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Biomedical subjects

R Wyler

Publications and source records attributed to R Wyler.

At least 91 records · Page 5Linked to original sources

[Natural borna virus infection in rabbits].

Two spontaneous cases of Bornea disease in rabbits are reported. With the help of fluorescence-serological methods it was possible to detect virus-specific antibodies in the brain and serum of both animals. Demonstration of viral antigen in the brain is a valuable supplement to cell culture from brains. The findings confirm earlier reports that the natural host spectrum of Borna virus includes the rabbit, in addition to the horse and sheep.

Animals↗

[Interferon and herpes].

Interferon, a protein produced by cells, is the only non-toxic antiviral inhibiting virus multiplication in the cell. Although the industrial-technical production of the substance is more expensive the exogenic interferon treatment (interferon which is produced in cell cultures is being administered to the organism) is preferred to the endogenous interferon therapy (by application of slightly-toxic substances the organism is stimulated to produce interferon) since with the first therapy the factor toxicity can be neglected. Clinical trials with exogenous interferon treatment of herpes virus infections of men gave encouraging results, they must however be confirmed by double blind studies. Should it come to a clinical application of interferon on a large scale, first of all methods of production must be worked out to make available sufficient exogenous interferon for treatment of patients.

Herpes Simplex↗

The effect of cordycepin on the multiplication of Semliki Forest virus and on polyadenylation of viral RNA.

Cordycepin (3'-deoxyadenosine), at a concentration of 20 microgram/ml, has a marked effect on Semliki Forest virus multiplication. The appearance of plaque forming units is delayed by about 2 hours and the yield greatly reduced. The incorporation of [3H] uridine into intracellular viral RNAs reaches less than 50 per cent of controls. However, no specific effect on poly (A) synthesis could be detected. The binding efficiency of viral RNAs on nitrocellulose membranes and poly (U) sepharose is not affected by cordycepin. The average poly (A) length of total intracellular viral RNA was calculated on the basis of the ratio of the radioactivity of adenosine-monophosphate: adenosine and found to be about 35 nucleotides in treated and untreated cells.

Animals↗

HindIII and Sst I restriction sites mapped on rabbit poxvirus and vaccinia virus DNA.

The DNAs of two closely related orthopoxviruses, rabbit poxvirus (RPV) and vaccinia virus (VV), were mapped by overlapping-fragment analysis using restriction endonucleases HindIII and Sst I. The exact arrangement of these fragments was accomplished by total digestion of isolated partial restriction products and by end-fragment determination. RPV and VV DNAs showed identical restriction patterns in an internal region comprising approximately 60% of the genome. The size, by electrophoretical analysis of the RPV DNA, was 118 X 10(6) daltons, some 6 X 10(6) daltons less than VV DNA. The two opposite terminal restriction fragments of RPV DNA cross-hybridized to each other.

Base Sequence↗

Ultrastructure of tubular inclusions in endothelial cells of pituitary tumors associated with acromegaly.

Tubular inclusions were present in 13 out of 43 pituitary adenomas of acromegalic patients and in a single chromophobe pituitary adenoma. There were none in 76 other pituitary adenomas with differing endocrinological symptomatology. The arrays were usually located in the perinuclear cistern of capillary endothelial cells. The tubule diameter in osmium fixed material measured 19-26 nm and the light core averaged 6-11 nm. A longitudinal period of about 4.5 nm could be demonstrated with PTA block staining. Fixation with glutaraldehyde and block staining with ethidium bromide as well as permanganate fixation followed by RNAse treatment showed only the core of the tubules consisting of globular subunits. Several histochemical reactions (perchloric acid extraction, methenamine-silver staining, trypsin and DNAse digestion of frozen sections) suggested that the particles consist of a core of DNA coated with protein. No virus multiplication could be detected in cell cultures or in mice innoculated with fresh tumor material. No significant antibody titers against several virus antigens could be demonstrated.

Acromegaly↗

Production of large quantities of interferon with calf testicular cells and leucocytes.

Interferon (IF) was induced in calf testicle monolayer cultures and leucocycte suspension cultures with Semliki forest virus and Newcastle disease virus to evaluate the potency of those cells for producing IF in large quantities for clinical experiments. Interferon activity was measured by an RNA-inhibition test using Semliki forest virus as challenge. To produce 10(6) units of IF, leucocytes from 67-5 litres of blood or 7-2 X 10(9) testicle cells were needed.

Animals↗

[Interferon].

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Animals↗

The enhancing effect of copper, nickel, and cobalt ions on plaque formation by Semliki Forest virus (SFV) in chicken embryo fibroblasts.

In cultured chicken embryo fibroblasts treated with copper-(copper cation 10-minus 3.5-10-minus 5 M), nickel and cobalt salts an enhancement of the plating efficiency of Semliki Forest virus could be observed. This augmented plaque formation was most probably due to a higher adsorption rate of virions to the cell surface under the influence of the transition metal ions. The plating efficiency of West Nile virus in chicken-embryo fibroblasts and, to a lesser degree, of poliovius type 1 and 2 in KB-cells was also enhanced by copper sulfate.

Adsorption↗