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Biomedical subjects

H Gelderblom

Publications and source records attributed to H Gelderblom.

At least 73 records · Page 4Linked to original sources
PubMed1985

Capsid symmetry of viruses of the proposed Birnavirus group.

The capsid architecture of three members of the tentatively formed group of bisegmented ds RNA containing animal viruses (Birnavirus group) was studied in comparison with the fine structure of reovirus type 1 using high resolution negative staining and shadowing techniques followed by rotational enhancement analysis. IPNV of the trout, IBDV of the chicken, and eel virus (Berlin) are single-shelled particles with a capsid diameter of 61-65 nm and thus clearly distinguishable from the double-shelled reovirus being 80-85 nm in size. The capsid symmetries of both groups of viruses are skew, with a triangulation number T=13. The handedness of the capsid is dextro for IBDV and EV, and laevo for IPNV and reovirus type 1.

Animals↗
PubMed1985

Transduction of virulence in herpes simplex virus type 1 from a pathogenic to an apathogenic strain by a cloned viral DNA fragment.

Herpes simplex virus (HSV) type 1 strain HFEM, the genome of which contains a deletion of about 4 kilobasepairs (kbp) between 0.7 and 0.8 viral map units, is apathogenic in the tree shrew when the animals are inoculated intravenously, intraperitoneally and/or subcutaneously. Similar results were obtained using Balb/c mice. Studies of the state of viral latency in animals infected with HSV-1 strain HFEM revealed that this strain was unable to colonize the ganglia of tree shrews. Infectious virus could be recovered only from the spleens of latently infected tree shrews. Thus, this system offers new opportunities for investigating the gene functions responsible for the virulence of HSV-1. Marker rescue experiments were performed by the contransfection technique using native DNA of HSV-1 strain HFEM and Bam H I DNA fragment B derived from the pathogenic HSV-1 strain F and cloned in a bacterial vector. A number of different intratypic recombinants were established in which the deleted region of HSV-1 strain HFEM had been repaired. The pathogenicity of these recombinants was examined in vivo. One of the recombinants (HSV-R-HFehx-C19) caused generalized and lethal herpes virus infection in juvenile and adult tupaias, indicating that the virulence of the pathogenic HSV-1 strain F can be transduced by the cloned Bam H I DNA fragment B to the apathogenic HSV-1 strain HFEM.

Animals↗
PubMed1985

Characterization of antisera against scrapie-associated fibrils (SAF) from affected hamster and cross-reactivity with SAF from scrapie-affected mice and from patients with Creutzfeldt-Jakob disease.

Antisera raised in rabbits and also for the first time in mice against scrapie-associated fibril (SAF) protein from hamster brain have been quantified by a modified ELISA technique (NC-ELISA) and used for a detailed analysis of SAF proteins obtained from hamster, mouse, and from patients who died of Creutzfeldt-Jakob disease. The antisera predominantly detected five bands in a Western blot analysis with apparent molecular weights of about 26000 (26K), 24K, 20K, 18K and 16K. By gel electrophoresis these antigens seem to be identical in mouse, hamster and man. The amount of material in the various bands, however, varies according to host or agent. In control materials from healthy brain SAF protein was found to be absent even when this material was used in a 50-fold excess compared to diseased brain.

Animals↗
PubMed1985

Methylation pattern of fish lymphocystis disease virus DNA.

The content and distribution of 5-methylcytosine in DNA from fish lymphocystis disease virus was analyzed by high-pressure liquid chromatography, nearest-neighbor analysis, and with restriction endonucleases. We found that 22% of all C residues were methylated, including methylation of the following dinucleotide sequences: CpG to 75%, CpC to ca. 1%, and CpA to 2 to 5%. Comparison of relative digestion of viral DNA with MspI and HpaII indicated that CCGG sequences were almost completely methylated at the inner C. The degree of methylation of GCGC was much lower. The methylation pattern of fish lymphocystis disease virus DNA differed from that of the host cell DNA.

Animals↗
PubMed1984

Morphogenesis and fine structure of eel virus (Berlin), a member of the proposed Birnavirus group.

Eel Virus (Berlin) is associated with the occurrence of skin tumors in European eels. The genome of the virus consists of two segments of double-stranded (ds) RNA. The agent is assembled exclusively in the cytoplasm. Isometric particles with a diameter of 61 nm and in addition tubular structures and smaller particles were observed. The virion has a single shell: its capsid is composed of 132 interconnected morphological units with T = 13 dextro symmetry. According to particle size and bipartite nature of the genome, this virus has to be assigned to the tentatively proposed group of bisegmented ds RNA animal viruses.

Anguilla↗
PubMed1983

Analysis of the genome of fish lymphocystis disease virus isolated directly from epidermal tumours of pleuronectes.

Virions of fish lymphocystis disease virus (FLDV), a member of the iridovirus family, were isolated directly from lymphocystis disease lesions of individual flatfishes and purified by sucrose and subsequent cesium chloride gradient centrifugation to homogeneity as judged by electron microscopy. The isolated FLDV DNAs appear to be heterogeneous in size. Contour length measurements of 43 DNA molecules gave an average length of 49 +/- 23 microns, corresponding to 93 +/- 44 X 10(6) D. Molecular weight estimations of FLDV DNA by restriction enzyme analysis resulted in only 64.8 X 10(6) D indicating an excess length of the DNA of about 50%. FLDV DNA was sensitive to lambda 5'-exonuclease and to E. coli 3'-exonuclease III without preference of any one terminal DNA restriction fragment. Denaturation and reannealing experiments of FLDV DNA resulted in the formation of circular DNA molecules of 34.25 microns contour length (= 65.22 X 10(6) D). This result suggests that FLDV DNA contains directly repeated sequences at both ends and that it is terminally redundant. FLDV DNA is methylated in cytosine. FLDV DNA did not hybridize with frog virus DNA indicating that the two iridoviruses are not closely related to each other. Restriction enzyme analysis and Southern blot hybridizations revealed that FLDV isolates can be classified into two different strains: FLDV strain 1 occurs in flounders and plaice, whereas strain 2 is usually found in lesions of dabs.

Animals↗
PubMed1983

Characteristics of mastadenovirus h 8, the causative agent of epidemic keratoconjunctivitis.

Adenovirus 8 (Ad 8, strain 1127) has the general structural features of an adenovirus; it produces the genus-specific hexon antigen. The fiber length of 12 nm corresponds to that of other subgenus D adenoviruses. In hemagglutination-inhibition, Ad 8 is related to Ad9 and Ad 15/H9. The slow multiplication, compared to most other subgenus D viruses, was shown not to be caused by an extended growth cycle, but appears to be due to an inefficient virus release into the medium. After restriction analysis with the enzymes Sma I and Bgl II, the typical fragment patterns of species from subgenus D were obtained, while very different patterns emerged from the analysis with Hind III, Bam HI, and Bst E II endonucleases. Several strains of Ad 8 produced more penton-associated toxin than Ad 15/H9 used as reference virus from subgenus D, which could explain the "clumping CPE" caused by Ad 8. Ad 8 toxin was neutralized by antisera from many adenovirus species. The poor virus yield of Ad 8 was not improved by removing soluble viral or cellular substances; all other attempts to improve virus yield by varying the conditions of cell culture also failed.

Adenoviridae Infections↗
PubMed1983

Mink lung cells as a tool for detection of Mycoplasma hyorhinis contamination in cell cultures and virus stocks.

In an extensive host range study of M. hyorhinis mink lung cells (MvlLu, ATCC CCL 64) were found to be the cells of choice for the propagation of this mycoplasm, which otherwise is often difficult to grow in a cell-free medium. Furthermore, rapid plaque assay and plaque purification procedures were developed for M. hyorhinis. The titer of M. hyorhinis grew to 1 X 10(7) to 1 X 10(8) pfu/ml within three d postinoculation on mink lung cells. DNA restriction enzyme analysis of the genome of M. hyorhinis was performed. Endonucleases Bst EII and Xho I are the most suitable enzymes for cleaving M. hyorhinis DNA into distinct fragment patterns. Thus, the use of the combination mink lung cells for mycoplasma growth with subsequent restriction enzyme analysis leads to an unambiguous detection and identification of M. hyorhinis strains even in minute amounts.

Animals↗
PubMed1983

Induction of generalized and lethal herpesvirus infection in the tree shrew by intrahepatic transfection of herpes simplex virus DNA.

The infectivity of herpes simplex virus (HSV) genome was investigated in vivo using the tree shrew, which is highly susceptible to HSV, as an animal model. Individual tree shrews were inoculated intrahepatically with 0.2 ml of a transfection mixture containing 25 micrograms HSV DNA, 50 micrograms salmon sperm DNA, and 250 micrograms DEAE-dextran. Seven out of nine tree shrews transfected with HSV DNA developed a generalized herpesvirus infection. The new virus progeny was found in different organs of transfected animals.

Animals↗
PubMed1983

Goat herpesviruses: biological and physicochemical properties.

Two herpesvirus isolates from goats are known which cause afflictions of the digestive tract in kids and, in some cases, abortion. An antigenic relationship of these goat herpesviruses with infectious bovine rhinotracheitis/infectious pustular vulvo-vaginitis virus (bovid herpesvirus 1, BHV-1) was reported and because of the species-specific pathogenicity, the goat isolates were named caprine herpesvirus 1. In this report the two isolates are further characterized and compared with BHV-1. Although the caprine herpesviruses share many biological and physicochemical properties with BHV-1, they can be differentiated from the bovine viruses with respect to growth cycle, one-way cross-neutralization and, most importantly, the restriction endonuclease fragments of their DNAs. The molecular weight of the caprine herpesvirus DNA, based on electron microscopic length measurement is 90 X 10(6), similar to that of BHV-1 (95 X 10(6]. On the basis of these genomic differences, we propose that DNA restriction endonuclease patterns of the caprine herpesviruses should be designated as prototypic of bovid herpesvirus 6 (BHV-6).

Animals↗
PubMed1982

The fibers of fowl adenoviruses.

Purified virions from 14 strains of fowl adenoviruses (FAV) representing 11 serotypes were examined by electron microscopy. Pentons of all strains turned out to have two projections at their penton bases. It is shown that the double fibers also protrude from the intact virion. The length of both fibers was measured on free pentons and is given for each serotype. Double fibers seem to be a common feature of FAV. The serologically unrelated Egg Drop Syndrome (EDS) avian adenovirus strain 127 was confirmed to have single fibers only.

Adenoviridae↗
PubMed1982

Tree shrew (Tupaia) herpesviruses.

Five Tupaia herpesviruses have been isolated until now: four in our laboratory which were termed THV-2, 3, 4, and 5, whereas THV-1 has been isolated by Melnick and his colleagues. THV-2 was isolated from tumour cell culture of a high-grade malignant lymphoma of a Tupaia, THV-3 was released from a cell culture of another Tupaia lymphoma, THV-4 from a spleen tissue culture of a moribund animal with finely granulated liver cirrhosis, and THV-5 from cultured spleen cells of an apparently healthy tree shrew. THV-1 to 5 were efficiently propagated, plaque-purified and cloned on Tupaia embryonic fibroblasts. The five isolates of Tupaia herpesviruses are easily distinguished from each other by restriction enzyme analysis of their genomes. THV-1 to 4 are highly pathogenic (lethality 100%) for juvenile Tupaias by intravenous inoculation. In contrast, only 25% lethality was found by intraperitoneal administration. THV-1 to 4 can persist as a latent infection in spleens of Tupaias and rabbits, which allows the recovery of infectious virus from cultured spleens of both animals. THV-2 and 3 induced hyperplasia of the thymus of rabbits which developed malignant thymoma in a few cases. The biological properties and genomic size and structure indicate that THV cannot be considered to belong to one of the three existing subfamilies of herpesviruses.

Animals↗
PubMed1981

The plaque-forming factor for mink lung cells present in cytomegalovirus and herpes-zoster virus stocks identified as Mycoplasma hyorhinis.

Previous investigation of the ability of cytomegalovirus and varicella-zoster virus to replicate in a variety of cell lines suggested that both virus types plaqued with high efficiency in mink lung cells. However, many of the virus isolates used appeared to be contaminated with mycoplasma. We now report that the observed cytopathic effect is due to a mycoplasma which grows lytically to high titre in mink lung cells, but is difficult to cultivate in cell-free media. The mycoplasma was plaque-purified and shown to contain DNA with a buoyant density of 1.684 g/ml, with restriction endonuclease patterns identical to the porcine mycoplasma M. hyorhinis. This was confirmed by serological identification.

Animals↗