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The biocompatibility of 10 materials used for surgical drainage was evaluated in a cytotoxicity test and in rat subcutaneous tissue implantation test. All rubber materials and silikolatex were found to be cytotoxic. There was no correspondence of the results of the cytotoxicity test with those of the implantation test. Therefore various procedures for biocompatibility-testing should be used.

The efficiency of (E)-5-(2-bromovinyl)- and 5-vinyl-1-beta-D-arabinofuranosyluracil (BrVaraU, VaraU) as inhibitors of three herpes simplex virus type 1 (HSV-1) strains was assessed in comparison to (E)-5-(2-bromovinyl)-2'-deoxyuridine (BrVUdR), 9-(2-hydroxyethoxymethyl)guanine (ACV), and trisodium phosphonoformate (Na3PFA) using a plaque assay in human embryonic lung fibroblast (HELF) cell cultures. The following order of decreasing activity was found: BrVaraU greater than VaraU greater than BrVU-dR greater than ACV much greater than Na3PFA. In HELF cell cultures, the selectivity indexes of VaraU and BrVaraU were 10 times higher than those of BrVUdR and ACV. Protection of mice from encephalitis and death due to intracerebral (i.c.) infection with a clinical HSV-1 isolate was nearly complete if mice were treated intraperitoneally (i.p.) with two daily doses of VaraU and BrVaraU (100 or 200 mg/kg per day) over a period of 5 or 10 days. The efficacy was similar to ACV, but, using a treatment schedule of three daily i.p. doses over 10 days, with equimolar amounts of the nucleoside analogs, VaraU and BrVaraU (140 and 180 mg/kg per day) were superior to ACV (130 mg/kg per day) (P less than 0.05).

4-Methyl-2-amino-pyridine-palladium chloride (MAP) showed an antiviral activity against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in a serum-free medium under in vitro conditions. The replication of these viruses on primary rabbit testes cells was completely suppressed by 10(-5) M/l MAP. In animal tests using ABD2-mice the course of HSV-1 and HSV-2 encephalitis was not influenced by MAP indicated by mean survival time and lethality.

(E)-5-(2-Bromovinyl)-2'-deoxyuridine (1; BrVUdR) inhibits the replication of herpes simplex virus type 1 (HSV-1) and of varicella-zoster virus (VZV) in vitro at concentrations of 0.01 to 0.23 mumol/l, whereas herpes simplex virus type 2 (HSV-2) is influenced only at 5.5 to 27 mumol/l. In comparison to some classical and newly developed antiherpetics, i. e. 5-iodo-2'-desoxyuridine (2; idoxuridine, IDU), 9-beta-D-arabinofuranosyladenine (4; vidarabine Ara-A), 9-(2-hydroxyethoxymethyl) guanine (5; acyclovir, ACV) and 2'-fluoro-5-iodo-1-beta-D-aracytosine (6;FIAC) the following order of decreasing activity was found:1 greater than 6 greater than 5 greater than 2 greater than 4 (against HSV-1) and 6 greater than 2 greater than 5 greater than 1 greater than 4 (against HSV-2). The high selectivity of the antiviral effect of BrVUdR towards HSV-1 and TZV is based on the fact, that proliferation of different mammalian cell lines is inhibited by 50% only at concentrations as high as 90 to 170 mumol/l, resulting in a therapeutical index of 1000 to 10,000. Successful treatment of an HSV-1 encephalitis in mice as well as an HSV-1 keratitis of rabbits confirmed the efficiency of 1 in experimental animal infections. No toxic side effects in both local and systemic applications were observed. Promising data from cell culture and animal experiments recommend 1 as a potential candidate for the local and systemic treatment of HSV-1 and VZV infections in man.

Ammonium humate, isolated from peat water, is a higher molecular polyphenolic compound with a strong antiviral activity against herpes simplex virus type 1 and type 2. Three cell lines were chosen for examining the cytotoxicity of ammonium humate: rabbit kidney primary cells, HEp-2- and FL-cells. As the light microscopic examination of both, the monolayers and the stained cover-glass cultures, revealed, concentrations of up to 5 microgram/ml ammonium humate can be used without hesitation for rabbit kidney primary cells (Fig. 1, 2) 200 microgram/ml for HEp-2-cells (Fig. 3, 4, 5), and 2000 microgram/ml for FL-cells. Fresh prepared rabbit kidney primary cells and suspended FL-cells (Tab. 1) are most sensitive against ammonium humate than monolayers. A remarcable plaque inhibition effect on the multiplication of herpes simplex virus type 1 and type 2 has been observed in all cell systems at concentrations of 0.5-20 microgram/ml ammonium humate (Fig. 6). The inhibition of virus multiplication at concentrations of greater than 10 microgram/ml ammonium humate was independent of the incubation temperature (Fig. 8). The adsorption of the virus to the cell surface has been found to be the most humate-sensitive phase of the herpesvirus multiplication cycle (Fig. 7, 9, 10). A prophylactic effect in vitro could be observed at concentrations greater than 10 microgram/ml ammonium humate (Fig. 11, 12).

Ammonium humate (prepared from marsh water humic acids) as well as enzymically oxidized diphenolic compounds such as the oxidation products of chlorogenic and caffeic acids have strong antiviral activities in vitro. The effective concentrations lie considerably outside the cytotoxic range of the compounds mentioned.

After immunization with autologous testicle cells which were infected with herpes virus hominis type 1 or 2, histologically homogeneous, eosinophilie PAS-positive substances could be detected in five out of six rabbits, mainly within the interstitium. These substances have been found by immunofluorescence microscopic techniques to be antibodies against testicle tissue.

The sensitivity of different herpes simplex virus type 2 (HSV-2) strains to inhibition by 5-vinyl-1-beta-D-arabinofuranosyluracil (VaraU) was evaluated in comparison to 9-(2-hydroxyethoxymethyl)guanine (ACV; acyclovir) and trisodiumphosphonoformate (Na3PFA; foscarnet), using a plaque inhibition assay in primary rabbit testes (PRT) cells as well as in human embryonic lung fibroblast (HELF) cell cultures. The order of decreasing activity found was ACV much greater than VaraU greater than Na3PFA in PRT cells and ACV greater than VaraU much greater than Na3PFA in HELF cells, with 50% inhibition doses (ID50) of 1.8, 8.8, and greater than 110 microM for the three drugs in HELF cells, respectively. After 72hr of drug treatment, inhibition of HELF cell proliferation by VaraU (ID50, greater than 1000 microM) was less than that by ACV and Na3PFA, resulting in high selectivity indexes of greater than 100 against HSV-2 for VaraU and ACV. Their in vivo efficacy was assessed in a mouse encephalitis model. Using a treatment schedule of three daily intraperitoneal (ip) doses over a period of 5 days, only the survival times of mice were considerably prolonged by VaraU (150 or 300 mg/kg per day; P less than 0.05 or P less than 0.001, respectively). In contrast, ACV treatment (150 mg/kg per day) led to a nearly complete prevention of encephalitis and death (P less than 0.001). Similar therapy results with VaraU application through the drinking water were obtained using only one-sixth of the high ip dose (approximately 50 mg/kg per day) but over a prolonged period of treatment. Under similar conditions no therapeutic effect of oral Na3PFA was observed.

(E)-5-(2-Bromovinyl-2'-deoxyuridine (BrVUdR) showed strong antiviral activity against different laboratory strains and clinical isolates of herpes simplex virus type 1 (HSV-1) on primary rabbit testes (PRT) cells with a 50% inhibition of plaque formation (ID50) at 0.01-0.02 microM. One laboratory strain (HSV-1-S), however, was completely refractory even at concentrations as high as 100 microM. In contrast, the ID50S for all herpes simplex virus type 2 (HSV-2) strains were about 10(2) - 10(3) times higher (8-25 microM) than for the HSV-1 strains. No toxicity in mice treated with 140 mg BrVUdR/kg/day for 14 days was observed, and successful treatments of herpes encephalitis in mice induced experimentally by intracerebral infection with one laboratory strain (HSV-1-Kupka) and one clinical isolate (HSV-1-64) were achieved. Treatment of encephalitis in mice induced by the strain HSV-1-S insensitive to BrVUdR in cell culture failed to be effective. Similar antibody titers against HSV-1 were found in surviving mice of the control and of the BrVUdR-treated groups.

The effect of (E)-5-(2-bromovinyl)- and 5-vinyl-1-beta-D-arabinofuranosyluracil (BrVaraU, VaraU) in comparison to 9-(2-hydroxyethoxymethyl)guanine (ACV) on the proliferation of human lymphoblastoid P3HR-1 cells in culture and on the expression of Epstein-Barr virus capsid antigen (VCA) in the same cells was evaluated. After 7 days of cell growth, at 100 mumol/l the total number of new generations in drug-treated cultures was similar or 5 and 10% below that in drug-free control cultures, for VaraU, ACV, and BrVaraU, respectively. During the same time the percentage of VCA-expressing cells decreased from 6.3% in drug-free cultures to 1.3, 1.5, and 2.0% in cultures treated with VaraU, ACV and BrVaraU, respectively. In VaraU-treated cultures a further decrease in the percentage of VCA-positive cells down to 0.5% was revealed 7 days after drug removal. VaraU was also effective in reducing the proportion of VCA-expressing cells at 10 and 1 mumol/l. At 14 days after drug removal, the inhibitory effect of ACV was nearly reversed, whereas BrVaraU showed a prolonged VCA- suppressing effect.

To evaluate the cytotoxicity of antiviral substances in a primary screening programme both biological (viability and alterations of cell morphology) and biochemical methods. (51Cr release) are recommended. Because of their different sensitivities the examination of primary as well as permanent cell lines is necessary.

It is reported of a new technique for the cleansing and cold sterilization of glass-ware which is particularly suited for virological laboratories and other laboratories working at cell and tissue cultures. The combined use of an alkaline cleansing agent and sterilization with Wofasteril, a peracetic acid preparation, permits to accelerate considerably the return of culture flasks for re-use.

The cytotoxicity and antiviral activity of the caffeic acid oxidation product (KOP), a higher molecular polyphenolic compound of strong antiviral activity against herpesvirus hominis type 1 and type 2 (HVH 1, HVH 2), were tested in 6 cell cultures: rabbit kidney primary cells (RKP), rabbit testis primary cells (RTP), primary human embryo lung fibroblasts (LF), calf testis primary cells (CTP), FL- and HEp-2 cells. A marked inhibitory effect on the multiplication of HVH 1 and 2 has been observed in all cell systems at non-cytotoxic concentrations of 0.1-20 micrograms/ml KOP. The adsorption of the virus to cell surface was the most KOP-sensitive phase of herpesvirus multiplication cycle.