Pharmacology, Toxicology and Environmental Health Commons^™

Development Of Single Nanoparticle Optical Assays For Imaging Single Living Cells, William John Brownlow

Chemistry & Biochemistry Theses & Dissertations

Multi-drug resistance (MDR) has been reported in both prokaryotes and eukaryotes; the pathogenic gram-negative bacteria Pseudomonas aeruginosa can extrude a variety of structurally and functionally diverse substrates via a number of membrane transport systems leading to MDR. We have developed a novel nanoparticle assay to characterize both the membrane transport system composed of the MexAB-OprM efflux pump and the membrane permeability induced by antibiotics. Gold (Au) and silver (Ag) nanoparticles were investigated for use as probes to explore membrane transport in P. aeruginosa.

The surface plasmon absorption (color) of Au nanoparticle solutions was found to change in the presence …

Bioprospecting, Philip A. Reed

STEMPS Faculty Publications

The article discusses that the product applications of bioprospecting are almost limitless. This area of biotechnology has been labeled bioprospecting, and it is a practice that is creating worldwide controversy. Defined simply, bioprospecting is "scientific research that looks for a useful application, process, or product in nature." However, as with most biotechnologies, the definition does not address the complexities of bioprospecting. Archeologists are finding that some biotechnologies, such as the use of herbs for medicine and the use of fermentation and yeast in food products, date back 5,000 to 10,000 years (De Miranda, 2004). The four main categories of biotechnologies …

Enhancement Of Disease And Pathology By Synergy Of Trichuris Suis And Campylobacter Jejuni In The Colon Of Immunologically Naive Swine, Linda S. Mansfield, David T. Gauthier, Sheila R. Abner, Kathryn M. Jones, Stacey R. Wilder, Joseph F. Urban

Biological Sciences Faculty Publications

Campylobacter jejuni, a leading cause of bacterial gastroenteritis, has different age distribution and disease expression in developing and developed countries, which may be due to the endemnicity of infection and the age of acquisition of immunity. Differences in disease expression are not solely dependent on the C jejuni strain or virulence attributes. Another modulating factor in developing countries may be endemic nematode infections such as Trichuris, which drive type 2 cytokine responses and down-regulate type I immune responses. In this study, three-day-old germfree pigs given dual infections with Trichuris suis and C jejuni had more frequent, more severe …

Recognizing Toxic Species In Aquatic Habitats: A Potential Concern In Lake Management, Mikolaj Kokocinski, Harold G. Marshall

Biological Sciences Faculty Publications

The importance of distinguishing toxic and non-toxic algal species is becoming a more common problem for management decisions associated with various freshwater and estuarine habitats. An example is given where two dinoflagellates, originally unidentified as closely resembling the toxin producing Pfiesteria spp., have been compared to these species. In order to clarify any relationship to Pfiesteria spp., scanning electron microscopy was used to determine the plate tabulation patterns of these dinoflagellates and make comparisons to the tabulation present in Pfiesteria spp. The results indicated significant differences in the plate tabulations of these taxa to distinguish them from Pfiesteria …

Embryo And Gamete Development Upon Exposure To Cca Components: Cro3, Cuo, And As2o5, Nerbana Talaat-Elsebaei Mahmoud

Theses and Dissertations in Biomedical Sciences

Production of functional gametes and healthy embryos is essential for proliferation of all vertebrates, especially humans. Many compounds have toxic effects on developing gametes and embryos among which are chromium trioxide (CrO₃), cupric oxide (CuO) and arsenic pentaoxide (As₂O₅) as a mixture (CCA) or individually. Controversy surrounding the safety of CCA-treated wood centers primarily on the toxicity of its components and the potential for these metals to be released from the wood.

The aim of this research is to test the hypothesis that CCA components have deleterious effects on embryo development, oocyte maturation and …

The Standardized Fish Bioassay Procedure For Detecting And Culturing Actively Toxic Pfiesteria, Used By Two Reference Laboratories For Atlantic And Gulf Coast States, Joann M. Burkholder, Harold G. Marshall, David W. Seaborn, Nora J. Deamer-Melia

Biological Sciences Faculty Publications

In the absence of purified standards of toxins from Pfiesteria species, appropriately conducted fish bioassays are the "gold standard" that must be used to detect toxic strains of Pfiesteria slop. from natural estuarine water or sediment samples and to culture actively toxic Pfiesteria. In this article, we describe the standardized steps of our fish bioassay as an abbreviated term for a procedure that includes two sets of trials with fish, following the Henle-Koch postulates modified for toxic rather than infectious agents. This procedure was developed in 1991, and has been refined over more than 12 years of experience in …

Validation Of Passive Air Sampling Monitors Onboard United States Navy Submarines, Larry A. Mcfarland

Community & Environmental Health Theses & Dissertations

An operating submarine creates a unique air quality mixture of compounds that result from a combination of human metabolism, construction materials, materials brought onboard and compounds created through the interaction of ship systems. A comprehensive study of submarine atmospheres is ongoing during deployments of U.S. Navy nuclear submarines. As part of the overall effort, a paired air sampling comparison field validation was conducted to compare the air sampling effectiveness of passive diffusive monitors compared to more traditional active air sampling methods when sampling for acrolein, formaldehyde and ozone in the enclosed submarine atmosphere. Acrolein monitors containing 2-hydroxymethylpiperidine (HMP) impregnated glass …

Investigations On The Use Of Ion Mobility Spectrometry For Clinical Chemistry Applications, Henri Parson Patten

Theses and Dissertations in Biomedical Sciences

The major objective of this research is to examine ion mobility spectrometry as a rapid screening tool for specific application to clinical chemistry research and laboratory use. Methodology was developed for target analytes representing several classes of physiologically active substances, including anesthetics, illicit drugs, and their metabolites. The IMS characteristics of animal tissues and other compounds such as amino acids and proteins were determined. Quality assurance and control procedures were developed for specific quality data objectives. Criteria were established relating to use of IMS for assessing the precision and accuracy of data, qualitative screening, and semi-quantitative analyses.

It was found …

Pfiesteria Piscicida And Dinoflagellates Similar To Pfiesteria, Harold G. Marshall

Virginia Journal of Science

Pfiesteria pisiccida is a microscopic, unicellular organism that is classified as both a mixotrophic and heterotrophic dinoflagellate, which has been associated with both fish deaths and a cause of human illness (Burkholder et al., 1992; Glasgow et al., 1995; Burkholder and Glasgow, 1997). This species possesses a complex life cycle that includes motile forms (e.g. zoospores, gametes, amoebae) and a cyst stage that may remain dormant in the sediment (Burkholder et al., 1995b). Pfiesteria piscicida is known to have toxin and non-toxin producing populations, where cyst transformation into the toxic motile zoospores may be initiated by the presence of certain …

The Accuracy Of Nitrous Oxide Passive Dosimeters As Compared With An Infra-Red Spectrographic Reference Method, Susan Allen

Community & Environmental Health Theses & Dissertations

Nitrous oxide is a gas often used in dental, surgical and veterinary operations as an anesthetic agent. Employees stationed in proximity of fugitive gas emissions may potentially suffer adverse health effects from chronic exposure to this agent. Passive dosimeters can be worn in the breathing zone of potentially affected personnel during exposure periods, then later analyzed to quantify nitrous oxide exposure. This study sought to establish the accuracy of several commercially available passive monitoring devices for nitrous oxide by comparison against an infra-red spectrophotometric reference method.

The Effect Of Illicit Drugs On The Cardiovascular And Hormonal Responses In Pregnant Rabbits, Andrea Alana Chambliss

Biological Sciences Theses & Dissertations

The purpose of this study is to determine the effect of acute administration of heroin and ecgonine methyl ester (EME) on renin and atrial natriuretic peptide (ANP) secretion in time dated New Zealand White rabbits. Thirteen rabbits were studied. Arterial blood pressure and pCOz, increased significantly from a control value of 80 ± 8 mmHg and 30 ± 2 mmHg respectively to 93 ± 18 mmHg and 31 ± 1 mmHg. pO₂ decreased from 99 ± 8 mmHg to 90 ± 11 mmHg 10 minutes after heroin administration. EME caused arterial blood pressure to significantly increase from a control …

Trans-Resveratrol Inhibits Calcium Influx In Thrombin-Stimulated Human Platelets, Yuliya Dobrydneva, Roy L. Williams, Peter F. Blackmore

Chemistry & Biochemistry Faculty Publications

1 The phytoestrogenic compound trans-resveratrol (trans-3,5,4'-trihydroxystilbene) is found in appreciable quantities in grape skins and wine. It has been shown that both products rich in trans-resveratrol and pure trans-resveratrol inhibit platelet aggregation both in vivo and in vitro. However the mechanism of this action still remains unknown.

2 An essential component of the aggregation process in platelets is an increase in intracellular free Ca²⁺ ([Ca²⁺]_i). Ca²⁺ must enter the cell from the external media through specific and tightly regulated Ca²⁺ channels in the plasma membrane. The objective …

Pfiesteria Piscicida And Dinoflagellates Similar To Pfiesteria, Harold G. Marshall

Biological Sciences Faculty Publications

Pfiesteria pisiccida is a microscopic, unicellular organism that is classified as both a mixotrophic and heterotrophic dinoflagellate, which has been associated with both fish deaths and a cause of human illness (Burkholder et al., 1992; Glasglow et al., 1995; Burkholder and Glasgow, 1997). This species possesses a complex life cycle that includes motile forms (e.g. zoospores, gametes, amoebae) and a cyst stage that may remain dormant in the sediment (Burkholder et al, 1995b). Pfiesteria piscicida is known to have toxin and non-toxin producing populations, where cyst transformation into the toxic motile zoospores may be initiated by the presence of certain …

Monitoring Results For Pfiesteria Piscidida And Pfiesteria-Like Organisms From Virginia Waters In 1998, Harold G. Marshall, David W. Seaborn, Jennifer Wolny

Virginia Journal of Science

Results of an extensive 1998 monitoring program for the presence of Pfiesteria-like organisms (PLO) in Virginia estuaries indicate these dinoflagellates are widely distributed in both the water column, and as cysts in the sediment, however Pfiesteria piscicida was not detected at this time. The highest concentrations of PLO were in estuaries along the Virginia shore line of the Potomac River, and in western Chesapeake Bay estuaries from the Little Wicomico River to the Rappahannock River. The most common PLO included Cryptoperidiniopsis sp. and Gymnodinium galatheanum. The lowest PLO concentrations were at ocean side locations. PLO were also …

Water Quality Relationships To Concentrations Of Pfiesteria-Like Organisms In Virginia Estuaries For 1998, Everett P. Weber, Harold G. Marshall

Virginia Journal of Science

A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large …

Monitoring Results For Pfiesteria Piscidida And Pfiesteria-Like Organisms From Virginia Waters In 1998, Harold G. Marshall, David W. Seaborn, Jennifer Wolny

Biological Sciences Faculty Publications

Results of an extensive 1998 monitoring program for the presence of Pfiesteria-like organisms (PLO) in Virginia estuaries indicate these dinoflagellates are widely distributed in both the water column, and as cysts in the sediment, however Pfiesteria piscicida was not detected at this time. The highest concentrations of PLO were in estuaries along the Virginia shore line of the Potomac River, and in western Chesapeake Bay estuaries from the Little Wicomico River to the Rappahannock River. The most common PLO included Cryptoperidiniopsis sp. and Gymnodinium galatheanum. The lowest PLO concentrations were at ocean side locations. PLO were also …

Water Quality Relationships To Concentrations Of Pfiesteria-Like Organisms In Virginia Estuaries For 1998., Everett P. Weber, Harold G. Marshall

Biological Sciences Faculty Publications

A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large …

Mouse Embryo Development In The Presence Of Capsaicin, Carlos Santiago Villar-Gosalvez

Theses and Dissertations in Biomedical Sciences

Capsaicin is the pungent agent found in hot peppers of the Capsicum genus. It is a potent neurotoxin that stimulates the degranulation and degeneration of C-afferent neurons. Capsaicin is widely used as a food condiment and medicine. Human exposure of capsaicin can exceed levels shown to be neurotoxic in laboratory animals. Additionally, capsaicin can cross the blood/placenta barrier and affect an embryo in utero. In order to assay the potential for toxicity to human embryos, mouse embryos were exposed to capsaicin and the effect of the capsaicin on embryo development was measured. Embryos were co-cultured in Krebs medium with 1% …

Evaluation Of Toxicity, Bioavailability And Speciation Of Lead, Zinc And Cadmium In Mine/Mill Wastewaters, Mujde Erten-Unal, Bobby G. Wixson, Nord Gale, Jerry L. Pitt

Civil & Environmental Engineering Faculty Publications

The toxicity of common compounds of lead, cadmium and zinc was evaluated in waters similar to that found in the world's largest lead producing area in Missouri. Static, acute toxicity tests were performed using fathead minnows (Pimephales promelas) and water fleas (Daphnia magna) respectively. Test organisms were subjected to varying amounts of sulfide, carbonate, chloride and sulfate salts of lead, zinc and cadmium mixed in hard, alkaline waters typical to this region. Median lethal concentrations were calculated using nominal versus measured metal concentrations. Measured metal concentrations included four different metal fractionation (extraction/filtration) techniques at different pH …

Effect Of Cocaine On Rabbit Renin Angiotensin System: Cocaine Detection In Adult And Fetal Tissue And Adult Plasma Using Ion Mobility Spectrometry, Barbara Belinda Guinn

Biological Sciences Theses & Dissertations

Ion mobility spectrometry (IMS) was used to detect cocaine and/or the metabolite ecgonine methyl ester (EME) in tissue and plasma samples from male, maternal, and fetal New Zealand White (NZW) rabbits. EME was consistently detected in all adult plasma samples 5 minutes after the injection of cocaine hydrochloride (cocaine•HCI, 2 mg/kg). EME was also in the liver, kidneys, testicles, and ovaries. Five minutes after the injection of cocaine•HCI, the male arterial pressure (MAP) increased from a mean control value of 79 ± 3.2 mmHg to 88 ± 4.1 mmHg, and the pCO₂ increased from a control value of28 ± …

Evaluation Of The Effects Of Afff Inputs On The Vip Biological Nutrient Removal Process And Pass-Through Toxicity. Phase 1a. Volume Ii. Appendix Vii. Acute Toxicity Test Results, Mujde Erten-Unal, Gary C. Schafran

Civil & Environmental Engineering Faculty Publications

This report discusses the results of a bench scale study conducted to evaluate the potential inhibitory effects of untreated AFFF wastewater to the Virginia Initiative Plant VIP biological nutrient removal process. A bench-scale study was conducted to evaluate the potential inhibitory effects of untreated AFFF wastewater to the nitrification process of the Virginia Initiative Plant biological nutrient removal system. Under this testing, bench-scale reactors simulating the nitrification process were loaded at various AFFF concentrations and the influence on the process performance was evaluated. The purpose of this effort was to determine the level of AFFF that could be incorporated into …

Human Immunodeficiency Virus (Hiv)/Hepatitis B Virus (Hbv) Risk Perception Related To Needlestick Injuries At A Medical School In Norfolk, Virginia, Ronald B. Hartman

Community & Environmental Health Theses & Dissertations

A limited number of studies have been conducted to assess the perceptions of risk of medical students and residents for acquiring Human Immunodeficiency Virus (HIV) or Hepatitis B Virus (HBV) via percutaneous (needlestick) injuries while performing clinical training. The purpose of this study is to investigate these perceptions of risk, and to determine whether there is an association between a high perception of risk and a low incidence of needlestick injury. The method of investigation was a four-page survey questionnaire. The instrument was investigated for reliability by use of a pilot study with a small group of medical students and …

Comparison Of Positive Screening And Confimatory Results From Federally Mandated Drug Testing Of Urine, Mary M. Stuck

Community & Environmental Health Theses & Dissertations

The purpose of this study was to analyze the accuracy of FDA approved immunoassays for the detection of drug positive urine samples.

Federal civilian employees are tested under the strict protocol of the Department of Health and Human Services mandatory guidelines for federal workplace drug testing programs. The guidelines provide for a two instrument testing protocol for the analysis of urine samples. The first is an FDA approved immunoassay. Samples which test positive on this screening immunoassay are then submitted for confirmatory testing with the "gold standard" gas chromatography/mass spectrometry.

Agency monthly drug testing summaries, required under the DHHS guidelines …

Lead Activation Of A Developmentally Regulated Calcium Channel In Rat Hippocampal Nerve Terminals, Troy E. Rhodes

Theses and Dissertations in Biomedical Sciences

Low level lead (Pb²⁺) exposure may produce lasting deficits in learning and memory by altering calcium (Ca²⁺) dependent processes. Isolated presynaptic nerve terminals from rat hippocampus were loaded with the intracellular (Ca²⁺) indicator Fura-2. The changes in cytoplasmic free calcium ([Ca²⁺]_i) were measured by stopped-flow fluorescence spectroscopy following depolarization with elevated potassium on a millisecond time scale (Lentzner et al., 1992). Depolarization promoted a rapid increase in Ca²⁺_i which occured in two kinetically distinguishable phases: a fast component, representing the activity of rapidly inactivating Ca²⁺ channels (τ …

A Test Of An Alternate Calibration Matrix For Niosh Method 7300, Robert T. Vitek

Community & Environmental Health Theses & Dissertations

The purpose of this study was to determine if the analytical results (when determining cadmium, lead, and zinc concentrations) for air sample filters prepared and analyzed according to N:OSH Method 7300, differ significantly, from those obtained when the instrument is calibrated using EPA Method 200.7 acid matrix standards. The null hypothesis was that no statistically significant difference, measured at the 95% confidence level, would exist between results obtained from the two calibration standards. Careful standard and sample preparation, the use of an internal standard, and the application of working standard and working internal standard correction factors served to isolate the …

The Evaluation Of Succinylcholine Chloride For Harmful Effects Upon Early-Stage Mouse Embryos, Francis Warren Prescott

Biological Sciences Theses & Dissertations

Succinylcholine (SCh) chloride is a depolarizing neuromuscular blocking agent used to paralyze patients for surgical procedures. Over 1,800 clinical observations of newborn infants have demonstrated that succinylcholine does not cross the placenta in quantities detrimental to fetuses (Kolstad, et al., 1957, Bakhoum, et al., 1957, Hodges, et al., 1959, Duffield, et al., 1958, Dennis, et al., 1954, 1956, McNab, 1955, Coleman, et al., 1956, Lund, 1953). Later investigations which involved comparison of blood levels of SCh in the mother to those in fetuses bolstered the finding that SCh fails to cross the placenta in significant amounts (Moya and Kvisselgaard, 1961, …

Toxin Producing Phytoplankton In Chesapeake Bay, Harold G. Marshall

Biological Sciences Faculty Publications

Three diatoms and nine dinoflagellates, known to be associated with toxin production, have been identified within Chesapeake Bay. Over the past several decades this number has increased to its present level so that they now represent approximately 1.7% the total number of phytoplankton species reported for the Bay.

In Situ Regulation Of Cytosolic Phospolipase A₂, Beverly A. Rzigalinski

Theses and Dissertations in Biomedical Sciences

The 85 kDa cytosolic phospholipase A₂ (cPLA₂) is an agonist-responsive effector for intracellular signal transduction through the arachidonate cascade. In vitro studies have demonstrated that this enzyme is regulated by sub-micromolar calcium and is specific for arachidonate as the sn-2 fatty acyl group of phospholipid substrates. However, very little data is available regarding in situ mechanisms which govern the activity of cPLA₂. The primarily objective of these studies was to develop an in situ system for the study of cPLA₂, and investigate mobilization of arachidonate during signal transduction events.

Dimethylsulfoxide differentiation of the …

Validation Of A Bag Sampling Method For 1,3-Butadiene, Lori Eckenrode

Community & Environmental Health Theses & Dissertations

At this time there is no NIOSH approved means for bag sampling 1,3-butadiene. An attempt was made to use the application of cold (0°F) to inhibit the reactivity of the gas prior to analysis. The State of California Air Resources Board has an approved method for the gas chromatographic analysis of 1,3-butadiene from stationary sources. The method was utilized in the application of industrial hygiene monitoring of affected workers. The application of cold was found to be ineffective at inhibiting the highly reactive nature of 1,3-butadiene. Analyte losses were too great to classify the method as an accurate measure of …

Development And Standardization Of A Short-Term Assay For Evaluating Polluted Estuarine And Coastal Environments: The Medaka Embryo-Larval Assay, Michael Frederick Helmstetter

OES Theses and Dissertations

The eggs of the Japanese medaka (Oryzias latipes) were employed in a number of studies to develop a routine, standardized assay which can assess the acute and sublethal impacts of individual toxicants and complex mixtures. The eggs of this Cyprinodont minnow were topically treated with each toxicant or mixture dissolved in membrane permeable dimethylsulfoxide (DMSO) solvent. Nine chemicals were initially evaluated with two, pentachlorophenol (PCP) and tributyltin chloride (TBTCl), subsequently selected for extensive evaluations of salinity tolerance and the accuracy of the topical exposure method for representing a typical immersion exposure. The amount of material actually penetrating the eggs was …