[Virucidal effectiveness of some commercial products for chemothermal disinfection methods for temperature resistant viruses and bacteriophages--evaluation of a test model]. / Viruzidieprüfung einiger Handelsprodukte im chemothermischen Desinfektionsverfahren an temperaturresistenten Viren und Bakteriophagen--Erprobung eines Testmodells.

In the laboratory assay of chemothermal virus disinfection procedures a test system is required which allows to differentiate between the physical effects of the temperature and the chemical effects by the disinfectant used. From the four test viruses recommended by the German Association for the Control of Virus Diseases (Deutsche Vereinigung zur Bekämpfung der Viruskrankheiten) only SV 40 tumor virus showed a sufficient thermal stability at 55 degrees C to take it in consideration as test virus for chemothermal disinfection procedures. Bacteriophage Phi x 174 and lactococci phages P001, P008 and P109 are suggested for the evaluation of chemothermal disinfection procedures in food processing industries because of their thermal stability at 55 degrees C, for short exposition times even at 60 degrees C. For procedures which work at 60 degrees C, e.g. laundry disinfection, especially bovine parvovirus can be recommended as test virus. In case of a binary product consisting of two different compounds for mechanically cleaning and disinfection of surgical instruments we were able to evaluate the virucidal effectivity at 55 degrees C for both parts separately. Generally our results showed that products with insufficient virucidal activity against naked viruses even at 60 degrees C may not be assumed as sure virucidal disinfectants.

[Virucidal disinfection in gynecology]. / Viruzide Desinfektion in der Gynäkologie.

The different structure and stability of viruses requires the application of virucidal disinfection procedures in gynaecology. For this purpose disinfectants should be used which are tested according to the guidelines of the German Association for the Control of Virus Diseases (DVV; Deutsche Vereinigung zur Bekämpfung der Viruskrankheiten) in a virus suspension test and in nearly all cases only a slight increase of application conditions is necessary to get equal efficacy for the disinfection or surfaces of instruments. But the application solutions of instrument disinfectants should not be used longer than one day. Experiments testing the virucidal effectivity of such solutions showed an insufficient decontamination of infectious materials already after 3 days usage.

[The development of a purification method for Borna disease virus]. / Versuche zur Entwicklung eines Reinigungsverfahrens für das Virus der Bornaschen Erkrankung.

Borna disease virus represents an unknown neurotropic agent. It causes encephalitis in horses and sheep. The same or a similar type of virus might be responsible for psychiatric disorders in man. So far, it has been impossible to purify this agent to such an extent that it could be analyzed biochemically or electronmicroscopically. Therefore, different conventional virus purification techniques are applied in order to develop a method for obtaining purified Borna disease virus from infectious rat brain or persistently infected cell culture material.

Inhibition of the in vitro-reactivation of latent herpes simplex virus infection in spinal ganglia: comparison of various immune factors. Brief report.

In order to study whether the latency of herpes simplex virus (HSV) is immunologically controlled, the influence of different immune mechanisms on the in vitro-reactivation of the virus in latently infected lumbosacral ganglia of mice was investigated. Combined addition of macrophages and antibodies to cultures of ganglionic tissue proved most effective in delaying virus reactivation. This was achieved to a lesser degree when applying antibodies only, whereas macrophages alone were not effective, nor were immune lymphocytes, nor was interferon from L-cells or from the peritoneal cavity of mice.

Influence of interferon on persistent infection caused by Borna disease virus in vitro.

The effect of interferon (IFN) on infection and maintenance of persistent infection of Borna disease (BD) virus in cell cultures was investigated. Acutely BD virus-infected primary rabbit brain and rat lung cells produced significant levels of interferon detectable 3 days post-infection in the culture supernatants. Rat brain and rat lung cells persistently infected with BD virus produced only moderate levels of IFN over a long period. In contrast, persistently infected Madin-Darby canine kidney (MDCK) cells did not produce detectable amounts of IFN. Exogenous homologous IFN completely inhibited the expression of BD virus antigen in acutely infected rabbit brain cells, when added during the first 24 h after infection. IFN added later (2 to 6 days post-infection) reduced virus titres to different degrees depending on the onset of treatment. However, IFN added to persistently infected rat lung cells did not appear to influence the degree or quality of BD virus antigen expression or the intracellular amount of infectious virus. Two facts indicate that IFN is not involved in the establishment or maintenance of persistent BD virus infection in vitro. Thus, MDCK cells, which could not be induced to produce IFN, can be readily persistently infected with BD virus in vitro, and exogenous IFN did not appear to influence persistent BD virus infection.

Serum interferon levels in patients having radiotherapy for cervical carcinoma.

The well-known stimulation of interferon (IFN) both by non-specific and immune-specific stimulants, the effect of IFN on tumor therapy and against radiation damage gave us reason to examine cervical cancer patients undergoing radiation therapy for the presence of IFN. IFN was found in several serum samples of only two out of 47 patients.