Chemical warfare agent and biological toxin-induced pulmonary toxicity: could stem cells provide potential therapies?

Chemical warfare agents (CWAs) as well as biological toxins present a significant inhalation injury risk to both deployed warfighters and civilian targets of terrorist attacks. Inhalation of many CWAs and biological toxins can induce severe pulmonary toxicity leading to the development of acute lung injury (ALI) as well as acute respiratory distress syndrome (ARDS). The therapeutic options currently used to treat these conditions are very limited and mortality rates remain high.

Downstream procedures and outcomes after stress testing for chest pain without known coronary artery disease in the United States.

Background: Millions of Americans with suspected coronary artery disease undergo noninvasive cardiac stress testing annually. Downstream procedures and subsequent outcomes among symptomatic patients without known coronary disease referred for stress testing are not well characterized in contemporary community practice.

Methods: We examined administrative insurance billing data from a national insurance provider from November 2004 through June 2007.

Neuroprotective effects of imidazenil against chemical warfare nerve agent soman toxicity in guinea pigs.

The chemical warfare nerve agent, soman irreversibly inhibits acetylcholinesterase (AChE) leading to hypercholinergy and seizures which trigger glutamate toxicity and status epilepticus ultimately resulting in neuropathology and neurobehavioral deficits. The standard emergency treatment comprising of anticholinergic, AChE reactivator and anticonvulsant does not completely protect against soman toxicity. We have evaluated imidazenil, a new anticonvulsant imidazo benzodiazepine with high affinity and intrinsic efficacy at α5-, α2-, and α3- but low intrinsic efficacy at α1-containing GABA(A) receptors and is devoid of cardiorespiratory depression, sedative/hypnoitc and amnestic actions and does not elicit tolerance and dependence liabilities unlike diazepam, for protection against soman toxicity.

Association between physician billing and cardiac stress testing patterns following coronary revascularization.

Context: The degree to which financial factors may influence use of cardiac stress imaging procedures is unknown.

Objective: To examine the association of physician billing and nuclear stress and stress echocardiography testing following coronary revascularization.

Design, Setting, And Patients: Using data from a national health insurance carrier, 17,847 patients were identified between November 1, 2004, and June 30, 2007, who had coronary revascularization and an index cardiac outpatient visit more than 90 days following the procedure.

[+]-Huperzine A protects against soman toxicity in guinea pigs.

The chemical warfare nerve agent (CWNA) soman irreversibly inhibits acetylcholinesterase (AChE) causing seizure, neuropathology and neurobehavioral deficits. Pyridostigmine bromide (PB), the currently approved pretreatment for soman, is a reversible AChE inhibitor that does not cross the blood-brain barrier (BBB) to protect against central nervous system damage. [-]-Huperzine A, a natural reversible AChE inhibitor, rapidly passes through the BBB and has numerous neuroprotective properties that are beneficial for protection against soman.

Gene-delivered butyrylcholinesterase is prophylactic against the toxicity of chemical warfare nerve agents and organophosphorus compounds.

Gene delivery using an adenoviral system has been effective in introducing therapeutic proteins in vitro and in vivo. This study tested the feasibility of using adenovirus to deliver clinically relevant amounts of butyrylcholinesterase (BChE), a proven bioscavenger of nerve agents. The adenovirus construct expressed full-length mouse BChE.

Patterns of cardiac stress testing after revascularization in community practice.

Objectives: The purpose of this study was to determine the pattern of cardiac stress testing after coronary revascularization in community practice.

Background: The American College of Cardiology Foundation appropriate use criteria provide guidance for the use of cardiac stress imaging after coronary revascularization. However, little is known regarding the use of routine cardiac stress testing in coronary artery bypass grafting or percutaneous coronary intervention patients as well as their downstream use of invasive procedures after noninvasive testing in community practice.

A multicenter assessment of the use of single-photon emission computed tomography myocardial perfusion imaging with appropriateness criteria.

Objectives: The aim of this study was to assess the feasibility of evaluation for appropriate use of radionuclide myocardial perfusion imaging (MPI) in multiple clinical sites and to determine use patterns as well as identify areas of apparent inappropriate use.

Background: Although cardiac imaging is highly valued for decision-making, the growth and expense related to these procedures has raised questions regarding overuse. The publication of appropriate use criteria (AUC), including those for MPI, were designed to provide guidance in the rational use of testing.

Manganese superoxide dismutase V16A single-nucleotide polymorphism in the mitochondrial targeting sequence is associated with reduced enzymatic activity in cryopreserved human hepatocytes.

Mitochondrial manganese superoxide dismutase (MnSOD), encoded by the SOD2 gene, represents a major cellular defense against environmental carcinogens that cause oxidative stress. Two single-nucleotide polymorphisms -9 T>C (V16A in the MnSOD mitochondrial targeting sequence) and -102 C>T (in the SOD2 promoter sequence) modify risk toward various types of malignancies and overall survival. Since little is known about the effects of these polymorphisms on overall enzyme function in normal human tissue, the goal of this study was to evaluate their functional effects in cryopreserved human hepatocytes.

Structure-activity relationships for thiol reactivity and rat or human hepatocyte toxicity induced by substituted p-benzoquinone compounds.

Covalent binding of toxic chemicals to cellular targets is a molecular interaction that initiates a wide array of adverse biological effects. The creation of a covalent bond can be cited as a key initiating step along many toxicity pathways which must be predicted in order to predict the potential of a chemical to cause specific harmful effects. Currently, quantitative structure-activity relationship (QSAR) models are being improved by focusing on endpoints such as simple electrophile reactivity for covalent interactions rather than on commonly used complex toxicity endpoints.

Structure-activity relationships for halobenzene induced cytotoxicity in rat and human hepatocytes.

Halobenzenes are ubiquitous environmental contaminants, which are hepatotoxic in both rodents and humans. The molecular mechanism of halobenzene hepatotoxicity was investigated using Quantitative structure-activity relationships (QSAR) and accelerated cytotoxicity mechanism screening (ACMS) techniques in rat and human hepatocytes. The usefulness of isolated hepatocytes for prediciting in vivo xenobiotic toxicity was reassessed by correlating the LC(50) of 12 halobenzene congeners in phenobarbital (PB) induced rat hepatocytes in vitro determined by ACMS to the hepatotoxicities reported in vivo in PB-induced male Sprague-Dawely (SD) rats.

New cytochrome P450 2D6*56 allele identified by genotype/phenotype analysis of cryopreserved human hepatocytes.

Genotype/phenotype analysis with human hepatocytes has identified a new inactive CYP2D6 allele, CYP2D6*56. Cryopreserved human hepatocytes from 51 livers were evaluated for CYP2D6 activity with dextromethorphan as the probe substrate. Hepatocyte lots that lacked CYP2D6 activity were further evaluated for CYP2D6 expression and known genetic variations, including CYP2D6*2, *3, *4, *5, *6, *7, *8, *9, *10, *11, *14, *15, *17, *18, *19, *20, *25, *26, *29, *30, *35, *40, *41, *43, and various multiple copy CYP2D6 alleles (*1xn, *2xn, and *4xn) by the AmpliChip CYP450 prototype microarray (Roche Molecular Systems, Inc.