Decreased lung ischemia-reperfusion injury in rats after preoperative administration of cyclosporine and tacrolimus

AbstractObjectives: Calcineurin inhibitors reduce experimental reperfusion injury in the liver, brain, heart, kidney, and small bowel. These studies were undertaken to determine whether these agents are similarly protective against lung ischemia-reperfusion injury. Methods: Left lungs of male rats were rendered ischemic for 90 minutes and reperfused for as long as 4 hours. Treated animals received cyclosporine A (INN: ciclosporin; 1 or 5 mg/kg) or tacrolimus (0.2 mg/kg) 6 hours before ischemia, at reperfusion, or 2 hours after reperfusion. Injury was quantitated in terms of tissue polymorphonuclear leukocyte accumulation (myeloperoxidase content), vascular permeability (iodine 125-labeled bovine serum albumin extravasation), and bronchoalveolar lavage leukocyte content. Separate tissue samples were processed for nuclear protein and cytokine messenger RNA. Results: Treatment with cyclosporine (5 mg/kg) or tacrolimus (0.2 mg/kg) 6 hours before reperfusion reduced lung vascular permeability by 54% and 56% relative to control animals (P <.03). The protective effects of cyclosporine and tacrolimus treatment before reperfusion correlated with 42% and 43% reductions in tissue polymorphonuclear leukocyte (myeloperoxidase) content (P <.008) and marked reductions in bronchoalveolar lavage leukocyte accumulation (P <.01). Administration of cyclosporine or tacrolimus at the time of reperfusion or 2 hours into the reperfusion period offered little or no protection. Animals treated before reperfusion also demonstrated marked reductions in nuclear factor κB activation and expression of proinflammatory cytokine messenger RNA. Conclusion: Cyclosporine and tacrolimus treatment before reperfusion was protective against lung ischemia-reperfusion injury in rats. The mechanism of these protective effects may involve the inhibition of nuclear factor κB, a central transcription factor mediating inflammatory injury. The decreased expression of cytokine messenger RNA indicates that both cyclosporine and tacrolimus may exert their protective effects at the pretranscriptional level.J Thorac Cardiovasc Surg 2002;123:756-6

Facile and sustainable functionalization method for preparing graphene layers with different solubility parameters

Graphene has exceptional properties: high charge-carrier mobilities, in-plane thermal conductivity, very high elastic modulus. Such properties essentially arise from the six atoms aromatic ring repeating unit of graphene layers. Hence, objective of graphene synthesis and functionalization should be to obtain and preserve such structure. Graphene functionalization has indeed great importance: electronic and solubility properties, self-assembly and phaseforming behaviour are affected by functional groups. In this work, a functionalization method was developed (1,2), able to introduce functional groups in peripheral positions of graphene layers, without appreciably altering graphene structure. Functionalization was performed by using molecules whose basic structure is shown in Figure 1. A pyrrole ring with different substituents on the nitrogen atom was used. Synthesis of these molecules was performed with high atom economy (larger than 80%), high yield (up to 99%) and thus high atom efficiency, the only byproduct being water, in the absence of solvent and catalyst (3). Reaction between such molecules and nanosized high surface area graphites was performed by simply mixing them, donating either mechanical or thermal energy. Functionalization occurred with almost quantitative yield. This process has a low environmental impact. Thanks to such functionalization method, solubility parameter of graphene layer was changed in a broad range, obtaining stable layers’ suspension in water, hexane, toluene. Form such suspensions, few layers graphenes were isolated. Moreover, even dispersions of graphene layers were prepared in polymer matrices such as poly(1,4-cis-isoprene), poly(styrene-cobutadiene), poly(urethane). This work presents a facile, sustainable, economically viable functionalization method of graphene layers, suitable for preparing few layers graphene from nanosized graphite and for matching the solubility parameters of polymer matrices, achieving even dispersions and intimate interactions

Determining a Core Curriculum in Surgical Infections for Fellowship Training in Acute Care Surgery Using the Delphi Technique

Background: Recent data highlight the educational, financial, and healthcare benefits of acute care surgery (ACS). These data serve as the impetus to create ACS fellowships, which now are accredited by the American Association for the Surgery of Trauma. However, the core components of a curriculum fundamental for ACS training and that yield competence and proficiency have yet to be determined. Methods: Experts in ACS from the United States (n=86) were asked to propose topics in surgical infectious diseases of potential importance in developing a core curriculum for ACS fellowship training. They were then required to rank these topics in order of importance to identify those considered most fundamental. Results: Thirty-one filters ranking in the highest tertile are proposed as topics of surgical infectious diseases that are fundamental to any curriculum of ACS fellowship training. The majority pertains to aspects of thoracic infections (n=8), although topics of soft tissue infections (n=5) comprised four of the top 10 (40%) filters. Abdominal infections (n=6), the biology of sepsis (n=6), and risk, prevention, and prophylaxis (n=6) completed the list. Conclusion: This study identifies the most important topics of surgical infectious disease that merit consideration for incorporation into a core curriculum of ACS training. Hopefully, this information will assist in the development of ACS fellowships that optimize the training of future ACS surgeons.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140213/1/sur.2012.202.pd

No hypoperfusion is produced in the epicardium during application of myocardial topical negative pressure in a porcine model

ABSTRACT: BACKGROUND: Topical negative pressure (TNP), commonly used in wound therapy, has been shown to increase blood flow and stimulate angiogenesis in skeletal muscle. We have previously shown that a myocardial TNP of -50 mmHg significantly increases microvascular blood flow in the myocardium. When TPN is used in wound therapy (on skeletal and subcutaneous tissue) a zone of relative hypoperfusion is seen close to the wound edge. Hypoperfusion induced by TNP is thought to depend on tissue density, distance from the negative pressure source, and the amount negative pressure applied. When applying TNP to the myocardium, a significant, long-standing zone of hypoperfusion could theoretically cause ischemia, and negative effects on the myocardium. The current study was designed to elucidate whether hypoperfusion was produced during myocardial TNP. METHODS: Six pigs underwent median sternotomy. Laser Doppler probes were inserted horizontally into the heart muscle in the LAD area, at depths of approximately, 1-2 mm. The microvascular blood flow was measured before and after the application of a TNP. Analyses were performed before left anterior descending artery (LAD) occlusion (normal myocardium) and after 20 minutes of LAD occlusion (ischemic myocardium). RESULTS: A TNP of -50 mmHg induced a significant increase in microvascular blood flow in normal myocardium (**p = 0.01), while -125 mmHg did not significantly alter the microvascular blood flow. In ischemic myocardium a TNP of -50 mmHg induced a significant increase in microvascular blood flow (*p = 0.04), while -125 mmHg did not significantly alter the microvascular blood flow. CONCLUSION: No hypoperfusion could be observed in the epicardium in neither normal nor ischemic myocardium during myocardial TNP

Prediction of 60 day case-fatality after aneurysmal subarachnoid haemorrhage: results from the International Subarachnoid Aneurysm Trial (ISAT)

Aneurysmal subarachnoid haemorrhage (aSAH) is a devastating event with substantial case-fatality. Our purpose was to examine which clinical and neuro-imaging characteristics, available on admission, predict 60 day case-fatality in aSAH and to evaluate performance of our prediction model. We performed a secondary analysis of patients enrolled in the International Subarachnoid Aneurysm Trial (ISAT), a randomised multicentre trial to compare coiling with clipping in aSAH patients. Multivariable logistic regression analysis was used to develop a prognostic model to estimate the risk of dying within 60 days from aSAH based on clinical and neuro-imaging characteristics. The model was internally validated with bootstrapping techniques. The study population comprised of 2,128 patients who had been randomised to either endovascular coiling or neurosurgical clipping. In this population 153 patients (7.2%) died within 60 days. World Federation of Neurosurgical Societies (WFNS) grade was the most important predictor of case-fatality, followed by age, lumen size of the aneurysm and Fisher grade. The model discriminated reasonably between those who died within 60 days and those who survived (c statistic = 0.73), with minor optimism according to bootstrap re-sampling (optimism corrected c statistic = 0.70). Several strong predictors are available to predict 60 day case-fatality in aSAH patients who survived the early stage up till a treatment decision; after external validation these predictors could eventually be used in clinical decision making

The Surgical Infection Society revised guidelines on the management of intra-abdominal infection

Background: Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations. Methods: Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council. Results: This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included. Summary: The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline

An Adequately Robust Early TNF-α Response Is a Hallmark of Survival Following Trauma/Hemorrhage

Background: Trauma/hemorrhagic shock (T/HS) results in cytokine-mediated acute inflammation that is generally considered detrimental. Methodology/Principal Findings: Paradoxically, plasma levels of the early inflammatory cytokine TNF-α (but not IL-6, IL-10, or NO2-/NO3-) were significantly elevated within 6 h post-admission in 19 human trauma survivors vs. 4 non-survivors. Moreover, plasma TNF-α was inversely correlated with Marshall Score, an index of organ dysfunction, both in the 23 patients taken together and in the survivor cohort. Accordingly, we hypothesized that if an early, robust pro-inflammatory response were to be a marker of an appropriate response to injury, then individuals exhibiting such a response would be predisposed to survive. We tested this hypothesis in swine subjected to various experimental paradigms of T/HS. Twenty-three anesthetized pigs were subjected to T/HS (12 HS-only and 11 HS + Thoracotomy; mean arterial pressure of 30 mmHg for 45-90 min) along with surgery-only controls. Plasma obtained at pre-surgery, baseline post-surgery, beginning of HS, and every 15 min thereafter until 75 min (in the HS only group) or 90 min (in the HS + Thoracotomy group) was assayed for TNF-α, IL-6, IL-10, and NO2-/NO3-. Mean post-surgery±HS TNF-α levels were significantly higher in the survivors vs. non-survivors, while non-survivors exhibited no measurable change in TNF-α levels over the same interval. Conclusions/Significance: Contrary to the current dogma, survival in the setting of severe, acute T/HS appears to be associated with an immediate increase in serum TNF-α. It is currently unclear if this response was the cause of this protection, a marker of survival, or both. This abstract won a Young Investigator Travel Award at the SHOCK 2008 meeting in Cologne, Germany. © 2009 Namas et al

Inhaled carbon monoxide protects against the development of shock and mitochondrial injury following hemorrhage and resuscitation

Aims: Currently, there is no effective resuscitative adjunct to fluid and blood products to limit tissue injury for traumatic hemorrhagic shock. The objective of this study was to investigate the role of inhaled carbon monoxide (CO) to limit inflammation and tissue injury, and specifically mitochondrial damage, in experimental models of hemorrhage and resuscitation. Results: Inhaled CO (250 ppm for 30 minutes) protected against mortality in severe murine hemorrhagic shock and resuscitation (HS/R) (20% vs. 80%; P<0.01). Additionally, CO limited the development of shock as determined by arterial blood pH (7.25±0.06 vs. 7.05±0.05; P<0.05), lactate levels (7.2±5.1 vs 13.3±6.0; P<0.05), and base deficit (13±3.0 vs 24±3.1; P<0.05). A dose response of CO (25-500 ppm) demonstrated protection against HS/R lung and liver injury as determined by MPO activity and serum ALT, respectively. CO limited HS/R-induced increases in serum tumor necrosis factor-α and interleukin-6 levels as determined by ELISA (P<0.05 for doses of 100-500ppm). Furthermore, inhaled CO limited HS/R induced oxidative stress as determined by hepatic oxidized glutathione:reduced glutathione levels and lipid peroxidation. In porcine HS/R, CO did not influence hemodynamics. However, CO limited HS/R-induced skeletal muscle and platelet mitochondrial injury as determined by respiratory control ratio (muscle) and ATP-linked respiration and mitochondrial reserve capacity (platelets). Conclusion: These preclinical studies suggest that inhaled CO can be a protective therapy in HS/R; however, further clinical studies are warranted