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Biomedical subjects

J Hilfenhaus

Publications and source records attributed to J Hilfenhaus.

At least 73 records · Page 4Linked to original sources
PubMed1977

A rapid microassay for detecting antibodies against poliovirus based on [14C]thymidine uptake of treated cell cultures.

DNA synthesis of mammalian cells propagated in microplates can easily be measured if cell cultures incubated with [14C]thymidine are harvested on the glass fibre filters by a semiautomatic harvesting technique. Soon after infection with poliovirus, [14C]thymidine uptake of U cells (established, human amniotic cell line) is inhibited. This inhibition can be prevented by previous virus neutralization with antibody. Based on this effect a rapid, precise assay method was set up to determine neutralizing antibody titres against poliovirus. There was a good correlation between titres obtained by this assay and those obtained by 50% end point titrations in cytopathogenic effect inhibition assays.

Animals↗
PubMed1977

Administration of human interferon to rabies virus-infected monkeys after exposure.

The treatment of rabies-infected cynomolgus monkeys (Macaca fascicularis) with human interferon after exposure was studied. The monkeys were infected with rabies street virus by the intramuscular route; larger than or equal to 24 hr after infection, human interferon was administered intramuscularly or by lumbar spinal injection into the cerebrospinal fluid. Whereas 90% of the infected untreated monkeys died, 40%-80% of animals treated with interferon survived. No or only low levels of neutralizing antibody to rabies virus were found in the sera of monkeys that survived after a single intramuscular injection of human interferon. Distinctly higher antibody titers, however, were detected in the sera of surviving monkeys that had been given six consecutive intralumbar doses of interferon beginning three days after infections. Therefore, we conclude that in these monkeys rabies virus propagated until it spread into the central nervous system, where further viral replication was inhibited by the human interferon administered by the intralumbar route.

Animals↗
PubMed1976

Growth inhibition of human lymphoblastoid Daudi cells in vitro by interferon preparations.

Human interferon (HIF) preparations inhibited the propagation of Daudi cells in stationary suspension cultures, while a control preparation showed no such effect. The growth inhibition (= anticellular) activity of differently pretreated HIF preparations was determined by the reduction of 14C-labelled thymidine (14C-TDR) uptake in a microassay system. These studies demonstrated that the degree of anticellular activity is directly proportional to the antiviral activity of different HIF preparations. These preparations were obtained from peripheral leukocytes (lHIF) or diploid fibroblasts (fHIF). Together with gel chromatography results, and the sensitivity of the anticellular activity to tryptic digestion and heat inactivation, these results suggest that the anticellularly active substance is a protein which is very similar to, or identical with, interferon.

Burkitt Lymphoma↗
PubMed1976

Propagation of Semliki Forest virus in various human lymphoblastoid cell lines.

Semliki Forest virus (SFV) propagation was studied in one marmoset and eight human lymphoblastoid cell lines. In eight of these cell lines SFV propagated well. Only in the Daudi (human) cell line virus replication was suppressed. This suppression takes place after virus adsorption but before virus inhibitory effects on cell functions.

Cell Line↗
PubMed1976

Freeze-drying of a purified human diploid cell rabies vaccine.

A rabies vaccine prepared in human diploid cell strains was purified by continuous-flow sucrose density gradient centrifugation. The peak fractions containing 35-40% sucrose were diluted with a stabilizer consisting of degraded gelatine in a Tris-EDTA-buffer, and then inactivated with beta-propiolactone and freeze-dried to a residual moisture of approximately 2.5%. This vaccine was stable as proved by accelerated stability tests.

Cell Line↗
PubMed1975

[Sensitivity of various primate cells and animal viruses to the antiviral activity of human leukocyte interferon (author's transl)].

U cells (a permanent, human amnion cell line) were protected against infection with Semliki Forest Virus (SFV) by human interferon (HIF) from peripheral leukocytes. Despite the usual genus-specific action of interferons, mouse L929 cultures (a permanent mouse fibroblast cell line) were also protected by HIF. The antiviral action of HIF in six other primate cell cultures was also examined. It is of interest that two lymphoblastoid cell lines, RPMI1788 and Kaplan, were insensitive to HIF. The sensitivity of ten different viruses against HIF in primary African green monkey kidney cell cultures was compared. Among the viruses tested SFV was the most sensitive whereas two strains of vaccinia virus were barely inhibited. In contrast, type 1 herpes simplex virus was relatively sensitive to the action of HIF.

Amnion↗