title: Cellular tolerance to pulsed hyperthermia.
abstract: Transient heating of tissues leading to cellular stress or death is very common in medicine and biology. In procedures involving a mild (below 70 degrees C) and prolonged (minutes) heating, such as hyperthermal tumor therapy, the cellular response to thermal stress is relatively well studied. However, there is practically no data on cell viability at higher temperatures and shorter exposures, while the demand for this knowledge is growing. Two main reasons motivate this research: (i) a growing number of laser therapies and surgical procedures involving pulsed heating, and (ii) cellular viability data at short exposures to high temperatures provide a unique insight into the understanding of processes leading to thermally induced cellular death. We designed a technique and performed a study of cell viability under pulses of heat from 0.3 to 100 ms in duration with peak temperatures as high as 130 degrees C. We found that the threshold of cellular death in this range can be accurately approximated by the Arrhenius law with the activation energy of 1 eV, a significantly lower value than was reported in studies based on multisecond exposures.
authors.affiliation: Hansen Experimental Physics Laboratory, Stanford University, Stanford, California 94305, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Simanovskii
authors.forename: M A
authors.initials: MA
authors.lastname: Mackanos
authors.forename: A R
authors.initials: AR
authors.lastname: Irani
authors.forename: C E
authors.initials: CE
authors.lastname: O'Connell-Rodwell
authors.forename: C H
authors.initials: CH
authors.lastname: Contag
authors.forename: H A
authors.initials: HA
authors.lastname: Schwettman
authors.forename: D V
authors.initials: DV
authors.lastname: Palanker
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects*; D003198:Computer Simulation; D004307:Dose-Response Relationship, Radiation; D005334:Fever / Q000473:pathology / Q000503:physiopathology; D006358:Hot Temperature; D007834:Lasers; D018499:Linear Energy Transfer / Q000502:physiology*; D051379:Mice; D008954:Models, Biological; D041681:NIH 3T3 Cells; D011829:Radiation Dosage