Magnesium hydride attenuates intestinal barrier injury during hemorrhage shock by regulating neutrophil extracellular trap formation via the ROS/MAPK/PAD4 pathway.

Magnesium hydride (MgH2) is a hydrogen storage material that is known for its high capacity and safety and is capable of releasing hydrogen in a controlled manner when administered orally. This release of hydrogen has been associated with a range of biological effects, including anti-inflammatory properties, antioxidant activity, and protection of the intestinal barrier. Previous research has shown that neutrophil extracellular traps (NETs) play a role in the dysfunction of the intestinal barrier in conditions such as sepsis and critical illnesses. However, it remains unclear as to whether MgH2 can protect the intestinal barrier by inhibiting NET formation, and the underlying mechanisms have yet to be elucidated. A rat model of hemorrhagic shock was created, and pretreatment or posttreatment procedures with MgH2 were performed. After 24 h, samples from the small intestine and blood were collected for analysis. In vitro, human neutrophils were incubated with either phorbol-12-myristate-13-acetate (PMA) or MgH2. Reactive oxygen species generation and the expression of key proteins were assessed. The results demonstrated that MgH2 administration led to a decrease in inflammatory cytokines in the serum and mitigated distant organ dysfunction in rats with HS. Furthermore, MgH2 treatment reversed histopathological damage in the intestines, improved intestinal permeability, and enhanced the expression of tight junction proteins (TJPs) during HS. Additionally, MgH2 treatment was found to suppress NET formation in the intestines. In vitro pretreatment with MgH2 alleviated intestinal monolayer barrier disruption that was induced by NETs. Mechanistically, MgH2 pretreatment reduced ROS production and NET formation, inhibited the activation of ERK and p38, and suppressed the expression of the PAD4 protein. These findings indicated that MgH2 may inhibit NET formation in a ROS/MAPK/PAD4-dependent manner, which reduces NET-related intestinal barrier damage, thus offering a novel protective role in preventing intestinal barrier dysfunction during HS.

Quaternized chitosan/oxidized bacterial cellulose cryogels with shape recovery for noncompressible hemorrhage and wound healing.

Management of noncompressible torso hemorrhage is an urgent clinical requirement, desiring biomaterials with rapid hemostasis, anti-infection and excellent resilient properties. In this research, we have prepared a highly resilient cryogel with both hemostatic and antibacterial effects by chemical crosslinking and electrostatic interaction. The network structure crosslinked by quaternized chitosan and genipin was interspersed with oxidized bacterial cellulose after lyophilization. The as-prepared cryogel can quickly return to the original volume when soaking in water or blood. The appropriately sized pores in the cryogel help to absorb blood cells and further activate coagulation, while the quaternary ammonium salt groups on quaternized chitosan inhibit bacterial infections. Both cell and animal experiments showed that the cryogel was hypotoxic and could promote the regeneration of wound tissue. This research provides a new pathway for the preparation of double crosslinking cryogels and offers effective and safe biomaterials for the emergent bleeding management of incompressible wounds.

Neutrophil extracellular traps aggravate intestinal epithelial necroptosis in ischaemia-reperfusion by regulating TLR4/RIPK3/FUNDC1-required mitophagy.

Neutrophil extracellular trap (NET) has been confirmed to be related to gut barrier injury during intestinal ischaemia-reperfusion (II/R). However, the specific molecular regulatory mechanism of NETs in II/R-induced intestinal barrier damage has yet to be fully elucidated. Here, we reported increased NETs infiltration accompanied by elevated inflammatory cytokines, cellular necroptosis and tight junction disruption in the intestine of human II/R patients. Meanwhile, NETs aggravated Caco-2 intestinal epithelial cell necroptosis, impairing the monolayer barrier in vitro. Moreover, Pad4-deficient mice were used further to validate the role of NETs in II/R-induced intestinal injury. In contrast, NET inhibition via Pad4 deficiency alleviated intestinal inflammation, attenuated cellular necroptosis, improved intestinal permeability, and enhanced tight junction protein expression. Notably, NETs prevented FUN14 domain-containing 1 (FUNDC1)-required mitophagy activation in intestinal epithelial cells, and stimulating mitophagy attenuated NET-associated mitochondrial dysfunction, cellular necroptosis, and intestinal damage. Mechanistically, silencing Toll-like receptor 4 (TLR4) or receptor-interacting protein kinase 3 (RIPK3) via shRNA relieved mitophagy limitation, restored mitochondrial function and reduced NET-induced necroptosis in Caco-2 cells, whereas this protective effect was reversed by TLR4 or RIPK3 overexpression. The regulation of TLR4/RIPK3/FUNDC1-required mitophagy by NETs can potentially induce intestinal epithelium necroptosis.

Neutrophil extracellular traps promote intestinal barrier dysfunction by regulating macrophage polarization during trauma/hemorrhagic shock via the TGF-ß signaling pathway.

The mechanism by which neutrophil extracellular traps (NETs) may cause intestinal barrier dysfunction in response to trauma/hemorrhagic shock (T/HS) remains unclear. In this study, the roles and mechanisms of NETs in macrophage polarization were examined to determine whether this process plays a role in tissue damage associated with T/HS. Rat models of T/HS and macrophage polarization were developed and the levels of NETs formation in the intestinal tissue of T/HS rats were assessed. NET formation was inhibited in models of T/HS to examine the effect on intestinal inflammation and barrier injury. The proportions of pro-inflammatory and anti-inflammatory macrophages in the damaged intestinal tissues were measured. Finally, high-throughput sequencing was performed to investigate the underlying mechanisms involved in this process. The study revealed that the level of NETs formation was increased and that inhibition of NETs formation alleviated the intestinal inflammation and barrier injury. Moreover, the number of pro-inflammatory macrophages increased and the number of anti-inflammatory macrophages decreased. RNA sequencing analysis indicated that NETs formation decreased the expression of transforming growth factor-beta receptor 2 (TGFBR2), bioinformatic analyses revealed that TGFBR2 was significantly enriched in the transforming growth factor-beta (TGF-ß) signaling pathway. Verification experiments showed that NETs impeded macrophage differentiation into the anti-inflammatory/M2 phenotype and inhibited TGFBR2 and TGF-ß expression in macrophages. However, treatment with DNase I and overexpression of TGFBR2, and inhibition of TGF-ß promoted and prevented this process, respectively. NETs may regulate the macrophage polarization process by promoting intestinal barrier dysfunction in T/HS rats through the TGFBR2-mediated TGF-ß signaling pathway.

Neutrophil extracellular traps drive intestinal microvascular endothelial ferroptosis by impairing Fundc1-dependent mitophagy.

Microvascular endothelial damage caused by intestinal ischemia‒reperfusion (II/R) is a primary catalyst for microcirculation dysfunction and enterogenous infection. Previous studies have mainly focused on how neutrophil extracellular traps (NETs) and ferroptosis cause intestinal epithelial injury, and little attention has been given to how NETs, mainly from circulatory neutrophils, affect intestinal endothelial cells during II/R. This study aimed to unravel the mechanisms through which NETs cause intestinal microvascular dysfunction. We first detected heightened local NET infiltration around the intestinal microvasculature, accompanied by increased endothelial cell ferroptosis, resulting in microcirculation dysfunction in both human and animal II/R models. However, the administration of the ferroptosis inhibitor ferrostatin-1 or the inhibition of NETs via neutrophil-specific peptidylarginine deiminase 4 (Pad4) deficiency led to positive outcomes, with reduced intestinal endothelial ferroptosis and microvascular function recovery. Moreover, RNA-seq analysis revealed a significant enrichment of mitophagy- and ferroptosis-related signaling pathways in HUVECs incubated with NETs. Mechanistically, elevated NET formation induced Fundc1 phosphorylation at Tyr18 in intestinal endothelial cells, which led to mitophagy inhibition, mitochondrial quality control imbalance, and excessive mitochondrial ROS generation and lipid peroxidation, resulting in endothelial ferroptosis and microvascular dysfunction. Nevertheless, using the mitophagy activator urolithin A or AAV-Fundc1 transfection could reverse this process and ameliorate microvascular damage. We first demonstrate that increased NETosis could result in intestinal microcirculatory dysfunction and conclude that suppressed NET formation can mitigate intestinal endothelial ferroptosis by improving Fundc1-dependent mitophagy. Targeting NETs could be a promising approach for treating II/R-induced intestinal microcirculatory dysfunction.

Sequential changes in body composition and metabolic response after pancreatic trauma.

OBJECTIVES: Pancreatic trauma and subsequent pancreatic operation result in early pathophysiologic alterations. Understanding changes in energy expenditure and body composition is essential for optimal management. This study aims to observe changes in energy expenditure and body composition in patients during the early postoperative days (PODs) after pancreatic trauma. METHODS: This is a retrospective review of patients who underwent surgery for blunt pancreatic trauma in a single trauma center. Data of body composition by bioimpedance spectroscopy and energy expenditure by indirect calorimetry were collected and analyzed in patients during the early PODs. The association of body composition parameters with major complications was analyzed. RESULTS: Forty-one patients were included. Compared with POD-3, the total body water, extracellular water, fat-free mass, and skeletal muscle mass on POD-7 and -14 decreased significantly (all P < 0.05). The phase angle (PhA) increased significantly from POD-3 to -14 (P < 0.05). Resting energy expenditure was significantly higher than predicted and remained high throughout the study period. Over the 14-d study period, delivered energy was escalated to the level of resting energy expenditure. The PhA was significantly lower in patients with severe morbidity than in those without (3.6 [3.3-4.2] versus 4.5 [4.2-5.0]; P < 0.001). A multivariate analysis found that PhA was the independent variable for severe complications, with an odds ratio of 0.069 (95% CI, 0.011-0.427; P = 0.004). The predictive ability of PhA revealed an area under the receiver operating characteristic curve of 0.837, with an optimal threshold of 4.23. CONCLUSIONS: Changes in body composition and hypermetabolism state were observed from POD-3 to -14 after pancreatic trauma. A postoperative value of PhA < 4.23 is associated with severe complications.

Hesperetin attenuates sepsis-induced intestinal barrier injury by regulating neutrophil extracellular trap formation via the ROS/autophagy signaling pathway.

Background: Hesperetin (HES), one of the major flavonoids that has various biological activities, such as anti-inflammatory and antioxidant activities, may preserve the intestinal barrier during sepsis. However, the detailed mechanism remains unclear. Our previous studies confirmed that neutrophil extracellular traps (NETs) may jeopardize the intestinal barrier via a reactive oxygen species (ROS)-dependent pathway during sepsis. Therefore, we hypothesized that HES may inhibit NET formation and protect the intestinal barrier function during sepsis. Methods: Mice were pretreated with HES (50 mg kg-1) intraperitoneally for one week, and sepsis models were then induced using lipopolysaccharides (LPS) (10 mg kg-1). The mice were randomly divided into three groups: (1) sham group; (2) LPS group; and (3) HES + LPS group. Twenty-four hours after LPS injection, the serum and terminal ileum specimens were collected for subsequent studies. To detect ROS production and NET formation in vitro, human neutrophils were collected and incubated with phorbol-12-myristate-13-acetate (PMA) and various concentrations of HES. The level of autophagy was measured by an immunofluorescence assay and western blot analysis. TUNEL staining was utilized to analyze cell apoptosis. Results: The outcomes demonstrated that HES decreased inflammatory cytokine and myeloperoxidase (MPO) levels in serum and attenuated distant organ dysfunction in LPS-induced septic mice. Meanwhile, HES treatment reversed intestinal histopathological damage in septic mice, improving intestinal permeability and enhancing tight junction expression. Moreover, we found that neutrophil infiltration and NET formation in the intestine were suppressed during sepsis after HES pretreatment. In vitro, HES treatment reduced PMA-induced ROS production and NET formation, which were reversed by hydrogen peroxide (H2O2) administration. Notably, HES also inhibited NET formation by reducing the microtubule-associated protein light chain 3 (LC3)-II/LC3-I ratio (an indicator of autophagy) in PMA-induced neutrophils, which was reversed by rapamycin. Moreover, when autophagy was suppressed by chloroquine or induced by rapamycin, apoptosis in cells will be switched with autophagy. Conclusion: Taken together, these findings suggest that HES may inhibit NET formation in a ROS/autophagy-dependent manner and switch neutrophil death from NETosis to apoptosis, which reduced NETs-related intestinal barrier damage, providing a novel protective role in intestinal barrier dysfunction during sepsis.

Postoperative hemorrhage following pancreatic injury: Risk factors and clinical outcomes.

BACKGROUND: Postoperative hemorrhage (POH) is a severe adverse event following pancreatic injury. The present study aimed to investigate the risk factors and outcomes of POH after pancreatic injury. METHODS: All patients with a confirmed diagnosis of pancreatic injury who underwent surgical intervention between January 2010 and December 2018 were identified and extracted from the trauma database. Logistic regression was performed to identify the risk factors for POH and specific outcomes. RESULTS: A total of 88 cases that underwent surgical intervention were analyzed, and POH occurred in 31 (35.23%) patients. After multivariable analysis, independent predictors of POH were intra-abdominal abscess (IAA) (p = .002), intestinal fistula (p = .008), shock on admission (p = .003), absence of abdominal suction drainage (p = .005), and higher body mass index (BMI) (p = .005). In addition, patients with POH after pancreatic injury also showed more complications, prolonged hospital and ICU durations, and a significantly higher mortality rate (p = .004). CONCLUSIONS: Patients with IAA, intestinal fistula, shock on admission, absence of abdominal suction drainage, and higher BMI score were associated with POH after pancreatic injury. Moreover, POH was associated with a poor prognosis. CLINICAL TRIAL REGISTER: The study was registered on ClinicalTrials.gov (Unique identifier: NCT03681041).

Neutrophil extracellular trap formation index predicts occurrences of deep surgical site infection after laparotomy.

BACKGROUND: Deep surgical site infections (DSSIs) are serious complications after laparotomy. Neutrophil extracellular traps (NETs) play a vital role in the development of DSSI. Here, we focused on a new approach to predicting the occurrence of DSSI through the detection of the NET formation index (NFI), and compared its prediction ability with other clinical infection indicators. METHODS: Patients who received laparotomy were prospectively enrolled in this study. General information, APACHE II score, SOFA score, and serum infection indicators were recorded. The postoperative abdominal drainage fluid was collected within 3 days after the operation for quantification of the NFI. RESULTS: A total of 92 consecutive patients were included, with 22 patients were diagnosed with DSSI. The NFI in the DSSI group was 32.70%±19.33% while the corresponding index was 10.70%±8.25% in the non-DSSI group (P<0.01). The mean APACHE II and SOFA score had significant differences between the two groups. The NFI was positively correlated with the APACHE II score (P<0.01, r=0.269) and SOFA score (P=0.013, r=0.258). Patients with a high NFI (NFI >13.86%) had a higher risk of developing DSSI. According to the receiver operating characteristic (ROC) curve, the area under the ROC curve (AUC) of the NFI, C-reactive protein (CRP) and procalcitonin (PCT) were 0.912, 0.748 and 0.731, respectively. CONCLUSIONS: In this cohort of surgical patients, the quantification of the NFI had a considerable predictive value for early identification of DSSI. The NFI in drainage fluid turned out to be a more sensitive and specific predictor of DSSI than serum infection indicators including CRP and PCT.

De-escalation antibiotic therapy alleviates organ injury through modulation of NETs formation during sepsis.

Empiric broad-spectrum antimicrobials therapy is suggested to be started immediately for sepsis patients. Empiric antimicrobial therapy should be narrowed once pathogen identification and sensitivities are established. However, the detailed mechanisms of de-escalation strategy are still unclear. Here we hypothesized neutrophil extracellular traps (NETs) played an essential role and de-escalation strategy might alleviate organs injury through regulation of NETs formation in sepsis. We evaluated the effect of imipenem and ceftriaxone on NETs formation in vitro and examined the role of reactive oxygen species (ROS). Next, we designed de-escalation and escalation strategy in cecum ligation and puncture (CLP) models. Organ injury, inflammatory cytokines, NETs levels were compared and evaluated. In CLP models, de-escalation therapy resulted in an increased serum MPO-DNA level during the early stage and decreased MPO-DNA level during late stage, which exerted the reverse effects in escalation therapy. Inflammatory response and organ injury exacerbated when eliminated NETs with DNAse I during the early stage of sepsis (p < 0.01). Histopathological analysis showed decreased injury in lung, liver, and intestine in de-escalation therapy compared with escalation therapy (p < 0.01). De-escalation therapy results in the highest 6-day survival rate compared with the control group (p < 0.01), however, no significant difference was found between de-escalation and escalation group (p = 0.051). The in vitro study showed that the imipenem could promote, while the ceftriaxone could inhibit the formation of NETs in PMA-activated PMNs through a ROS-dependent manner. We firstly demonstrate that de-escalation, not escalation, therapy reduces organ injury, decreases inflammatory response by promoting NETs formation in the early stage, and inhibiting NETs formation in the late stage of sepsis.

Bioelectrical impedance analysis-guided fluid management promotes primary fascial closure after open abdomen: a randomized controlled trial.

BACKGROUND: Fluid overload (FO) after resuscitation is frequent and contributes to adverse outcomes among postinjury open abdomen (OA) patients. Bioelectrical impedance analysis (BIA) is a promising tool for monitoring fluid status and FO. Therefore, we sought to investigate the efficacy of BIA-directed fluid resuscitation among OA patients. METHODS: A pragmatic, prospective, randomized, observer-blind, single-center trial was performed for all trauma patients requiring OA between January 2013 and December 2017 to a national referral center. A total of 140 postinjury OA patients were randomly assigned in a 1:1 ratio to receive either a BIA-directed fluid resuscitation (BIA) protocol that included fluid administration with monitoring of hemodynamic parameters and different degrees of interventions to achieve a negative fluid balance targeting the hydration level (HL) measured by BIA or a traditional fluid resuscitation (TRD) in which clinicians determined the fluid resuscitation regimen according to traditional parameters during 30 days of ICU management. The primary outcome was the 30-day primary fascial closure (PFC) rate. The secondary outcomes included the time to PFC, postoperative 7-day cumulative fluid balance (CFB) and adverse events within 30 days after OA. The Kaplan-Meier method and the log-rank test were utilized for PFC after OA. A generalized linear regression model for the time to PFC and CFB was built. RESULTS: A total of 134 patients completed the trial (BIA, n = 66; TRD, n = 68). The BIA patients were significantly more likely to achieve PFC than the TRD patients (83.33% vs. 55.88%, P < 0.001). In the BIA group, the time to PFC occurred earlier than that of the TRD group by an average of 3.66 days (P < 0.001). Additionally, the BIA group showed a lower postoperative 7-day CFB by an average of 6632.80 ml (P < 0.001) and fewer complications. CONCLUSION: Among postinjury OA patients in the ICU, the use of BIA-guided fluid resuscitation resulted in a higher PFC rate and fewer severe complications than the traditional fluid resuscitation strategy.

Neutrophil extracellular traps impair intestinal barrier functions in sepsis by regulating TLR9-mediated endoplasmic reticulum stress pathway.

Increased neutrophil extracellular traps (NETs) formation has been found to be associated with intestinal inflammation, and it has been reported that NETs may drive the progression of gut dysregulation in sepsis. However, the biological function and regulation of NETs in sepsis-induced intestinal barrier dysfunction are not yet fully understood. First, we found that both circulating biomarkers of NETs and local NETs infiltration in the intestine were significantly increased and had positive correlations with markers of enterocyte injury in abdominal sepsis patients. Moreover, the levels of local citrullinated histone 3 (Cit H3) expression were associated with the levels of BIP expression. To further confirm the role of NETs in sepsis-induced intestinal injury, we compared peptidylarginine deiminase 4 (PAD4)-deficient mice and wild-type (WT) mice in a lethal septic shock model. In WT mice, the Cit H3-DNA complex was markedly increased, and elevated intestinal inflammation and endoplasmic reticulum (ER) stress activation were also found. Furthermore, PAD4 deficiency alleviated intestinal barrier disruption and decreased ER stress activation. Notably, NETs treatment induced intestinal epithelial monolayer barrier disruption and ER stress activation in a dose-dependent manner in vitro, and ER stress inhibition markedly attenuated intestinal apoptosis and tight junction injury. Finally, TLR9 antagonist administration significantly abrogated NETs-induced intestinal epithelial cell death through ER stress inhibition. Our results indicated that NETs could contribute to sepsis-induced intestinal barrier dysfunction by promoting inflammation and apoptosis. Suppression of the TLR9-ER stress signaling pathway can ameliorate NETs-induced intestinal epithelial cell death.

Protective effect of ethyl pyruvate on gut barrier function through regulations of ROS-related NETs formation during sepsis.

BACKGROUND: Sepsis impairs the function of the intestinal barrier through neutrophil extracellular traps (NETs). Reactive oxygen species (ROS)-induced activation of mitogen-activated protein kinase (MAPK) is involved in NET formation. Ethyl pyruvate (EP), a potent and effective ROS scavenger, ameliorates sepsis-associated intestinal barrier dysfunction, but the detailed mechanism is unknown. The current study aimed to explore the eff ;ects of EP on sepsis-induced intestinal barrier dysfunction and whether ROS and NETs were involved. METHODS: A sepsis model was induced in mice by intraperitoneal injection of LPS (10 mg/kg). The mice were divided into 4 groups: (1) sham group; (2) LPS group; (3) DNase-1 + LPS group; and (4) EP + LPS group. EP or DNase-1 was intraperitoneally injected after the LPS model was established. After 24 h, the small intestine and blood were collected for analysis. Human neutrophils were harvested and incubated with phorbol-12-myristate-13-acetate (PMA) or PMA + EP, and ROS and NET generation was measured. RESULTS: EP significantly decreased proinflammatory cytokines and MPO-DNA in the LPS model. In addition, EP suppressed NET formation in the intestines of endotoxemic mice. The decrease in NETs induced by EP or DNase-1 alleviated histopathological damage, intestinal cell apoptosis and increased tight junction expression. In vitro, the treatment of EP abolished PMA-induced ROS production and NET formation which could be reversed by H2O2 treatment. Meanwhile, EP also abolished MAPK ERK1/2 and p38 activation during PMA-induced NET formation. CONCLUSION: This study was the first to demonstrate that EP alleviated NET formation and sepsis-induced intestinal damage through blockage of ROS mediated MAPK ERK1/2 and p38 activation.

ß-Lactams modulate neutrophil extracellular traps formation mediated by mTOR signaling pathway.

BACKGROUND: Some biotics, like ß-Lactams, have shown immunomodulation effects during sepsis, but the detailed mechanism was still unclear. Here we postulated that neutrophils play an essential role and ß-Lactams exert immunomodulation effects through modulating neutrophil extracellular traps (NETs) formation. METHODS: NETs formation induced by two ß-Lactams, Meropenem (MEM) and ceftazidime/tazobactam (CAZ/TB) in neutrophils from healthy donors and HL-60 cells was performed. Reactive oxygen species (ROS) generation and the activity of nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase were examined. Additionally, the upstream signal pathway of NETs formation, including protein kinase C (PKC), protein kinase B (Akt) and mammalian target of rapamycin (mTOR), were detected. RESULTS: MEM and CAZ/TB modulate NETs formation in activated PMNs, not resting PMNs. Both reduced ROS generation in resting PMNs and increased in activated PMNs. To test the activity of NADPH oxidase, we detected NADPH in MEM and CAZ/TB pre-cultivated activated PMNs, which showed that MEM and CAZ/TB modulates NETs formation through activation of NADHP oxidase by affecting the subunits of key enzymes. However, MEM reduced levels of phosho-PKC-Akt-mTOR, with no changes in CAZ/TB. CONCLUSIONS: We firstly demonstrate that ß-Lactams showed the definitive immunomodulation effects through modulating NETs formation, which is depended on PKC-Akt-mTOR signal pathway.

Predictors of irreversible intestinal resection in patients with acute mesenteric venous thrombosis.

BACKGROUND: Acute mesenteric venous thrombosis (AMVT) can cause a poor prognosis. Prompt transcatheter thrombolysis (TT) can achieve early mesenteric revascularization. However, irreversible intestinal ischemia still occurs and the mechanism is still unclear. AIM: To evaluate the clinical outcomes of and to identify predictive factors for irreversible intestinal ischemia requiring surgical resection in AMVT patients treated by TT. METHODS: The records of consecutive patients with AMVT treated by TT from January 2010 to October 2017 were retrospectively analyzed. We compared patients who required resection of irreversible intestinal ischemia to patients who did not require. RESULTS: Among 58 patients, prompt TT was carried out 28.5 h after admission. A total of 42 (72.4%) patients underwent arteriovenous combined thrombolysis, and 16 (27.6%) underwent arterial thrombolysis alone. The overall 30-d mortality rate was 8.6%. Irreversible intestinal ischemia was indicated in 32 (55.2%) patients, who had a higher 30-d mortality and a longer in-hospital stay than patients without resection. The significant independent predictors of irreversible intestinal ischemia were Acute Physiology and Chronic Health Evaluation (APACHE) II score (odds ratio = 2.368, 95% confidence interval: 1.047-5.357, P = 0.038) and leukocytosis (odds ratio = 2.058, 95% confidence interval: 1.085-3.903, P = 0.027). Using the receiver operating characteristic curve, the cutoff values of the APACHE II score and leukocytosis for predicting the onset of irreversible intestinal ischemia were calculated to be 8.5 and 12 × 109/L, respectively. CONCLUSION: Prompt TT could achieve a favorable outcome in AMVT patients. High APACHE II score and leukocytosis can significantly predict the occurrence of irreversible intestinal ischemia. Therefore, close monitoring of these factors may help with the early identification of patients with irreversible intestinal ischemia, in whom ultimately surgical resection is required, before the initiation of TT.

Early intravenous administration of tranexamic acid ameliorates intestinal barrier injury induced by neutrophil extracellular traps in a rat model of trauma/hemorrhagic shock.

BACKGROUND: Early intravenous administration of tranexamic acid has been shown to protect the intestinal barrier after a model of trauma-hemorrhagic shock in the rat, but the potential mechanism remains unclear. Our previous studies have demonstrated that neutrophil extracellular traps contribute to the intestinal barrier dysfunction during sepsis and other critical conditions. Meanwhile, there are high levels of neutrophil infiltration in the intestine during trauma-hemorrhagic shock. Here, we hypothesized that neutrophil extracellular trap formation played a vital role during trauma-hemorrhagic shock-induced intestinal injury and that tranexamic acid, a serine protease inhibitor, may inhibit neutrophil extracellular trap formation and protect intestinal barrier function in trauma-hemorrhagic shock. METHODS: A model of trauma-hemorrhagic shock in male rats was established. The rats were divided into 6 groups: (1) sham group; (2) trauma-hemorrhagic shock group; (3) trauma-hemorrhagic shock + DNase I group; (4) trauma-hemorrhagic shock + tranexamic acid group; (5) trauma-hemorrhagic shock + tranexamic acid (different time) group; and (6) trauma-hemorrhagic shock + tranexamic acid (different doses) group. The DNase I solution was injected intravenously to disrupt neutrophil extracellular traps immediately after the trauma-hemorrhagic shock model was completed. After 24 hours, the small intestine and blood were collected for analysis. Human neutrophils were harvested and incubated with phorbol-12-myristate-13-acetate or tranexamic acid, generation of reactive oxygen species, and key proteins expression were detected. RESULTS: Trauma-hemorrhagic shock induced the formation of intestinal neutrophil extracellular traps and disrupted the intestinal tight junction proteins. Clearing of neutrophil extracellular traps by DNase I resulted in increased expression of tight junction proteins and alleviated the intestinal injury. Early intravenous tranexamic acid administration (1 hour after trauma-hemorrhagic shock) decreased neutrophil extracellular trap formation and prevented tight junction protein disruption compared to the non-tranexamic acid group; however, after delayed administration of tranexamic acid (6 hours), there were no changes in neutrophil extracellular trap formation and intestinal injuries compared to the non-tranexamic acid group. Furthermore, tranexamic acid inhibited neutrophil extracellular trap formation and protected the intestinal barrier in a dose-dependent manner and high-dose (20 mg/kg) treatment of tranexamic acid showed a better effect compared with the therapeutic dose (10 mg/kg). The results of thromboelastography demonstrated that the R and K values in the high-dose group decreased (R, 1.85 ± 0.14 vs 3.87 ± 0.16 minutes, P < .001; K, 0.95 ± 0.04 vs 1.48 ± 0.07 minutes, P < .001), accompanied by a decrease in LY30, indicating that treatment with a high dose of tranexamic acid may cause hypercoagulability and shutdown of fibrinolysis. In addition, less neutrophil extracellular trap formation was detected in neutrophils incubated with neutrophils via an reactive oxygen species-dependent pathway. CONCLUSION: We first demonstrated a novel role of neutrophil extracellular traps in the pathophysiology of intestinal barrier dysfunction during trauma-hemorrhagic shock. Notably, early but not delayed intravenous administration of tranexamic acid effectively inhibits neutrophil extracellular trap formation and protects intestinal barrier function. Therefore, these results suggested a potential theoretic intervention for the protection of the intestinal barrier during trauma-hemorrhagic shock. In such a process, tranexamic acid appears to regulate neutrophil extracellular trap formation via the classic reactive oxygen species/mitogen-activated protein kinase pathway.

Outcomes and clinical characteristics of transmural intestinal necrosis in acute mesenteric ischemia.

Background: Acute mesenteric ischemia (AMI) is a rare life-threatening condition, especially for the patients with transmural intestinal necrosis (TIN). However, the optimal time for surgical intervention is controversial. As a series study, this study aimed to identify the outcomes and clinical characteristic of patients with TIN. Methods: Clinical data of 158 patients with AMI from January 2010 to December 2017 were retrospectively analyzed in a national gastrointestinal referral center in China to confirm the outcomes and identify predictors for TIN. Results: According to the results of pathological assessment and follow-up, 62 patients were TIN and 96 were non-TIN. Patients with TIN have a higher mortality and incidence of severe complications. The significant independent predictors for TIN were arterial lactate level (OR: 4.76 [2.29 ∼ 9.89]), free intraperitoneal fluid (OR: 9.49 [2.56 ∼ 35.24]) and pneumatosis intestinalis (OR: 7.08 [1.68 ∼ 29.82]) in computed tomography (CT) scan imaging. The overall area under the receiver operating characteristics (ROC) curve of the model was 0.934 (95% confidence interval: 0.893 ∼ 0.974). Using ROC curve, the cutoff value of arterial lactate level predicting the onset of TIN was 2.65 mmol/L. Conclusions: Patients concomitant with TIN manifest a higher risk of poor prognosis. The three predictors for TIN were arterial lactate level >2.65 mmol/L, free intraperitoneal fluid and pneumatosis intestinalis. Close monitoring these predictors would help identify AMI patients developed TIN and in urgent need for bowel resection.

Endovascular stent placement for isolated superior mesenteric artery dissection with intestinal ischaemia.

BACKGROUND: Isolated superior mesenteric artery dissection (ISMAD) is rare, especially when associated with intestinal ischaemia. We report our clinical experience managing this condition. PATIENTS AND METHODS: Medical records from 22 patients with ISMAD and intestinal ischaemia were retrospectively analysed. Conservative treatment was given to all patients as first line therapy. Subsequently, 15 patients received endovascular stent placement and three patients received endovascular stent placement plus intestinal resection and anastomosis. RESULTS: After conservative treatment, the symptoms of three patients were remarkably relieved; however, a repeat contrast CT showed that stenosis was aggravated. Hence, endovascular stent placement was performed in all 15 patients. Enteral nutrition was successfully restored in 12 patients. Three patients showed signs of chronic intestinal ischaemia, including peritonitis and ileus. These patients underwent intestinal resection and anastomosis. Enteral nutrition was restored at postoperative week two. No signs of intestinal ischaemia recurred during two-years of follow-up. CONCLUSIONS: We recommend endovascular stent placement as a feasible, effective, and minimally invasive procedure in patients with ISMAD and symptoms of intestinal ischaemia.