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Biomedical subjects

J Robin

Publications and source records attributed to J Robin.

At least 73 records · Page 4Linked to original sources
PubMed1986

Identification of the glycoproteins of lymphocystis disease virus (LDV) of fish.

Analysis of highly purified fish Lymphocystis Disease Virus (LDV), strain Leetown NFH, by three different methods, namely periodic Acid Schiff reaction, radiolabelling with tritiated fucose and N-acetyl-D-glucosamine and staining with three lectins, indicated that ten glycoproteins were associated with the virus structure. Six of them were detected by all of the three methods, three by both radiolabelling and lectin staining but only one by the lectin technique. Localization of these glycoproteins at the surface or inside the virion is discussed.

Animals↗
PubMed1986

A charring method for quantitative determination of carbohydrates on thin-layer chromatograms.

A new method for the quantitative determination of carbohydrates on thin-layer chromatography has been devised. The method is based on charring the spots with sulphuric acid generated from interaction of sulphuryl chloride with water vapour, and quantification of carbohydrates by photodensitometry of the chromatograms. In contrast to current methods, this one does not require the use of several reagents and the charred plates can be stored without fading. The method is simple, sensitive and reproducible.

Carbohydrates↗
PubMed1985

Calcofluor and ink-potassium hydroxide preparations for identifying fungi.

Calcofluor and ink-potassium hydroxide preparations identified Fusarium solani, Aspergillus fumigatus, and Candida albicans, the three most common ocular fungal pathogens, in scrapings, biopsy specimens, and tissue sections of corneal mycotic infections in rabbits. These stains also identified fungal organisms in specimens from four human patients with keratomycoses. Neither procedure requires more than a few minutes to perform or extensive training or experience to interpret. The specimen stained with calcofluor can be examined immediately, but may not identify all fungi. The more sensitive ink-potassium hydroxide preparation should be examined after 18 to 24 hours, and is less likely to provide false-positive results than the calcofluor method.

Animals↗
PubMed1984

Morphology and ultrastructure of Lymphocystis disease virus, a fish iridovirus, grown in tissue culture.

The morphology and the ultrastructure of the Lymphocystis disease virus (LDV) strain Leetown , a fish iridovirus , was studied by electron microscopy. The virus was grown on bluegill fry (BF-2) cells at 21 degrees. LDV showed an icosahedral shape by ultrathin sections and negative staining, with a diameter of about 200 nm. The shell of the virion seemed to be composed of two unitary membranes with a total diameter of 16 nm. The outer membrane demonstrated swelling in negative staining, exhibiting a central core and the presence of globular subunits at its external surface organized in geometrical arrays of 60 and 90 degrees. Glutaraldehyde fixation preserved very effectively the icosahedral structure with the subunits remaining invisible. The internal structure of the virions was composed of osmiophilic threads or granules of 6 to 8 nm in diameter surrounded by an amorphous material of 10 to 20 nm in thickness. External filaments were observed at the surface of the particles in ultrathin sections, giving the appearance of a halo surrounding the shell. In negative staining these filaments were rarely observed; in one virus preparation, they appeared in bundles.

Animals↗
PubMed1983

The role of the penetrating wound in the development of sympathetic ophthalmia experimental observations.

Clinical observations have established that sympathetic ophthalmia (SO) develops after a penetrating wound but not subsequent to often more severe intraocular disturbances such as extensive photocoagulation. A feature of the penetrating wound that appears important in the pathogenesis of SO is the access it provides for intraocular antigens to reach regional lymph nodes. The intraocular compartment has no lymphatic drainage and appears to function like a number of alymphatic biologic sites. In an experimental model of SO, subconjunctival injection of retinal S antigen in one eye induced a bilateral sympathetic uveitis, whereas intraocular injection in one eye was ineffective in inducing sympathetic disease.

Animals↗
PubMed1983

Bluegill virus is a ribovirus of positive-strand polarity.

RNA was extracted from purified Bluegill virus (BGV) and fractionated onto a poly (U)-Sepharose-4 B column. More than 70 per cent of this RNA became bound and could be subsequently eluted from the column. By polynucleotide phosphorylase digestion, the poly (A) sequences were located at the 3'-terminus of the RNA. This RNA and purified BGV RNA were infectious as shown by plaque assay titration of the virus produced. Furthermore, we were unable to detect RNA polymerase activity in preparations of BGV. These results indicate that the genome in the BGV particle is a positive-strand RNA.

Animals↗
PubMed1983

The chemical composition of lymphocystis disease virus of fish.

After concentration with PEG-6000 and purification on a metrizamide gradient, the Lymphocystis Disease Virus (LDV) can be shown as a particle with a chemical composition of 1,6% DNA, 42,3% protein and 17,1% lipid, most of them being phospholipids. Sugars might constitute a major portion of the 39% unidentified components.

Animals↗
PubMed1982

Plaque assay of bluegill virus using a methylcellulose overlay.

The EFDL strain of Bluegill virus (BGV) has been titrated in BF-2 cells by the plaque method using 1% methylcellulose overlay. Visible plaques, formed 7 days postinfection, ranged in diameter from 0.5 to 1 mm. Dose-response experiments indicated that a single particle initiated the formation of a plaque. The titration of BGV by this new plaque method provided an accurate technique for the determination of virus concentration.

Animals↗
PubMed1982

The genome of Bluegill virus.

The EFDL strain of Bluegill virus , fish virus, was grown in a Bluegill Fry cell line (BF-2) in medium containing [3H] uridine or [32P] orthophosphate. This virus was purified from the cellular material by precipitation with PEG 6000 followed by isopycnic centrifugation in a Percoll gradient. As calculated from reconstruction experiments, only 8.5 and 0.5%, respectively, of the host proteins and the host RNA were recovered with the viral band, whereas the recovery of viral infectivity was approximately 20%. Electron microscopy of the viral band showed mostly intact virus particles. The nucleic acid extracted from purified virus was found to have the following properties: (i) it migrated homogeneously during electrophoresis at the rate expected from a single-stranded nucleic acid of molecular weight 2.17 X 10(6), (ii) it sedimented as a single molecular species when analyzed by velocity centrifugation in sucrose gradients, (iii) it banded in a neutral Cs2SO4 gradient at a density of 1.69 g/cm3 as expected for single-stranded RNA, (iv) its base composition is that of a single-stranded RNA molecule: 14.89% C, 12.77% A, 37.03% U, and 35.23% G. The nucleic acid of Bluegill virus thus appears to be a single-stranded RNA molecule of approximately 2.17 X 10(6) molecular weight.

Animals↗
PubMed1982

Electron microscopic study of bluegill virus.

Bluegill virus (BGV) grown in BF-2 cells was studied by negative staining and ultrathin sections of infected cells. Although BGV resembles bunyaviruses in gross physical appearance, it differs from this group in several important aspects. Thus, BGV cannot be classified as a member of the Bunyaviridae family and could be a representative of a novel family of enveloped RNA viruses.

Animals↗
PubMed1981

Purification of lymphocystis disease virus (LDV) grown in tissue culture. Evidences for the presence of two types of viral particles.

Lymphocystis disease virus was highly purified from host cells by precipitation with PEG-6000 and isopycnic centrifugation in a metrizamide gradient. Metrizamide gradient centrifugation produce two distinct bands at equilibrium. As calculated from reconstruction experiments, only 4 and 0.3% respectively of the host DNA and the host proteins were recovered at the position of the bands. The final recovery of infectivity was about 41%. Electron microscopy of the bands showed two types of particles: small and dense particles measuring 100-150 nm and lymphocystis virions that measured about 300-350 nm in diameter.

Animals↗
PubMed1980

Isolation and preliminary characterization of herpes Channel Catfish virus DNA.

The DNA of Channel Catfish virus (CCV) was selectively extracted from infected cells with a 5% solution of sodium deoxycholate, deproteinized using sodium sarcosinate and pronase, and purified by phenol extraction followed by equilibrium density gradient centrifugation in a cesium chloride solution. CCV DNA displays a buoyant density of 1.715 g/cm3 in such a solution, as would be expected from a duplex DNA containing 56.1% of guanine plus cytosine. As estimated from both its sedimentation coefficient and length in the electron microscope, CCV DNA is a linear duplex molecule of approximately 85 x 10(6) daltons.

Animals↗