Cysts of unknown etiology in marine fishes of the Northwest Atlantic and Gulf of Mexico

1987 ◽  
Vol 65 (2) ◽  
pp. 296-303 ◽  
Author(s):  
Sharon A. MacLean ◽  
Carol M. Morrison ◽  
Robert A. Murchelano ◽  
Sherie Everline ◽  
Joyce J. Evans

Results of light and electron microscopic examinations of cysts of unknown etiology (CUEs) occurring in the gills of Atlantic mackerel, red hake, white hake, cod, haddock, and silver hake are presented. CUEs were found also in gills and viscera of winter flounder, Atlantic croaker, spot, windowpane flounder, and sand lance. CUEs measured 150–400 μm in diameter and consisted of an external fibrous cuticle, usually a thick median band, and a central core that frequently contained eosinophilic vesicles. Structures resembling mitochondria were found in the band and in vesicles of the core, but no other organelles were apparent. Cytochemical staining and ultramicroscopy revealed aggregates of glycogen in the core ground substance; no structural components were stained with Sudan black B or by the Feulgen technique. Extensive encapsulation of CUEs by fibroblasts was typical. Of 717 mackerel examined, 76.8% had CUEs in the gills; numbers ranged from 1 to 353 per fish. The prevalence and intensity of occurrence of CUEs increased with the age of the mackerel.

1993 ◽  
Vol 50 (8) ◽  
pp. 1768-1778 ◽  
Author(s):  
W. D. Bowen ◽  
J. W. Lawson ◽  
B. Beck

The grey seal (Halichoerus grypus) population on the Scotian Shelf has grown significantly over the past 20 yr, thus increasing the potential for competitive interactions between grey seals and fisheries. The relative contribution (percent wet weight) and size of prey eaten were estimated from otoliths and squid beaks recovered from 143 stomachs that contained food of the 528 collected from 1988 to 1990. Although 22 taxa were found, only four species (Atlantic herring, silver hake, Atlantic cod, and squid) accounted for 80% of the estimated weight of food eaten. The mean length of prey eaten ranged from 19 to 35 cm for six species. Only 17% of the cod and none of the pollock and squid eaten were of the length taken in commercial fisheries. However, about 80% of the silver hake and herring eaten were of commercial size. Offshore at Sable Island, northern sand lance, silver hake, and squid (in order of importance) accounted for 86.1% of the wet weight ingested by seals during summer; sand lance and cod accounted for 96.1% of prey eaten in winter. At inshore locations, herring, cod, and pollock made up 90% of the diet in summer; Atlantic mackerel, cod, squid, and herring made up 83% of the diet in winter.


Author(s):  
T. Kanetaka ◽  
M. Cho ◽  
S. Kawamura ◽  
T. Sado ◽  
K. Hara

The authors have investigated the dissolution process of human cholesterol gallstones using a scanning electron microscope(SEM). This study was carried out by comparing control gallstones incubated in beagle bile with gallstones obtained from patients who were treated with chenodeoxycholic acid(CDCA).The cholesterol gallstones for this study were obtained from 14 patients. Three control patients were treated without CDCA and eleven patients were treated with CDCA 300-600 mg/day for periods ranging from four to twenty five months. It was confirmed through chemical analysis that these gallstones contained more than 80% cholesterol in both the outer surface and the core.The specimen were obtained from the outer surface and the core of the gallstones. Each specimen was attached to alminum sheet and coated with carbon to 100Å thickness. The SEM observation was made by Hitachi S-550 with 20 kV acceleration voltage and with 60-20, 000X magnification.


Blood ◽  
1950 ◽  
Vol 5 (1) ◽  
pp. 79-88 ◽  
Author(s):  
MARVIN L. BLOOM ◽  
GEORGE B. WISLOCKI

Abstract By Baker’s method for the staining of lipids, various types of cytoplasmic rods and granules in leukocytes give a positive acid hematein test but are negative after the pyridine-extraction test. According to Baker,8 this combination of results indicates the presence of phospholipids. Some of the rods and granules which are stained appear to be mitochondria, judging from their shape, size and distribution. as well as from the fact that they coincide in all respects with mitochondria demonstrable by supravital staining. Baker8 pointed out that in a great variety of cells his method stained mitochondria, although he did not report having examined leukocytes. In addition to mitochondria, Baker’s method stains the specific granules of the three varieties of granular leukocytes. In the neutrophilic leukocytes, the granules appear gray or black; in some of the eosinophilic leukocytes, they are intensely black, while in others they are unstained although surrounded by stained ground substance; and in the basophilic leukocytes, some of the granules of individual cells are stained while others are not. Provided the method is chemically specific, it follows that the specific granules of these leukocytes contain phospholipids. The appearance of the eosinophils indicates that many of them possess granules composed of protein surrounded by phospholipid, although some of them contain granules with lipid in their interiors. These differences in the eosinophils suggest possible functional stages, related perhaps to the age of the cells or some other metabolic factors. In the monocytes, besides a general stippling of the cytoplasm corresponding to mitochondria, the region of the attraction sphere often contains numerous deeply stained granules. Sudan black B stains both the mitochondria and the specific leukocytic granules in a manner similar to Baker’s method. However, certain slight differences were noticed. Platelets were brought out moderately distinctly by the acid hematein procedure, whereas in sudan black preparations they were barely visible. A variability was noted in the staining of the granules of the eosinophilic leukocytes in Baker’s method, in contrast to the uniformity of their staining with sudan black. This difference should perhaps be interpreted as indicating that the eosinophilic granules contain other lipid substances besides phospholipids. Mitochondnia, in whatsoever type of leukocyte they are observed, appear to stain more deeply and distinctly by Baker’s method than with sudan black, a circumstance suggesting that mitochondria are very rich in phospholipids.


1975 ◽  
Vol 42 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Alan R. Hudson ◽  
David G. Kline

✓ Biopsies from partially lacerated nerves were taken at the sites of proximal stimulus, laceration, and distal recording, and from stimuli and recording sites of control nerves. Electron microscopic examination of the partially lacerated major fasciculus revealed three zones of injury. The laceration zone showed neurotemetic changes, the adjacent or intermediate zone, partial degeneration, and the zone most peripheral to the laceration, changes in ground substance. Progression of the original injury is apparently due to ongoing changes in the intermediate and peripheral zones while much of the relative early recovery is due to reversal of changes in these zones. Regeneration through the laceration or neurotemetic zone is limited but does account for a small amount of late recovery of function.


2020 ◽  
Vol 21 (21) ◽  
pp. 8051
Author(s):  
Yiu Wing Sunny Cheung ◽  
Sung-Eun Nam ◽  
Calvin K. Yip

Macroautophagy (also known as autophagy) is a major pathway for selective degradation of misfolded/aggregated proteins and damaged organelles and non-selective degradation of cytoplasmic constituents for the generation of power during nutrient deprivation. The multi-step degradation process, from sequestering cytoplasmic cargo into the double-membrane vesicle termed autophagosome to the delivery of the autophagosome to the lysosome or lytic vacuole for breakdown, is mediated by the core autophagy machinery composed of multiple Atg proteins, as well as the divergent sequence family of selective autophagy receptors. Single-particle electron microscopy (EM) is a molecular imaging approach that has become an increasingly important tool in the structural characterization of proteins and macromolecular complexes. This article summarizes the contributions single-particle EM have made in advancing our understanding of the core autophagy machinery and selective autophagy receptors. We also discuss current technical challenges and roadblocks, as well as look into the future of single-particle EM in autophagy research.


Author(s):  
Rizwan Ahmed ◽  
Gyunyoung Heo ◽  
Dong-Keun Cho ◽  
Jongwon Choi

Reactor core components and structural materials of nuclear power plants to be decommissioned have been irradiated by neutrons of various intensities and spectrum. This long term irradiation results in the production of large number of radioactive isotopes that serve as a source of radioactivity for thousands of years for future. Decommissioning of a nuclear reactor is a costly program comprising of dismantling, demolishing of structures and waste classification for disposal applications. The estimate of radio-nuclides and radiation levels forms the essential part of the whole decommissioning program. It can help establishing guidelines for the waste classification, dismantling and demolishing activities. ORIGEN2 code has long been in use for computing radionuclide concentrations in reactor cores and near core materials for various burn-up-decay cycles, using one-group collapsed cross sections. Since ORIGEN2 assumes a constant flux and nuclide capture cross-sections in all regions of the core, uncertainty in its results could increase as region of interest goes away from the core. This uncertainty can be removed by using a Monte Carlo Code, like MCNP, for the correct calculations of flux and capture cross-sections inside the reactor core and in far core regions. MCNP has greater capability to model the reactor problems in much realistic way that is to incorporate geometrical, compositional and spectrum information. In this paper the classification of radioactive waste from the side structural components of a CANDU reactor is presented. MCNP model of full core was established because of asymmetric structure of the reactor. Side structural components of total length 240 cm and radius 16.122 cm were modeled as twelve (12) homogenized cells of 20 cm length each along the axial direction. The neutron flux and one-group collapsed cross-sections were calculated by MCNP simulation for each cell, and then those results were applied to ORIGEN2 simulation to estimate nuclide inventory in the wastes. After retrieving the radiation level of side structural components of in- and ex-core, the radioactive wastes were classified according to the international standards of waste classification. The wastes from first and second cell of the side structural components were found to exhibit characteristics of class C and Class B wastes respectively. However, the rest of the waste was found to have activity levels as that of Class A radio-active waste. The waste is therefore suitable for land disposal in accordance with the international standards of waste classification and disposal.


1975 ◽  
Vol 151 (1) ◽  
pp. 157-166 ◽  
Author(s):  
J Thyberg ◽  
S Lohmander ◽  
D Heinegård

Proteoglycan monomers from guinea-pig costal cartilage, bovine nasal and bovine tracheal cartilage were observed in the electron microscope after being spread in a monomolecular layer with cytochrome c. The proteoglycan molecule appeared as an extended central core filament to which side-chain filaments were attached at various intervals. The molecules from the three sources displayed great ultrastructural similarities. On average, the core filament was about 290 nm long, there were about 25 side-chain filaments per core filament, the side-chain filaments were about 45 nm long, and the distance between the attachment points of the side-chain filaments to the core filament was about 11 nm. With regard to the overall size of the molecules, no evidence of distinct subpopulations was obtained. Good correlation was found between ultrastructural data for the proteoglycan molecules and chemical data obtained by enzyme digestions and gel chromatography. Together these data strongly support the interpretation of the electron-microscopic pictures as indicating a central filament corresponding to the protein core and side-chain filaments corresponding to the chondroitin sulphate chain clusters of the proteoglycan monomers.


1961 ◽  
Vol 114 (5) ◽  
pp. 825-832 ◽  
Author(s):  
Councilman Morgan ◽  
Konrad C. Hsu ◽  
Richard A. Rifkind ◽  
Alice W. Knox ◽  
Harry M. Rose

Immersion of chorioallantoic membranes infected by influenza virus in ferritin-conjugated antibody globulin prior to fixation permits recognition of viral antigen at the cellular surface. In some cases the antigen is confined to sites at which viral particles appear to be in process of release, whereas in others it is present along the entire cellular surface. During infection part or all of the cellular membrane presumably is transformed so that it contains the antigenic and structural components which coat the virus during emergence. It is suggested that detached fragments of cytoplasm possessing surface hemagglutinin but incapable of initiating infection constitute at least one form of "incomplete virus."


1968 ◽  
Vol 25 (5) ◽  
pp. 903-919 ◽  
Author(s):  
W. B. Scott ◽  
S. N. Tibbo

In the northern part of its western Atlantic range, the swordfish feeds on relatively few species of fish. Volumetrically the most important species are Atlantic mackerel, barracudinas, silver hake, redfish, and Atlantic herring. Squid are also important in the diet, and accounted for nearly one-fifth of the volume in the stomachs examined. There is evidence that the swordfish frequently uses its sword to attack and disable even small individual food items before ingesting them.


1976 ◽  
Vol 33 (11) ◽  
pp. 2551-2559 ◽  
Author(s):  
David E. Hinton ◽  
Raymond T. Jones ◽  
Roger Lee Herman

Light and electron microscopic studies were performed on tissues of hatchery-reared rainbow trout (Salmo gairdneri) having a disease of currently unknown etiology with external symptoms of severe edema which causes increased mortality rate. Comparison with unaffected trout tissues revealed loss of cellularity in glomerular tufts with a replacement of mesangial cells by connective tissue. Ultrastructural studies showed the material to be collagen and established the diagnosis of glomerular mesangial fibrosis. The glomerular lesion was associated with alterations in lining epithelium of proximal tubules and extensive debris within tubule lumens. The findings are compared to glomerular lesions in mammalian and amphibian kidney.


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