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Full-Text Articles in Life Sciences
Research Needs For The Risk Assessment Of Health And Environmental Effects Of Endocrine Disruptors: A Report Of The Us Epa-Sponsored Workshop, Rj Kavlock, Gp Daston, C Derosa, P Fennercrisp, Le Gray, S Kaattari, Et Al
Research Needs For The Risk Assessment Of Health And Environmental Effects Of Endocrine Disruptors: A Report Of The Us Epa-Sponsored Workshop, Rj Kavlock, Gp Daston, C Derosa, P Fennercrisp, Le Gray, S Kaattari, Et Al
VIMS Articles
The hypothesis has been put forward that humans and wildlife species have suffered adverse health effects after exposure to endocrine-disrupting chemicals. Reported adverse effects include declines in populations, increases in cancers, and reduced reproductive function. The U.S. Environmental Protection Agency sponsored a workshop in April 1995 to bring together interested parties in an effort to identify research gaps related to this hypothesis and to establish priorities for future research activities. Approximately 90 invited participants were organized into work groups developed around the principal reported health effects-carcinogenesis, reproductive toxicity, neurotoxicity, and immunotoxicity--as well as along the risk assessment paradigm--hazard identification, dose-response …
An Unidentified Haplosporidian Parasite Of Bay Scallop Argopecten Irradians Cultured In The Shandong And Liaoning Provinces Of China, Fle Chu, Em Burreson, F Zhang, K Chew
An Unidentified Haplosporidian Parasite Of Bay Scallop Argopecten Irradians Cultured In The Shandong And Liaoning Provinces Of China, Fle Chu, Em Burreson, F Zhang, K Chew
VIMS Articles
Since 1988 growers of bay scallop Argopecten irradians in China have been experiencing mortality in their cultured stocks. Although poorly documented, mortality apparently began near Qingdao and has since spread to other areas of Shandong and Liaoning provinces. Samples of cultured scallops were collected from several growing areas in these provinces and analyzed by histological methods for pathogens. An unidentified haplosporidian parasite was observed in a high proportion of scallops from two of the stocks examined. Most infections were of low intensity, but one heavy infection was also observed. Only plasmodia stages were observed; they occurred intercellularly in connective tissues …
Enhanced Immunogenicity Of Renibacterium Salmoninarum In Chinook Salmon After Removal Of The Bacterial Cell Surface-Associated 57 Kda Protein, Pa Wood, Sl Kaattari
Enhanced Immunogenicity Of Renibacterium Salmoninarum In Chinook Salmon After Removal Of The Bacterial Cell Surface-Associated 57 Kda Protein, Pa Wood, Sl Kaattari
VIMS Articles
A study was conducted to determine the effect of endogenous serine protease activity on the immunogenicity of Renibacterium salmoninarum cells in chinook salmon Oncorhynchus tshawytscha. Salmon were immunized with either R. salmoninarum cells possessing p57 (p57(+)) or substantially depleted of p57 (p57(-)). The resultant antisera were examined by whole cell ELISA and immunoblot procedures using p57(+), p57(-), proteinase-K-treated, and periodate-treated whole cells. These analyses revealed that the removal of p57 by the endogenous serine protease significantly enhanced the immunogenicity of the cell, resulting in a 20-fold increase in detectable antibody titers. The bulk of this antibody activity was directed at …
Histopathology Of The Renal And Splenic Haemopoietic Tissues Of Coho Salmon Oncorhynchus Kisutch Experimentally Infected With Renibacterium Salmoninarum, E Flano, P Lopez-Fierro, B Razquin, S Kaattari, A Villena
Histopathology Of The Renal And Splenic Haemopoietic Tissues Of Coho Salmon Oncorhynchus Kisutch Experimentally Infected With Renibacterium Salmoninarum, E Flano, P Lopez-Fierro, B Razquin, S Kaattari, A Villena
VIMS Articles
We report the histopathological changes occurring in the renal and splenic haemopoietic tissues of coho salmon Oncorhynchus kisutch experimentally infected with renibacterium salmoninarum. In both tissues we were able by light microscopy to distinguish 3 different grades in the progression of the infection. The grades of infection were characterized according to the location of the bacteria and the tissue injuries. Ultrastructural observation revealed sinusoidal cells, macrophages, reticular and barrier cells to be infected by the pathogen, and necrosis of the tissue to be general in advanced stages of the infection. Despite destruction of the haemopoietic tissue, plasmacytopoietic foci were frequently …
Epizootiology Of Perkinsus Marinus Disease Of Oysters In Chesapeake Bay, With Emphasis On Data Since 1985, Eugene Burreson, Lisa M. Ragone Calvo
Epizootiology Of Perkinsus Marinus Disease Of Oysters In Chesapeake Bay, With Emphasis On Data Since 1985, Eugene Burreson, Lisa M. Ragone Calvo
VIMS Articles
Since 1987 Perkinsus marinus has been the most important pathogen of the eastern oyster, Crassostrea virginica, in Chesapeake Bay because of its widespread distribution and persistence in low salinity areas. The pathogen became established on all oyster beds in the Chesapeake Bay as a result of natural spread during the consecutive drought years from 1985 to 1988 or by movement of infected oysters during the same period. Elevated salinities resulting from drought conditions and concomitant warm winters allowed P. marinus to proliferate in what were historically low salinity areas. Oyster mortality was high on most beds and landings of market …
Propagation And In Vitro Studies Of Perkinsus Marinus, Jerome F. Lapeyre
Propagation And In Vitro Studies Of Perkinsus Marinus, Jerome F. Lapeyre
VIMS Articles
The development of continuous cultures of Perkinsus marinus (Apicomplexa) is a major breakthrough that will lead to a better understanding of this deadly oyster pathogen. More than 10 P. marinus isolates are currently in continuous cultures. Culture media used to propagate P. marinus range from media designed for the culture of mammalian cells to protein-free chemically defined media. Continuous cultures of P. marinus can be initiated from a variety of infected oyster tissues or from isolated hypnospores (i.e., the enlarged stage of P. marinus from oyster tissue incubated in Ray's fluid thioglycollate medium). P. marinus cells adapt well to culture …
Optimal Culture Conditions For The Propagation Of The Oyster Pathogen Perkinsus Marinus (Apicomplexa) In Protein Deficient Medium, Jf Lapeyre, M Faisal
Optimal Culture Conditions For The Propagation Of The Oyster Pathogen Perkinsus Marinus (Apicomplexa) In Protein Deficient Medium, Jf Lapeyre, M Faisal
VIMS Articles
The protozoan, Perkinsus marinus, acclimated and proliferated in the culture medium JL-ODRP-1 without bovine serum albumin. The principal culture conditions for the optimal propagation of P. marinus in this protein deficient culture medium, were determined. The greatest growth rates of the parasite occurred at 28 degrees C, 661 mOsm/kg and pH 7.5. Decreasing seeding densities from 16 x 10(5) to 1 x 10(5) also increased growth rate. After several passages in the absence of 5% CO2 tension, the growth rate of P. marinus was similar to its original value in the presence of 5% CO2 tension. This protein deficient culture …
Shell Disease In The Gold Lip Pearl Oyster, Pinctada Maxima And The Eastern Oyster, Crassostrea Virginica, Frank O. Perkins
Shell Disease In The Gold Lip Pearl Oyster, Pinctada Maxima And The Eastern Oyster, Crassostrea Virginica, Frank O. Perkins
VIMS Articles
A description is provided of the anomalous conchiolin deposits which are formed by Pinctada maxima and which are associated with unusual morta]jties. Comparisons are made with brown ring disease found in Ruditapes philippinarum and juvenile Crassostrea virg inica. In P. maxima, the deposits are not organized into a ring but rather a.re broad-based and result in retraction of the mantle with the deposits lying outside the edge of the mantle. Vibrio sp. have been implicated in causing the di seases of P. max ima and R. philippinarum whereas the etiological agent of the disease in C. virginica is unknown. It …
A Comparison Of Crassostrea Gigas And Crassostrea Virginica: Effects Of Temperature And Salinity On Susceptibility To The Protozoan Parasite, Perkinsus Marinus, Fu-Lin C. Chu, Aswani Volety, G Constantin
A Comparison Of Crassostrea Gigas And Crassostrea Virginica: Effects Of Temperature And Salinity On Susceptibility To The Protozoan Parasite, Perkinsus Marinus, Fu-Lin C. Chu, Aswani Volety, G Constantin
VIMS Articles
The susceptibility of diploid and triploid (2N and 3N) Crassostrea gigas to Perkinsus marinus was compared, in the laboratory, with that of Crassostrea virginica al three test temperatures (10, 15, and 25 degrees C) at 20-22 ppt and at three test salinities (3, 10, and 20 ppt) at a temperature of 19-22 degrees C. Experimental oysters were challenged twice with freshly isolated P, marinus meronts, after acclimation to test temperatures and salinities. Although infection prevalence and intensity increased with temperature (p = 0.0001) and salinity in P. marinus-challenged oysters of both oyster species: they were highest in C. virginica groups. …
Foreword, Frank O. Perkins
History Of Perkinsus Marinus, A Pathogen Of Oysters In Chesapeake Bay 1950-1984, Jd Andrews
History Of Perkinsus Marinus, A Pathogen Of Oysters In Chesapeake Bay 1950-1984, Jd Andrews
VIMS Articles
The pathogen Perkinsus marinus (Dermo) was discovered in Chesapeake Bay in 1950. It was already widely distributed in the Bay and caused annual mortality below the mouth of the Rappahannock River. Annual mortality in trayed oysters at the Virginia Institute of Marine Science (VIMS) varied annually from 24% to 57% at this most favorable site for the disease. Over 2 million bushels of seed oysters from the James River public beds were transplanted annually to private beds in 4 major growing areas. These were Hampton Roads, lower Bay proper, Mobjack Bay at mouth of York River, and the Rappahannock River. …
Laboratory Investigations Of Susceptibility, Infectivity, And Transmission Of Perkinsus Marinus In Oysters, Fu-Lin C. Chu
Laboratory Investigations Of Susceptibility, Infectivity, And Transmission Of Perkinsus Marinus In Oysters, Fu-Lin C. Chu
VIMS Articles
The protozoan parasite, Perkinsus marinus (Dermo), has caused significant mortality in the eastern oyster, Crassostrea virginica, along the east coast of the United States and the Gulf of Mexico, since the 1950s. Because of its current expanded distribution and increased abundance, P. marinus is now considered more prevalent in the mid-Atlantic waters and the Chesapeake Bay in particular, than another protozoan pathogen, Haplosporidium nelsoni (MSX). The susceptibility, infectivity/pathogenicity, and transmission of P. marinus in eastern oysters were investigated in numerous laboratory studies, The influence of environmental factors such as temperature, salinity, and pollution on the interaction between the host oyster …
The Structure Of Perkinsus Marinus (Mackin, Owen And Collier, 1950) Levine, 1978 With Comments On Taxonomy And Phylogeny Of Perkinsus Spp., Frank O. Perkins
The Structure Of Perkinsus Marinus (Mackin, Owen And Collier, 1950) Levine, 1978 With Comments On Taxonomy And Phylogeny Of Perkinsus Spp., Frank O. Perkins
VIMS Articles
A description of the structure of the Crassostrea virginica pathogen Perkinsus marinus is provided from observations at the light and transmission electron microscope levels of detail and includes cellular multiplication (palintomy) in the host and zoosporulation in estuarine water as well as observations of cells in axenic culture. The description is primarily a review of previously published information; however, new information is provided on development of walled outgrowths from hypnospores derived from fluid thioglycollate medium treatment of infected host tissue. The protoplast within the outgrowths subdivides to yield small unicells which escape into the ambient water, or the protoplast emerges …