5/6/2010 MAJ Eric D. Lombardini, VMD, MSc., DACVPM, DACVP Chief, Division of Comparative Pathology Armed Forces Radiobiology Research Institute Uniformed Services University of the Health Sciences Overview: Fish research models Fish necropsy Research complications Infectious diseases Neoplastic diseases Non‐infectious diseases Photo:10 & 104 Teleosts Bony fish Greater than 18,000 species described Photo: 11 Photo 12 1 5/6/2010 Extraordinary diversity Photos: 1-4 Photo: 5 2 5/6/2010 Photo: 6 More Toadfish in Space: NASA will Study Balance in Two Wood’s Hole Toadfish, a Senator and Six Astronauts in Upcoming Shuttle Mission (1996 mission) Photo: 7 1908 Nobel Prize in Physiology Phagocytosis after experimenting on the larvae of starfish Photo: 40 Photo: 41 3 5/6/2010 Historical use of fish in research Genetics Embryology Renal physiology Endocrinology Nerve physiology Toxicology Morphology Nutrition Pharmacology Photo: 8 Parasitology Specific neoplastic models More than just Zebrafish… Swordtail‐ Genetics of melanomas in Xiphoporus fishes Trout‐coding sequences of the MHCII beta chain of homozygous rainbow trout White perch‐Using white perch to study abnormal hepatic copper metabolism Japanese medaka‐Freshwater fish in research on radiation biology Goldfish‐The goldfish visual pathway: Intermediate filament proteins in nerve growth and development Elasmobranchs‐In vitro metabolism of the pre‐carcinogen aflatoxin B1 by liver preparations of the calf, nurse shark and clearnose skate Anglerfish‐Simultaneous assessment of prohormone transport and processing in four separate islet cell types Salmon‐Advantages of using aquatic animals for biomedical research on reproductive toxicology Eel‐Effects of anaesthesia and surgery on levels of adrenaline and noradrenaline in blood plasma of the eel Toadfish‐Ichthyotoxins from the oyster toadfish Etc… Fish Models Examples include: Melanoma Diabetes Mellitus Neurofibromatosis Hepatic copper storage disease (Wilson’s disease) Oro‐facial‐digital syndrome Hepatocellular carcinoma Dehydration studies Na/K‐ATPase activity in muscle Renal excretion of xenobiotics Genotoxic and epigenetic carcinogenesis Gene regulation and developmental genetics Mutagenesis 4 5/6/2010 Benefits of transgenic fish versus mammals in research External fertilization Transparent embryos Ploidy manipulation Sex manipulation Rapid growth Total environment control Increased availability of standardized genetic stock Genetic mechanisms correlate well with rodents and humans Photo: 105 Transparent Zebrafish Cell Stem Cell, Volume 2, Issue 2, 183-189, 7 February 2008 Embryology: Convergent extension movements and ciliary function are mediated by ofd1, a zebrafish orthologue of the human oral‐facial‐ digital type 1 syndrome gene Glomerular function and structure in ofd1 MO‐injected embryos. Hum Mol Genet. 2009 January 15; 18(2): 289–303. 5 5/6/2010 Neuroanatomy: Figure 1 ‐ 4 day old zebrafish embryo labelled with SV2 and acetylated tubulin antibodies showing axon tracts(green) and neuropil(red)viewed from lateral(top) and dorsal(bottom) orientations. www.ucl.ac.uk/zebrafish‐ group/research/neuroanatomy.php Carcinogenesis: tp53 mutant zebrafish develop malignant peripheral nerve sheath tumors Fig. 5. Tumorigenesis features of tp53 M214K mutant zebrafish. (A‐D) When compared with wild‐type zebrafish (A and C), zMPNST development in tp53 mutant zebrafish is identifiable upon external observation because of ocular (B) or abdominal tumor localizations (D). (E‐H) When compared with wild‐type zebrafish (E and G), histopathology staining with hematoxylin/eosin reveals zMPNST in the eye (F) and abdominal cavity (H), as indicated by the stars (×4). (I‐K) Histopathological features of tumors (I) composed predominantly of spindle cells (J) and to a varying degree of epitheloid cells (K) are consistent with the diagnosis of zMPNST. [Bar, 200 μm (E, F, I‐K).] PNAS January 11, 2005 vol. 102 no. 2 407‐412 Melanoma: Review Article: Genetic and environmental melanoma models in fish Pigment cell and melanoma research; 2010 ‐Gordon‐Kosswig model (Sd‐ Spotted Disease) ‐Xmrk‐2 Oncogene overexpression ‐loss of the Diff tumor suppressor 6 5/6/2010 Toxicology: Identification of a Primary Target of Thalidomide Teratogenicity Takumi Ito, Hideki Ando, Takayuki Suzuki, Toshihiko Ogura, Kentaro Hotta, Yoshimasa Imamura, Yuki Yamaguchi, and Hiroshi Handa Science 12 March 2010: 1345‐1350. MUTATION In embryos, thalidomide‐induced malformations, bottom, of a fin of a zebrafish, left, and a wing of a chick, right, using mutated cereblon, a protein. NYTimes 17 March 2010 Necropsy: Fish Necropsy (Generic) Swim Bladder Gills Heart Liver (Atrium;Ventricle; Bulbus arteriosus) 7 5/6/2010 Fish Necropsy (Generic) Stomach Intestine/rectum Pyloric ceca ovary Fish Necropsy (Generic) Kidney 8 5/6/2010 Pathology General Concepts Necrotizing versus Granulomatous disease Variation in leukocytes between species 74 bacterial pathogens of fish, dozens of fungi, hhddundreds of known viruses, thhdousands of parasites, innumerable toxins and miscellaneous or physiological pathologies. Emerging diseases Viral Infections DNA: Herpesvirus Iridovirus Adenovirus RNA: Picornavirus Paramyxovirus Reovirus Togavirus Birnavirus Rhabdovirus Retrovirus Piscine iridovirus Gross findings: Range in appearance from miliary pale nodules to a cutaneous mass effect. Histopathological findings: Markedly hypertrophic dermal fibroblasts (lymphocystis cells). Cells may measure > 300 µm with vacuolated to granular pale basophilic cytoplasm surrounded by a 10‐ 30µm amphophilic hyaline wall. Occasionally there is the presence of basophilic fibrillar inclusion material. 9 5/6/2010 Lymphocystis Photo: 20 Lymphocystis Photo: 46 Lymphocysitis Photo: 45 10 5/6/2010 Lymphocystis Lymphocystis Lymphocystis Photo: 21 11 5/6/2010 Journal of Fish Diseases, Volume 33 Issue 2 , Pages 93 ‐ 186 (February 2010) Iridovirus infections in finfish –critical review with emphasis on ranaviruses (p 95‐122) Photo: 114 Liver of redfin perch, found dead 10 days post‐bath inoculation with epizootic haematopoietic necrosis virus. Hepatocytes that surround a focus of hepatic necrosis frequently contain basophilic intracytoplasmic inclusion bodies (arrows) (H & E, bar = 50 µm). Carp Pox (CyHV‐1) Photo: 34 & 35 Carp Pox Photo: 44 12 5/6/2010 KHV Koi herpesvirus (KHV) is a highly contagious viral disease that may cause significant morbidity and mortality in common carp (Cyprinus carpio) (Hedrick et al. 2000; OATA 2001) The white patches are due to necrosis (death) of the gill tissue. Gill lesions caused by KHV disease are the most common clinical signs in affected koi. Other external signs of KHV may include bleeding gills, sunken eyes, pale patches or blisters on the skin. Koi herpesvirus (KHV) disease (CyHV‐3) Photo: 14 Koi Herpesvirus Photos: 70 & 71 13 5/6/2010 KHV Photo: 80 IcHV‐1 Photo: 99 & 100 VHS (Viral hemorrhagic septicemia) Affects >50 species of fish (Fresh water and marine) Multiple strains Family Rhabdoviridae Gross: Visceral, cutaneous and muscular petechial hemorrhage Exopthalmus, ascites, eccymoses around eyes, skin, gills and fins Histo: Variable necrosis of kidneys (hematopoetic 1st), spleen, liver, and skeletal muscle en.wikipedia.org/wiki/File:VHS.png 14 5/6/2010 VHS Photo: 29 VHS Photo: 30 Spring Viremia of Carp Photo: 83 15 5/6/2010 Ulcerative Dermatitis in Winter Flounder Photo: 31 Bacterial Infectious Diseases In zebrafish, the pneumatic duct acts as the primary point of invasion for systemic fungal and bacterial infections, spreading to the gas bladder Primarily opportunistic infections of which the 1° agents: Aeromonas sp. and Pseudomonas sp. Clinical signs of Gram negative septicemia are non‐ specific and include: ascites, exopthalmia, cutaneous hemorrhages (body and fins), cutaneous ulceration Non‐specific signs of septicemia Ascites or “Dropsy” Photo: 43 &45 16 5/6/2010 Non‐specific signs of septicemia Exopthalmia Photo: 28 Non‐specific signs of septicemia Cutaneous hemorrhages Photo: 19 Non‐specific signs of septicemia Ulceration Photo: 32 17 5/6/2010 Aeromonas salmonicida Furunculosis of salmonids Goldfish Ulcer Disease Carp Erythrodermatitis Trout Ulcer Disease. Several other species of AeromonasPhoto: 36 , including: A. hydrophila, A. formicans, A. liquefaciens, and A. hydrophila complex are capable of causing a disease known as “Motile Aeromonas Septicemia” or “Bacterial Hemorrhagic Septicemia”. Furunculosis Aeromonas salmonicida (4 subspecies: salmonicida, achromogenes, masoucida and smithia Opportunist resulting in septicemia Predominantly salmonid fishes, but also affects goldfish and other cyprinids. “Furunculosis” is derived from the presence of “blisters” or furuncules on the surface of chronically infected fish Significant resistance to both Terramycin and sulfamerazine Furunculosis Photo: 78 18 5/6/2010 Photos: 37 & 91 Koi Ulcer Disease Photo: 33 Yersinia ruckeri Photos: 48 & 49 19 5/6/2010 Enteric septicemia of catfish (ESC) Edwardsiella ictaluri Photo: 53 Edwardsiella tarda (Emphysematous Putrefactive Disease EPD) Photos: 38 & 39 Renibacterium salmonarium Gross findings: Muscular cavitation; Vesicular dermatitis (Spawning rash); necrotizing nephritis & splenitis. Histopathological findings: Granulomatous and necrotizing nephritis, splenitis, hepatitis, endocarditis and pancreatitis; occasionally with giant cell formation. Histiocytes are expanded by intracytoplasmic gram‐positive bacteria