In vitro andin vivo inhibition of virus multiplication by microwave hyperthermia

Abstract

The effect of microwave hyperthermia (41 degrees and 43 degrees C) on virus multiplication have been explored in vitro (HSV-1 infected primary rabbit kidney cultures) and in vivo (mice infected with HSV-1 or vaccinia). In vitro the cells were inoculated with HSV-1 and heated to 41 degrees or 43 degrees C either before or after infection. Virus yields were significantly decreased when the cells were exposed to hyperthemia within the first few hours after infection, while hyperthemia was without effect when applied before infection or with several hours delay after infection. In mice inoculated intranasally with HSV-1, mortality due to herpes encephalitis was significantly reduced upon daily exposure to microwave hyperthermia from the day of infection onward. In mice inoculated intravenously with vaccinia, a significant decrease in the number of specific tail lesions was observed if the animals were exposed to microwave hyperthermia within the first three days after infection, while irradiation prior to infection or delayed until several days after infection did not exhibit an appreciable effect. Our data suggest that microwave hyperthermia interferes directly with the virus multiplication cycle both in vitro and in vivo.

Comparison of intravenous versus intraperitoneal administration of oncolytic herpes simplex virus 1 for peritoneal carcinomatosis in mice

“…Hyperthermia has been shown to improve drug potency as well as tissue penetration (32). Unfortunately, hyperthermia is inhibitory to lytic HSV-1 replication (33, 34), including replication of ICP6-defective HSV-1 mutants such as hrR3 (35). Cytotoxic chemotherapy also appears to be inhibitory to HSV-1 replication (unpublished data).…”

Effects of Microwave Exposure in utero on Embryonal, Fetal and Postnatal Development of Mice

“…Details of induc tion of these experimental infections in mice are de scribed elsewhere [23,24]. Briefly, mice were inocu lated intranasally with viable herpes viruses (HSV|, strain KOS) in a dose of 104 T C ID so, dissolved in 0.02 ml of Parker medium [23], or infected intraperitoneally with 2 X 108 cells of Staphylococcus aureus strain AM 717 [24]. Mortality from these infections was checked daily during 14 days.…”

“…On the 21st day of life the ability of the pups to cope with sublethal infections caused by pathogenic staphylococci or herpes virus particles was assessed. Details of induc tion of these experimental infections in mice are de scribed elsewhere [23,24]. Briefly, mice were inocu lated intranasally with viable herpes viruses (HSV|, strain KOS) in a dose of 104 T C ID so, dissolved in 0.02 ml of Parker medium [23], or infected intraperitoneally with 2 X 108 cells of Staphylococcus aureus strain AM 717 [24].…”