Oxygenated polycyclic aromatic hydrocarbons (OPAHs) are a class of environmentally prevalent compounds with little known information on their effect in vivo. In a recent study conducted using zebrafish as a model, 38 OPAHs were screened for toxicity. This investigation focuses on two of these OPAHs, 7,12-B[a]AQ and BEZO. Both 7,12-B[a]AQ...
Flame retardants are in many home products including couches, chairs, and electronics. The most commonly used flame retardants contained polybrominated diphenyl ethers (PBDEs) until 2004, when the majority of these chemicals were phased out. PBDEs were found to be persistent, bioaccumulative, and toxic to both humans and the environment. Organophosphate...
microRNAs (miRNAs), ~21-24 nucleotide-long RNAs that post-transcriptionally regulate gene expression, have rapidly become one of the most extensively studied mechanisms of the past decade. Since their discovery as temporal regulators of post-embryonic development in C. elegans, miRNAs have been functionally implicated in almost every cellular process investigated to date. miRNAs...
Due to their unique physical, chemical, and magnetic properties, nanomaterials have great potential for industrial development. There is a pressing need to develop rapid whole animal-based testing assays to assess the potential toxicity of engineered nanomaterials. To meet this challenge the embryonic zebrafish model was employed to determine the toxicity...
All animals have developed the critical ability to detect, respond to, and detoxify a large array of environmental chemicals and stressors that can cause adverse health effects. Important examples of landmark contaminants around the world are polycyclic aromatic hydrocarbons (PAHs) and dioxins, both of which can act via the aryl...
Polycyclic aromatic hydrocarbons (PAHs) and oxygen-substituted PAHs (OPAHs) are environmental contaminants present in urban air, dust, soil and water resulting from incomplete combustion of organic materials or fossil fuels; found in crude oil and coal; and formed through photoxidation or biotransformation of microbial. It is widely recognized that PAHs pose...
Since 2007, electronic cigarette (e-cigarette) sales in the U.S. have surpassed those of tobacco cigarettes. This is due, in part, to manufacturer’s claims that they are a safer alternative to tobacco cigarettes. However, formaldehyde, acrolein, and diacetyl have been detected in e-cigarettes and public knowledge of e-cigarette composition and potential...
Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants that occur in complex mixtures. These environmental mixtures can consist of both parent PAHs and their derivatives. Several parent PAHs are known or suspected mutagens and/or carcinogens, and a handful of PAH derivatives are known to be more potent mutagens and/or carcinogens...
Billions of pounds of bisphenol A (BPA) are produced annually around the globe for the manufacture of numerous consumer products, including polycarbonate food and water containers, the protective resin linings of food cans, thermal printing paper, and dental fillings. BPA exposure during nervous system development has been associated with learning...
Zebrafish are capable of fully regenerating organs and tissue such as their caudal fin, which is similar to a human regrowing an arm or a leg. In contrast, most mammals including humans have a greatly reduced capacity for wound healing. The ability of zebrafish to undergo this regenerative process, called...
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RobertL. Tanguay
Zebrafish are capable of fully regenerating organs and tissue such as
Ubiquitous fine particulate matter (PM2.5) exposures significantly impact global public health, yet little is known about the mechanisms causing these known adverse health effects. Oxidative stress due to PM2.5 associated chemical constituents, such as polycyclic aromatic hydrocarbons (PAHs), is a proposed possible mechanism for PM2.5 mediated health effects. Variations in...
There are more than 87,000 chemicals in current use with little to no toxicity information available. Assessing such a large number of chemicals using traditional methods would take an unreasonable amount of time and money, and require the use a large number of animals. The incorporation of high-throughput in vivo...
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RobertL. Tanguay
There are more than 87,000 chemicals in current use with little to no
The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that is a member of the basic helix-loop-helix PER-ARNT-SIM (bHLH/PAS) protein family of cellular sensors. The AHR is conserved across multiple animal phyla and is required for proper vertebrate development. A structurally diverse group of chemicals, including polycyclic aromatic...
The emerging field of regenerative medicine is mainly approached by two different aspects. First is the use of stem cell based models to generate a suite of differentiated cells for therapeutic applications and the alternative approach is to utilize the non-mammalian models that have the inherent capacity to regenerate their...
Incorporation of nanoparticles (NPs) into consumer products is on the rise and human exposure to NPs is unavoidable. Currently, there is insufficient data to assess the safety of nanoparticles. I conducted a series of five studies using the zebrafish model to determine which NP components (i.e., core material or surface...
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RobertL. Tanguay
Incorporation of nanoparticles (NPs) into consumer products is on the
rise
Dithiocarbamates are widely used agricultural pesticides, industrial chemicals and
effluent additives. DTCs and their related compounds have historical and current
relevance in clinical and experimental medicine. DTC developmental toxicity is well
established, but poorly understood. Dithiocarbamates according to the U.S. EPA have a
mechanism of action involving, "the inhibition of...
Numerous human conditions would be improved if therapies to encourage tissue regeneration were available. The goal of regenerative medicine is to encourage the body's intrinsic ability to repair and restore tissues lost by disease, injury or aging. While certain vertebrates have the inherent capacity to regenerate, mammals do not. To...
Nanoparticles (NPs), defined as materials having at least one dimension (height, width, diameter) in the nanoscale, are increasingly being incorporated into a wide variety of products and are replacing traditional bulk materials in many applications. This is because they can be more efficacious, more sustainable, and can have unique characteristics...
Fluorinated chemicals (FCs) have been used since the 1950s in many industrial and commercial applications because of their unique properties such as chemical inertness, resistance to heat and their ability to repel water and oils. Concerns regarding potential environmental or human health risk from FCs exposure have emerged due to...
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RobertL. Tanguay
Fluorinated chemicals (FCs) have been used since the 1950s in many
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment as components of fossil fuels and by-products of combustion. Defining toxicity mechanisms for this large family of multi-ring structures and substituted derivatives is a substantial challenge. Several PAHs, such as benzo(a)pyrene (BaP), are mutagenic, toxic to wildlife, and classified as probable...
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RobertL. Tanguay
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the
Firemaster 550 (FM550) is an additive flame retardant mixture used within polyurethane foam and is increasingly found in house dust and the environment due to leaching. In this study, we sought to investigate mono-substituted isopropylated triaryl phosphate (mITP), a major component of FM550, which has been shown to cause cardiotoxicity...
Polycyclic aromatic hydrocarbons (PAHs) are among the most widely known and studied environmental contaminants, originating from a range of natural and anthropogenic sources. PAHs are known to occur in the environment as complex mixtures, containing both unsubstituted PAHs, as well as a range of PAH derivatives. Among the less-studied of...
The numerous different types of nanomaterials and paucity of reliable in vivo information on toxicity has resulted in enduring uncertainties associated with health and safety risks, thereby slowing progress in nanotherapeutic assessment and development. This dissertation explores how the embryonic zebrafish model can be applied to prioritize commonly used nanomaterial...
Laboratories around the world are using the zebrafish model for biomedical research and conducting investigations using morphological, physiological, behavioral, and genomic endpoints. All assays provide information, but physiological and behavioral endpoints or phenotypes are a fast way to understand how an animal is responding to its environment. We investigate the...
Vitamin E was first described in 1922 as an unknown factor required for impregnated rats to carry their offspring to term. In fact, when vitamin E was chemically characterized it was given the name "tocopherol" derived from the Greek: tokos = childbirth; phero = to bear; and –ol, indicating an...
Chlorinated and non-chlorinated solvents are used in a variety of industrial processes and as a consequence, they have become environmental contaminants as well. Because of this, they lead to both occupational and environmental exposures. Exposure to these compounds can potentially result in various forms of neurological damage with a wide...
A study was conducted to evaluate the developmental toxicity of three commonly detected mycotoxins in food (deoxynivalenol, patulin, and zearalenone) using the zebrafish (Danio rerio) model. Mycotoxin exposures were carried out at five concentrations (0.0064, 0.064, 0.64, 6.4, and 64 μM). Morphological and photomotor screenings were conducted at 24 hours...
Antisense morpholino oligomers are synthetic macromolecules can modify gene expression. While these compounds have great potential to treat a broad range of human diseases, they suffer from poor cellular delivery. Conjugating cell-penetrating peptides onto these morpholinos is one option of addressing delivery, however development remains slow due to the cost...
As engineered nanomaterials (ENM) become more common in consumer products, it is crucial to rapidly assess toxicity of unique ENM. Previous studies rarely focused on standardizing nanotoxicity testing, leading to inconsistent and irreproducible results. This study characterized a variety of ENM of different size, shape, core type, and surface charge...
Two experiments were conducted looking at both acute and sub-acute laminitis. An acute nutritional induction model was used to examine whether blood profiles and gene expression are similar to other studies conducted using an endotoxin induction model. Twelve sheep were randomly assigned to three treatment groups which were control, 4-hour...
Since its inception as a laboratory animal in the early 1970s, the zebrafish has proven itself a rising star in the world of comparative biomedical sciences due to its short generation time, ease of care, external fertilization, and transparent larvae. In a very few decades, the zebrafish has been utilized...
The microsporidian parasite, Pseudoloma neurophilia, is the most commonly diagnosed infectious disease in laboratory populations of the zebrafish, Danio rerio. Infections by P. neurophilia are generally subclinical, however, they can become acute either incidentally or due to experimental immune suppression. Non-protocol induced variation can confound results in laboratory experiments using...
The human health effects of exposure to numerous single environmental contaminants have been well characterized. Yet, biomonitoring studies have detected multiple environmental chemicals in humans, highlighting the need to investigate the health effects of exposure to multiple environmental chemicals. Environmental data is highly complex, therefore current methods of defining environmental...
Throughout their lifetime individuals are exposed to complex mixtures of chemicals. The study of chemical mixtures is an internationally recognized research priority, but seemingly complex challenge. To reduce the intricacy of studying mixtures, researchers have identified different prioritization methods based on exposure or the toxicity of chemicals. However, understanding the...
The goal of this dissertation was to improve our abilities in acquiring critical in vivo data by establishing embryo-larva zebrafish as an exemplary model to quantitatively evaluate cancer progression. The living environment that encompasses a tumor has a significant effect on how cancer develops, grows and metastasizes. In order to...
Composition and structure of Oregon ash
(Fraxinus latifolia) woodlands in the William L. Finley
National Wildlife Refuge, Oregon are described. Twenty
stands dominated by Fraxinus latifolia were sampled with
500 m2 circular macroplots in which floristic microplot
data were collected for plant community synthesis. Plant
communities were identified by computer-assisted...
In a story of his life Les reflects on what he
has gained and what he has lost while seeking success in
the moving and shifting of military and academic life
through homes and schools all over the United States.
He describes himself as between races, languages, and
cultures.
The atmospheric transport and deposition of semi-volatile organic compounds (SOCs), including current and historic use pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), to mountain ecosystems may result in the exposure of tadpoles to these SOCs. This exposure has been implicated in amphibian population declines in California. Tadpoles encounter...
Graphene and its derivatives are two-dimensional hexagonal lattices that possess desirable physicochemical properties leading to an ever-expanding list of industrial and biomedical uses. Graphene oxides (GOs) are becoming a popular graphene alternative and while there have been human safety studies, investigations of developmental toxicity are lacking. The use of distinct...
The field of toxicology is challenged with a vast number of environmental chemicals and mixtures to which humans and ecosystems are exposed with limited toxicity data available. Chemical hazard assessment traditionally utilizes mammalian models and can be both cost- and time-limiting and may pose ethical concerns. To rapidly tackle this...
Per- and polyfluoroalkyl substances (PFAS) are contaminants of concern because they do not readily degrade in the environment. Some in vivo studies report that PFAS alter neurological development and are carcinogenic. Perfluorohexanesulfonamide (FHxSA) and 6:2 fluorotelomer sulfonate (6:2 FTS) are two PFASs, which are often detected in drinking water sources....
Per- and polyfluoroalkyl substances (PFAS) are a broad class of anthropogenic chemicals characterized by highly stable carbon-fluorine (C-F) bonds. PFAS are widely used in industrial and consumer products for their surface-active and stain-resistant properties and are ubiquitously detected in environmental media, biota, and human biomatrices. Although some PFAS are known...
Many research projects suffer from limited data causing poor statistical analysis or limited results. The movement to high throughput methods has been building for many years and cross many different disciplines. Lots of these methods start out using pathways that generate large amounts of data but have limited methods to...
The use of zebrafish in behavioral neuroscience is rapidly growing. Zebrafish can be assessed for alterations in multiple behavioral endpoints, creating opportunities to use this powerful model to identify chemicals that alter behavioral phenotypes. To evaluate the utility of zebrafish for neurotoxicity research, we designed custom instrumentation to evaluate numerous...
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Johnson, RobertL. Tanguay (PhD), and Andrea Knecht
(PhD)
Department of Toxicology, Oregon State
The use of zebrafish in behavioral neuroscience is rapidly growing. Zebrafish can be assessed for alterations in multiple behavioral endpoints, creating opportunities to use this powerful model to identify chemicals that alter behavioral phenotypes. To evaluate the utility of zebrafish for neurotoxicity research, we designed custom instrumentation to evaluate numerous...
Full Text:
Truong (PhD), Eric Johnson, RobertL. Tanguay (PhD), and Andrea Knecht (PhD)
Department of Toxicology
The use of zebrafish in behavioral neuroscience is rapidly growing. Zebrafish can be assessed for alterations in multiple behavioral endpoints, creating opportunities to use this powerful model to identify chemicals that alter behavioral phenotypes. To evaluate the utility of zebrafish for neurotoxicity research, we designed custom instrumentation to evaluate numerous...
Full Text:
develop until 17 hours post fertilization (hpf) (Saint-Amant, L. and P. Drapeau (1998). When
embryos are
The use of zebrafish in behavioral neuroscience is rapidly growing. Zebrafish can be assessed for alterations in multiple behavioral endpoints, creating opportunities to use this powerful model to identify chemicals that alter behavioral phenotypes. To evaluate the utility of zebrafish for neurotoxicity research, we designed custom instrumentation to evaluate numerous...
Human exposure to the carcinogenic polycyclic aromatic hydrocarbons (PAHs) benzo[a]pyrene (B[a]P) and dibenzo[a,l]pyrene (DB[a,l]P) is through environmental complex mixtures, such as urban dust particulate matter (UDPM) and diesel exhaust (DE), however the potency of these PAH within a mixture is not established. To determine the effect of these mixtures on...
Arachidonic acid (ARA) and docosahexaenoic acid (DHA) are polyunsaturated fatty acids required for proper embryonic development, specifically neurodevelopment. However, little is known regarding their conversion to other metabolites during embryogenesis. The oxidation of ARA gives rise to the biologically active eicosanoids and the oxidation of DHA gives rise to the...
Surface disinfection of fertilized fish eggs is widely used in aquaculture to reduce
extraovum pathogens that may be released from brood fish during spawning, and this is routinely
used in zebrafish (Danio rerio) research laboratories. Most laboratories use approximately 25-50 ppm unbuffered chlorine solution for 5-10 min. Treatment of embryos...