58 research outputs found

    Some Histologic Gill Lesions of Several Estuarine Finfishes Related to Exposure to Contaminated Sediments: A Preliminary Report

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    Collections were made during 1983, \u2784 and \u2785 in the Elizabeth River, whose sediments are heavily contaminated with PAHs, heavy metals and other anthropogenic materials. Comparison samples were from the cleaner Nansemond River, another subestuary feeding into Hampton Roads (the lower James River) nearby. Most samples from all stations included three transient quasi-catadromous nektonic sciaenids, Atlantic croaker (Micropogonias undulatus), spot (Leiostomus xanthurus) and weakfish (Cynoscion regalis), and two endemic estuarine benthic fishes, hogchoker (Trinectes maculatus) and oyster toadfish (Opsanus tau).https://scholarworks.wm.edu/vimsbooks/1161/thumbnail.jp

    Bibliography of the Monogenetic Trematode Literature of the World, 1758 to 1969

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    In preparing this bibliography we have attempted to collect all literature references pertaining to the Monogenea. Accordingly it represents an up-to-date (through September 1969) guide to the literature of these parasites, and is of maximum scope, including not only taxonomic literature but also references to ecological and physiological studies on Monogenea as well as reports of preferred methods of treating infestations of these parasites

    Skin ulcers in estuarine fishes: a comparative pathological evaluation of wild and laboratory-exposed fish.

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    The toxic dinoflagellate Pfiesteria piscicida Steidinger & Burkholder has recently been implicated as the etiologic agent of acute mass mortalities and skin ulcers in menhaden, Brevoortia tyrannus, and other fishes from mid-Atlantic U.S. estuaries. However, evidence for this association is largely circumstantial and controversial. We exposed tilapia (Oreochromis spp.) to Pfiesteria shumwayae Glasgow & Burkholder (identification based on scanning electron microscopy and molecular analyses) and compared the resulting pathology to the so-called Pfiesteria-specific lesions occurring in wild menhaden. The tilapia challenged by high concentrations (2,000-12,000 cells/mL) of P. shumwayaeexhibited loss of mucus coat and scales plus mild petecchial hemorrhage, but no deeply penetrating chronic ulcers like those in wild menhaden. Histologically, fish exhibited epidermal erosion with bacterial colonization but minimal associated inflammation. In moribund fish, loss of epidermis was widespread over large portions of the body. Similar erosion occurred in the mucosa lining the oral and branchial cavities. Gills exhibited epithelial lifting, loss of secondary lamellar structure, and infiltration by lymphoid cells. Epithelial lining of the lateral line canal (LLC) and olfactory organs exhibited severe necrosis. Visceral organs, kidney, and neural tissues (brain, spinal cord, ganglia, peripheral nerves) were histologically normal. An unexpected finding was the numerous P. shumwayae cells adhering to damaged skin, skin folds, scale pockets, LLC, and olfactory tissues. In contrast, histologic evaluation of skin ulcers in over 200 wild menhaden from Virginia and Maryland portions of the Chesapeake Bay and the Pamlico Estuary, North Carolina, revealed that all ulcers harbored a deeply invasive, highly pathogenic fungus now known to be Aphanomyces invadans. In menhaden the infection always elicited severe myonecrosis and intense granulomatous myositis. The consistent occurrence of this fungus and the nature and severity of the resulting inflammatory response indicate that these ulcers are chronic (age >1 week) and of an infectious etiology, not the direct result of an acute toxicosis initiated by Pfiesteria toxin(s) as recently hypothesized. The disease therefore is best called ulcerative mycosis (UM). This study indicates that the pathology of Pfiesteria laboratory exposure is fundamentally different from that of UM in menhaden; however, we cannot rule out Pfiesteria as one of many possible early initiators predisposing wild fishes to fungal infection in some circumstances

    HLA-A*32:01 is strongly associated with vancomycin-induced drug reaction with eosinophilia and systemic symptoms

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    Background Vancomycin is a prevalent cause of the severe hypersensitivity syndrome drug reaction with eosinophilia and systemic symptoms (DRESS) which leads to significant morbidity and mortality and commonly occurs in the setting of combination antibiotic therapy which impacts future treatment choices. Variations in human leukocyte antigen (HLA) class I in particular have been associated with serious T-cell mediated adverse drug reactions which has led to preventive screening strategies for some drugs. Objective To determine if variation in the HLA region is associated with vancomycin-induced DRESS. Methods Probable vancomycin DRESS cases were matched 1:2 with tolerant controls based on sex, race, and age using BioVU, Vanderbilt’s deidentified electronic health record database. Associations between DRESS and carriage of HLA class I and II alleles were assessed by conditional logistic regression. An extended sample set from BioVU was utilized to conduct a time-to-event analysis of those exposed to vancomycin with and without the identified HLA risk allele. Results Twenty-three individuals met inclusion criteria for vancomycin-associated DRESS. 19/23 (82.6%) cases carried HLA-A*32:01 compared to 0/46 (0%) of the matched vancomycin tolerant controls (p=1x10-8) and 6.3% of the BioVU population (n=54,249) (p=2x10-16). Time-to-event analysis of DRESS development during vancomycin treatment among the HLA-A*32:01 positive group indicated that 19.2% developed DRESS and did so within four weeks. Conclusions HLA-A*32:01 is strongly associated with vancomycin DRESS in a population of predominantly European ancestry. HLA-A*32:01 testing could improve antibiotic safety, help implicate vancomycin as the causal drug and preserve future treatment options with co-administered antibiotics

    Modeling Initiation of Ewing Sarcoma in Human Neural Crest Cells

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    Ewing sarcoma family tumors (ESFT) are aggressive bone and soft tissue tumors that express EWS-ETS fusion genes as driver mutations. Although the histogenesis of ESFT is controversial, mesenchymal (MSC) and/or neural crest (NCSC) stem cells have been implicated as cells of origin. For the current study we evaluated the consequences of EWS-FLI1 expression in human embryonic stem cell-derived NCSC (hNCSC). Ectopic expression of EWS-FLI1 in undifferentiated hNCSC and their neuro-mesenchymal stem cell (hNC-MSC) progeny was readily tolerated and led to altered expression of both well established as well as novel EWS-FLI1 target genes. Importantly, whole genome expression profiling studies revealed that the molecular signature of established ESFT is more similar to hNCSC than any other normal tissue, including MSC, indicating that maintenance or reactivation of the NCSC program is a feature of ESFT pathogenesis. Consistent with this hypothesis, EWS-FLI1 induced hNCSC genes as well as the polycomb proteins BMI-1 and EZH2 in hNC-MSC. In addition, up-regulation of BMI-1 was associated with avoidance of cellular senescence and reversible silencing of p16. Together these studies confirm that, unlike terminally differentiated cells but consistent with bone marrow-derived MSC, NCSC tolerate expression of EWS-FLI1 and ectopic expression of the oncogene initiates transition to an ESFT-like state. In addition, to our knowledge this is the first demonstration that EWS-FLI1-mediated induction of BMI-1 and epigenetic silencing of p16 might be critical early initiating events in ESFT tumorigenesis

    Epigenetic targeting of Hedgehog pathway transcriptional output through BET bromodomain inhibition

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    Hedgehog signaling drives oncogenesis in several cancers and strategies targeting this pathway have been developed, most notably through inhibition of Smoothened. However, resistance to Smoothened inhibitors occurs via genetic changes of Smoothened or other downstream Hedgehog components. Here, we overcome these resistance mechanisms by modulating GLI transcription via inhibition of BET bromodomain proteins. We show the BET bromodomain protein, BRD4, regulates GLI transcription downstream of SMO and SUFU and chromatin immunoprecipitation studies reveal BRD4 directly occupies GLI1 and GLI2 promoters, with a substantial decrease in engagement of these sites upon treatment with JQ1, a small molecule inhibitor targeting BRD4. Globally, genes associated with medulloblastoma-specific GLI1 binding sites are downregulated in response to JQ1 treatment, supporting direct regulation of GLI activity by BRD4. Notably, patient- and GEMM-derived Hedgehog-driven tumors (basal cell carcinoma, medulloblastoma and atypical teratoid/rhabdoid tumor) respond to JQ1 even when harboring genetic lesions rendering them resistant to Smoothened antagonists
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