Circulating microRNA profiles in human patients with acetaminophen hepatotoxicity or ischemic hepatitis.

We have identified, by quantitative real-time PCR, hundreds of miRNAs that are dramatically elevated in the plasma or serum of acetaminophen (APAP) overdose patients. Most of these circulating microRNAs decrease toward normal levels during treatment with N-acetyl cysteine (NAC). We identified a set of 11 miRNAs whose profiles and dynamics in the circulation during NAC treatment can discriminate APAP hepatotoxicity from ischemic hepatitis. The elevation of certain miRNAs can precede the dramatic rise in the standard biomarker, alanine aminotransferase (ALT), and these miRNAs also respond more rapidly than ALT to successful treatment. Our results suggest that miRNAs can serve as sensitive diagnostic and prognostic clinical tools for severe liver injury and could be useful for monitoring drug-induced liver injury during drug discovery.

Use of OpdA, an organophosphorus (OP) hydrolase, prevents lethality in an African green monkey model of acute OP poisoning.

Organophosphorus (OP) pesticides are a diverse class of acetylcholinesterase (AChE) inhibitors that are responsible for tremendous morbidity and mortality worldwide, killing approximately 300,000 people annually. Enzymatic hydrolysis of OPs is a potential therapy for acute poisoning. OpdA, an OP hydrolase isolated from Agrobacterium radiobacter, has been shown to decrease lethality in rodent models of OP poisoning. This study investigated the effects of OpdA on AChE activity, plasma concentrations of OP, and signs of toxicity after administration of dichlorvos to nonhuman primates. A dose of 75 mg/kg dichlorvos given orally caused apnea within 10 min with a progressive decrease in heart rate. Blood AChE activity decreased to zero within 10 min. Respirations and AChE activity did not recover. The mean dichlorvos concentration rose to a peak of 0.66 µg/ml. Treated monkeys received 1.2mg/kg OpdA iv immediately after poisoning with dichlorvos. In Opda-treated animals, heart and respiratory rates were unchanged from baseline over a 240-minute observation period. AChE activity slowly declined, but remained above 25% of baseline for the entire duration. Dichlorvos concentrations reached a mean peak of 0.19 µg/ml at 40 min after poisoning and decreased to a mean of 0.05 µg/ml at 240 min. These results show that OpdA hydrolyzes dichlorvos in an African green monkey model of lethal poisoning, delays AChE inhibition, and prevents lethality.

Amatoxin poisoning: case reports and review of current therapies.

BACKGROUND: Diagnosis and management of Amanita mushroom poisoning is a challenging problem for physicians across the United States. With 5902 mushroom exposures and two resultant deaths directly linked to Amanita ingestion in 2009, it is difficult for physicians to determine which patients are at risk for lethal toxicity. Identification of amatoxin poisoning can prove to be difficult due to delay in onset of symptoms and difficulty with identification of mushrooms. Consequently, it is difficult for the Emergency Physician to determine proper disposition. Further, treatment options are controversial. OBJECTIVES: To review current data to help health care providers effectively identify and treat potentially deadly Amanita mushroom ingestions. CASE REPORTS: We present two cases of Amanita mushroom ingestion in the northeastern United States treated with N-acetylcysteine, high-dose penicillin, cimetidine, and silibinin, a semi-purified fraction of milk thistle-derived silymarin, as part of their treatment regimen. The mushroom species was identified by a consultant as Amanita Ocreata. CONCLUSIONS: We present the successful treatment of 2 patients who ingested what we believe to be an Amanita species never before identified in the northeastern United States.

Circulating Cell and Plasma microRNA Profiles Differ between Non-ST-Segment and ST-Segment-Elevation Myocardial Infarction.

BACKGROUND: Differences in plasma and whole blood expression microRNAs (miRNAs) in patients with an acute coronary syndrome (ACS) have been determined in both in vitro and in vivo studies. Although most circulating miRNAs are located in the cellular components of whole blood, little is known about the miRNA profiles of whole blood subcomponents, including plasma, platelets and leukocytes in patients with myocardial ischemia. METHODS: Thirteen patients with a ST-segment-elevation (STEMI) or non-ST-segment elevation (NSTEMI) myocardial infarction were identified in the University of Massachusetts Medical Center Emergency Department (ED) or cardiac catheterization laboratory between February and June of 2012. Whole blood was obtained from arterial blood samples at the time of cardiac catheterization and cell-specific miRNA profiling was performed. Expression of 343 miRNAs was quantified from whole blood, plasma, platelets, and peripheral blood mononuclear cells using a high-throughput, quantitative Real-Time polymerase-chain reaction system (qRT-PCR). RESULTS: MiRNAs associated with STEMI as compared to NSTEMI patients included miR-25-3p, miR-221-3p, and miR-374b-5p. MiRNA 30d-5p was associated with plasma, platelets, and leukocytes in both STEMI and NSTEMI patients; miRNAs 221-3p and 483-5p were correlated with plasma and platelets only in NSTEMI patients. CONCLUSIONS: Cell-specific miRNA profiles differed between patients with STEMI and NSTEMI. The miRNA distribution is also unique amongst plasma, platelets, and leukocytes in patients with ischemic heart disease or ACS. Our findings suggest unique miRNA profiles among the circulating subcomponents in patients presenting with myocardial ischemia.

Trends in atrial fibrillation in patients hospitalized with an acute coronary syndrome.

BACKGROUND: Atrial fibrillation is common among patients with cardiovascular disease and is a frequent complication of the acute coronary syndrome. Data are needed on recent trends in the magnitude, clinical features, treatment, and prognostic impact of preexisting and new-onset atrial fibrillation in patients hospitalized with an acute coronary syndrome. METHODS: The study population consisted of 59,032 patients hospitalized with an acute coronary syndrome at 113 sites in the Global Registry of Acute Coronary Events Study between 2000 and 2007. RESULTS: A total of 4494 participants (7.6%) with acute coronary syndrome reported a history of atrial fibrillation and 3112 participants (5.3%) developed new-onset atrial fibrillation during their hospitalization. Rates of new-onset atrial fibrillation (5.5%-4.5%) and preexisting atrial fibrillation (7.4%-6.7%) declined during the study. Preexisting atrial fibrillation was associated with older age and greater cardiovascular disease burden, whereas new-onset atrial fibrillation was closely related to the severity of the index acute coronary syndrome. Patients with atrial fibrillation were less likely than patients without atrial fibrillation to receive evidence-based therapies and more likely to develop in-hospital complications, including heart failure. Overall hospital death rates in patients with new-onset and preexisting atrial fibrillation were 14.5% and 8.9%, respectively, compared with 1.2% in those without atrial fibrillation. Short-term death rates in patients with atrial fibrillation declined over the study period. CONCLUSIONS: Despite a reduction in the rates of, and mortality from, atrial fibrillation, this arrhythmia exerts a significant adverse effect on survival among patients hospitalized with an acute coronary syndrome. Opportunities exist to improve the identification and treatment of patients with acute coronary syndrome with, or at risk for, atrial fibrillation to reduce the incidence and resultant complications of this dysrhythmia.

Circulating microRNAs in exosomes indicate hepatocyte injury and inflammation in alcoholic, drug-induced, and inflammatory liver diseases.

UNLABELLED: MicroRNAs are fine tuners of diverse biological responses and are expressed in various cell types of the liver. Here we hypothesized that circulating microRNAs (miRNAs) may serve as biomarkers of liver damage and inflammation. We studied miRNA-122, which is abundant in hepatocytes, and miR-155, -146a, and -125b, which regulate inflammation in immune cells in mouse models of alcoholic liver disease (ALD), drug (acetaminophen, APAP)-induced liver injury (DILI), and Toll-like receptor (TLR) 9+4 ligand-induced inflammatory cell-mediated liver damage. We found that serum/plasma miR-122 correlated with alanine aminotransferase (ALT) increases in the liver damage caused by alcohol, APAP, and TLR9 (CpG)+4 (LPS) ligands. MiR-155, a regulator of inflammation, was increased in serum/plasma in alcoholic and inflammatory liver injury. Alcohol failed to increase serum miR-122 in TLR4-deficient and p47phox-deficient mice that were protected from ALD. We found the most robust increase in plasma miR-122 in DILI and it correlated with the highest ALT levels. Consistent with the massive inflammatory cell infiltration in the liver, plasma miR-155 and miR-146a were significantly elevated after CpG+LPS administration. We show for the first time that, depending on the type of liver injury, circulating miRNAs are associated either with the exosome-rich or protein-rich compartments. In ALD and in inflammatory liver injury, serum/plasma miR-122 and miR-155 were predominantly associated with the exosome-rich fraction, whereas in DILI/APAP injury these miRNAs were present in the protein-rich fraction. CONCLUSION: Our results suggest that circulating miRNAs may serve as biomarkers to differentiate between hepatocyte injury and inflammation and the exosome versus protein association of miRNAs may provide further specificity to mechanisms of liver pathology.

Plasma microRNA profiles distinguish lethal injury in acetaminophen toxicity: a research study.

AIM: To investigate plasma microRNA (miRNA) profiles indicative of hepatotoxicity in the setting of lethal acetaminophen (APAP) toxicity in mice. METHODS: Using plasma from APAP poisoned mice, either lethally (500 mg/kg) or sublethally (150 mg/kg) dosed, we screened commercially available murine microRNA libraries (SABiosciences, Qiagen Sciences, MD) to evaluate for unique miRNA profiles between these two dosing parameters. RESULTS: We distinguished numerous, unique plasma miRNAs both up- and downregulated in lethally compared to sublethally dosed mice. Of note, many of the greatest up- and downregulated miRNAs, namely 574-5 p, 466 g, 466 f-3p, 375, 29 c, and 148 a, have been shown to be associated with asthma in prior studies. Interestingly, a relationship between APAP and asthma has been previously well described in the literature, with an as yet unknown mechanism of pathology. There was a statistically significant increase in alanine aminotransferase levels in the lethal compared to sublethal APAP dosing groups at the 12 h time point (P < 0.001). There was 90% mortality in the lethally compared to sublethally dosed mice at the 48 h time point (P = 0.011). CONCLUSION: We identified unique plasma miRNAs both up- and downregulated in APAP poisoning which are correlated to asthma development.

Community trends in the use and characteristics of persons with acute myocardial infarction who are transported by emergency medical services.

OBJECTIVE: Limited data exist on recent trends in ambulance use and factors associated with ambulance use in patients hospitalized with acute myocardial infarction (AMI), particularly from the more generalizable perspective of a community-wide investigation. This population-based prospective epidemiologic study describes the decade-long trends (1997-2007) in the use of emergency medical services (EMS) by residents of the Worcester, Massachusetts, metropolitan area who are hospitalized for AMI and the characteristics of patients with AMI who are transported to the hospital by EMS (n = 3789) compared with those transported by other means (n = 1505). METHODS: The study population consisted of 5294 patients hospitalized for AMI at 11 greater Worcester medical centers in 5 annual periods between 1997 and 2007. Information on the use of EMS and the factors associated with EMS use was obtained through the review of hospital medical records. RESULTS: There was a progressive increase in the proportion of greater Worcester residents with AMI who were transported to central Massachusetts hospitals by ambulance over time (66.9% transported in 1997; 74.9% transported in 2007). Patients transported by EMS were older, more likely to be women, and more likely to have a greater prevalence of previously diagnosed comorbidities. CONCLUSION: Our findings provide encouragement for the use of EMS in residents of a large central New England community hospitalized with AMI. Despite increasing trends in ambulance use, more research is needed to explore the reasons why patients with AMI do not use EMS in the setting of an acute cardiac emergency.

The Relationship Between Atrial Fibrillation and Chronic Kidney Disease : Epidemiologic and Pathophysiologic Considerations for a Dual Epidemic.

Atrial fibrillation (AF) presently affects over 2 million Americans, and the magnitude and population burden from AF continues to increase concomitant with the aging of the U.S. POPULATION: Chronic kidney disease (CKD) is present in 13% of individuals in the U.S., and the prevalence of CKD is also rapidly increasing. The increasing population burden of CKD and AF will profoundly affect the clinical and public health, since CKD and AF are both associated with lower quality of life, increased hospitalization rates, and a greater risk of heart failure, stroke, and total mortality. AF and CKD often co-exist, each condition predisposes to the other, and the co-occurrence of these disorders worsens prognosis relative to either disease alone. The shared epidemiology of CKD and AF may be explained by the strong pathophysiologic connections between these diseases. In order to promote a better understanding of CKD and AF, we have reviewed their shared epidemiology and pathophysiology and described the natural history of patients affected by both diseases.

Herbal medicines for the management of opioid addiction: safe and effective alternatives to conventional pharmacotherapy?

Striking increases in the abuse of opioids have expanded the need for pharmacotherapeutic interventions. The obstacles that confront effective treatment of opioid addiction - shortage of treatment professionals, stigma associated with treatment and the ability to maintain abstinence - have led to increased interest in alternative treatment strategies among both treatment providers and patients alike. Herbal products for opioid addiction and withdrawal, such as kratom and specific Chinese herbal medications such as WeiniCom, can complement existing treatments. Unfortunately, herbal treatments, while offering some advantages over existing evidence-based pharmacotherapies, have poorly described pharmacokinetics, a lack of supportive data derived from well controlled clinical trials, and severe toxicity, the cause for which remains poorly defined. Herbal products, therefore, require greater additional testing in rigorous clinical trials before they can expect widespread acceptance in the management of opioid addiction.

Advanced molecular biologic techniques in toxicologic disease.

The advancement of molecular biologic techniques and their capabilities to answer questions pertaining to mechanisms of pathophysiologic events have greatly expanded over the past few years. In particular, these opportunities have provided researchers and clinicians alike the framework from with which to answer clinical questions not amenable for elucidation using previous, more antiquated methods. Utilizing extremely small molecules, namely microRNA, DNA, protein, and nanoparticles, we discuss the background and utility of these approaches to the progressive, practicing physician. Finally, we consider the application of these tools employed as future bedside point of care tests, aiding in the ultimate goal of unsurpassed patient care.

Bedside ultrasound diagnosis of acalculous cholecystitis from epstein-barr virus.

Acalculous cholecystitis is thought to occur in patients with a severe systemic illness or during long periods of intravenous nutrition. We discuss a case of acalculous cholecystitis secondary to Epstein-Barr virus detected by bedside ultrasound. We hope to alert clinicians who are actively using bedside ultrasound of an important, yet not commonly discussed, association. [West J Emerg Med. 2011;12(4):

Perturbation of hyaluronan interactions inhibits malignant properties of glioma cells.

Malignant progression of gliomas is characterized by acquisition of inappropriate growth and invasive properties. In vitro, these malignant properties are reflected in, and measured by, the ability to grow in an anchorage-independent manner and to invade artificial extracellular matrices. The results of numerous studies have suggested that the extracellular and pericellular matrix polysaccharide, hyaluronan, plays an important role in these attributes of malignant cancer cells. However, with respect to glioma cells, most studies have addressed the effect of exogenously added hyaluronan rather than the function of endogenous tumor cell-associated hyaluronan. In this study we manipulate hyaluronan-glioma cell interactions by two methods. The first is administration of small hyaluronan oligosaccharides that compete for endogenous hyaluronan polymer interactions, resulting in attenuation of hyaluronan-induced signaling. The second is overexpression of soluble hyaluronan-binding proteins that act as a competitive sink for interaction with endogenous hyaluronan, again leading to attenuated signaling. We find that both treatments inhibit anchorage-independent growth, as measured by colony formation in soft agar, and invasiveness, as measured by penetration of reconstituted basement membrane matrices. Based on our findings, we conclude that endogenous hyaluronan interactions are essential for these two fundamental malignant properties of glioma cells.