Multiple Insults Research Articles

The multistep road to ventilator-associated lung abscess: A retrospective study of S.aureus ventilator-associated pneumonia.

ObjectWe observed some cases of lung abscess (LA) in ICU patients suffering S.aureus ventilator-associated pneumonia (S.aureus-VAP). We aimed to assess which of the host and/or bacteria-related features are associated with LA.MethodsWe conducted a retrospective study from January 2009 to July 2013 in a trauma surgical ICU within a teaching hospital. All adult patients presenting with S.aureus-VAP were included. We compared two groups of patients according to the formation or not of LA concomitantly to S.aureus-VAP.ResultsSeventy-nine S.aureus-VAP patients, predominantly males (85%) of rather young age (mean [SD]: 35yr [21–64]) with severe trauma (initial Simplified Acute Score II = 42 [32–52]) related-ICU admission, were included. Among them, 10 (14%) developed LA. Patient’s characteristics significantly associated with LA development were: a younger age (p = 0.003), road traffic accidents admission (p = 0.017), head injury (p = 0.002), lower Glasgow Coma Scale (p = 0.009), blunt chest trauma (p = 0.01) pneumothorax (p = 0.01) and lung contusions (p = 0.002). No microbiological factors were significantly associated with LA formation. Abscesses were mostly bilateral, ≥5 cm of diameter and with a posterior location.ConclusionsOur results do not favor a specific virulence of S.aureus, but rather highlight the role of multiple insults to the lung, promoting LA formation. Despite a similar severity score, patients with LA had more serious trauma, combining severe both chest and head insults.

WITHDRAWN: Majewski Osteodysplastic Primordial Dwarfism, Type II with marked loss of subcutaneous fat, severe anemia, clenched hands and skeletal anomalies in an Egyptian patient

Abstract We report a 4 month old male, 4th in order of birth of healthy consanguineous Egyptian parents with typical characteristics of Majewski Osteodysplastic Primordial Dwarfism, Type II (MOPD II). The patient had intrauterine growth retardation, sparse scalp hair, sparse eyebrows and eyelashes, high arched palate, micrognathia, low set ears, short neck, clenched fists, groove between thumb and palm of hand, arachnodactyly, flexion contractures of elbow and knee. He also had thin dry skin with marked decreased subcutaneous fat and prominent superficial veins over chest and abdomen and mild hypertrichosis over lower back and buttocks. MRI brain revealed global hypovolemic brain changes in the form of dilated ventricles and widened cortical sulci, multiple old vascular insults and fusiform dilatation of right internal carotid artery (ICA).

Abstract LB-315: Cyclin dependent kinase 7 represents a promising therapeutic target in glioma

Abstract Cyclin dependent kinase 7 (CDK7), the enzyme which facilitates cell cycle progression and stabilizes RNA polymerase II-based transcription, is central to two critical instigators of high grade glioma (HGG). Yet this target has not been identified or evaluated for HGG therapy. CDK7 can be inhibited using THZ1, a novel irreversible inhibitor of CDK7 whose mechanism(s) of action are largely unknown. We hypothesized that, due to its crucial role in activating the central drivers of HGG, CDK7 inhibition would offer a therapy which is broad in its efficacy across multiple HGG subtypes. In this study, we sought to prove this by determining the efficacy of THZ1 against HGG and to elucidate the biological processes disrupted by the drug. We used microarray and RT-qPCR to monitor transcript expression and splicing, multiplex immunofluorescence to monitor subnuclear compartment integrity, western blotting for protein expression, cell viability assays, flow cytometry to measure cell cycle, DNA damage and mitosis and high resolution respirometry to monitor mitochondrial health. We show that low nanomolar THZ1 has profound antitumor activity against 14 HGG patient-derived primary cell lines and ex vivo HGG patient tissue slices. CDK7 appears indispensable for gliomagenesis as THZ1 perturbed the transcriptome and disabled CDK activation, leading to cell cycle arrest, nuclear DNA damage and caspase-independent cell death. THZ1 also disabled mitochondrial function by halting transcription of the nuclear-encoded mitochondrial ribosomal genes, subsequently reducing mitochondrial translation of the electron transport chain which, in turn, hampered oxidative respiration. This also resulted in the release of the mitochondrial located nuclease, apoptosis inducing factor, to translocate to the nucleus to augment DNA damage. THZ1 also inhibited the expression of multiple RTKs such as EGFR, PDGFR-α and MET, reducing signaling flux through downstream pathways such as AKT, ERK1/2 and STAT3. Finally, THZ1 disrupted nucleolar, Cajal-body and nuclear speckle formation resulting in reduced cytosolic translation and aberrant mRNA splicing. Hence, THZ1 sets in motion a convergence of multiple cellular insults to potently kill cells in a caspase-independent manner, providing the first description of the biological processes affected by THZ1. We also generated a THZ1 resistant patient-derived HGG cell line following six months of selection which possessed an IC50 40-fold greater than parental cells. Further analysis demonstrated a 30,000-fold upregulation of the ABCB1 (P-glycoprotein) transporter but not the ABCC1 or ABCG2 transporters. Blocking ABCB1 activity using Tariquidar or Zoriquidar fully reversed resistance to THZ1, demonstrating that ABCB1 mediated efflux of THZ1 is the main resistance mechanism to the drug. These studies validate CDK7 as a therapeutic target in HGG and provide new insights into the anti-tumor activity of THZ1 and the resistance mechanisms employed by HGG to counteract THZ1 therapy. Citation Format: Sameer A. Greenall, Terrance G. Johns. Cyclin dependent kinase 7 represents a promising therapeutic target in glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-315. doi:10.1158/1538-7445.AM2017-LB-315

An Unbiased High-Throughput Screen to Identify Novel Effectors That Impact on Cardiomyocyte Aggregate Levels.

Postmitotic cells, such as cardiomyocytes, seem to be particularly susceptible to proteotoxic stimuli, and large, proteinaceous deposits are characteristic of the desmin-related cardiomyopathies and crystallin cardiomyopathic diseases. Increased activity of protein clearance pathways in the cardiomyocyte, such as proteasomal degradation and autophagy, has proven to be beneficial in maintaining cellular and cardiac function in the face of multiple proteotoxic insults, holding open the possibility of targeting these processes for the development of effective therapeutics. Here, we undertake an unbiased, total genome screen for RNA transcripts and their protein products that affect aggregate accumulations in the cardiomyocytes. Primary mouse cardiomyocytes that accumulate aggregates as a result of a mutant CryAB (αB-crystallin) causative for human desmin-related cardiomyopathy were used for a total genome-wide screen to identify gene products that affected aggregate formation. We infected cardiomyocytes using a short hairpin RNA lentivirus library in which the mouse genome was represented. The screen identified multiple candidates in many cell signaling pathways that were able to mediate significant decreases in aggregate levels. Subsequent validation of one of these candidates, Jak1 (Janus kinase 1), a tyrosine kinase of the nonreceptor type, confirmed the usefulness of this approach in identifying previously unsuspected players in proteotoxic processes.

Microcephalic osteodysplastic primordial dwarfism (MOPD) type I with severe anemia and MRI brain findings of MOPD type II

We report a 4month old male, 4th in order of birth of healthy consanguineous Egyptian parents with typical characteristics of microcephalic osteodysplastic primordial dwarfism most probably belongs to type I (MOPD I). The patient had intrauterine growth retardation, sparse scalp hair, sparse eyebrows and eyelashes, high arched palate, micrognathia, low set ears, short neck, clenched fists, groove between thumb and palm of hand, arachnodactyly, flexion contractures of elbow and knee. He also had thin dry skin with marked decreased subcutaneous fat and prominent superficial veins over chest and abdomen and mild hypertrichosis over lower back and buttocks. However, the patient had severe anemia and MRI brain findings revealed global hypovolemic brain changes in the form of dilated ventricles and widened cortical sulci, multiple old vascular insults and aneurismal dilatation of right internal carotid artery (ICA) which are consistent with MOPD II.

PDGF-BB Preserves Mitochondrial Morphology, Attenuates ROS Production, and Upregulates Neuroglobin in an Astrocytic Model Under Rotenone Insult.

Platelet-derived growth factor, subtype BB (PDGF-BB) is a mitogenic growth factor produced in different cell types such as platelets, fibroblasts, neurons, and astrocytes. Previous reports have shown that different PDGF isoforms exert a neuroprotective effect in neurons and astrocytes against multiple degenerative insults. Previously, we showed that pretreatment with PDGF-BB for 24h increased cell viability, preserved nuclear morphology and mitochondrial membrane potential following stimulation with rotenone, and reduced free radical production nearly to control conditions. In the present study, we explored the potential mechanisms associated with PDGF-BB protection against oxidative damage. Our results showed that PDGF-BB protected astrocytic cells through multiple responses, including decrease in the expression of cytoskeleton proteins, attenuated free radicals (reactive oxygen species (ROS)) production, preservation of mitochondrial ultrastructure, and improved expression of neuroglobin (Ngb1). In summary, these findings point out that PDGF-BB protects astrocytic cells by a reduction in ROS production and activation of antioxidant mechanisms.

Renal Function Outcomes of High-risk Neuroblastoma Patients Undergoing Radiation Therapy

To analyze the renal function outcomes in patients undergoing radiation therapy for neuroblastoma. The clinical metrics of renal function were analyzed in patients undergoing radiation therapy for high-risk neuroblastoma from 2000 to 2015. The blood urea nitrogen (BUN) and creatinine values before radiation therapy were compared with last available follow-up values and analyzed with the clinical circumstances, including follow-up length, age at primary irradiation, nephrectomy, and radiation technique. The creatinine clearance was estimated using the Shull method. With a median follow-up period of 3.5years, none of the 266 patients studied developed a chronic renal insufficiency. For all patients, the creatinine level increased from 0.44 to 0.51mg/dL and the BUN increased from 10.53 to 15.52mg/dL. Three patients required antihypertensive medication. The patients who underwent intensity modulated radiation therapy did not experience increased creatinine levels during the follow-up period; however, they had a reduced median follow-up length compared with patients treated with anteroposterior/posteroanterior beams (4.7 vs 3.3years). A longer follow-up length was associated with an increased creatinine level. The preradiation therapy creatinine level increased with patient age, similar to that of the last follow-up creatinine level, suggesting that the changes in creatinine could likely be explained by physiologic increases associated with aging rather than radiation-induced renal damage. The creatinine clearance did not decrease in any circumstance. The present cohort had excellent renal outcomes after radiation therapy for neuroblastoma. No patient developed chronic renal insufficiency, and the small increases in BUN and creatinine we observed correlated, as expected, with increases in patient age. The results of the present study revealed a possible advantage for intensity modulated radiation therapy in preserving renal function; however, the follow-up length is a recognized confounding variable. The kidneys are vital structures to consider when planning radiation therapy for neuroblastoma patients, and we have found encouraging evidence that modern techniques to spare them in the setting of multiple treatment-related insults have been successful.

Aflatoxin Exposure During Pregnancy, Maternal Anemia, and Adverse Birth Outcomes.

Pregnant women and their developing fetuses are vulnerable to multiple environmental insults, including exposure to aflatoxin, a mycotoxin that may contaminate as much as 25% of the world food supply. We reviewed and integrated findings from studies of aflatoxin exposure during pregnancy and evaluated potential links to adverse pregnancy outcomes. We identified 27 studies (10 human cross-sectional studies and 17 animal studies) assessing the relationship between aflatoxin exposure and adverse birth outcomes or anemia. Findings suggest that aflatoxin exposure during pregnancy may impair fetal growth. Only one human study investigated aflatoxin exposure and prematurity, and no studies investigated its relationship with pregnancy loss, but animal studies suggest aflatoxin exposure may increase risk for prematurity and pregnancy loss. The fetus could be affected by maternal aflatoxin exposure through direct toxicity as well as indirect toxicity, via maternal systemic inflammation, impaired placental growth, or elevation of placental cytokines. The cytotoxic and systemic effects of aflatoxin could plausibly mediate maternal anemia, intrauterine growth restriction, fetal loss, and preterm birth. Given the widespread exposure to this toxin in developing countries, longitudinal studies in pregnant women are needed to provide stronger evidence for the role of aflatoxin in adverse pregnancy outcomes, and to explore biological mechanisms. Potential pathways for intervention to reduce aflatoxin exposure are urgently needed, and this might reduce the global burden of stillbirth, preterm birth, and low birthweight.

Adult Lysophosphatidic Acid Receptor 1-Deficient Rats with Hyperoxia-Induced Neonatal Chronic Lung Disease Are Protected against Lipopolysaccharide-Induced Acute Lung Injury.

Aim: Survivors of neonatal chronic lung disease or bronchopulmonary dysplasia (BPD) suffer from compromised lung function and are at high risk for developing lung injury by multiple insults later in life. Because neonatal lysophosphatidic acid receptor-1 (LPAR1)-deficient rats are protected against hyperoxia-induced lung injury, we hypothesize that LPAR1-deficiency may protect adult survivors of BPD from a second hit response against lipopolysaccharides (LPS)-induced lung injury.Methods: Directly after birth, Wistar control and LPAR1-deficient rat pups were exposed to hyperoxia (90%) for 8 days followed by recovery in room air. After 7 weeks, male rats received either LPS (2 mg kg−1) or 0.9% NaCl by intraperitoneal injection. Alveolar development and lung inflammation were investigated by morphometric analysis, IL-6 production, and mRNA expression of cytokines, chemokines, coagulation factors, and an indicator of oxidative stress.Results: LPAR1-deficient and control rats developed hyperoxia-induced neonatal emphysema, which persisted into adulthood, as demonstrated by alveolar enlargement and decreased vessel density. LPAR1-deficiency protected against LPS-induced lung injury. Adult controls with BPD exhibited an exacerbated response toward LPS with an increased expression of pro-inflammatory mRNAs, whereas LPAR1-deficient rats with BPD were less sensitive to this “second hit” with a decreased pulmonary influx of macrophages and neutrophils, interleukin-6 (IL-6) production, and mRNA expression of IL-6, monocyte chemoattractant protein-1, cytokine-induced neutrophil chemoattractant 1, plasminogen activator inhibitor-1, and tissue factor.Conclusion: LPAR1-deficient rats have increased hyperoxia-induced BPD survival rates and, despite the presence of neonatal emphysema, are less sensitive to an aggravated “second hit” than Wistar controls with BPD. Intervening in LPA-LPAR1-dependent signaling may not only have therapeutic potential for neonatal chronic lung disease, but may also protect adult survivors of BPD from sequelae later in life.

Acute-on-chronic liver failure: adiagnostic and therapeutic challenge for intensive care

ZusammenfassungDas akut-auf-chronische Leberversagen („acute-on-chronic liver failure“, ACLF) ist ein emergentes Krankheitssyndrom, das durch einen oder mehrere akute Trigger bei vorgeschädigter Leber ausgelöst wird und vom progressiven hepatalen und nichthepatalen Organversagen, einem gravierenden Risiko infektiöser Komplikationen sowie hoher kurzfristiger Letalität gekennzeichnet ist. Wenngleich pathophysiologisch noch weitgehend unverstanden erfordert das ACLF frühzeitige diagnostische und therapeutische Maßnahmen, die sich auf zugrunde liegende Ursachen sowie das Verhindern von Komplikationen richten, um die Prognose betroffener Patienten zu verbessern.

The Hepatitis B Flare That Wasn't

Background: Acute exacerbation of chronic hepatitis B virus occurs as either a flare of HBV in immune clearance phase or as a reactivation of HBV in patients with inactive or resolved HBV infection. In rare situations, HBV causes systemic autoimmunity that improves with antiviral therapy. However, in certain patients, puritan forms of autoimmune hepatitis develop independent of HBV that requires immunosuppressive therapy. Report: We present the case of a religious nun, who presented with suspected reactivation of HBV leading to jaundice and grade 2 hepatic encephalopathy not responding to 3 weeks of antiviral therapy with fluctuating jaundice and elevated transaminases. A timely liver biopsy based on a strong clinical suspicion led to a final diagnosis. We also briefly discuss the importance of liver biopsy in this scenario. Conclusion: We present the case of a patient who was incidentally detected to have HBV infection during work up of a flare of AIH. Treating physicians must be astute in analysing blood tests in the light of clinical symptoms and signs for comprehensive diagnosis of multiple insults that could occur in the liver.

Hyperoxia-Induced Proliferative Retinopathy: Early Interruption of Retinal Vascular Development with Severe and Irreversible Neurovascular Disruption.

Bronchopulmonary dysplasia (BPD) is a major cause of neonatal morbidity in premature infants, occurring as a result of arrested lung development combined with multiple postnatal insults. Infants with BPD exposed to supplemental oxygen are at risk of retinopathy of prematurity as well. Thus, we studied the effects of hyperoxia on the retinal vasculature in a murine model of BPD. The retinal phenotype of this model, which we termed hyperoxia-induced proliferative retinopathy (HIPR), shows severe disruption of retinal vasculature and loss of vascular patterning, disorganized intra-retinal angiogenesis, inflammation and retinal detachment. Neonatal mice were subjected to 75% oxygen exposure from postnatal day (P)0 to P14 to model BPD, then allowed to recover in room air for 1 (P15), 7 (P21), or 14 days (P28). We quantified retinal thickness, protein levels of HIF-1α, NOX2, and VEGF, and examined the cellular locations of these proteins by immunohistochemistry. We examined the retinal blood vessel integrity and inflammatory markers, including macrophages (F4/80) and lymphocytes (CD45R). Compared to controls, normal retinal vascular development was severely disrupted and replaced by a disorganized sheet of intra-retinal angiogenesis in the HIPR mice. At all time-points, HIPR showed persistent hyaloidal vasculature and a significantly thinner central retina compared to controls. HIF-1α protein levels were increased at P15, while VEGF levels continued to increase until P21. Intra-retinal fibrinogen was observed at P21 followed by sub-retinal deposition in at P28. Inflammatory lymphocytes and macrophages were observed at P21 and P28, respectively. This model presents a severe phenotype of disrupted retinal vascular development, intra-retinal angiogenesis inflammation and retinal detachment.

Combined damage produced by multiple mild cerebral insults assessed using MRI in neonatal rats

PurposeTo determine whether damage to neonatal brain is exacerbated with multiple mild cerebral insults as detected with MRI and corroborated using histology. Materials and methodsThe combined brain injury produced by multiple procedures was compared in neonatal rats having: Sham surgery at P5, Sham surgery at P5 plus a diffuse mild transient unilateral cerebral hypoxia ischemia (HI) at P7, HI alone, and a minor photothrombotic (PT) stroke at P5 followed by HI. MRI after the ischemic insults was followed by final histology. ResultsPT produced lesions with increased T2 and decreased apparent diffusion coefficient for water (ADC) but no significant effects of a second HI. However, near the PT lesion/parietal cortex there were patchy areas of enhanced T2 and decreased ADC in 6/9, 3/8 and 0/8 animals in the PT+HI, Sham+HI and HI groups, respectively (P<0.05). Patches corresponded histologically to increased vacuolation and cell death and were more pronounced in the PT+HI and Sham+PT groups than the HI group. ConclusionThe extent of damage produced by a minor neonatal stroke followed by a diffuse HI two days later results in heterogeneous enhancement of T2, ADC and histological injury near the lesion. Surgical procedures including mechanical head manipulation followed by HI also produced some enhanced heterogeneity of hypoxic-ischemic injury affirming the need for sham controls.

Sexual Preferences in Nutrient Utilization Regulate Oxygen Consumption and Reactive Oxygen Species Generation in Schistosoma mansoni: Potential Implications for Parasite Redox Biology.

Schistosoma mansoni, one of the causative agents of human schistosomiasis, has a unique antioxidant network that is key to parasite survival and a valuable chemotherapeutic target. The ability to detoxify and tolerate reactive oxygen species increases along S. mansoni development in the vertebrate host, suggesting that adult parasites are more exposed to redox challenges than young stages. Indeed, adult parasites are exposed to multiple redox insults generated from blood digestion, activated immune cells, and, potentially, from their own parasitic aerobic metabolism. However, it remains unknown how reactive oxygen species are produced by S. mansoni metabolism, as well as their biological effects on adult worms. Here, we assessed the contribution of nutrients and parasite gender to oxygen utilization pathways, and reactive oxygen species generation in whole unpaired adult S. mansoni worms. We also determined the susceptibilities of both parasite sexes to a pro-oxidant challenge. We observed that glutamine and serum importantly contribute to both respiratory and non-respiratory oxygen utilization in adult worms, but with different proportions among parasite sexes. Analyses of oxygen utilization pathways revealed that respiratory rates were high in male worms, which contrast with high non-respiratory rates in females, regardless nutritional sources. Interestingly, mitochondrial complex I-III activity was higher than complex IV specifically in females. We also observed sexual preferences in substrate utilization to sustain hydrogen peroxide production towards glucose in females, and glutamine in male worms. Despite strikingly high oxidant levels and hydrogen peroxide production rates, female worms were more resistant to a pro-oxidant challenge than male parasites. The data presented here indicate that sexual preferences in nutrient metabolism in adult S. mansoni worms regulate oxygen utilization and reactive oxygen species production, which may differently contribute to redox biology among parasite sexes.

Predictors of Mortality at 3 Months and 6 Months Excluding 1 Month Mortality in Patients with Acute on Chronic Liver Failure (ACLF)—A Single Centre Experience

Background and Aim: Acute on Chronic Liver Failure (ACLF) is a newly described clinical entity. Most of the studies assess the 28 days mortality with SOFA, MELD and CTP scores correlating with outcome. We have taken only those patients who survived the first 1 month. Our aim was to analyse the different variables and assess the predictors of mortality. Methods: This is a retrospective single centre cohort study from the department of Medical Gastroenterology Medical College Thiruvananthapuram (January 2012–December 2014). All consecutive patients satisfying the APASL criteria and surviving for more than one month were taken for analysis. Results: Of the 101 patients, 83.2% were males with mean age 46.6 years. Ascites present in all with 35.6% having Spontaneous bacterial peritonitis. The major chronic aetiologies were alcohol (60.4%) and hepatitis B (19.8%). The acute insults were single in 73.3% and multiple in others. The major acute insults were alcoholic hepatitis (52.5%) and chronic hepatitis B flare (14.9%). The observed mortality at 3 months and 6 months were 21.4% and 32.1% respectively. Neither the acute insult nor the chronic aetiology had significant association with outcome. But the presence of multiple acute insults correlated with outcome at 3 months (P = 0.032). By ROC analysis, predictor of mortality at 3 months was age (P = 0.025) with cut off 45.8 years. The predictors of mortality at 6 months were age (P = 0.002) with cut off 47.5 years. Serum sodium level associated with mortality at 6 months only (P = 0.009) with cut off 132.5. Conclusion: In this single centre study, the mortality was 21.4% at 3 months and 32.1% at 6 months excluding the first month mortality. At 3 months, age >45.8 years correlated with worst outcome. At 6 months age >47.5 years and serum sodium level <132.5 correlated with mortality. The authors have none to declare.

Development of an Ethanol-induced Fibrotic Liver Model in Zebrafish to Study Progenitor Cell-mediated Hepatocyte Regeneration.

Sustained liver fibrosis with continuation of extracellular matrix (ECM) protein build-up results in the loss of cellular competency of the liver, leading to cirrhosis with hepatocellular dysfunction. Among multiple hepatic insults, alcohol abuse can lead to significant health problems including liver failure and hepatocellular carcinoma. Nonetheless, the identity of endogenous cellular sources that regenerate hepatocytes in response to alcohol has not been properly investigated. Moreover, few studies have effectively modeled hepatocyte regeneration upon alcohol-induced injury. We recently reported on establishing an ethanol (EtOH)-induced fibrotic liver model in zebrafish in which hepatic progenitor cells (HPCs) gave rise to hepatocytes upon near-complete hepatocyte loss in the presence of fibrogenic stimulus. Furthermore, through chemical screens using this model, we identified multiple small molecules that enhance hepatocyte regeneration. Here we describe in detail the procedures to develop an EtOH-induced fibrotic liver model and to perform chemical screens using this model in zebrafish. This protocol will be a critical tool to delineate the molecular and cellular mechanisms of how hepatocyte regenerates in the fibrotic liver. Furthermore, these methods will facilitate potential discovery of novel therapeutic strategies for chronic liver disease in vivo.

Immune triage: prioritization of host immune responses.

Abstract The immune response is important in many functions, including host defense against pathogens, wound healing, development, response to cancer, and maintenance of homeostatic physiological responses. We are interested in the concept of immune triage, in that a given host must be able to deal effectively with multiple insults, and at times prioritize immune responses. It is important for the overall health status of the host that the immune system responds effectively to protect essential organs. We have developed several mouse models, focusing on the lung immune response, that allow us to examine different aspects of immune triage. The lung is an essential and delicate organ and thus pulmonary immune responses must be tightly regulated. We have determined that lung infection with influenza A virus (IAV) alters the response to bacterial lung infections. Depending on the bacterial infection, previous infection with IAV can suppress or augment the immune response to bacteria. We have also determined that pulmonary infection with IAV alters many aspects of the systemic immune response. There is a global suppression to systemic bacterial infection, and a decrease in the wound healing response. Our data indicate that the immune system prioritizes lung infections over many other responses. This is most likely due to the importance of the lung in host survival. We have established several regulatory mechanisms by which this immune triage occurs. By understanding how the immune system responds to multiple insults we can improve our understanding of the immune network on a global level.

Targeting the Cholinergic System for Neuroprotection and/or Enhancement of Functional Recovery Following Neurotrauma.

Development of novel pharmacotherapies for the treatment of traumatic injury to the nervous system has been ongoing for over 40 years. Despite many promising compounds discovered using animal models, no treatments have successfully translated into the clinic. The central dogma in this field is that brain trauma initiates a complex chain of biochemical events leading to secondary brain damage and sustained neurological deficits. The delayed secondary brain injury is likely to result from multiple insults including oxidative stress, mitochondrial dysfunction, breakdown of the blood brain barrier, dysregulated release of glutamate, pro-inflammatory cytokines, and other mediators. However, therapies targeting these systems have generally met with failure in clinical trials. The purpose of this review is to summarize the models used for preclinical neurotrauma research, provide a brief overview of previous failed clinical trials in head and spinal cord injury, and finally, to review involvement of the cholinergic system and discuss implications for future research. Possibilities and pitfalls of targeting the cholinergic system for neuroprotection and/or enhancement of functional recovery are also discussed.

The multiple-hit pathogenesis of non-alcoholic fatty liver disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent and represents a growing challenge in terms of prevention and treatment. Despite its high prevalence, only a small minority of affected patients develops inflammation and subsequently fibrosis and chronic liver disease, while most of them only exhibit simple steatosis. In this context, the full understanding of the mechanisms underlying the development of NAFLD and non-alcoholic steatohepatitis (NASH) is of extreme importance; despite advances in this field, knowledge on the pathogenesis of NAFLD is still incomplete. The ‘two-hit’ hypothesis is now obsolete, as it is inadequate to explain the several molecular and metabolic changes that take place in NAFLD. The “multiple hit” hypothesis considers multiple insults acting together on genetically predisposed subjects to induce NAFLD and provides a more accurate explanation of NAFLD pathogenesis. Such hits include insulin resistance, hormones secreted from the adipose tissue, nutritional factors, gut microbiota and genetic and epigenetic factors. In this article, we review the factors that form this hypothesis.

Surgical Unroofing for Anomalous Aortic Origin of Coronary Arteries

Anomalous aortic origin of a coronary artery (AAOCA) from an opposite sinus of Valsalva is an uncommon congenital defect that is typically only discovered on cardiac catheterization or on autopsy following sudden cardiac death. Conjectured mechanisms for the ischemia are generally believed to relate to the unique and easily obstructed geometry of the coronary ostium and the stenotic intramural coronary segment. Given the potentially devastating consequences of not repairing an AAOCA—that is, sudden cardiac death—these patients should undergo repair of the anomaly when it is discovered. Multiple options for surgically correcting the AAOCA have been developed, and the most used approaches include coronary artery bypass grafting, coronary reimplantation, and unroofing of the intramural segment. Here we present the technique for surgical unroofing of the intramural segment of an anomalous coronary artery of aortic origin.