Mesenteric ischemia: still a deadly puzzle for the medical community

Honokiol ameliorates pyroptosis in intestinal ischemia‑reperfusion injury by regulating the SIRT3‑mediated NLRP3 inflammasome

Intestinal ischemia‑reperfusion (IIR) injury is caused by the restoration of blood supply after a period of ischemia. It occurs in numerous clinical pathologies, such as intestinal obstruction, incarcerated hernia and septic shock, with mortality rates of 50‑80%. Honokiol (HKL), isolated from the herb Magnolia officinalis, is a biphenolic natural product with antioxidative, antibacterial, antitumor and anti‑inflammatory properties. Additionally, HKL has protective effects in ischemia‑reperfusion injuries, but its role and specific mechanisms in IIR injury are yet to be elucidated. In the present study, the superior mesenteric artery was ligated in rats to establish an IIR model. Hematoxylin and eosin staining and ELISA revealed that HKL administration ameliorated IIR‑induced injury in rats, which was demonstrated by a reduced destruction to the intestinal mucosa, as well as a reduced serum intestinal fatty acid‑binding protein concentration and Chiu's score in 10 mg/kg HKL treated IIR‑induced rats compared with those without HKL treatment. Additionally, immunohistochemical (IHC) staining and western blotting revealed that the occludin and tight junction protein 1 protein levels were increased in the 10 mg/kg HKL treated IIR‑induced rats compared with those without HKL treatment. Furthermore, an in vitro hypoxia/reoxygenation (H/R) cell model was established using IEC‑6 cells. Cell Counting Kit‑8 and lactate dehydrogenase (LDH) assays indicated that HKL mitigated the H/R‑inhibited cell viability and decreased the LDH levels in cell supernatants. Mechanistically, immunofluorescent (IF) staining and western blotting revealed that HKL inhibited H/R‑triggered pyroptosis. Furthermore, Mito‑Tracker, mitochondrial membrane potential and MitoSOX staining as well as western blotting revealed that reducing mitochondrial reactive oxygen species (ROS) inhibited the H/R‑induced pyroptosis by mitigating mitochondrial dysfunction. In the present H/R cell model, HKL improved the mitochondrial function by increasing the expression of sirtuin 3 (SIRT3), while IF staining and western blotting indicated that silencing SIRT3 notably reduced the beneficial effect of HKL on pyroptosis. In addition, IHC staining and western blotting revealed that HKL treatment mitigated the IIR‑induced pyroptosis in rats. Therefore, HKL treatment may mitigate IIR‑induced mitochondrial dysfunction and reduce mitochondrial ROS production by increasing the expression of SIRT3 protein, potentially resulting in an inhibition of pyroptosis during IIR.

Microfluidic intestinal organoid-on-a-chip uncovers therapeutic targets by recapitulating oxygen dynamics of intestinal IR injury

Increasing evidence demonstrates that mammals have different reactions to hypoxia with varied oxygen dynamic patterns. It takes ∼24 h for tri-gas incubator to achieve steady cell hypoxia, which fails to recapitulate ultrafast oxygen dynamics of intestinal ischemia/reperfusion (IR) injury. Inspired from the structure of native intestinal villi, we engineered an intestinal organoid chip embedded with engineered artificial microvessels based on co-axial microfluidic technology by using pH-responsive ZIF-8/sodium alginate scaffold. The chip was featured on: (i) eight times the oxygen exchange efficiency compared with the conventional device, tri-gas incubator, (ii) implantation of intestinal organoid reproducing all types of intestinal epithelial cells, and (iii) bio-responsiveness to hypoxia and reoxygenation (HR) by presenting metabolism disorder, inflammatory reaction, and cell apoptosis. Strikingly, it was found for the first time that Olfactomedin 4 (Olfm4) was the most significantly down-regulated gene under a rapid HR condition by sequencing the RNA from the organoids. Mechanistically, OLFM4 played protective functions on HR-induced cell inflammation and tissue damage by inhibiting the NF-kappa B signaling activation, thus it could be used as a therapeutic target. Altogether, this study overcomes the issue of mismatched oxygen dynamics between in vitro and in vivo, and sets an example of next-generation multisystem-interactive organoid chip for finding precise therapeutic targets of IR injury.

Peptidome analysis reveals critical roles for peptides in a rat model of intestinal ischemia/reperfusion injury

Intestinal ischemia/reperfusion injury (IIRI) has the potential to be life threatening and is associated with significant morbidity and serious damage to distant sites in the body on account of disruption of the intestinal mucosal barrier. In the present study, we have explored this line of research by comparing and identifying peptides that originated from the intestinal segments of IIRI model rats by using liquid chromatography-mass spectrometry (LC-MS). We also analyzed the basic characteristics, cleavage patterns, and functional domains of differentially expressed peptides (DEPs) between the IIRI model rats and control (sham-operated) rats and identified bioactive peptides that are potentially associated with ischemia reperfusion injury. We also performed bioinformatics analyses in order to identify the biological roles of the DEPs based on their precursor proteins. Enrichment analysis demonstrated the role of several DEPs in impairment of the intestinal mucosal barrier caused by IIRI. Based on the results of comprehensive ingenuity pathway analysis, we identified the DEPs that were significantly correlated with IIRI. We identified a candidate precursor protein (Actg2) and seven of its peptides, and we found that Actg2-6 had a more significant difference in its expression, a longer half-life, and better lipophilicity, hydrophobicity, and stability than the other candidate Actg2 peptides examined. Furthermore, we observed that Actg2-6 might play critical roles in the protection of the intestinal mucosal barrier during IIRI. In summary, our study provides a better understanding of the peptidomics profile of IIRI, and the results indicate that Actg2-6 could be a useful target in the treatment of IIRI.

Acute mesenteric ischemia: which predictive factors of delayed diagnosis at emergency unit?

PURPOSE

Acute mesenteric ischemia (AMI) is frequently diagnosed late, leading to a poor prognosis. Our aims were to identify predictive factors of delayed diagnosis and to analyze the outcomes of patients with AMI admitted in emergency units.

METHODS

All the patients with AMI (2015-2020), in two Emergency units, were retrospectively included. Two groups were defined according to the time of diagnosis between the arrival at emergency unit and the CT scan: ≤ 6 h (early), > 6 h (delayed).

RESULTS

119 patients (mean age = 71 ± 7 years) were included. The patients with a delayed diagnosis (n = 33, 28%) were significantly associated with atypical presentation, including lower rates of abdominal pain (73 vs 89%, p = 0.003), abdominal tenderness (33 vs 43%, p = 0.03), and plasma lactate (4 ± 2 vs 6 ± 7 mmol/l, p = 0.03) when compared with early diagnosis. After multivariate analysis, the absence of abdominal pain was the only independent predictive factor of delayed diagnosis (Odd Ratio = 0.17; 95% CI = 0.03-0.88, p = 0.03). Patients with delayed diagnosis tended to be associated to lower rates of revascularization (9 vs 17%, p = 0.4), higher rates of major surgical morbidity (90 vs 57%, p = 0.1), longer length of stay (16 ± 23 vs 13 ± 15 days, p = 0.4) and, at the end of follow-up, higher rate of short small bowel syndrome (18 vs 7%, p = 0.095).

CONCLUSION

AMI is a challenge for emergency physicians. History of patient, physical exam, biological data are not sufficient to diagnose AMI. New biomarkers, and awareness of emergency physicians should improve and accelerate the diagnosis of AMI.

Cocaine-induced mesenteric ischaemia requiring small bowel resection

Cocaine use causes profound vasoconstriction leading to various systemic complications. Gastrointestinal complications such as mesenteric ischaemia are difficult to recognise and may result in serious consequences if not treated promptly. We report on the case of a 47-year-old man presenting with mesenteric ischaemia on a background of acute on chronic cocaine consumption, where diagnosis was not evident until second presentation. He underwent an emergency laparotomy with small bowel resection and jejunostomy formation and made a good recovery with eventual reversal surgery. The literature on cocaine-induced bowel ischaemia shows significant variability in presentation and outcome. Laboratory investigations are non-specific, and early recognition is vital. Given the increasing recreational use of cocaine in the UK, it is imperative to have a high clinical index of suspicion for mesenteric ischaemia in patients presenting with non-specific abdominal pain, and to ensure a detailed social history covering recreational drug use is not forgotten.

Amphetamine-induced small bowel ischemia - A case report

Nonocclusive mesenteric ischemia is most common in elderly patients with multiple comorbidities. Nevertheless, there are some reports of acute bowel ischemia in young patients with a history of recreational drug abuse. We describe the case of a 33-year-old patient who presented with acute abdominal pain following amphetamine consumption. Multidetector computed tomography showed nonocclusive segmental ischemia of the distal ileum, and the patient underwent emergency surgery with ileocecal resection. The patient recovered quickly and was discharged without any postoperative complications. An early and precise diagnosis of patients with intestinal ischemia having a history of amphetamine abuse is of utmost importance for prompt and proper treatment. Especially in younger patients, multidetector computed tomography should be tailored to use with less radiation. A single portal venous scan proved sufficient in our case.

Sensitivity and Specificity of the Platelet-Lymphocyte Ratio and the Neutrophil-Lymphocyte Ratio in Diagnosing Acute Mesenteric Ischemia in Patients Operated on for the Diagnosis of Mesenteric Ischemia: A Retrospective Case-Control Study

Aim: The present study aims to determine whether various hematological parameters and ratios of patients could be used to diagnose AMI. Materials and Methods: The subjects of the study are the patients who were hospitalized with an acute mesenteric ischemia (AMI) pre-diagnosis and underwent surgery as a consequence. The patients who were determined to have the diagnosis of AMI intraoperatively are categorized in the AMI Group. The patients whose operations do not reveal AMI (negative exploration) are categorized in the Control Group. These two groups are compared in terms of hematological parameters and rates. Results: In the study, the PLR (p = 0.017), NLR (p = 0.33), PDW (0.023), RDW (p = 0.025) values are significantly higher in the AMI group compared to the control group while the LYMP (p = 0.023) count is significantly lower. Conclusions: For the patients admitted to the emergency clinics with suspected AMI, the increased PLR, NLR, PDW, and RDW values together with the reduced lymphocyte count can be used to support the diagnosis.

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio Are Effective Predictors of Prognosis in Patients with Acute Mesenteric Arterial Embolism and Thrombosis

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been shown to be valuable prognostic markers for a variety of pathological conditions including solid tumors, sepsis, and others. However, the prognostic values of the NLR and PLR in patients with acute mesenteric arterial embolism (AMAE) and acute mesenteric arterial thrombosis (AMAT) have not been elucidated. The aim of this study was to determine the predictive value of the NLR and PLR for poor prognosis in patients with AMAE and AMAT.

METHODS

A total of 137 patients with AMAE (n = 77) or AMAT (n = 60) were divided into a poor outcome group (cases of intestinal necrosis or death) and a better outcome group (cases without intestinal necrosis who survived successfully), according to prognosis. Neutrophil, platelet, and lymphocyte counts were recorded before pharmacotherapy or surgery. The NLR and PLR were calculated, and logistic regression analysis was performed to test their prognostic values.

RESULTS

The cutoff values for NLR and PLR were 11.05 and 156.26, respectively. The PLR was linearly associated with the NLR (R = 0.769, P < 0.001). NLR (odds ratio [OR] = 6.835, 95% confidence interval [CI] = 2.282-20.469, P = 0.001), PLR (OR = 4.871, 95% CI = 1.627-14.587, P = 0.005), and coronary heart disease (OR = 3.388, 95% CI = 1.156-9.929, P = 0.026) were found to be independent prognostic factors for the patients.

CONCLUSIONS

NLR ≥ 11.05, PLR ≥ 156.26, and coronary heart disease were shown to be risk factors for poor prognosis in patients with AMAE and AMAT. According to these factors, patients can be divided into 3 prognostic groups: good, NLR < 11.05 with PLR < 156.26; moderate, NLR < 11.05 with PLR ≥ 156.26 or NLR ≥ 11.05 with PLR < 156.26; and poor, NLR ≥ 11.05 with PLR ≥ 156.26.

Short-interval postconditioning protects the bowel against ischaemia-reperfusion injury in rats

Objective

Acute mesenteric ischaemia leads to intestinal damage. Restoration of blood flow results in further damage to tissue, which is called reperfusion injury. This study aimed to investigate the protective effects of short-interval postconditioning and to determine the optimal interval for reperfusion in an experimental rat model of intestinal ischaemia.

Methods

Forty adult male Wistar rats were grouped as follows: sham (Sh), ischaemia + reperfusion (IR), ischaemia + postconditioning for 5 seconds (PC5), ischaemia + postconditioning for 10 seconds (PC10), and ischaemia + postconditioning for 20 seconds (PC20). For postconditioning, 10 cycles of reperfusion (5, 10, or 20 seconds) interspersed by 10 cycles of 10 seconds of ischaemia were performed. Blood glutathione reductase (GR) and glutathione peroxidase (GPx) levels were measured. Intestinal tissue damage was assessed histopathologically.

Results

GR levels were significantly higher in the PC5 group than in the IR group (37.7 ± 9.0 vs. 18.5 ± 2.0 min/g Hb). GPx levels were significantly higher in the PC10 group than in the IR group (43.2 ± 9.2 vs. 15.9 ± 4.6 U/g Hb). The histopathological score was significantly lower in the PC5 group (1.1 ± 0.1) than in the IR group (2.1 ± 0.2).

Conclusion

Short-interval postconditioning reduces reperfusion injury in the ischaemic bowel and the optimal interval for reperfusion is 5 seconds. The long-term effects of short-interval postconditioning and the optimal reperfusion interval in intestinal ischaemia–reperfusion in rats need to be investigated.

Embolic superior mesenteric artery (SMA) occlusion secondary to a cardiac sarcoma

We present a case of embolic acute mesenteric ischaemia (AMI) secondary to an underlying cardiac sarcoma, an exceedingly rare presentation only reported twice before. A 46-year-old man presented to accident and emergency department during the night with severe abdominal pain and vomiting. An urgent CT angiograph demonstrated superior mesenteric artery (SMA) occlusion with ischaemic small bowel. Joint surgical effort from vascular and general surgeons successfully recanalised the SMA and a 20 cm segment of small bowel was resected. Postoperatively, an echocardiogram demonstrated a mass within the left atrium. After cardiothoracic resection, the mass was found to be a rare undifferentiated cardiac sarcoma. Further staining on the embolus retrieved from the SMA revealed scattered spindle cells with a similar immunohistochemistry profile to that of the resected cardiac sarcoma. The patient was subsequently discharged well on lifelong warfarin.

Radiological Evaluation of Bowel Ischemia

Intestinal ischemia, which refers to insufficient blood flow to the bowel, is a potentially catastrophic entity that may require emergent intervention or surgery in the acute setting. Although the clinical signs and symptoms of intestinal ischemia are nonspecific, computed tomography (CT) findings can be highly suggestive in the correct clinical setting. In our article, we review the CT diagnosis of arterial, venous, and nonocclusive intestinal ischemia. We discuss the vascular anatomy, pathophysiology of intestinal ischemia, CT techniques for optimal imaging, key and ancillary radiological findings, and differential diagnosis.

Liporotein-associated phospholipase-A2 can be a diagnostic marker inthe early stage diagnosis of acute mesenteric ischemia

BACKGROUND/AIM

The purpose of this experimental study was to investigate the role of lipoprotein-associated phospholipase-A2 (Lp-PLA2) in the diagnosis of acute mesenteric ischemia (AMI) in the early stage.

MATERIALS AND METHODS

Twenty-seven New Zealand rabbits were randomly divided into 3 groups in this study. Blood specimens were obtained from the groups at hours 0, 1, 3, and 6. Using the blood samples drawn from all groups, Lp-PLA2 and C-reactive protein (CRP) parameters were investigated.

RESULTS

There was a significant rise in the levels of both Lp-PLA2 and CRP starting at hour 1 (P < 0.05) (hour 1; Lp-PLA2, P = 0.003) in the ischemia group. In the sham group, the levels of Lp-PLA2 and CRP started to rise at hour 3 (P < 0.05) (hour 3; Lp-PLA2, P = 0.011). At hour 6 of ischemia, the area under the ROC curve was 100%, and the cut-off value of 63.91 ng/mL revealed a sensitivity of 88% and a specificity of 100% for Lp-PLA2.

CONCLUSION

These findings showed the role of serum Lp-PLA2 and CRP levels in the early diagnosis of AMI. Thus, further studies are needed to describe the role of Lp-PLA2 in the early diagnosis of AMI.

The Receptor for Advanced Glycation Endproducts Does Not Contribute to Pathology in a Mouse Mesenteric Ischemia/Reperfusion-Induced Injury Model

The receptor for advanced glycation endproducts (RAGE) can engage a diverse class of ligands and contribute to the immune and inflammatory response to infection and injury. It is known to be a pathogenic receptor in many inflammatory diseases, including ischemia/reperfusion (IR) injuries in several tissues; however, its role has not been investigated in IR injuries of the intestine to date. Mesenteric (or intestinal) IR leads to recruitment of inflammatory cells into intestinal interstitial spaces, which markedly disrupts intestinal mucosa. IR-induced mucosal injury is accompanied by the development of a local and systemic inflammatory response and remote organ injury, and results in high mortality in the clinic. We hypothesized that elimination of RAGE signaling using RAGE^−/− mice would result in decreased local and remote organ injury and reduced inflammation in a mesenteric IR model, and thus be a target for therapeutic intervention. We found that RAGE ligands including HMGB-1 and C3a were elevated after mesenteric IR indicating the potential for enhanced RAGE activation in this model. However despite this, wild-type and RAGE^−/− mice both displayed similar degrees of mesenteric injury, neutrophil infiltration, intestinal edema, cytokine generation, neutrophil mobilization, and remote organ injury after mesenteric IR. We, therefore, conclude that despite its role in other organ IR injuries, and the robust production of RAGE ligands after intestinal ischemia, RAGE itself does not directly influence tissue injury and the inflammatory response in mesenteric IR.

Neutrophil-to-lymphocyte ratio as a diagnostic biomarker for the diagnosis of acute mesenteric ischemia

PURPOSE

Due to the diagnostic challenges and dreadful consequences of delayed treatment of acute mesenteric ischemia (AMI), a variety of diagnostic markers have been previously studied. However, the diagnostic value of neutrophil-to-lymphocyte ratio (NLR), which has been suggested to be a predictor of inflammation, has never been studied for AMI.

METHODS

The data of 70 patients who underwent laparotomy (n = 8) and/or bowel resection (n = 62) for AMI (n = 70) between January 2009 and March 2014 were retrospectively analyzed. To investigate the studied parameters' role in the differential diagnosis of AMI, control groups were selected from most common reasons of inflammation-related emergent surgery, acute appendicitis (AA, n = 62) and normal appendix (NA, n = 61). White blood cell (WBC), red cell distribution width (RDW), NLR and mean platelet volume (MPV) values were recorded. Outcome variables of the study were defined as diagnostic and prognostic role of NLR in AMI.

RESULTS

RDW and NLR values were found to be higher in the AMI group than the AA group (p < 0.001 and p < 0.001). Also, WBC and MPV values were higher in the AMI group than the NA group (p = 0.001 and p < 0.001). Combined sensitivity, specificity, positive predictive value and negative predictive value of RDW and NLR for recommended cut-off values were 69.4, 71.2, 57.8 and 80.4 %, respectively.

CONCLUSION

High NLR value (>9.9) seems to be a valuable diagnostic marker of acute mesenteric ischemia. Combined use of NLR, RDW and other clinical assessment, could help the diagnosis of AMI, especially in the absence of advanced imaging modalities and expert radiologic interpretation.

Membrane lipid interactions in intestinal ischemia/reperfusion-induced Injury

Ischemia, lack of blood flow, and reperfusion, return of blood flow, are a common phenomenon affecting millions of Americans each year. Roughly 30,000 Americans per year experience intestinal ischemia-reperfusion (IR), which is associated with a high mortality rate. Previous studies of the intestine established a role for neutrophils, eicosanoids, the complement system and naturally occurring antibodies in IR-induced pathology. Furthermore, data indicate involvement of a lipid or lipid-like moiety in mediating IR-induced damage. It has been proposed that antibodies recognize exposure of neo-antigens, triggering action of the complement cascade. While it is evident that the pathophysiology of IR-induced injury is complex and multi-factorial, we focus this review on the involvement of eicosanoids, phospholipids and neo-antigens in the early pathogenesis. Lipid changes occurring in response to IR, neo-antigens exposed and the role of a phospholipid transporter, phospholipid scramblase 1 will be discussed.

The diagnosis of acute mesenteric ischemia: A systematic review and meta-analysis

OBJECTIVES

Acute mesenteric ischemia is an infrequent cause of abdominal pain in emergency department (ED) patients; however, mortality for this condition is high. Rapid diagnosis and surgery are key to survival, but presenting signs are often vague or variable, and there is no pathognomonic laboratory screening test. A systematic review and meta-analysis of the available literature was performed to determine diagnostic test characteristics of patient symptoms, objective signs, laboratory studies, and diagnostic modalities to help rule in or out the diagnosis of acute mesenteric ischemia in the ED.

METHODS

In concordance with published guidelines for systematic reviews, the medical literature was searched for relevant articles. The Quality Assessment Tool for Diagnostic Accuracy Studies-2 (QUADAS-2) for systematic reviews was used to evaluate the overall quality of the trials included. Summary estimates of diagnostic accuracy were computed by using a random-effects model to combine studies. Those studies without data to fully complete a two-by-two table were not included in the meta-analysis portion of the project.

RESULTS

The literature search identified 1,149 potentially relevant studies, of which 23 were included in the final analysis. The quality of the diagnostic studies was highly variable. A total of 1,970 patients were included in the combined population of all included studies. The prevalence of acute mesenteric ischemia ranged from 8% to 60%. There was a pooled sensitivity for l-lactate of 86% (95% confidence interval [CI] = 73% to 94%) and a pooled specificity of 44% (95% CI = 32% to 55%). There was a pooled sensitivity for D-dimer of 96% (95% CI = 89% to 99%) and a pooled specificity of 40% (95% CI = 33% to 47%). For computed tomography (CT), we found a pooled sensitivity of 94% (95% CI = 90% to 97%) and specificity of 95% (95% CI = 93% to 97%). The positive likelihood ratio (+LR) for a positive CT was 17.5 (95% CI = 5.99 to 51.29), and the negative likelihood ratio (-LR) was 0.09 (95% CI = 0.05 to 0.17). The pooled operative mortality rate for mesenteric ischemia was 47% (95% CI = 40% to 54%). Given these findings, the test threshold of 2.1% (below this pretest probability, do not test further) and a treatment threshold of 74% (above this pretest probability, proceed to surgical management) were calculated.

CONCLUSIONS

The quality of the overall literature base for mesenteric ischemia is varied. Signs, symptoms, and laboratory testing are insufficiently diagnostic for the condition. Only CT angiography had adequate accuracy to establish the diagnosis of acute mesenteric ischemia in lieu of laparotomy.

Septic embolism in the intensive care unit

Septic embolism encompasses a wide range of presentations and clinical considerations. From asymptomatic, incidental finding on advanced imaging to devastating cardiovascular or cerebral events, this important clinico-pathologic entity continues to affect critically ill patients. Septic emboli are challenging because they represent two insults—the early embolic/ischemic insult due to vascular occlusion and the infectious insult from a deep-seated nidus of infection frequently not amenable to adequate source control. Mycotic aneurysms and intravascular or end-organ abscesses can occur. The diagnosis of septic embolism should be considered in any patient with certain risk factors including bacterial endocarditis or infected intravascular devices. Treatment consists of long-term antibiotics and source control when possible. This manuscript provides a much-needed synopsis of the different forms and clinical presentations of septic embolism, basic diagnostic considerations, general clinical approaches, and an overview of potential complications.

Localized leptin release may be an important mechanism of curcumin action after acute ischemic injuries

BACKGROUND

Previous studies have demonstrated that both curcumin and leptin are protective factors against acute injuries. Here, we investigated whether leptin and its signaling pathway mediate the protective effects of curcumin.

METHODS

A solid dispersion of curcumin-polyvinylpyrrolidone K30 was prepared and administered intraperitoneally. In vivo intestinal ischemia/reperfusion (I/R) injury in mice determined the effects of curcumin administration on inflammation, oxygen radical production, and leptin expression. In vitro studies using the venous epithelial cell line ECV-304 examined hypoxia/reoxygenation-induced leptin expression and release after curcumin administration. Furthermore, the effects on the leptin-regulated ERK1/2 and p38 MAPK signaling pathways were also explored.

RESULTS

Intestinal I/R induced marked bowel injuries. Curcumin treatment significantly improved animal survival and reduced the pathologic injuries in the intestines. Furthermore, the elevated intestinal water content and levels of malondialdehyde, interleukin 1β (IL-1β) and IL-6 were significantly decreased, but levels of superoxide dismutase increased. Interestingly, we found that the decreased leptin and its receptor Ob-Rb were restored by curcumin administration. In addition, in vitro studies showed that curcumin increased leptin expression and release after hypoxia/reoxygenation-induced cell injuries. Moreover, curcumin treatment restored decreased ERK1/2 phosphorylation (p-ERK1/2) and inhibited overactive p38 (p-p38) after injuries, and the effect was reversed by a leptin-specific antibody or Ob-R blocker.

CONCLUSION

These data suggest that leptin and Ob-Rb-dependent ERK and p38 MAPK signaling pathways may be involved in curcumin protection against intestinal I/R injury, and leptin may be a potential target of curcumin in intestinal I/R injury and other related acute diseases.

Risk factors effecting mortality in acute mesenteric ischemia and mortality rates: a single center experience

The objective of this study is to discuss the effective factors on morbidity and mortality in patients who were operated on for acute mesenteric ischemia. Between 2006 and 2011, 95 patients, who underwent emergent surgery for acute mesenteric ischemia, were analyzed retrospectively. The study group consisted of 56 men (58.9%) and 39 women (41.1%), with an average age of 68.4 ± 14.4 years. Elapsed time between the onset of the symptoms and the surgical operation was less than 24 hours in 47 (49.5%) cases, and more than 24 hours in 48 cases (50.5%) (P < 0.001). Although all of the patients had intestinal necroses, colon involvement was seen in 38 patients, and mortality was higher in this group of patients (P < 0.001). Mortality rate was 42.1%. This was higher in older patients, those with increased leukocyte levels, increased elapsed time to laparotomy, and when the colon was involved.

The effects of dexmedetomidine on mesenteric arterial occlusion-associated gut ischemia and reperfusion-induced gut and kidney injury in rabbits

OBJECTIVE

We assessed the antioxidant activity of dexmedetomidine (Dex) administered during the ischemic period in a rabbit model of mesenteric ischemia/reperfusion (I/R) injury using biochemical and histopathological methods.

METHODS

A total of 24 male New Zealand white rabbits weighing between 2.5 and 3.0 kg were randomly divided into three groups: the sham group (Group S, n = 8), the I/R group (Group I/R, n = 8), and the I/R plus Dex treatment group (Group Dex, n = 8). In the I/R group, ischemia was achieved with 60 min of mesenteric occlusion. The sham group provided normal basal values. The rabbits in Group I/R were operated to achieve I/R. Group Dex received intravenous Dex 30 min after the commencement of reperfusion (10 μg/kg Dex was infused within 10 min, and then a maintenance dose of 10 μg/kg/h Dex was infused intravenously). For the measurement of tissue malondialdehyde, total antioxidant status, total oxidant status, lipid hydroperoxide levels, superoxide dismutase, catalase, and myeloperoxidase activity levels in the renal tissue samples of animals, the rabbits in each group were sacrificed 3 h after reperfusion. The histopathological examination scores were determined using the intestinal and renal tissues.

RESULTS

The mean malondialdehyde, total oxidant status, myeloperoxidase, and lipid hydroperoxide levels were significantly higher in Group I/R than in Groups S and Dex (P < 0.05). There also were significant decreases in the mean total antioxidant status, catalase, and superoxide dismutase activities in Group I/R compared with Groups S and Dex (P < 0.05). The histopathological examination scores of the intestinal and renal tissues were significantly higher in Group I/R compared with Groups S and Dex (P < 0.05).

CONCLUSION

Dex treatment may have biochemical and histopathological benefits by preventing I/R-related cellular damage of intestinal and renal tissues as shown in an experimental mesenteric ischemia model. The preference to use Dex for anesthesia during the mesenteric ischemia procedure may attenuate I/R injury in intestinal and renal tissues.

Serum ischemia-modified albumin levels in an experimental acute mesenteric ischemia model

OBJECTIVES

This experimental study aimed to assess the changes in the levels of serum ischemia-modified albumin (IMA) and interleukin-6 (IL-6) by time in cases of acute mesenteric ischemia due to superior mesenteric artery occlusion.

METHODS

Twenty-one New Zealand rabbits were randomly divided into three groups. Blood samples were collected at hours 0, 1, 3, and 6 from animals in a control group; a sham group following a simple laparotomy; and in an ischemia group following superior mesenteric artery ligation. All blood samples were analyzed for serum IMA and IL-6 levels, and then the time-dependent changes of biomarkers were investigated.

RESULTS

The serum IMA levels of the ischemia group at hours 3 and 6 were significantly higher than those of the control and sham groups (hour 3, p = 0.017; hour 6, p = 0.001). The increase in serum IL-6 levels in the ischemia group at hours 1, 3, and 6 compared to the control and sham groups was also significant (hour 1, p = 0.002; hour 3, p = 0.003; hour 6, p = 0.003).

CONCLUSIONS

IMA may be helpful as a marker in the diagnosis of acute mesenteric ischemia; however, its diagnostic value and use as a routine biochemical test should be assessed in further studies.

Diagnosis and treatment of acute mesenteric artery ischemia: an analysis of 26 cases

AIM: To evaluate the diagnosis and treatment of acute mesenteric artery ischemia.

METHODS: A total of 26 patients with acute mesenteric artery ischemia were included in the study. The clinical features, diagnosis, treatment and prognosis of these patients were retrospectively analyzed.

RESULTS: Definite diagnosis was preoperatively established in 11 patients, of which 6 were diagnosed by color Doppler ultrasonography, 9 by spiral CT, and 6 by digital subtraction angiography (DSA). The remaining 15 patients with bloody ascites were diagnosed by exploratory laparotomy. Of all patients, 4 received systemic anticoagulation, 5 were subjected to Fogarty balloon catheterization for thrombus removal and completely recovered, 8 underwent partial small bowel resection, 7 underwent subtotal small bowel and right-sided colon resection, and 2 underwent second-look operation. Six patients died in six months after operation.

CONCLUSION: Ultrasound is considered as a first-line diagnostic technique for acute mesenteric artery ischemia. Exploratory laparotomy should be performed in patients with bloody ascites. Early diagnosis and treatment are key to decreasing the mortality and morbidity of acute mesenteric artery ischemia.

Ischemic colitis: surging waves of update

Ischemic colitis is the most common type of intestinal ischemia, and it represents the consequences of acute or, more commonly, chronic blockage of blood flow through arteries that supply the large intestine. Ischemic colitis is manifested through a continuum of injury and considered as an illness of the elderly. The incidence of ischemic colitis has been underestimated, because many mild cases may go unreported. Patients experience abdominal pain, usually, localized to the left side of the abdomen, along with tenderness and bloody diarrhea. Severe ischemia may lead to bowel necrosis and perforation, which results in an acute abdomen and shock, frequently, being accompanied by lactic acidosis. Although computed tomography may have indicative findings, colonoscopy is the golden standard of diagnosis. Supportive care with intravenous fluids, optimization of hemodynamic status, avoidance of vasoconstrictive drugs, bowel rest, and empiric antibiotics will produce clinical improvement within 1 to 2 days in most patients. The condition resolves completely with conservative treatment, in most cases, but late diagnosis or severe ischemia can be associated with high rates of complications and death. However, when the interruption to the blood supply is more severe or more prolonged, the affected portion of the large intestine may have to be surgically removed. The present paper aims at bringing ischemic colitis up to date, by reviewing the current medical literature and extracting the contemporary data, about its presentation, diagnosis and treatment, which is of benefit to the readership, who may encounter this potentially fatal entity.