Herpes simplex virus was grown in different lines of human tumor and normal cells. The progeny virus was assayed for resistance to iododeoxycytidine, an indicator of a forward mutation in the virus genome. Virus grown in cells from 4 of 5 tumor lines demonstrated greater fractions mutated to iododeoxycytidine resistance than did virus grown in 7 normal human skin cell lines. The data indicate that some lines of human tumor cells modify the herpesvirus replication process, making it more mutagenic. In 2 cases of osteosarcoma patients, normal skin fibroblasts of the patients yielded normal levels of mutagenesis, while their tumor cells gave enhanced mutagenesis.

Animals↗

PubMedDate not supplied

Virus leakage through natural membrane condoms.

The authors determined virus leakage from condoms made from processed sheep caecum using two viral probes simultaneously. They poured a mixture of two viruses, the bacteriophage, phi X174 (4 X 10(7) pfu/ml), and the human pathogen, herpes simplex virus (about 1 X 10(6) pfu/ml), in a buffered solution into condoms, which were suspended into beakers also containing buffered solution. The authors then assayed aliquots from the beakers to measure the extent of virus leakage from the condoms. With one brand of condom, 10 out of 24 samples leaked small amounts of phi X174; with the other brand of condom, 13 out of 24 samples gave similar leakage. The extent of leakage varied over two orders of magnitude from condom to condom within each brand. Of the 23 condoms that leaked the smaller virus, phi X174 (27 nm in diameter), only two also leaked the larger herpesvirus (120-150 nm in diameter). These data demonstrate that (1) large and small viruses can leak from natural membrane condoms; (2) there is considerable variation from condom to condom in allowing leakage of the viruses; and (3) leakage of a small virus does not necessarily indicate that a larger virus will leak from that particular condom. The authors explain some inconsistencies in the published literature.

Animals↗

PubMedDate not supplied

An estimation of squamous cell carcinoma risk from ultraviolet radiation emitted by fluorescent lamps.

The risk of squamous cell carcinoma (SCC) from ultraviolet radiation (UV) emitted by unfiltered fluorescent lamps was assessed. The assessment employed a mathematical power model based on human epidemiological data, which relates the SCC incidence in the United States white population to ambient solar UV. The annual numbers of new SCC on anatomical sites chronically exposed to solar UV (head/face/neck and hands) were estimated for indoor workers. Then the number of SCC that may be caused by additional UV exposure from indoor fluorescent lighting was estimated: the lifetime exposure of indoor workers to typical fluorescent lighting (if unfiltered) may add 3.9% (1.6-12%) to the risk from solar UV, resulting in the induction of an additional 1500 (600-4500) SCC per annum in the United States. This calculated projection must be compared with the 110,000 SCC caused by solar exposure. Thus, this analysis suggests there may be a small increased risk of SCC from exposure to UV-emitting fluorescent lamps.

Carcinoma, Squamous Cell↗

PubMedDate not supplied

A sensitive method for evaluating condoms as virus barriers.

A standard test is needed to evaluate condoms as barriers against sexually transmitted diseases, particularly those caused by viruses. The proposed method presented here consists of a previously published simple method using physiologic-based conditions plus improvements to increase test sensitivity and decrease confounding factors such as contamination. Limitations of the method were determined by measuring virus penetration through small, well-defined holes. The method can detect penetration of 2 nL (2 x 10(-6) mL) of challenge virus suspension as well as a hole of 2 microns diameter in a latex condom. The data also indicated that virus penetration of latex condoms occurred quickly, and the hole was then apparently closed or blocked.

Bacteriophage phi X 174↗