@misc{burkholder_dickey_kinder_reed_mallin_mciver_cahoon_melia_brownie_smith_et al._2006, title={Comprehensive trend analysis of nutrients and related variables in a large eutrophic estuary: A decadal study of anthropogenic and climatic influences}, volume={51}, ISSN={["1939-5590"]}, DOI={10.4319/lo.2006.51.1_part_2.0463}, abstractNote={We used a decadal data set, with weekly to biweekly sampling in April—October and monthly sampling in November—March, to characterize climatic (hurricane‐level storms, a sustained 3‐yr drought) and anthropogenic influences on N and P concentrations and loadings to a large eutrophic, poorly flushed estuary, the Neuse Estuary of the Albemarle—Pamlico Estuarine System. Mass volume transport data were obtained with cross‐estuary transect flow measurements taken near the entrance to the estuary. Although trends were minimally influenced by hurricanes, analyses were significantly affected by the sustained drought near the end of the study. As examples, decreasing trends in total N (TN), total P (TP), and bottom‐water dissolved oxygen concentrations, and in TN loadings were significant considering all data, but these trends were not significant when the sustained drought was excluded from analysis. In addition, the trend in TN loading was especially sensitive to the initial sampling period. NH4+ concentrations dramatically increased (overall by ~500%) as a persistent trend regardless of attempts to control for climatic events. An increasing trend in NH4+ also was documented in an adjacent, rapidly flushed Coastal Plain estuary, the Cape Fear. The NH4+ data suggest a regional‐scale effect of high inputs from inadequately controlled, increasing nonpoint sources. The fragility of TN loading trends, the striking increase in NH4+ concentrations, and the lack of management emphasis on controlling nonpoint sources such as “new” industrialized swine production collectively do not support recent reports of achievement of a 30% reduction in TN loading to the Neuse. Nonpoint sources remain a critical target for reduction to alleviate the negative effects of cultural eutrophication in this system, as in many estuaries throughout the world.}, number={1}, journal={LIMNOLOGY AND OCEANOGRAPHY}, author={Burkholder, JoAnn M. and Dickey, David A. and Kinder, Carol A. and Reed, Robert E. and Mallin, Michael A. and McIver, Matthew R. and Cahoon, Lawrence B. and Melia, Greg and Brownie, Cavell and Smith, Joy and et al.}, year={2006}, month={Jan}, pages={463–487} }
 @article{parrow_elbraechter_krause_burkholder_deamer_htyte_allen_2006, title={The taxonomy and growth of a Crypthecodinium species (Dinophyceae) isolated from a brackish-water fish aquarium}, volume={28}, ISSN={["1814-232X"]}, DOI={10.2989/18142320609504145}, abstractNote={An unidentified heterotrophic dinoflagellate found growing in abundance in a brackish-water fish aquarium was isolated and serially cultivated using a fish cell line as the food source. Prominent characteristics of this dinoflagellate included a cingulum that did not fully encircle the motile cell, cell division in non-motile cysts, and a theca composed of thin but structured plates. Morphological analysis of flagellate cells by scanning electron microscopy revealed a Kofoid thecal plate tabulation of 4', 4a, 4", 'X', 5 or 6c, ?s, 5"', 1p, 1"", most consistent with the original description of Crypthecodinium setense Biecheler. This Crypthecodinium species exhibited a high maximum division rate (3.2 divisions day−1) and cell yield (>106 cells ml−1) when fed cultured fish cells. Small sub-unit rDNA phylogenetic analyses supported relatedness with a previously studied Crypthecodinium-like dinoflagellate, but a significant difference in aligned gene sequences was found. This study provides the first clear demonstration of the plate tabulation of a Crypthecodinium species since the original description over 60 years ago, allowing the original morphological conception of Crypthecodinium to be linked with molecular phylogenetic information.}, number={2}, journal={AFRICAN JOURNAL OF MARINE SCIENCE}, author={Parrow, M. W. and Elbraechter, M. and Krause, M. K. and Burkholder, J. M. and Deamer, N. J. and Htyte, N. and Allen, E. H.}, year={2006}, month={Sep}, pages={185–191} }
 @article{parrow_burkholder_deamer_ramsdell_2005, title={Contaminant-free cultivation of Pfiesteria shumwayae (Dinophyceae) on a fish cell line}, volume={39}, ISSN={["0948-3055"]}, DOI={10.3354/ame039097}, abstractNote={Geographically distinct strains of the heterotrophic dinoflagellate Pfiesteria shumwayae were cultivated on a fish cell line in the apparent absence of bacteria and other microbial conta- minants. Cultures were established with a high rate of success by inoculating single purified P. shumwayae cells into fish cell cultures containing a simple saltwater medium suitable for both cell types, and resulting isolates were serially cultivated on fish cells for months without visible signs of abnormality or reduced viability. P. shumwayae fed phagocytically on the fish cells and exhibited higher cell production than reported using other culturing methods. Compared to previous methods of studying the interaction between Pfiesteria spp. and fishes, this system enabled closer and more direct observation of the dinoflagellates and was also more economical and sustainable as a culturing method. The absence of bacteria and other contaminating microorganisms should facilitate important physiological and biochemical investigations. The methods used were inadequate for cultivating strains of P. piscicida, suggesting a possible difference in nutritional requirements between the 2 Pfiesteria species.}, number={1}, journal={AQUATIC MICROBIAL ECOLOGY}, author={Parrow, MW and Burkholder, JM and Deamer, NJ and Ramsdell, JS}, year={2005}, month={Apr}, pages={97–105} }
 @article{burkholder_gordon_moeller_law_coyne_lewitus_ramsdell_marshall_deamer_cary_et al._2005, title={Demonstration of toxicity to fish and to mammalian cells by Pfiesteria species: Comparison of assay methods and strains}, volume={102}, ISSN={0027-8424 1091-6490}, url={http://dx.doi.org/10.1073/pnas.0500168102}, DOI={10.1073/pnas.0500168102}, abstractNote={
            Toxicity and its detection in the dinoflagellate fish predators
            Pfiesteria piscicida
            and
            Pfiesteria shumwayae
            depend on the strain and the use of reliable assays. Two assays, standardized fish bioassays (SFBs) with juvenile fish and fish microassays (FMAs) with larval fish, were compared for their utility to detect toxic
            Pfiesteria
            . The comparison included strains with confirmed toxicity, negative controls (noninducible
            Pfiesteria
            strains and a related nontoxic cryptoperidiniopsoid dinoflagellate), and
            P. shumwayae
            strain CCMP2089, which previously had been reported as nontoxic. SFBs, standardized by using toxic
            Pfiesteria
            (coupled with tests confirming
            Pfiesteria
            toxin) and conditions conducive to toxicity expression, reliably detected actively toxic
            Pfiesteria
            , but FMAs did not.
            Pfiesteria
            toxin was found in fish- and algae-fed clonal
            Pfiesteria
            cultures, including CCMP2089, but not in controls. In contrast, noninducible
            Pfiesteria
            and cryptoperidiniopsoids caused no juvenile fish mortality in SFBs even at high densities, and low larval fish mortality by physical attack in FMAs. Filtrate from toxic strains of
            Pfiesteria
            spp. in bacteria-free media was cytotoxic. Toxicity was enhanced by bacteria and other prey, especially live fish. Purified
            Pfiesteria
            toxin extract adversely affected mammalian cells as well as fish, and it caused fish death at environmentally relevant cell densities. These data show the importance of testing multiple strains when assessing the potential for toxicity at the genus or species level, using appropriate culturing techniques and assays.
          }, number={9}, journal={Proceedings of the National Academy of Sciences}, publisher={Proceedings of the National Academy of Sciences}, author={Burkholder, J. M. and Gordon, A. S. and Moeller, P. D. and Law, J. M. and Coyne, K. J. and Lewitus, A. J. and Ramsdell, J. S. and Marshall, H. G. and Deamer, N. J. and Cary, S. C. and et al.}, year={2005}, month={Feb}, pages={3471–3476} }
 @article{burkholder_eggleston_glasgow_brownie_reed_janowitz_posey_melia_kinder_corbett_et al._2004, title={Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound ecosystems}, volume={101}, ISSN={["0027-8424"]}, DOI={10.1073/pnas.0306842101}, abstractNote={Ecosystem-level impacts of two hurricane seasons were compared several years after the storms in the largest lagoonal estuary in the U.S., the Albemarle–Pamlico Estuarine System. A segmented linear regression flow model was developed to compare mass-water transport and nutrient loadings to a major artery, the Neuse River Estuary (NRE), and to estimate mean annual versus storm-related volume delivery to the NRE and Pamlico Sound. Significantly less water volume was delivered by Hurricane Fran (1996), but massive fish kills occurred in association with severe dissolved oxygen deficits and high contaminant loadings (total nitrogen, total phosphorus, suspended solids, and fecal bacteria). The high water volume of the second hurricane season (Hurricanes Dennis, Floyd, and Irene in 1999) delivered generally comparable but more dilute contaminant loads, and no major fish kills were reported. There were no discernable long-term adverse impacts on water quality. Populations of undesirable organisms, such as toxic dinoflagellates, were displaced down-estuary to habitats less conducive for growth. The response of fisheries was species-dependent: there was no apparent impact of the hurricanes on commercial landings of bivalve molluscs or shrimp. In contrast, interacting effects of hurricane floodwaters in 1999 and intensive fishing pressure led to striking reductions in blue crabs. Overall, the data support the premise that, in shallow estuaries frequently disturbed by hurricanes, there can be relatively rapid recovery in water quality and biota, and benefit from the scouring activity of these storms.}, number={25}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Burkholder, J and Eggleston, D and Glasgow, H and Brownie, C and Reed, R and Janowitz, G and Posey, M and Melia, G and Kinder, C and Corbett, R and et al.}, year={2004}, month={Jun}, pages={9291–9296} }
 @article{parrow_burkholder_deamer_zhang_2002, title={Vegetative and sexual reproduction in Pfiesteria spp. (Dinophyceae) cultured with algal prey, and inferences for their classification.}, volume={1}, DOI={10.1016/s1568-9883(02)00009-4}, abstractNote={Algal-fed clonal zoospore cultures of Pfiesteria piscicida and Pfiesteria shumwayae enabled description of certain conserved morphological and reproductive features. Common modes of reproduction (especially via division cysts) were documented in herbivorous P. piscicida and P. shumwayae using cultures fed algal prey, together with supporting photography and flow cytometric DNA measurements. Other cysts were characterized such as vacuolate cysts in starved P. piscicida cultures and temporary cysts in both species fed algal prey. This study also represents the first report of sexual reproduction in Pfiesteria spp. cultures fed algal prey rather than live fish; the first report of a technique for cell cycle synchronization for these heterotrophic dinoflagellates; and the first information on storage products of cells released from Pfiesteria reproductive cysts. Sexual reproduction in algal-fed P. piscicida clonal cultures was evidenced by fusing gametes, cells with two longitudinal flagella, and nuclear cyclosis. Both isogamous and anisogamous fusions were observed, and resulting cells with two trailing flagella (i.e., planozygotes and planomeiocytes) sometimes comprised ≥50% of the flagellated cells. These cells continued feeding activity and eventually (hours) lost their flagella and formed cysts. Nuclear cyclosis and a subsequent cell division were observed in thin-walled reproductive cysts prior to release of two flagellated cells. One gamete fusion event was also documented in 1 of 20 algal-fed clones of P. shumwayae, with an aplanozygote as the product. We obtained high cell synchrony (≥90% 1C) in the tested cultures using our preferential lysis technique and tracked the decline in lipid content of excysted zoospore populations over time. The data from this study were considered together with previous research to gain insights about relationships between Pfiesteria spp. and other heterotrophic dinoflagellates. Pfiesteria spp. should be regarded as free-living predators rather than parasites because they are prey generalists without demonstrated “host” specificity and their flagellated feeding stages are not morphologically distinct from swimming stages. Although they originally were placed within the Dinamoebales because amoebae can predominate, this study as well as other published research consistently has shown that the dominant stage varies depending on culture conditions, prey type/availability and strains. The peridinoid plate structure of each Pfiesteria species, which thus far has been conserved across culture conditions and strains, supports placement of Pfiesteria spp. within the Peridiniales. At the species level, plate structure (differing by one precingular plate) and molecular data (18S rDNA) indicate that the two Pfiesteria spp. are closely related in comparison to species grouped within other genera.}, number={1}, journal={Harmful Algae}, author={Parrow, M. and Burkholder, J. M. and Deamer, N. J. and Zhang, C.}, year={2002}, pages={5–33} }
 @article{cancellieri_burkholder_deamer-melia_glasgow_2001, title={Chemosensory attraction of zoospores of the estuarine dinoflagellates, Pfiesteria piscicida and P-shumwayae, to finfish mucus and excreta}, volume={264}, ISSN={["1879-1697"]}, DOI={10.1016/S0022-0981(01)00299-4}, abstractNote={Toxic strains of the estuarine dinoflagellates, Pfiesteria piscicida and P. shumwayae, can cause fish death and disease, whereas other estuarine ‘lookalike’ species such as cryptoperidiniopsoids have not been ichthyotoxic under ecologically relevant conditions. Chemosensory attraction of three functional types of these Pfiesteria spp. were separately evaluated for their attraction to fresh fish mucus and excreta. Clonal cultures of actively toxic (TOX-A, engaged in killing fish) and temporarily nontoxic (tested as toxic but without access to live fish for >1 week to 5 months (in most experiments, ≤3 months) as ‘short-duration’ TOX-B; and without access to live fish for ≥1.5 years as ‘long-duration’ TOX-B) functional types of P. piscicida and P. shumwayae were derived from the same clones whereas the non-inducible cultures (NON-IND, tested as incapable of toxic activity in the presence of fish), of necessity, were from different clonal isolates. NON-IND cultures previously had been grown on algal prey for 3–8 months, and had repeatedly been tested as incapable of causing fish distress, disease or death via toxic activity. Attraction to fish materials was based on the number of zoospores that entered microcapillary tubes containing sterile-filtered 15-ppt water (controls), vs. entry into tubes with sterile-filtered mucus and excreta (collected in 15-ppt water) that had been collected from live tilapia, bluegill, hybrid striped bass, and Atlantic menhaden (tested separately within 3 h of removal from live fish). TOX-A zoospores of both Pfiesteria species exhibited the strongest attraction to the fish mucus and excreta, with comparable response to the materials from all four test fish species. Short-duration TOX-B zoospores showed an intermediate response that apparently depended on the duration of mucus separation from the live fish: the shorter the separation period, the stronger the zoospore attraction to the fish materials. In contrast to TOX-A and short-duration TOX-B zoospores, NON-IND and long-duration TOX-B zoospores generally showed little or no response to the fish materials. Zoospores of the cryptoperidiniopsoid demonstrated a moderate attraction that did not appear to depend on the time of isolation from fish. TOX-A zoospores were also tested for attraction to sterile-filtered vs. non-filtered fish mucus (time separated from the live animal, 3–96 h). These zoospores, which initially had been actively attracted, were no longer attracted to the unfiltered fish materials after 48 h, whereas attraction to the sterile-filtered fish mucus and excreta persisted throughout the duration of the experiment. Thus, the attractant signal in the materials was degraded or effectively blocked by the bacterial community within hours of isolation from live fish. This study indicates the importance of functional type or toxicity status, and the importance of the history of exposure to live fish, in the behavioral ecology of Pfiesteria spp. Initial attraction to fish materials strongly depended on the functional type, and on the history of toxic activity. Non-inducible and long-duration TOX-B cultures of Pfiesteria spp., unlike actively toxic and short-duration TOX-B (potentially toxic) strains, initially were virtually unresponsive to fish mucus.}, number={1}, journal={JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY}, author={Cancellieri, PJ and Burkholder, JM and Deamer-Melia, NJ and Glasgow, HB}, year={2001}, month={Sep}, pages={29–45} }
 @article{moeller_morton_mitchell_sivertsen_fairey_mikulski_glasgow_deamer-melia_burkholder_ramsdell_2001, title={Current progress in isolation and characterization of toxins isolated from Pfiesteria piscicida}, volume={109}, ISSN={["0091-6765"]}, DOI={10.2307/3454921}, journal={ENVIRONMENTAL HEALTH PERSPECTIVES}, author={Moeller, PDR and Morton, SL and Mitchell, BA and Sivertsen, SK and Fairey, ER and Mikulski, TM and Glasgow, H and Deamer-Melia, NJ and Burkholder, JM and Ramsdell, JS}, year={2001}, month={Oct}, pages={739–743} }
 @article{glasgow_burkholder_mallin_deamer-melia_reed_2001, title={Field ecology of toxic Pfiesteria complex species and a conservative analysis of their role in estuarine fish kills}, volume={109}, ISSN={["1552-9924"]}, DOI={10.2307/3454919}, journal={ENVIRONMENTAL HEALTH PERSPECTIVES}, author={Glasgow, HB and Burkholder, JM and Mallin, MA and Deamer-Melia, NJ and Reed, RE}, year={2001}, month={Oct}, pages={715–730} }
 @article{burkholder_glasgow_deamer-melia_2001, title={Overview and present status of the toxic Pfiesteria complex (Dinophyceae)}, volume={40}, ISSN={["2330-2968"]}, DOI={10.2216/i0031-8884-40-3-186.1}, abstractNote={Abstract This paper reviews the Pfiesteria issue and Pfiesteria science and presents new information on variation in toxicity among Pfiesteria strains, culture effects on their toxicity, the trophic interactions of Pfiesteria spp ., and impacts on fish and mammals. We also assess Pfiesteria spp. impacts on fish in comparison to certain other estuarine dinoflagellates of similar appearance. Species of the toxic Pfiesteria complex (TPC) thus far include P. piscicida and P. shumwayae. These species share morphological and genetic similarities, and both have toxic strains that (1) show strong attraction to live fish;(2) exhibit toxicity that is triggered by live fish or their fresh tissues and excreta; and (3) produce toxin(s) that cause fish stress, disease and death under ecologically relevant conditions (the standardized fish bioassay process involves testing live Pfiesteria cells at similar densities to those encountered during Pfiesteria-related fish kill/disease events). Both Pfiesteria species also have a complex life cycle with multiple amoeboid, flagellated and cyst stages, several of which are ichthyotoxic. TPC species are eurythermal and euryhaline, with prey spanning the estuarine food web, from bacteria to mammalian tissues. They can be stimulated directly or indirectly by nitrogen and phosphorus enrichment. Toxic strains can be either actively or potentially toxic (the TOX-A and TOX-B functional types, respectively); in addition, c.40% of randomly isolated clones have been found to be benign [the noninducible or NON-IND functional type, which apparently lacks the ability to produce bioactive substances (toxins) that cause fish disease or death]. These functional types differ significantly in response to algal prey, predators, nutrients and fish. Moreover, as an apparent artifact of culture conditions, toxic strains generally lose their ability to cause fish death and disease and become NON-IND within weeks to months. At low cell densities, toxic strains can be causative agents of acute and/or chronic diffuse and focal lesions and of other fish diseases, as demonstrated in fish bioassays. A partially purified, water-soluble Pjiesteria toxin disrupts calcium metabolism in rat pituitary cells and mimics an adenosine triphosphate neurotransmitter that targets P2X7 purinoreceptors found predominantly on immune cells. Respiratory, visual, and neurological impacts have been sustained by people exposed to aerosols from fish-killing Pfiesteria cultures or to water and aerosols during estuarine fish kills associated with toxic Pfiesteria. Neurocognitive impacts from exposure to toxic Pfiesteria have been replicated experimentally in small mammals. Toxic strains of Pfiesteria species have been confirmed from mid-Atlantic and Gulf Coast estuaries in the United States and from northern Europe and New Zealand, indicating that these toxic dinoflagellates are cosmopolitan in distribution.}, number={3}, journal={PHYCOLOGIA}, author={Burkholder, JM and Glasgow, HB and Deamer-Melia, N}, year={2001}, month={May}, pages={186–214} }
 @article{burkholder_glasgow_deamer-melia_springer_parrow_zhang_cancellieri_2001, title={Species of the toxic Pfiesteria complex, and the importance of functional type in data interpretation}, volume={109}, ISSN={["1552-9924"]}, DOI={10.2307/3454912}, journal={ENVIRONMENTAL HEALTH PERSPECTIVES}, author={Burkholder, JM and Glasgow, HB and Deamer-Melia, NJ and Springer, J and Parrow, MW and Zhang, C and Cancellieri, PJ}, year={2001}, month={Oct}, pages={667–679} }
 @article{burkholder_marshall_glasgow_seaborn_deamer-melia_2001, title={The standardized fish bioassay procedure for detecting and culturing actively toxic Pfiesteria, used by two reference laboratories for Atlantic and Gulf Coast states}, volume={109}, ISSN={["1552-9924"]}, DOI={10.2307/3454922}, journal={ENVIRONMENTAL HEALTH PERSPECTIVES}, author={Burkholder, JM and Marshall, HG and Glasgow, HB and Seaborn, DW and Deamer-Melia, NJ}, year={2001}, month={Oct}, pages={745–756} }
 @article{levin_rezvani_christopher_glasgow_deamer-melia_burkholder_moser_jensen_2000, title={Rapid neurobehavioral analysis of Pfiesteria piscicida effects in juvenile and adult rats}, volume={22}, ISSN={["0892-0362"]}, DOI={10.1016/S0892-0362(00)00080-5}, abstractNote={The estuarine dinoflagellate Pfiesteria piscicida is known to kill fish and has been associated with neurocognitive deficits in humans. We have developed a rat model to demonstrate that exposure to Pfiesteria causes significant learning impairments. This has been repeatedly seen as a choice accuracy impairment during radial-arm maze learning. Pfiesteria-induced effects were also seen in a locomotor activity test in the figure-8 apparatus. The current studies used the short-term radial-arm maze acquisition, the figure-8 activity test, and the functional observational battery (FOB) to assess Pfiesteria-induced neurobehavioral effects in adult and juvenile rats. In study 1, the neurobehavioral potency of three different Pfiesteria cultures (Pf 113, Pf 728, and Pf Vandermere) was assessed. Ninety-six (12 per group) adult female Sprague-Dawley rats were injected subcutaneously with a single dose of Pfiesteria taken from aquarium-cultured Pfiesteria (35,600 or 106,800 Pfiesteria cells per kilogram of rat body weight). One control group (N = 12) was injected with saline and one (N = 12) with aquarium water not containing Pfiesteria. All three of the Pfiesteria samples (p < 0.05) impaired choice accuracy over the first six sessions of training. At the time of the radial-arm maze choice accuracy impairment, no overt Pfiesteria-related effects were seen using an FOB, indicating that the Pfiesteria-induced choice accuracy deficit was not due to generalized debilitation. In the figure-8 apparatus, Pfiesteria treatment caused a significant decrease in mean locomotor activity. In study 2, the neurobehavioral effects of the Pf 728 sample type were assessed in juvenile rats. Twenty-four day-old male and female rats were injected with 35,600 or 106,800 Pf-728 Pfiesteria cells per kilogram of rat body weight. As with adult females, the juvenile rats showed a significant impairment in radial-arm maze choice accuracy. No changes in locomotor activity or the FOB were detected in the juvenile rats. Furthermore, there were no differences between male and female rats in the Pfiesteria-induced choice accuracy impairment. Pfiesteria effects on choice accuracy in the radial-arm maze in rats constitute a critical component of the model of Pfiesteria toxicity, because the hallmark of Pfiesteria toxicity in humans is cognitive dysfunction. Our finding that analysis of the first six sessions of radial-arm maze testing is sufficient for determining the effect means that this test will be useful as a rapid screen for identifying the critical neurotoxin(s) of Pfiesteria in future studies.}, number={4}, journal={NEUROTOXICOLOGY AND TERATOLOGY}, author={Levin, ED and Rezvani, AH and Christopher, NC and Glasgow, HB and Deamer-Melia, NJ and Burkholder, JM and Moser, VC and Jensen, K}, year={2000}, pages={533–540} }
 @article{levin_simon_schmechel_glasgow_deamer-melia_burkholder_moser_jensen_harry_1999, title={Pfiesteria toxin and learning performance}, volume={21}, ISSN={["0892-0362"]}, DOI={10.1016/S0892-0362(98)00041-5}, abstractNote={Pfiesteria piscicida is an estuarine dinoflagellate involved with fish kills along the east coast of the United States. We previously documented a radial-arm maze learning deficit in rats exposed to Pfiesteria that may be related to cognitive deficits seen in humans after accidental Pfiesteria exposure. The current study elucidated important behavioral parameters of this deficit. There were six dose groups. Forty (10/group) adult female Sprague–Dawley rats were injected (SC) with a single dose of Pfiesteria taken from aquarium-cultured Pfiesteria (35,600, 106,800, or 320,400 Pfiesteria cells/kg of rat body weight or a cell-free filtrate of the 106,800 cells/kg dose). One control group (N = 10) was injected with saline and one (N = 10) with aquarium water not containing Pfiesteria. Half of the rats in each group were tested on an 8-arm radial maze in a standard test room, and the other half were tested on the radial maze in a sound-attenuating chamber. In the standard maze room, there was a significant effect of Pfiesteria (p < 0.05) impairing choice accuracy improvement over the first six sessions of training among rats administered 106,800, 320,400, and the 106,800 cells/kg filtered sample. In contrast, there was no indication of an effect of Pfiesteria when the rats were tested on the same configuration radial maze in the sound-attenuating chamber. After 18 sessions of training in one room, the rats were switched for six sessions of testing in the other room and finally were switched back to their original room for three sessions. There was a significant Pfiesteria-induced deficit when the rats were tested in the standard test room but not when they were tested in the sound-attenuating chamber. When the Pfiesteria-exposed rats were initially switched from the sound-attenuating chamber to the standard test room they performed significantly worse than controls, whereas Pfiesteria-treated rats switched from the standard test room to the sound-attenuating chamber did not perform differently from controls. These results suggest that the Pfiesteria-induced learning impairment may result from the negative impact of distracting stimuli. At the time of the learning impairment, no overt Pfiesteria-related effects were seen using a functional observational battery and no overall response latency effects were seen, indicating that the Pfiesteria-induced choice accuracy deficit was not due to generalized debilitation. In the initial use of the figure-8 maze in this line of research, the rats in the same Pfiesteria treatment groups that showed significant deficits in the radial-arm maze showed greater declines in activity rates in a 1-h figure-8 locomotor activity test. Both the 106,800 and 320,400 Pfiesteria cells/kg groups showed significantly greater linear trends of activity decline relative to tank water-treated controls. This reflected an initial slight hyperactivity in the Pfiesteria-treated animals followed by a decrease to control levels. Pfiesteria effects in the figure-8 maze and in early radial-arm maze training may be useful in a rapid screen for identifying the critical toxin(s) of Pfiesteria in future studies. Published by Elsevier Science Inc.}, number={3}, journal={NEUROTOXICOLOGY AND TERATOLOGY}, author={Levin, ED and Simon, BB and Schmechel, DE and Glasgow, HB and Deamer-Melia, NJ and Burkholder, JM and Moser, VC and Jensen, K and Harry, GJ}, year={1999}, pages={215–221} }
 @article{fairey_edmunds_deamer-melia_glasgow_johnson_moeller_burkholder_ramsdell_1999, title={Reporter gene assay for fish-killing activity produced by Pfiesteria piscicida}, volume={107}, ISSN={["0091-6765"]}, DOI={10.2307/3434655}, abstractNote={Collaborative studies were performed to develop a functional assay for fish-killing activity produced by Pfiesteria piscicida. Eight cell lines were used to screen organic fractions and residual water fraction by using a 3-[4, 5-dimethylthiazol-(2-4)]-diphenyltetrazolium bromide cytotoxicity assay. Diethyl ether and a residual water fraction were cytotoxic to several cell lines including rat pituitary (GH(4)C(1)) cells. Residual water as well as preextracted culture water containing P. piscicida cells induced c-fos-luciferase expressed in GH(4)C(1) cells with a rapid time course of induction and sensitive detection. The reporter gene assay detected activity in toxic isolates of P. piscicida from several North Carolina estuaries in 1997 and 1998 and may also be suitable for detecting toxic activity in human and animal serum.}, number={9}, journal={ENVIRONMENTAL HEALTH PERSPECTIVES}, author={Fairey, ER and Edmunds, JSG and Deamer-Melia, NJ and Glasgow, H and Johnson, FM and Moeller, PR and Burkholder, JM and Ramsdell, JS}, year={1999}, month={Sep}, pages={711–714} }
 @article{burkholder_mallin_glasgow_larsen_mciver_shank_deamer-melia_briley_springer_touchette_et al._1997, title={Impacts to a coastal river and estuary from rupture of a large swine waste holding lagoon}, volume={26}, ISSN={["0047-2425"]}, DOI={10.2134/jeq1997.00472425002600060003x}, abstractNote={Abstract}, number={6}, journal={JOURNAL OF ENVIRONMENTAL QUALITY}, author={Burkholder, JM and Mallin, MA and Glasgow, HB and Larsen, LM and McIver, MR and Shank, GC and Deamer-Melia, N and Briley, DS and Springer, J and Touchette, BW and et al.}, year={1997}, pages={1451–1466} }