|
||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||
2) General Gestational Data
3) Implantation
4) General Characterization of the Placenta This is a typical zonary placenta weighing 5,900 g and measuring 85 cm in greatest length. The "ring" of placental tissue was 25 cm wide. It was complete and the circle was 100 cm in circumference. The villous tissue was 2-2.3 cm thick and darkly congested. At the sides there was the characteristic, irregular, brownish old hematoma, the so-called hemophagous organ. The maternal surface had much fresh clot attached and was irregular on its yellowish surface. There were no subdivisions of the placental tissues. The fetal surface was smooth although a focus of white, nodular squamous metaplasia of amnion was found (5x2 cm). The umbilical cord was mostly absent and less than 10 cm remained. Another placenta was kindly made available by Dr. Carlos Rodriguez of the New York Aquarium. It weighed 4,980 g, had a similar zonary shape and the same ‘hemophagous’ peripheral region. A third placenta, coming from a stillborn calf, was made available by Diana Procter (Vallejo, CA). It weighed 6,700 g, its cord was 36 cm long, 4.5 cm in circumference and 2.6 cm in diameter. |
||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||
5) Details of fetal/maternal barrier The trophoblast at the base is mostly syncytial in nature and the quite inapparent cytotrophoblast in the labyrinth appears to give rise to the syncytium. The syncytium is superficially invasive into the endometrium, destroys some of the stroma and opens some glands, but it does not grow into the maternal vascular lumens or into their walls. The other placentas available all had the same microscopic appearance. The colored material at the edges was crystalline (square crystals) and iron stain negative. |
||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||
6) Umbilical cord |
||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||
7) Uteroplacental circulation
8) Extraplacental membranes |
||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||
9) Trophoblast external to barrier
10) Endometrium
11) Various features |
||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||
12) Endocrinology
13) Genetics |
||||||||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||||||
14) Immunology
15) Pathological features
16) Physiologic data
17) Other resources
18) Other remarks - What additional Information is needed?
Acknowledgement
References Andersen, L.W., Born, E.W., Gjertz, I., Wiig, O., Holm, L.E. and Bendixen, C.: Population structure and gene flow of the Atlantic walrus (Odobenus rosmarus rosmarus) in the eastern Arctic based on mitochondrial DNA and microsatellite variation. Mol. Evol. 7:1323-1336, 1998. Arnason, U.: Comparative chromosome studies in Pinnipedia. Hereditas 76:179-225, 1974a. Arnason, U.: Phylogeny and speciation in Pinnipedia and Cetacea - a cytogenetic study. Thesis, Lund, 1974b. Arnason, U.: The relationship between the four principal pinniped karyotypes. Hereditas 87:227-242, 1977. Arnason, U.: Localization of nucleolar organizing regions in pinniped karyotypes. Hereditas 94:29-34, 1981. Barlough, J.E., Berry, E.S., Skilling, D.E., Smith, A.W. and Fay, F.H.: Antibodies to marine caliciviruses in the Pacific walrus (Odobenus rosmarus divergens Illiger) J. Wildl. Dis. 22:165-168, 1986. Calle, P.P., Seagars, D.J., McClave, C., Senne, D., House, C. and House, J.A.: Viral and bacterial serology of free-ranging Pacific walrus. J. Wildl. Dis. 38:93-100, 2002. Cornell, L.H., Golden, B.J. and Osborn, K.G.: Pseudopersistent urachus in a baby walrus. J. Amer. Vet. Med. Ass. 167:548-549, 1975. Costa, D.P. and Crocker, D.E.: Seals. Pp. 313-321, in Encyclopedia of Reproduction, Vol. 4, E. Knobil and J.D. Neill, eds. Academic Press, San Diego, 1998. Dailey, M.D. and Brownell, R.L., Jr.: A checklist of marine mammal parasites. Chapter 9, pp. 528-589, in Mammals of the Sea. Biology and Medicine. S.H. Ridgway, ed. Charles C. Thomas, Springfield, Illinois, 1972. Duffield Kulu, D.: Evolution and cytogenetics. Chapter 8, pp. 503-527, in Mammals of the Sea. Biology and Medicine. S.H. Ridgway, ed. Charles C. Thomas, Springfield, Illinois, 1972. Fay, F.H., Rausch, V.R. and Feltz, E.T.: Cytogenetic comparison of some pinnipeds (Mammalia: Eutheria). Canad. J. Zool. 45:773-778, 1967. Foster, G., MacMillan, A.P., Godfroid, J., Howie, F., Ross, H.M., Cloeckaert, A., Reid, R.J., Brew, S. and Patterson, I.A.: A review of Brucella sp. infection of sea mammals with particular emphasis on isolates from Scotland. Vet. Microbiol. 90:563-580, 2002. Gotch, A.F.: Mammals - Their Latin Names Explained. Blandford Press, Poole, Dorset, 1979. Gruber, A.D., Peters, M., Knieriem, A. and Wohlsein, P.: Atherosclerosis with multifocal myocardial infarction in a Pacific walrus (Odobenus rosmarus divergens Illiger). J. Zoo Wildl. Med. 33:139-144, 2002. Hayssen, V., van Tienhoven, A. and van Tienhoven, A.: Asdell's Patterns of Mammalian Reproduction: a Compendium of Species-specific Data. Comstock/Cornell University Press, Ithaca, 1993. Ledje, C. and Arnason, U.: Phylogenetic relationships within caniform carnivores based on analyses of the mitochondrial 12S rRNA gene. J. Mol. Evol. 43:641-649, 1006. Mossman, H.W.: Vertebrate Fetal Membranes. MacMillan, Houndmills, 1987. Nielsen, O., Stewart, R.E., Measures, L., Duignan, P. and House, C.: A morbillivirus antibody survey of Atlantic walrus, narwhal and beluga in Canada. J. Wildl. Dis. 36:508-517, 2000. Nielsen, O., Stewart, R.E., Nielsen, K., Measures, L. and Duignan, P.: Serologic survey of Brucella spp. antibodies in some marine mammals of North America. J. Wildl. Dis. 37:89-100, 2001. Nikulin, P.G.: On twinning in Chukchi walruses. Pacific Research Institute of Fisheries and Oceanography (TNIRO). Izvestia 39:353, 1954. Nishiwaki, M.: General Biology. Pp. 162-164, in: Mammals of the Sea. Biology and Medicine. S.H. Ridgway, ed. Charles C. Thomas, Springfield, Illinois, 1972. Nowak, R.M.: Walker's Mammals of the World. 6th ed. The Johns Hopkins Press, Baltimore, 1999. O'Brien, S.J., Menotti-Raymond, M., Murphy, W.J., Nash, W.G., Wienberg, J., Stanyon, R., Copeland, N.G., Jenkins, N.A., Womack, J.E. and Graves, J.A.: The promise of comparative genomics in mammals. Science 286:458-481, 1999. Pfarrer, C., Winther, H., Leiser, R. and Dantzer, V.: The development of the endotheliochorial mink placenta: light microscopy and scanning electron microscopical morphometry of maternal vascular casts. Anat. Embryol. 199:63-74, 1999. Proulx, J.F., MacLean, J.D., Gyorkos, T.W., Leclair, D., Richter, A.K., Serbir, B., Forbes, L. and Gajadhar, A.A.: Novel prevention program for trichinellosis in inuit communities. Clin. Infect. Dis. 34:1508-1514, 2002. Zarnke, R.L., Harder, T.C., Vos, H.W., VerHof, J.M. and Oosterhaus, A.D.: Serologic survey for phocid herpesvirus-1 and -2 in marine mammals from Alaska and Russia. J. Wildl. Dis. 33:459-465, 1997. |