title: Monitoring temperature and light exposure of biosamples exposed to ultraviolet and low energy radiation.
abstract: We previously showed that T-lymphocytes produce catalytic amounts of hydrogen peroxide (H2O2) in a membrane-associated process when irradiated with narrowband ultraviolet B (UVB) light. This form of phototherapy is thought to be highly effective for treatment of inflammatory skin diseases such as psoriasis, but also includes the potential for severe burning and development of skin cancer. Consequently, information on the therapeutic mechanism of narrowband UVB phototherapy and its regulation is warranted. Our laboratory is researching the mechanistic involvement of T-cell H2O2 production and its potential regulation by low energy electromagnetic field (EMF) radiation, which has been shown to beneficially influence inflammatory diseases such as psoriasis. To study photochemical H2O2 production in small samples such as suspensions of T-lymphocyte cell extracts, we use a reactor in which 12 microliter-sized samples are exposed to UVB. We simultaneously operate two identical systems, one for experimental, the other for control samples, within a walk-in environmental chamber maintained at 37 degrees C. The current paper addresses the control of UVB light exposure and temperature in our experimental setup. We quantified UVB light b y radiometric sp ot measurements and by chemical potassium ferrioxalate actinometry. We modified the actinometer so that UVB light of 5-hour experiments could be detected. Temperature was controlled by air convection and remained constant within 0.5 degrees C in air and liquid samples. Preliminary data of the effect of low energy EMF radiation on T-cell H2O2 production are presented.
authors.affiliation: Applied Biology and Biomedical Engineering, Rose-Hulman Institute of Technology Terre Haute, IN 47803, USA.
authors.forename: Hsin-Kai
authors.initials: HK
authors.lastname: Chen
authors.forename: Gabi Nindl
authors.initials: GN
authors.lastname: Waite
authors.forename: Penney L
authors.initials: PL
authors.lastname: Miller
authors.forename: Ellen F
authors.initials: EF
authors.lastname: Hughes
authors.forename: Lee R
authors.initials: LR
authors.lastname: Waite
mesh_terms: D004307:Dose-Response Relationship, Radiation; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D019169:Jurkat Cells; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D013601:T-Lymphocytes / Q000502:physiology* / Q000528:radiation effects*; D013696:Temperature; D013817:Thermography / Q000379:methods*; D014466:Ultraviolet Rays
chemical_list: D006861:Hydrogen Peroxide