Cerebral Blood Flow in Polytrauma: Transcranial Doppler Analysis in a Nonhuman Primate Shock Model.

Background: In combat-related trauma, resuscitation goals are to attenuate tissue hypoxia and maintain circulation. During hemorrhagic shock, compensatory and autoregulatory mechanisms are activated to preserve cerebral blood flow. Transcranial Doppler (TCD) ultrasonography may be an ideal noninvasive modality to monitor cerebral hemodynamics.

Nonhuman Primate (Rhesus Macaque) Models of Severe Pressure-Targeted Hemorrhagic and Polytraumatic Hemorrhagic Shock.

Background: We endeavored to develop clinically translatable nonhuman primate (NHP) models of severe polytraumatic hemorrhagic shock.

Methods: NHPs were randomized into five severe pressure-targeted hemorrhagic shock (PTHS) ± additional injuries scenarios: 30-min PTHS (PTHS-30), 60-min PTHS (PTHS-60), PTHS-60 + soft tissue injury (PTHS-60+ST), PTHS-60+ST + femur fracture (PTHS-60+ST+FF), and decompensated PTHS+ST+FF (PTHS-D). Physiologic parameters were recorded and blood samples collected at five time points with animal observation through T = 24 h.

Generation of complement molecular complex C5b-9 (C5b-9) in response to poly-traumatic hemorrhagic shock and evaluation of C5 cleavage inhibitors in non-human primates.

Severe trauma initiates a systemic inflammatory cascade and that involves early activation of complement and cleavage of C5 into C5a (anaphylatoxin) and C5b (C5b-9 membrane attack complex). We examined activation of C5 in non-human primate (NHP) models of hemorrhagic shock. Blood plasma concentrations of C5b-9 were significantly increased in NHPs in response to hemorrhage alone and were further increased with the addition of tissue trauma.

Cryopreservation of human whole blood allows immunophenotyping by flow cytometry up to 30days after cell isolation.

Immunophenotyping of whole blood (WB) by flow cytometry (FC) is used clinically to assess a patient's immune status and also in biomedical research. Current protocols recommend storage of immunolabeled samples at 4°C with FC analysis to be completed within seven days. This data acquisition window can be extended to up to one year post-labeling, but this requires cryopreservation of the samples at ultra-low temperatures (≤-80°C or in liquid nitrogen).

Development of a Nonhuman Primate (Rhesus Macaque) Model of Uncontrolled Traumatic Liver Hemorrhage.

Hemorrhage is the leading cause of potentially survivable trauma mortality, necessitating the development of improved therapeutic interventions. The objective of this study was to develop and characterize a reproducible clinically translatable nonhuman primate model of uncontrolled severe hemorrhage. Such a model is required to facilitate the development and meaningful evaluation of human-derived therapeutics.

Inflammatory cytokine and chemokine expression is associated with heterotopic ossification in high-energy penetrating war injuries.

Objective: Heterotopic ossification (HO) develops frequently after modern high-energy penetrating war injuries. The purpose of this prospective study was to identify and characterize the unique cytokine and chemokine profile associated with the development of HO as it pertained to the systemic inflammatory response after penetrating combat-related trauma.

Methods: Patients with high-energy penetrating extremity wounds were prospectively enrolled.

Inflammatory response is associated with critical colonization in combat wounds.

Background: Modern combat- or blast-related injuries are characterized by devastatingly massive zones of injury that violate soft tissue, bone, and neurovascular structures. In our translational research program, we have determined that healing of traumatic combat wounds is dependent on the immune response. Although the majority of combat wounds are not critically colonized with bacteria, there exists a correlation between critical colonization and the concentration of inflammatory cytokines and chemokines measured in wound effluent or patient serum.

Incidence of pulmonary embolus in combat casualties with extremity amputations and fractures.

Background: The objective of this retrospective study was to determine the incidence of pulmonary embolism (PE) in casualties of wartime extremity wounds and specifically in casualties with a trauma-associated amputation.

Methods: Records of all combat-wounded evacuated and admitted between March 1, 2003, and December 31, 2007, were retrospectively reviewed. Continuous and categorical variables were studied with the Student's t test, Fisher's exact test or χ² test; multivariate analysis was performed using a stepwise regression logistic model.

Development of a Bayesian model to estimate health care outcomes in the severely wounded.

Background: Graphical probabilistic models have the ability to provide insights as to how clinical factors are conditionally related. These models can be used to help us understand factors influencing health care outcomes and resource utilization, and to estimate morbidity and clinical outcomes in trauma patient populations.

Study Design: Thirty-two combat casualties with severe extremity injuries enrolled in a prospective observational study were analyzed using step-wise machine-learned Bayesian belief network (BBN) and step-wise logistic regression (LR).

Comparative analysis of angiogenic gene expression in normal and impaired wound healing in diabetic mice: effects of extracorporeal shock wave therapy.

Impaired wound healing is a persistent clinical problem which has been treated with mixed results. Studies aimed at elucidating the mechanism of impaired wound healing have focused on small cohorts of genes which leave an incomplete picture of the wound healing process. We aimed to investigate impaired wound healing via a comprehensive panel of angiogenic/inflammation-related genes and wound closure kinetics with and without the application of extracorporeal shock wave therapy (ESWT), which has been demonstrated to improve wound healing.

Probabilistic (Bayesian) modeling of gene expression in transplant glomerulopathy.

Transplant glomerulopathy (TG) is associated with rapid decline in glomerular filtration rate and poor outcome. We used low-density arrays with a novel probabilistic analysis to characterize relationships between gene transcripts and the development of TG in allograft recipients. Retrospective review identified TG in 10.

Metalloproteinase expression is associated with traumatic wound failure.

Background: Matrix metalloproteinases (MMPs) are crucial in the inflammatory and remodeling phases of wound healing. We previously reported the correlation between pro-inflammatory cytokines and timing of successful combat-wound closure. We now extend our studies to investigate the correlation between wound-remodeling MMP expression and wound healing.

Assessment of cadaveric organ viability during pulsatile perfusion using infrared imaging.

Assessment of pulsatile perfusion (PP) is limited to measurements of flow (V) and resistance (R). We investigated infrared (IR) imaging during PP as a means for precise organ assessment. IR was used to monitor 10 porcine kidneys during 18 hr of PP in an uncontrolled Donation after Cardiac Death model.

Extracorporeal shock wave therapy suppresses the early proinflammatory immune response to a severe cutaneous burn injury.

Following severe burn injury, persistent inflammation perpetuated by surface eschar, bacterial colonisation and neutrophil proteolytic activity can impede normal healing and result in further tissue damage. Extracorporeal shock wave treatment (ESWT) has been shown in the clinical setting to promote the healing of burn and difficult-to-heal wounds; however, the mechanism is unclear. We investigated the role of ESWT on the early proinflammatory response using a severe, full-thickness and highly inflammatory cutaneous burn wound in a murine model.

New directions for induction immunosuppression strategy in solid organ transplantation.

Background: Solid organ transplant centers are increasingly using induction immunosuppression strategies. Induction immunosuppression involves the use of intense therapy at the time of transplantation with the goal of preventing acute rejection and ultimately inducing a tolerogenic state. The objective of this review is to examine specialized induction agents currently in clinical use and highlight novel therapeutics on the horizon for induction immunosuppression.

Angiogenic response to extracorporeal shock wave treatment in murine skin isografts.

Skin grafts are commonly utilized and proven effective methods of open wound coverage. Revascularization through neoangiogenesis is a pivotal mechanism for skin graft integration and durability. Extracorporeal shock-wave treatment (ESWT) has been demonstrated to accelerate wound repair; however, its mechanism-of-action is unclear.

Human brain endothelial cells (HUBEC) promote SCID repopulating cell expansion through direct contact.

The objective of this study was to re-evaluate the previously published hematopoietic stem cell (HSC) expansion work using human brain endothelial cells (HUBEC). The expansion effect of contact and non-contact conditions was reported to be equivalent by others. However, we report here different results that the expansion can be achieved only with direct contact.

Differential cutaneous wound healing in thermally injured MRL/MPJ mice.

Adult wound repair occurs with an initial inflammatory response, reepithelialization, and the formation of a permanent scar. MRL/MpJ mice following ear-hole punch biopsies display accelerated healing and tissue regeneration. In this study, we characterized the healing responses in both MRL/MpJ and BALB/c mice following a 15% total body surface area full-thickness cutaneous burn injury.

The role of NO in macrophage dysfunction at early stage after burn injury.

Aim: To explore the role of nitric oxide (NO) in macrophage dysfunction at early stage after burn injury.

Method: Peritoneal macrophages were isolated and cultured from early stage burnt mice. NO production and inducible NO synthase (iNOS) expression in the macrophages were checked by the Greiss method and real-time PCR (TaqMan), respectively.

Effects of combined treatment with CD25- and CD154-specific monoclonal antibodies in non-human primate allotransplantation.

The CD154-specific monoclonal antibody (Mab) hu5c8 greatly prolongs allograft survival in primates. The CD25-specific Mab daclizumab has not, to date, been paired with hu5c8. We evaluated the effects of hu5c8 in vitro, alone and in combination with daclizumab on rhesus-mixed lymphocyte reactions (MLRs).

Results from a human renal allograft tolerance trial evaluating the humanized CD52-specific monoclonal antibody alemtuzumab (CAMPATH-1H).

Background: Profound T-cell depletion before allotransplantation with gradual posttransplant T-cell repopulation induces a state of donor-specific immune hyporesponsiveness or tolerance in some animal models. Alemtuzumab (Campath-1H, Millennium Pharmaceuticals, Cambridge, MA) is a humanized CD52-specific monoclonal antibody that produces profound T-cell depletion in humans and reduces the need for maintenance immunosuppression after renal transplantation. We therefore performed a study to determine if pretransplant T-cell depletion with alemtuzumab would induce tolerance in human renal allografts and to evaluate the nature of the alloimmune response in the setting of T-cell depletion.

Studies investigating pretransplant donor-specific blood transfusion, rapamycin, and the CD154-specific antibody IDEC-131 in a nonhuman primate model of skin allotransplantation.

Anti-CD154 variably prolongs allograft survival in nonhuman primates. Rodent studies suggest that adding pretransplant donor-specific transfusion (DST) and/or rapamycin to anti-CD154 improves survival. The CD154-specific Ab IDEC-131 was tested alone and in combination with rapamycin for its ability to inhibit rhesus MLRs.

Evidence for the requirement of T cell costimulation in the pathogenesis of natural Pneumocystis carinii pulmonary infection.

Pneumocystis carinii pneumonia (PCP) is a frequent and serious opportunistic infection in immunocompromized patients. Although the pathogenesis of PCP-mediated lung injury is poorly understood, a central involvement of host inflammatory responses has been implicated. We have found that while the loss of specific T cell costimulatory signals increases susceptibility to the spontaneous pneumocystis infection, PCP-induced pulmonary injury (and subsequent morbidity and mortality) involves other intact costimulatory pathways.

Combination induction therapy with monoclonal antibodies specific for CD80, CD86, and CD154 in nonhuman primate renal transplantation.

Background: Antibodies and fusion proteins specific for CD80, CD86, and CD154 have shown promise as agents capable of inducing donor-specific tolerance in rodents. These agents have also been shown to be synergistic with one another in many settings of counter-adaptive immunity. In the nonhuman primate, monoclonal antibodies specific for CD80 and CD86 have prolonged the time to rejection of renal allografts but have not resulted in tolerance.

Humanized anti-CD154 antibody therapy for the treatment of allograft rejection in nonhuman primates.

The anti-CD154 antibody hu5C8 prevents acute allograft rejection and prolongs allograft survival after withdrawal of therapy in nonhuman primates. This study describes the use of hu5C8 as a rescue agent for rejection developing after the withdrawal of hu5C8. Twelve rhesus monkeys that had received renal allografts under hu5C8 induction and subsequently rejected were studied.