17α-Ethinyl estradiol-3-sulfate increases survival and hemodynamic functioning in a large animal model of combined traumatic brain injury and hemorrhagic shock: a randomized control trial

Facing stress and inflammation: From the cell to the planet

As identified in 1936 by Hans Selye, stress is shaping diseases through the induction of inflammation. But inflammation display some yin yang properties. On one hand inflammation is merging with the innate immune response aimed to fight infectious or sterile insults, on the other hand inflammation favors chronic physical or psychological disorders. Nature has equipped the cells, the organs, and the individuals with mediators and mechanisms that allow them to deal with stress, and even a good stress (eustress) has been associated with homeostasis. Likewise, societies and the planet are exposed to stressful settings, but wars and global warming suggest that the regulatory mechanisms are poorly efficient. In this review we list some inducers of the physiological stress, psychologic stress, societal stress, and planetary stress, and mention some of the great number of parameters which affect and modulate the response to stress and render it different from an individual to another, from the cellular level to the societal one. The cell, the organ, the individual, the society, and the planet share many stressors of which the consequences are extremely interconnected ending in the domino effect and the butterfly effect.

Induced blood flow oscillations at 0.1 Hz protects oxygenation of severely ischemic tissue in humans

Generating 10-s (∼0.1 Hz) fluctuations or "oscillations" in arterial pressure and blood flow blunts reductions in cerebral tissue oxygenation in response to 15%-20% reductions in cerebral blood flow. To examine the effect of 0.1 Hz hemodynamic oscillations on tissue oxygenation during severe ischemia, we developed a partial limb ischemia protocol targeting a 70%-80% reduction in blood flow. We hypothesized that 0.1 Hz hemodynamic oscillations would attenuate reductions in tissue oxygenation during severe ischemia. Thirteen healthy humans (6 M and 7 F; 27.3 ± 4.2 yr) completed two experimental protocols separated by ≥48 h. In both conditions, an upper arm cuff was used to decrease brachial artery (BA) blood velocity by ∼70%-80% from baseline. In the oscillation condition (0.1 Hz), 0.1 Hz hemodynamic oscillations were induced by intermittently inflating and deflating bilateral thigh cuffs every 5 s during forearm ischemia. In the control condition (0 Hz), the thigh cuffs were inactive. BA blood flow, forearm tissue oxygenation (SmO2), and arterial pressure were measured continuously. The initial reduction in BA blood velocity was tightly matched between protocols (0 Hz: -76.9 ± 7.9% vs. 0.1 Hz: -75.5 ± 7.4%, P = 0.49). Although 0.1 Hz oscillations during forearm ischemia had no effect on the reduction in BA velocity (0 Hz: -73.0 ± 9.9% vs. 0.1 Hz: -73.3 ± 8.2%, P = 0.91), the reduction in SmO2 was attenuated (0 Hz: -35.7 ± 8.6% vs. 0.1 Hz: -27.2 ± 8.9%, P = 0.01). These data provide further evidence for the use of 0.1 Hz hemodynamic oscillations as a potential therapeutic intervention for conditions associated with severe tissue ischemia (e.g., hemorrhage and stroke).NEW & NOTEWORTHY We investigated the effects of induced 10-s (0.1 Hz) oscillations in blood flow on forearm tissue oxygenation during severe ischemia. Intermittent inflation of bilateral thigh cuffs was used as a clinically applicable method to drive blood flow oscillations. In support of our hypothesis, 0.1 Hz oscillations in blood flow blunted reductions in forearm tissue oxygenation. These results further support the potential use of oscillatory hemodynamics as a therapeutic intervention for ischemic conditions.

Effects of remote ischemic preconditioning on early markers of intestinal injury in experimental hemorrhage in rats

The maintenance of intestinal integrity and barrier function under conditions of restricted oxygen availability is crucial to avoid bacterial translocation and local inflammation. Both lead to secondary diseases after hemorrhagic shock and might increase morbidity and mortality after surviving the initial event. Monitoring of the intestinal integrity especially in the early course of critical illness remains challenging. Since microcirculation and mitochondrial respiration are main components of the terminal stretch of tissue oxygenation, the evaluation of microcirculatory and mitochondrial variables could identify tissues at risk during hypoxic challenges, indicate an increase of intestinal injury, and improve our understanding of regional pathophysiology during acute hemorrhage. Furthermore, improving intestinal microcirculation or mitochondrial respiration, e.g. by remote ischemic preconditioning (RIPC) that was reported to exert a sufficient tissue protection in various tissues and was linked to mediators with vasoactive properties could maintain intestinal integrity. In this study, postcapillary oxygen saturation (µHbO2), microvascular flow index (MFI) and plasmatic D-lactate concentration revealed to be early markers of intestinal injury in a rodent model of experimental hemorrhagic shock. Mitochondrial function was not impaired in this experimental model of acute hemorrhage. Remote ischemic preconditioning (RIPC) failed to improve intestinal microcirculation and intestinal damage during hemorrhagic shock.

Patient sex and outcomes in children with life-threatening hemorrhage

BACKGROUND

Recent data suggest female sex imparts a survival benefit after trauma in adults. The independent associations between patient sex and age with outcomes have not been examined in children with life-threatening hemorrhage (LTH) from all etiologies.

STUDY DESIGN AND METHODS

In a secondary analysis of a multicenter prospective observational study of children with LTH, Massive Transfusion in Children (MATIC), we analyzed if patient sex and age were associated with differences in severity of illness, therapies, and outcomes. Primary outcomes were 24 hour mortality and weight-adjusted transfusion volume during LTH. Kruskal-Wallis, chi-square testing, and multivariable linear regression were used for adjusted analyses.

RESULTS

Of 449 children, 45% were females and 55% were males. Females were more commonly younger, white, and with less trauma as the etiology of LTH compared to males. Markers of clinical severity were similar between groups, except injury severity score (ISS) was higher in females in the trauma subgroup. In terms of resuscitative practices, females received greater weight-adjusted total transfusion volumes compared to males (76 (40-150) mL/kg vs. 53 (24-100) mL/kg), as well as increased red blood cells (RBCs), plasma, and platelets compared to males. After adjustment for confounders, female sex and age 0-11 years were independently associated with increased transfusion volume during LTH. There were no differences in mortality or adverse outcomes according to patient sex.

CONCLUSION

Patient sex and age may impact factors associated with LTH and therapies received. Studies in developmental hemostasis are needed to determine the optimal transfusion strategy for LTH according to patient sex and age.

Sex dimorphisms in coagulation: Implications in trauma-induced coagulopathy and trauma resuscitation

Trauma-induced coagulopathy (TIC) is one of the leading causes of preventable death in injured patients. Consequently, it is imperative to understand the mechanisms underlying TIC and how to mitigate this mortality. An opportunity for advancement stems from the awareness that coagulation demonstrates a strong sex-dependent effect. Females exhibit a relative hypercoagulability compared to males, which persists after injury and confers improved outcomes. The mechanisms underlying sex dimorphisms in coagulation and its protective effect after injury have yet to be elucidated. This review explores sex dimorphisms in enzymatic hemostasis, fibrinogen, platelets, and fibrinolysis, with implications for resuscitation of patients with TIC.

A Perspective on Hormonal Contraception Usage in Central Nervous System Injury

Naturally occurring life stages in women are associated with changes in the milieu of endogenous ovarian hormones. Women of childbearing age may be exposed to exogenous ovarian hormone(s) because of their use of varying combinations of estrogen and progesterone hormones-containing oral contraceptives (OC; also known as "the pill"). If women have central nervous system (CNS) injury such as spinal cord injury (SCI) and traumatic brain injury (TBI) during their childbearing age, they are likely to retain their reproductive capabilities and may use OC. Many deleterious side effects of long-term OC use have been reported, such as aberrant blood clotting and endothelial dysfunction that consequently increase the risk of myocardial infarction, venous thromboembolism, and ischemic brain injury. Although controversial, studies have suggested that OC use is associated with neuropsychiatric ramifications, including uncontrollable mood swings and poorer cognitive performance. Our understanding about how the combination of endogenous hormones and OC-conferred exogenous hormones affect outcomes after CNS injuries remains limited. Therefore, understanding the impact of OC use on CNS injury outcomes needs further investigation to reveal underlying mechanisms, promote reporting in clinical or epidemiological studies, and raise awareness of possible compounded consequences. The goal of the current review is to discuss the impacts of CNS injury on endogenous ovarian hormones and vice-versa, as well as the putative consequences of exogenous ovarian hormones (OC) on the CNS to identify potential gaps in our knowledge to consider for future laboratory, epidemiological, and clinical studies.

Transforming research to improve therapies for trauma in the twenty-first century

Improvements have been made in optimizing initial care of trauma patients, both in prehospital systems as well as in the emergency department, and these have also favorably affected longer term outcomes. However, as specific treatments for bleeding are largely lacking, many patients continue to die from hemorrhage. Also, major knowledge gaps remain on the impact of tissue injury on the host immune and coagulation response, which hampers the development of interventions to treat or prevent organ failure, thrombosis, infections or other complications of trauma. Thereby, trauma remains a challenge for intensivists. This review describes the most pressing research questions in trauma, as well as new approaches to trauma research, with the aim to bring improved therapies to the bedside within the twenty-first century.

Assessment of ethynylestradiol-3-sulfate on coagulation, metabolism, and survival in pigs with traumatic hemorrhage

BACKGROUND

The beneficial effects of estrogens on survival from hemorrhage have been suggested in some preclinical models. This study investigated the effects of ethynylestradiol-3-sulfate (EE-3-S) on coagulation, metabolism and survival in pigs following traumatic hemorrhage.

METHODS

Twenty-six pigs were randomized into: normal saline group (NS, n = 10), EE-3-S group (EE-3, n = 11) groups, and no resuscitation group (NR, n = 5). Femur fracture was performed in each pig's left leg, followed by hemorrhage of 55% of estimated blood volume and a 10-minute shock period. Afterward, pigs were resuscitated with a small volume of either NS alone (4 mL/kg) or EE-3-S with NS (1 mL/kg at concentration of 1 mg/mL, plus NS solution of 3 mL/kg). Pigs in NR group were not resuscitated with any fluid. All pigs were then monitored for 6 hours or until death, with hemodynamics and survival times recorded. Blood samples were taken during the study for measurements of oxygen metabolism (oxygen delivery, extraction, and consumption) and coagulation function (using Rotem with Extem reagents).

RESULTS

All baseline measurements were similar among the three groups. In the NS group, femur fracture and hemorrhage immediately reduced mean arterial pressure (MAP, 74 ± 3 mm Hg to 44 ± 4 mm Hg) and increased heart rate (97 ± 5 bpm to 218 ± 14 bpm, both p < 0.05). Similar changes in MAP and heart rate were observed in the EE-3 and NR groups. There were no differences observed in changes of Rotem ® measurements or oxygen metabolism among the groups during the study. At 6 hours, four pigs in NS, four pigs in EE-3-S, and two pigs in the NR group survived to the end of the study. The mean survival times were similar among the NS (212 ± 43 minutes), EE-3 (212 ± 39 minutes), and NR (223 ± 63 minutes) groups ( p = 0.9845).

CONCLUSION

Following severe traumatic hemorrhage, hypotensive resuscitation with EE-3-S did not impact coagulation, metabolism, or survival in pigs.

Head Kinematics, Blood Biomarkers, and Histology in Large Animal Models of Traumatic Brain Injury and Hemorrhagic Shock

Traumatic brain injury (TBI) and severe blood loss resulting in hemorrhagic shock (HS) are each leading causes of mortality and morbidity worldwide, and present additional treatment considerations when they are comorbid (TBI+HS) as a result of competing pathophysiological responses. The current study rigorously quantified injury biomechanics with high precision sensors and examined whether blood-based surrogate markers were altered in general trauma as well as post-neurotrauma. Eighty-nine sexually mature male and female Yucatan swine were subjected to a closed-head TBI+HS (40% of circulating blood volume; n = 68), HS only (n = 9), or sham trauma (n = 12). Markers of systemic (e.g., glucose, lactate) and neural functioning were obtained at baseline, and at 35 and 295 min post-trauma. Opposite and approximately twofold differences existed for both magnitude (device > head) and duration (head > device) of quantified injury biomechanics. Circulating levels of neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and ubiquitin C-terminal hydrolase L1 (UCH-L1) demonstrated differential sensitivity for both general trauma (HS) and neurotrauma (TBI+HS) relative to shams in a temporally dynamic fashion. GFAP and NfL were both strongly associated with changes in systemic markers during general trauma and exhibited consistent time-dependent changes in individual sham animals. Finally, circulating GFAP was associated with histopathological markers of diffuse axonal injury and blood-brain barrier breach, as well as variations in device kinematics following TBI+HS. Current findings therefore highlight the need to directly quantify injury biomechanics with head mounted sensors and suggest that GFAP, NfL, and UCH-L1 are sensitive to multiple forms of trauma rather than having a single pathological indication (e.g., GFAP = astrogliosis).

KDM4A, involved in the inflammatory and oxidative stress caused by traumatic brain injury-hemorrhagic shock, partly through the regulation of the microglia M1 polarization

BACKGROUND

Microglial polarization and the subsequent neuroinflammatory response and oxidative stress are contributing factors for traumatic brain injury (TBI) plus hemorrhagic shock (HS) induced brain injury. In the present work, we have explored whether Lysine (K)-specific demethylase 4 A (KDM4A) modulates microglia M1 polarization in the TBI and HS mice.

RESULTS

Male C57BL/6J mice were used to investigate the microglia polarization in the TBI + HS model in vivo. Lipopolysaccharide (LPS)-induced BV2 cells were used to examine the mechanism of KDM4A in regulating microglia polarization in vitro. We found that TBI + HS resulted in neuronal loss and microglia M1 polarization in vivo, reflected by the increased level of Iba1, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, malondialdehyde (MDA) and the decreased level of reduced glutathione (GSH). Additionally, KDM4A was upregulated in response to TBI + HS and microglia were among the cell types showing the increased level of KDM4A. Similar to the results in vivo, KDM4A also highly expressed in LPS-induced BV2 cells. LPS-induced BV2 cells exhibited enhanced microglia M1 polarization, and enhanced level of pro-inflammatory cytokines, oxidative stress and reactive oxygen species (ROS), while this enhancement was abolished by the suppression of KDM4A.

CONCLUSION

Accordingly, our findings indicated that KDM4A was upregulated in response to TBI + HS and microglia were among the cell types showing the increased level of KDM4A. The important role of KDM4A in TBI + HS-induced inflammatory response and oxidative stress was at least partially realized through regulating microglia M1 polarization.

Polynitroxylated PEGylated hemoglobin protects pig brain neocortical gray and white matter after traumatic brain injury and hemorrhagic shock

Polynitroxylated PEGylated hemoglobin (PNPH, aka SanFlow) possesses superoxide dismutase/catalase mimetic activities that may directly protect the brain from oxidative stress. Stabilization of PNPH with bound carbon monoxide prevents methemoglobin formation during storage and permits it to serve as an anti-inflammatory carbon monoxide donor. We determined whether small volume transfusion of hyperoncotic PNPH is neuroprotective in a porcine model of traumatic brain injury (TBI) with and without accompanying hemorrhagic shock (HS). TBI was produced by controlled cortical impact over the frontal lobe of anesthetized juvenile pigs. Hemorrhagic shock was induced starting 5 min after TBI by 30 ml/kg blood withdrawal. At 120 min after TBI, pigs were resuscitated with 60 ml/kg lactated Ringer's (LR) or 10 or 20 ml/kg PNPH. Mean arterial pressure recovered to approximately 100 mmHg in all groups. A significant amount of PNPH was retained in the plasma over the first day of recovery. At 4 days of recovery in the LR-resuscitated group, the volume of frontal lobe subcortical white matter ipsilateral to the injury was 26.2 ± 7.6% smaller than homotypic contralateral volume, whereas this white matter loss was only 8.6 ± 12.0% with 20-ml/kg PNPH resuscitation. Amyloid precursor protein punctate accumulation, a marker of axonopathy, increased in ipsilateral subcortical white matter by 132 ± 71% after LR resuscitation, whereas the changes after 10 ml/kg (36 ± 41%) and 20 ml/kg (26 ± 15%) PNPH resuscitation were not significantly different from controls. The number of cortical neuron long dendrites enriched in microtubules (length >50 microns) decreased in neocortex by 41 ± 24% after LR resuscitation but was not significantly changed after PNPH resuscitation. The perilesion microglia density increased by 45 ± 24% after LR resuscitation but was unchanged after 20 ml/kg PNPH resuscitation (4 ± 18%). Furthermore, the number with an activated morphology was attenuated by 30 ± 10%. In TBI pigs without HS followed 2 h later by infusion of 10 ml/kg LR or PNPH, PNPH remained neuroprotective. These results in a gyrencephalic brain show that resuscitation from TBI + HS with PNPH protects neocortical gray matter, including dendritic microstructure, and white matter axons and myelin. This neuroprotective effect persists with TBI alone, indicating brain-targeting benefits independent of blood pressure restoration.

Estradiol provokes hypercoagulability and affects fibrin biology: A mechanistic exploration of sex dimorphisms in coagulation

BACKGROUND

Sex dimorphisms in coagulation are well established, with female-specific hypercoagulability conferring a survival benefit in the setting of trauma-induced coagulopathy (TIC). The mechanism behind these phenomena remains to be elucidated. We hypothesize that estradiol provokes a hypercoagulable profile and alters clot proteomics and fibrin crosslinking.

METHODS

Whole blood was collected from healthy adult volunteers (n = 30). A battery of thrombelastography (TEG) assays (native, kaolin, platelet-mapping, functional fibrinogen), whole blood thrombin generation, proteomics, and clot structure architecture (via analysis of fibrin crosslinks and fluorescent fibrinogen-visualized clots) were performed after pre-treatment of the blood with physiologic concentrations of beta-estradiol. In addition, a prospective study of coagulation through the menstrual cycle was conducted by collecting blood from women on peak and nadir estrogen days in the standard 28-day menstrual cycle.

RESULTS

On TEG, in females, estradiol provoked a hypercoagulable phenotype, specifically a shorter time to clot formation and greater thrombin generation, greater rate of clot propagation and functional fibrinogen, higher clot strength, and diminished clot fibrinolysis. In both males and females, estradiol increased platelet hyperactivity. Similar changes were seen in time to clot formation and clot strength in vivo during peak estrus of the menstrual cycle. On proteomic analysis, in both males and females, estradiol was associated with increases in abundance of several procoagulant and antifibrinolytic proteins. Crosslinking mass spectrometry analysis showed addition of estradiol increased the abundance of several FXIII crosslinks within the FIBA alpha chain in both sexes. Fluorescent fibrinogen analysis revealed a trend toward increased fiber resolvability index after addition of estradiol.

CONCLUSION

Estradiol provokes a hypercoagulable phenotype, affecting time to clot formation, clot propagation, clot strength, clot fibrinolysis, and clot structure. In sum, these data highlight the role of estradiol is driving female-specific hypercoagulability and highlights its potential role as a therapeutic adjunct in resuscitation of TIC.

Fresh Frozen Plasma Increases Hemorrhage in Blunt Traumatic Brain Injury and Uncontrolled Hemorrhagic Shock

BACKGROUND

Blunt traumatic brain injury (bTBI) and uncontrolled hemorrhagic shock (UCHS) are common causes of mortality in polytrauma. We studied the influence of fresh frozen plasma (FFP) resuscitation in a rat model with both bTBI and UCHS before achieving hemorrhage control.

METHODS

The bTBI was induced by an external weight drop (200 g) onto the bare skull of anesthetized male Lewis (Lew/SdNHsd) rats; UCHS was induced by resection of two-thirds of the rats' tails. Fifteen minutes following trauma, bTBI+UCHS rats underwent resuscitation with FFP or lactated Ringer's solution (LR). Eight groups were evaluated: (1) Sham; (2) bTBI; (3) UCHS; (4) UCHS+FFP; (5) UCHS+LR; (6) bTBI+UCHS; (7) bTBI+UCHS+FFP; and (8) bTBI+UCHS+LR. Bleeding volume, hematocrit, lactate, mean arterial pressure (MAP), heart rate, and mortality were measured.

RESULTS

The study included 97 rats that survived the immediate trauma. Mean blood loss up to the start of resuscitation was similar among UCHS only and bTBI+UCHS rats (P=0.361). Following resuscitation, bleeding was more extensive in bTBI+UCHS+FFP rats (5.2 mL, 95% confidence interval [CI] 3.7, 6.6) than in bTBI+UCHS+LR rats (2.5 mL, 95% CI 1.2, 3.8) and bTBI+UCHS rats (1.9 mL, 95% CI 0, 3.9) (P=0.005). Overall mortality increased if bleeding was above 4.5 mL (92.3% versus 8%; P<0.001). Mortality was 83.3% (10/12) in bTBI+UCHS+FFP rats, 41.7% (5/12) in bTBI+UCHS+LR rats, and 64.3% (9/14) in bTBI+UCHS rats.

CONCLUSION

The bTBI did not exacerbate bleeding in rats undergoing UCHS. Compared to LR, FFP resuscitation was associated with a significantly increased blood loss in bTBI+UCHS rats.

The effect of extended continuous nursing strategy applied to patients with mild brain injury on their quality of life and self-efficacy

Postoperative rehabilitation of craniocerebral injury requires a long process and has many complications. In addition, patients with severe craniocerebral injury are usually accompanied by impaired nervous system function, which will affect the patients’ normal life and work in a period of time after surgery. Reasonable rehabilitation nursing plays an active role in restructuring central nervous system function and coordinating muscle and joint activities. Since the rehabilitation of cerebral trauma is a long process, how to ensure the patients to carry out limb and brain function as well as self-care ability and self-care skills according to the rehabilitation exercise plan and intervention measures formulated before discharge has aroused hot debate. This study analyzed the impact of out-of-hospital continuous nursing strategy applied to patients with mild cerebral trauma on their quality of life and self-efficacy level.

Predictive role of shock index in the early formation of cerebral infarction in patients with TBI and cerebral herniation

Background and purpose

Traumatic brain injury (TBI) with brain herniation predisposes to posttraumatic cerebral infarction (PTCI), which in turn seriously affects the prognosis of patients. At present, there is a lack of effective indicators that can accurately predict the occurrence of PTCI. We aimed to find possible risk factors for the development of PTCI by comparing the preoperative and postoperative clinical data of TBI patients with brain herniation.

Methods

The clinical data of 120 patients with craniocerebral trauma and brain herniation were retrospectively analyzed. Among them, 54 patients had cerebral infarction within 3–7 days after injury. The two groups of patients were compared through univariate and multivariate logistic regression analysis, and a classification tree model and a nomogram model were constructed. Finally, receiver operating characteristic curve analysis and decision curve analysis were conducted to analyze the clinical utility of the prediction model.

Results

Logistic regression analysis showed that factors like the Glasgow Coma Scale (GCS) score (P = 0.002), subarachnoid hemorrhage (SAH) (P = 0.005), aspiration pneumonia (P &lt; 0.001), decompressive craniectomy (P &lt; 0.05), intracranial pressure (ICP) monitoring (P = 0.006), the shock index (SI) (P &lt; 0.001), the mean arterial pressure (MAP) (P = 0.005), and blood glucose (GLU) (P &lt; 0.011) appeared to show a significant statistical correlation with the occurrence of infarction (P &lt; 0.05), while age, sex, body temperature (T), D-dimer levels, and coagulation tests were not significantly correlated with PTCI after cerebral herniation. Combined with the above factors, Classification and Regression Tree was established, and the recognition accuracy rate reached 76.67%.

Conclusions

GCS score at admission, no decompressive craniectomy, no ICP monitoring, combined SAH, combined aspiration pneumonia, SI, MAP, and high GLU were risk factors for infarction, of which SI was the primary predictor of PTCI in TBI with an area under the curve of 0.775 (95% CI = 0.689–0.861). Further large-scale studies are needed to confirm these results.

Combined traumatic brain injury and hemorrhagic shock in ferrets leads to structural, neurochemical, and functional impairments

Aeromedical evacuation-relevant hypobaria after traumatic brain injury (TBI) leads to increased neurologic injury and mortality in rats relative to those maintained under normobaria. However, applicability of rodent brain injury research to humans may be limited by differences in neuroanatomy. Therefore, we developed a model in which ferrets are exposed to polytrauma consisting of controlled cortical impact TBI and hemorrhagic shock subjected 24 h later to 6 h of hypobaria or normobaria. Our objective was to determine if the deleterious effects of hypobaria observed in rats, with lissencephalic brains, are also present in a species with a human-like gyrencephalic brain. While no mortality was observed, magnetic resonance spectroscopy (MRS) results obtained 2 days post-injury indicated reduced cortical creatine, N-acetylaspartate, GABA, myo-inositol, and glutamate which was not affected by hypobaria. T2-weighted magnetic resonance imaging (MRI) quantification revealed increased hyperintensity volume representing cortical edema at the site of impact following polytrauma. Hypobaria did not exacerbate this focal edema but did lead to overall reductions in total cortical volume. Both normobaric and hypobaric ferrets exhibited impaired spatial memory 6 days post-injury on the Object Location Test, but no differences were noted between groups. Finally, cortical lesion volume was not exacerbated by hypobaria exposure on day 7 post-injury. Results suggest that air travel 24 h after polytrauma is associated with structural changes in the ferret brain. Future studies should investigate secondary injury from hypobaria following polytrauma in greater detail including alternative outcome measures, timepoints, and exposure to multiple flights.

Oxytocin and Related Peptide Hormones: Candidate Anti-Inflammatory Therapy in Early Stages of Sepsis

Sepsis is a potentially life-threatening systemic inflammatory syndrome characterized by dysregulated host immunological responses to infection. Uncontrolled immune cell activation and exponential elevation in circulating cytokines can lead to sepsis, septic shock, multiple organ dysfunction syndrome, and death. Sepsis is associated with high re-hospitalization and recovery may be incomplete, with long term sequelae including post-sepsis syndrome. Consequently, sepsis continues to be a leading cause of morbidity and mortality across the world. In our recent review of human chorionic gonadotropin (hCG), we noted that its major properties including promotion of fertility, parturition, and lactation were described over a century ago. By contrast, the anti-inflammatory properties of this hormone have been recognized only more recently. Vasopressin, a hormone best known for its anti-diuretic effect, also has anti-inflammatory actions. Surprisingly, vasopressin's close cousin, oxytocin, has broader and more potent anti-inflammatory effects than vasopressin and a larger number of pre-clinical studies supporting its potential role in limiting sepsis-associated organ damage. This review explores possible links between oxytocin and related octapeptide hormones and sepsis-related modulation of pro-inflammatory and anti-inflammatory activities.