnitude of standard MSC cell surface markers by flow cytometry and had similar differentiation potential. Metabolic activity and growth potential at each of the passages varied between the three primary cell cultures. More importantly, the functional potency of the MSCs on inhibition of endothelial permeability was also cell donor dependent.

Conclusion

This study suggests that for production of MSCs for cell-based therapy, it is imperative to examine donor variability and characterize derived MSCs for marker expression, growth and differentiation characteristics and testing potency in application dependent assays prior to selection of the optimal cell lineage for large scale expansion and dose production.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1877-4) contains supplementary material, which is available to authorized users.

Barriers to clinical research in trauma

As with all areas of medicine, high-quality clinical research is essential to improving the care of trauma patients. This research is crucial in developing evidence-based treatments that decrease cost, decrease morbidity, and improve mortality. Trauma continues to extract a significant toll on society and is the single largest cause of years of life lost in the United States. The need to conduct high-quality clinical research in trauma is not disputed. However, significant challenges and barriers unique to the field of trauma make performing this research more difficult. It is critical to be aware of these challenges and barriers to performing clinical research involving trauma patients so these challenges can be accounted for and solutions implemented to minimize their impact on research. This review will focus on the barriers and challenges that are encountered while performing clinical research in trauma.

Multipotent Adult Progenitor Cells, but Not Tissue Inhibitor of Matrix Metalloproteinase-3, Increase Tissue Sparing and Reduce Urological Complications following Spinal Cord Injury

Following spinal cord injury (SCI), inflammation amplifies damage beyond the initial insult, providing an opportunity for targeted treatments. An ideal protective therapy would reduce both edema within the lesion area and the activation/infiltration of detrimental immune cells. Previous investigations demonstrated the efficacy of intravenous injection of multipotent adult progenitor cells (MAPC^®) to modulate immune response following SCI, leading to significant improvements in tissue sparing, locomotor and urological functions. Separate studies have demonstrated that tissue inhibitor of matrix metalloproteinase-3 (TIMP3) reduces blood-brain barrier permeability following traumatic brain injury in a mouse model, leading to improved functional recovery. This study examined whether TIMP3, delivered alone or in concert with MAPC cells, improves functional recovery from a contusion SCI in a rat model. The results suggest that intravenous delivery of MAPC cell therapy 1 day following acute SCI significantly improves tissue sparing and impacts functional recovery. TIMP3 treatment provided no significant benefit, and further, when co-administered with MAPC cells, it abrogated the therapeutic effects of MAPC cell therapy. Importantly, this study demonstrated for the first time that acute treatment of SCI with MAPC cells can significantly reduce the incidence of urinary tract infection (UTI) and the use of antibiotics for UTI treatment.

Elevated plasma levels of TIMP-3 are associated with a higher risk of acute respiratory distress syndrome and death following severe isolated traumatic brain injury

Background:

Complications after injury, such as acute respiratory distress syndrome (ARDS), are common after traumatic brain injury (TBI) and associated with poor clinical outcomes. The mechanisms driving non-neurologic organ dysfunction after TBI are not well understood. Tissue inhibitor of matrix metalloproteinase-3 (TIMP-3) is a regulator of matrix metalloproteinase activity, inflammation, and vascular permeability, and hence has plausibility as a biomarker for the systemic response to TBI.

Methods:

In a retrospective study of 182 patients with severe isolated TBI, we measured TIMP-3 in plasma obtained on emergency department arrival. We used non-parametric tests and logistic regression analyses to test the association of TIMP-3 with the incidence of ARDS within 8 days of admission and in-hospital mortality.

Results:

TIMP-3 was significantly higher among subjects who developed ARDS compared with those who did not (median 2810 pg/mL vs. 2260 pg/mL, p=0.008), and significantly higher among subjects who died than among those who survived to discharge (median 2960 pg/mL vs. 2080 pg/mL, p<0.001). In an unadjusted logistic regression model, for each SD increase in plasma TIMP-3, the odds of ARDS increased significantly, OR 1.5 (95% CI 1.1 to 2.1). This association was only attenuated in multivariate models, OR 1.4 (95% CI 1.0 to 2.0). In an unadjusted logistic regression model, for each SD increase in plasma TIMP-3, the odds of death increased significantly, OR 1.7 (95% CI 1.2 to 2.3). The magnitude of this association was greater in a multivariate model adjusted for markers of injury severity, OR 1.9 (95% CI 1.2 to 2.8).

Discussion:

TIMP-3 may play an important role in the biology of the systemic response to brain injury in humans. Along with clinical and demographic data, early measurements of plasma biomarkers such as TIMP-3 may help identify patients at higher risk of ARDS and death after severe isolated TBI.

Level of evidence

III.

Resuscitation of Hypotensive Traumatic Brain Injured Animals With Spray-Dried Plasma Does Not Adversely Alter Physiology and Improves Blood-Brain Barrier Function

INTRODUCTION

According to the Defense and Veterans Brain Injury Center and the Armed Forces Health Surveillance Center, the number of soldiers who have sustained a traumatic brain injury (TBI) has risen dramatically over the past decade. Studies have shown that brain damage can be exacerbated if blood loss occurs (often occurring in polytrauma). As blood supply is critical for brain function and survival, TBI patients must be properly resuscitated to maintain blood volume, blood pressure, and cerebral perfusion. Recent studies have suggested that blood loss can damage the vascular endothelium and enhance blood-brain barrier (BBB) permeability. Brain endothelial cells and the tight junctions between them are key structural components of the BBB. As the BBB is critical for isolating the brain from potential pathogens and for regulating the influx of molecules into the brain, evaluation of resuscitation fluids for their efficacy to improve BBB function has clinical relevance. Although whole blood and fresh frozen plasma (FFP) contain the essential coagulation factors, ions, and other factors, the transport and storage of these products in remote, austere environments can be challenging. The use of spray-dried plasma (SDP) has several advantages including storage at ambient temperature, can be readily reconstituted before use, and infectious materials can be inactivated during the drying process. In this study, we compared FFP and SDP for their effects on blood pressure, cerebral blood flow, BBB integrity, and markers of endothelial cells and tight junction proteins, in TBI animals with blood loss.

MATERIALS AND METHODS

All procedures were reviewed and approved by the UTHealth animal welfare committee. Sprague Dawley rats received controlled cortical impact brain injury followed by removal of 25% blood volume. Animals were resuscitated 40 minutes later with either FFP or concentrated SDP (Resusix) Heart rate and blood pressure were monitored continuously using catheters implanted into the femoral artery. Cerebral perfusion was assessed using a scanning laser Doppler device. Twenty-four hours after the injury and resuscitation with either FFP or SDP, BBB integrity were monitored by measuring the amount of Evans Blue dye in the injured brain following its intravenous administration. As this dye is excluded from the uninjured brain, its presence in the injured brain is an indicator of BBB breakdown. In addition, von Willebrand Factor immunohistochemistry was used to examine endothelial cell loss, whereas claudin-5 immunohistochemistry was used to assess the loss of tight junctions, in FFP- and SDP-resuscitated TBI animals.

RESULTS

Our results show that post-TBI resuscitation with FFP and SDP had similar influences on cardiovascular physiology and cerebral perfusion. Resuscitation with SDP after TBI was found to decrease BBB permeability as indicated by reduced Evans Blue dye extravasation, and increased levels of von Willebrand Factor and claudin-5, as compared to resuscitation with FFP.

CONCLUSIONS

These preclinical results show that resuscitation with SDP may be superior to FFP, and support the further evaluation of this product as a resuscitation fluid for polytrauma patients with TBI.

Cellular therapies and stem cell applications in trauma

BACKGROUND

As the leading cause of mortality in the United States, trauma management have improved drastically over the past few decades with improved resuscitation and hemorrhage control. Stem cells are being used in an attempt to augment healing from trauma.

DATA SOURCES

PubMed and ClinicalTrials.gov were searched for published and registered pre-clinical and clinical trials for the application of stem cells to AKI, ARDS, shock, infection, TBI, wound healing, and bone healing.

CONCLUSIONS

Stem cell therapy for augmentation of healing traumatic injuries appears safe, as demonstrated by completed phase I/II trials. Further large scale studies are needed to assess the clinical efficacy.

Lyophilized plasma attenuates vascular permeability, inflammation and lung injury in hemorrhagic shock

In severe trauma and hemorrhage the early and empiric use of fresh frozen plasma (FFP) is associated with decreased morbidity and mortality. However, utilization of FFP comes with the significant burden of shipping and storage of frozen blood products. Dried or lyophilized plasma (LP) can be stored at room temperature, transported easily, reconstituted rapidly with ready availability in remote and austere environments. We have previously demonstrated that FFP mitigates the endothelial injury that ensues after hemorrhagic shock (HS). In the current study, we sought to determine whether LP has similar properties to FFP in its ability to modulate endothelial dysfunction in vitro and in vivo. Single donor LP was compared to single donor FFP using the following measures of endothelial cell (EC) function in vitro: permeability and transendothelial monolayer resistance; adherens junction preservation; and leukocyte-EC adhesion. In vivo, using a model of murine HS, LP and FFP were compared in measures of HS- induced pulmonary vascular inflammation and edema. Both in vitro and in vivo in all measures of EC function, LP demonstrated similar effects to FFP. Both FFP and LP similarly reduced EC permeability, increased transendothelial resistance, decreased leukocyte-EC binding and persevered adherens junctions. In vivo, LP and FFP both comparably reduced pulmonary injury, inflammation and vascular leak. Both FFP and LP have similar potent protective effects on the vascular endothelium in vitro and in lung function in vivo following hemorrhagic shock. These data support the further development of LP as an effective plasma product for human use after trauma and hemorrhagic shock.

Mesenchymal stem cell-derived extracellular vesicles attenuate pulmonary vascular permeability and lung injury induced by hemorrhagic shock and trauma

BACKGROUND

Mesenchymal stem cells (MSCs) have been shown to mitigate vascular permeability in hemorrhagic shock (HS) and trauma-induced brain and lung injury. Mechanistically, paracrine factors secreted from MSCs have been identified that can recapitulate many of the potent biologic effects of MSCs in animal models of disease. Interestingly, MSC-derived extracellular vesicles (EVs), contain many of these key soluble factors, and have therapeutic potential independent of the parent cells. In this study we sought to determine whether MSC-derived EVs (MSC EVs) could recapitulate the beneficial therapeutic effects of MSCs on lung vascular permeability induced by HS in mice.

METHODS

Mesenchymal stem cell EVs were isolated from human bone marrow-derived MSCs by ultracentrifugation. A mouse model of fixed pressure HS was used to study the effects of shock, shock + MSCs and shock + MSC EVs on lung vascular endothelial permeability. Mice were administered MSCs, MSC EVs, or saline IV. Lung tissue was harvested and assayed for permeability, RhoA/Rac1 activation, and for differential phosphoprotein expression. In vitro, human lung microvascular cells junctional integrity was evaluated by immunocytochemistry and endothelial cell impedance assays.

RESULTS

Hemorrhagic shock-induced lung vascular permeability was significantly decreased by both MSC and MSC EV infusion. Phosphoprotein profiling of lung tissue revealed differential activation of proteins and pathways related to cytoskeletal rearrangement and regulation of vascular permeability by MSCs and MSC EVs. Lung tissue from treatment groups demonstrated decreased activation of the cytoskeletal GTPase RhoA. In vitro, human lung microvascular cells, MSC CM but not MSC-EVs prevented thrombin-induced endothelial cell permeability as measured by electrical cell-substrate impedance sensing system and immunocytochemistry of VE-cadherin and actin.

CONCLUSION

Mesenchymal stem cells and MSC EVs modulate cytoskeletal signaling and attenuate lung vascular permeability after HS. Mesenchymal stem cell EVs may potentially be used as a novel "stem cell free" therapeutic to treat HS-induced lung injury.

Wnt3a, a Protein Secreted by Mesenchymal Stem Cells Is Neuroprotective and Promotes Neurocognitive Recovery Following Traumatic Brain Injury

Intravenous administration of bone marrow derived mesenchymal stem cells (MSCs) has been shown to reduce blood brain barrier compromise and improve neurocognition following traumatic brain injury (TBI). These effects occur in the absence of engraftment and differentiation of these cells in the injured brain. Recent studies have shown that soluble factors produced by MSCs mediate a number of the therapeutic effects. In this study, we sought to determine if intravenous administration of MSCs (IV-MSCs) could enhance hippocampal neurogenesis following TBI. Our results demonstrate that IV-MSC treatment attenuates loss of neural stem cells and promotes hippocampal neurogenesis in TBI injured mice. As Wnt signaling has been implicated in neurogenesis, we measured circulating Wnt3a levels in serum following IV-MSC administration and found a significant increase in Wnt3a. Concurrent with this increase, we detected increased activation of the Wnt/β-catenin signaling pathway in hippocampal neurons. Furthermore, IV recombinant Wnt3a treatment provided neuroprotection, promoted neurogenesis, and improved neurocognitive function in TBI injured mice. Taken together, our results demonstrate a role for Wnt3a in the therapeutic potential of MSCs and identify Wnt3a as a potential stand-alone therapy or as part of a combination therapeutic strategy for the treatment of TBI. Stem Cells 2016;34:1263-1272.

Friction Stir Processing of Stainless Steel for Ascertaining Its Superlative Performance in Bioimplant Applications

Substrate-cell interactions for a bioimplant are driven by substrate's surface characteristics. In addition, the performance of an implant and resistance to degradation are primarily governed by its surface properties. A bioimplant typically degrades by wear and corrosion in the physiological environment, resulting in metallosis. Surface engineering strategies for limiting degradation of implants and enhancing their performance may reduce or eliminate the need for implant removal surgeries and the associated cost. In the current study, we tailored the surface properties of stainless steel using submerged friction stir processing (FSP), a severe plastic deformation technique. FSP resulted in significant microstructural refinement from 22 μm grain size for the as-received alloy to 0.8 μm grain size for the processed sample with increase in hardness by nearly 1.5 times. The wear and corrosion behavior of the processed alloy was evaluated in simulated body fluid. The processed sample demonstrated remarkable improvement in both wear and corrosion resistance, which is explained by surface strengthening and formation of a highly stable passive layer. The methylthiazol tetrazolium assay demonstrated that the processed sample is better in supporting cell attachment, proliferation with minimal toxicity, and hemolysis. The athrombogenic characteristic of the as-received and processed samples was evaluated by fibrinogen adsorption and platelet adhesion via the enzyme-linked immunosorbent assay and lactate dehydrogenase assay, respectively. The processed sample showed less platelet and fibrinogen adhesion compared with the as-received alloy, signifying its high thromboresistance. The current study suggests friction stir processing to be a versatile toolbox for enhancing the performance and reliability of currently used bioimplant materials.

Development of an international comorbidity education framework

CONTEXT

The increasing number of people living with multiple chronic conditions in addition to an index condition has become an international healthcare priority. Health education curricula have been developed alongside single condition frameworks in health service policy and practice and need redesigning to incorporate optimal management of multiple conditions.

AIM

Our aims were to evaluate current teaching and learning about comorbidity care amongst the global population of healthcare students from different disciplines and to develop an International Comorbidity Education Framework (ICEF) for incorporating comorbidity concepts into health education.

METHODS

We surveyed nursing, medical and pharmacy students from England, India, Italy and Sweden to evaluate their understanding of comorbidity care. A list of core comorbidity content was constructed by an international group of higher education academics and clinicians from the same disciplines, by searching current curricula and analysing clinical frameworks and the student survey data. This list was used to develop the International Comorbidity Education Framework.

RESULTS

The survey sample consisted of 917 students from England (42%), India (48%), Italy (8%) and Sweden (2%). The majority of students across all disciplines said that they lacked knowledge, training and confidence in comorbidity care and were unable to identify specific teaching on comorbidities. All student groups wanted further comorbidity training. The health education institution representatives found no specific references to comorbidity in current health education curricula. Current clinical frameworks were used to develop an agreed list of core comorbidity content and hence an International Comorbidity Education Framework.

CONCLUSIONS

Based on consultation with academics and clinicians and on student feedback we developed an International Comorbidity Education Framework to promote the integration of comorbidity concepts into current healthcare curricula.

Serum from dengue virus-infected patients with and without plasma leakage differentially affects endothelial cells barrier function in vitro

Background

Although most of cases of dengue infections are asymptomatic or mild symptomatic some individuals present warning signs progressing to severe dengue in which plasma leakage is a hallmark.

Methodology/Principal findings

The present study used Electric Cell-substrate Impedance Sensing (ECIS^®) which allows for electrical monitoring of cellular barrier function measuring changes in Transendothelial Electric Resistance (TEER) to investigate the parameters associated with dengue induced leakage. Three groups of individuals were tested: dengue-positives with plasma leakage (leakage), dengue-positives without plasma leakage (no leakage), and dengue-negatives (control). Data show that TEER values of human umbilical vein endothelial cells (HUVECs) was significantly lower after incubation with serum from subjects of the leakage group in comparison to the no leakage or control groups. The serum levels of CXCL1, EGF, eotaxin, IFN-γ, sCD40L, and platelets were significantly decreased in the leakage group, while IL-10, IL-6, and IP-10 levels were significantly increased. We also found a strong correlation between TEER values and augmented levels of IP-10, GM-CSF, IL-1α, and IL-8, as well as decreased levels of CXCL1 and platelets.

Conclusions/Significance

The present work shows that the magnitude of the immune response contributes to the adverse plasma leakage outcomes in patients and that serum components are important mediators of changes in endothelial homeostasis during dengue infections. In particular, the increased levels of IP-10 and the decreased levels of CXCL1 and platelets seem to play a significant role in the disruption of vascular endothelium associated with leakage outcomes after DENV infection. These findings may have important implications for both diagnostic and therapeutic approaches to predict and mitigate vascular permeabilization in those experiencing the most severe clinical disease outcomes after dengue infection.

Concise Review: Mesenchymal Stem (Stromal) Cells: Biology and Preclinical Evidence for Therapeutic Potential for Organ Dysfunction Following Trauma or Sepsis

Several experimental studies have provided evidence that bone-marrow derived mesenchymal stem (stromal) cells (MSC) may be effective in treating critically ill surgical patients who develop traumatic brain injury, acute renal failure, or the acute respiratory distress syndrome. There is also preclinical evidence that MSC may be effective in treating sepsis-induced organ failure, including evidence that MSC have antimicrobial properties. This review considers preclinical studies with direct relevance to organ failure following trauma, sepsis or major infections that apply to critically ill patients. Progress has been made in understanding the mechanisms of benefit, including MSC release of paracrine factors, transfer of mitochondria, and elaboration of exosomes and microvesicles. Regardless of how well they are designed, preclinical studies have limitations in modeling the complexity of clinical syndromes, especially in patients who are critically ill. In order to facilitate translation of the preclinical studies of MSC to critically ill patients, there will need to be more standardization regarding MSC production with a focus on culture methods and cell characterization. Finally, well designed clinical trials will be needed in critically ill patient to assess safety and efficacy. Stem Cells 2017;35:316-324.

Effects of overweight and obesity on motor and mental development in infants and toddlers

BACKGROUND

A consequence of childhood obesity may be poor developmental outcomes.

OBJECTIVES

This study aimed to examine the relationship between weight and developmental delays in young children.

METHODS

We conducted a secondary analysis of the Early Childhood Longitudinal Study Birth Cohort data. Logistic regression models quantified the association between different weight statuses (normal weight <85th, overweight ≥90th, obese ≥95th percentile for weight) and delays in motor and mental development.

RESULTS

Children classified as overweight in both waves had higher percentages of delays in wave 2 (motor [7.5 vs. 6.2-6.4%], mental [8.6 vs. 5.9-6.7%]), as well as wave 1 and/or wave 2 (motor [14.8 vs. 10.9-13.0%], mental [11.9 vs. 9.0-10.1%]), compared with other children. This association was also found in children who were obese at both time points in wave 2 (motor delay [8.9 vs. 4.9-7.3%], mental delay [10.3 vs. 6.0-7.2%]), as well as wave 1 and/or wave 2 (motor delay [14.5 vs. 10.9-12.9%], mental delay [14.1 vs. 9.4-10.1%]). In the adjusted models, children classified as always obese were more likely to have a mental delay in wave 2 (adjusted odds ratio [aOR] 1.89, 95% confidence interval [CI]: 1.21-2.95) as well as wave 1 and/or wave 2 (aOR 1.56, 95% CI: 1.08-2.26). These children were also more likely to have motor delay (aOR 1.47, 95% CI: 1.02-2.13) in wave 1 and/or wave 2.

CONCLUSION

Overweight children are more likely than their normal-weight peers to have motor and mental developmental delays. Preventing obesity during infancy may facilitate reducing developmental delays in young children.

The effects of 22°C and 4°C storage of platelets on vascular endothelial integrity and function

BACKGROUND

Although a majority of the studies conducted to date on platelet (PLT) storage have been focused on PLT hemostatic function, the effects of 4°C PLTs on regulation of endothelial barrier permeability are still not known. In this study, we compared the effects of room temperature (22°C) stored and (4°C) stored PLTs on the regulation of vascular endothelial cell (EC) permeability in vitro and in vivo.

STUDY DESIGN AND METHODS

Day 1, Day 5, and Day 7 leukoreduced apheresis PLTs stored at 4 or 22°C were studied in vitro and in vivo. In vitro, PLT effects on EC permeability and barrier function, adhesion, and impedance aggregometry were investigated. In vivo, using a mouse model of vascular leak, attenuation of vascular leak and circulating PLT numbers were measured.

RESULTS

Treatment of EC monolayers with Day 5 or Day 7 PLTs, stored at both 22°C and 4°C, resulted in similar decreases in EC permeability on average. However, analysis of individual samples revealed significant variation that was donor dependent. Additional in vitro measurements revealed a decrease in inflammatory mediators, nonspecific PLT-endothelial aggregation and attenuated loss of aggregation over time to TRAP, ASPI, ADP, and collagen with 4°C storage. In mice, while 22°C and 4°C PLTs both demonstrated significant protection against vascular endothelial growth factor A (VEGF-A)-induced vascular leak 22°C PLTs exhibited increased protection compared to 4°C PLTs. Systemic circulating levels of 4°C PLTs were decreased compared to 22°C PLTs.

CONCLUSIONS

In vitro, 4°C-stored PLTs exhibit a greater capacity to inhibit EC permeability than 22°C-stored PLTs. In vivo, 22°C PLTs provide superior control of vascular leak induced by VEGF-A. This discrepancy may be due to increased clearance of 4°C PLTs from the systemic circulation.

Platelets regulate vascular endothelial stability: assessing the storage lesion and donor variability of apheresis platelets

BACKGROUND

In current blood banking practices, platelets (PLTs) are stored in plasma at 22°C, with gentle agitation for up to 5 days. To date, the effects of storage and donor variability on PLT regulation of vascular integrity are not known.

STUDY DESIGN AND METHODS

In this study, we examined the donor variability of leukoreduced fresh (Day 1) or stored (Day 5) PLTs on vascular endothelial barrier function in vitro and in vivo. In vitro, PLT effects on endothelial cell (EC) monolayer permeability were assessed by analyzing transendothelial electrical resistances (TEER). PLT aggregation, a measure of hemostatic potential, was analyzed by impedance aggregometry. In vivo, PLTs were investigated in a vascular endothelial growth factor A (VEGF-A)-induced vascular permeability model in NSG mice, and PLT circulation was measured by flow cytometry.

RESULTS

Treatment of endothelial monolayers with fresh Day 1 PLTs resulted in an increase in EC barrier resistance and decreased permeability in a dose-dependent manner. Subsequent treatment of EC monolayers with Day 5 PLTs demonstrated diminished vasculoprotective effects. Donor variability was noted in all measures of PLT function. Day 1 PLT donors were more variable in their effects on TEER than Day 5 PLTs. In mice, while all PLTs regardless of storage time demonstrated significant protection against VEGF-A-induced vascular leakage, Day 5 PLTs exhibited reduced protection when compared to Day 1 PLTs. Day 1 PLTs demonstrated significant donor variability against VEGF-A-challenged vascular leakage in vivo. Systemic circulating levels of Day 1 PLTs were higher than those of Day 5 PLTs

CONCLUSIONS

In vitro and in vivo, Day 1 PLTs are protective in measures of vascular endothelial permeability. Donor variability is most prominent in Day 1 PLTs. A decrease in the protective effects is found with storage of the PLT units between Day 1 and Day 5 at 22°C, thereby suggesting that Day 5 PLTs are diminished in their ability to attenuate vascular endothelial permeability.

TIMP3 Attenuates the Loss of Neural Stem Cells, Mature Neurons and Neurocognitive Dysfunction in Traumatic Brain Injury

Mesenchymal stem cells (MSCs) have been shown to have potent therapeutic effects in a number of disorders including traumatic brain injury (TBI). However, the molecular mechanism(s) underlying these protective effects are largely unknown. Herein we demonstrate that tissue inhibitor of matrix metalloproteinase-3 (TIMP3), a soluble protein released by MSCs, is neuroprotective and enhances neuronal survival and neurite outgrowth in vitro. In vivo in a murine model of TBI, intravenous recombinant TIMP3 enhances dendritic outgrowth and abrogates loss of hippocampal neural stem cells and mature neurons. Mechanistically we demonstrate in vitro and in vivo that TIMP3-mediated neuroprotection is critically dependent on activation of the Akt-mTORC1 pathway. In support of the neuroprotective effect of TIMP3, we find that intravenous delivery of recombinant TIMP3 attenuates deficits in hippocampal-dependent neurocognition. Taken together, our data strongly suggest that TIMP3 has direct neuroprotective effects that can mitigate the deleterious effects associated with TBI, an area with few if any therapeutic options.