Significant opportunities remain for pharmacologically enhancing the clinical effectiveness of proton and carbon ion-based radiotherapies to achieve both tumor cell radiosensitization and normal tissue radioprotection. We investigated whether pretreatment with the hydroxamate-based histone deacetylase inhibitors (HDACi) SAHA (vorinostat), M344, and PTACH impacts radiation-induced DNA double-strand break (DSB) induction and repair, cell killing, and transformation (acquisition of anchorage-independent growth in soft agar) in human normal and tumor cell lines following gamma ray and light ion irradiation. Treatment of normal NFF28 primary fibroblasts and U2OS osteosarcoma, A549 lung carcinoma, and U87MG glioma cells with 5–10 µM HDACi concentrations 18 h prior to cesium-137 gamma irradiation resulted in radiosensitization measured by clonogenic survival assays and increased levels of colocalized gamma-H2AX/53BP1 foci induction. We similarly tested these HDACi following irradiation with 200 MeV protons, 290 MeV/n carbon ions, and 350 MeV/n oxygen ions delivered in the Bragg plateau region. Unlike uniform gamma ray radiosensitization, effects of HDACi pretreatment were unexpectedly cell type and ion species-dependent with C-12 and O-16 ion irradiations showing enhanced G0/G1-phase fibroblast survival (radioprotection) and in some cases reduced or absent tumor cell radiosensitization. DSB-associated foci levels were similar for proton-irradiated DMSO control and SAHA-treated fibroblast cultures, while lower levels of induced foci were observed in SAHA-pretreated C-12 ion-irradiated fibroblasts. Fibroblast transformation frequencies measured for all radiation types were generally LET-dependent and lowest following proton irradiation; however, both gamma and proton exposures showed hyperlinear transformation induction at low doses (≤25 cGy). HDACi pretreatments led to overall lower transformation frequencies at low doses for all radiation types except O-16 ions but generally led to higher transformation frequencies at higher doses (>50 cGy). The results of these in vitro studies cast doubt on the clinical efficacy of using HDACi as radiosensitizers for light ion-based hadron radiotherapy given the mixed results on their radiosensitization effectiveness and related possibility of increased second cancer induction.
In the United States, more than 110,000 restaurants permanently closed due to the impacts of the COVID-19 pandemic. Yet many restaurants remained open, albeit under very different operating conditions. In light of evolving mandates and consumers' COVID-19 risk perceptions, restaurants faced the challenging task of determining how to communicate COVID-19 protective practices. Recommended COVID-19 protective messages varied and were dependent on whether restaurants offered indoor dining, takeout, or delivery options. Drawing from U.S. government recommendations and persuasion theory, two studies examine the direct and mediation effects of protective messaging advertised by restaurants on patronage intentions and consider consumer levels of concern about the virus as a moderator. Serial moderated mediation results indicate that communicating protective measures for takeout and patio dining services appeared to be most effective during this pandemic. Moreover, results extend to protective messages presented as both primary advertisement claims and voluntary disclosures footnoted at the bottom of an advertisement. Results have implications for restaurants that offer multiple dining options and provide useful consumer communication protection options for the present and future pandemics.
Abstract Do different loan application formats affect consumer loan requests? Six studies show that when consumers are asked to provide a preferred monthly payment (MP) (vs. loan amount [LA]), they request different principal amounts. This is because these loan application formats differ in the scale-compatible information they bring to consumers’ mind. When LAs are elicited, consumers think of and request the cost of the expenditure they seek to finance. When MPs are elicited, however, consumers think of their monthly budget slack to construct and then request MPs they perceive to be affordable. For lower cost loans with a given term and interest rate, the MP (vs. LA) format results in larger principal requests. This effect reverses for higher cost acquisitions because individuals’ budget slack caps out around $500 per month. These studies provide insight into how consumer loan application formats can affect consumer borrowing, as well as the psychological underpinnings responsible for the effect. Theoretical, managerial, and consumer welfare implications of the findings are discussed.
We report on effects of low-dose exposures of accelerated protons delivered at high-dose rate (HDR) or a simulated solar-particle event (SPE) like low-dose rate (LDR) on immediate DNA damage induction and processing, survival and in vitro transformation of low passage NFF28 apparently normal primary human fibroblasts. Cultures were exposed to 50, 100 and 1,000 MeV monoenergetic protons in the Bragg entrance/plateau region and cesium-137 γ rays at 20 Gy/h (HDR) or 1 Gy/h (LDR). DNA double-strand breaks (DSB) and clustered DNA damages (containing oxypurines and abasic sites) were measured using transverse alternating gel electrophoresis (TAFE) and immunocytochemical detection/scoring of colocalized γ-H2AX pS139/53BP1 foci, with their induction being linear energy transfer (LET) dependent and dose-rate sparing observed for the different damage classes. Relative biological effectiveness (RBE) values for cell survival after proton irradiation at both dose-rates ranged from 0.61-0.73. Transformation RBE values were dose-rate dependent, ranging from ∼1.8-3.1 and ∼0.6-1.0 at low doses (≤30 cGy) for HDR and LDR irradiations, respectively. However peak transformation frequencies were significantly higher (1.3-7.3-fold) for higher doses of 0.5-1 Gy delivered at SPE-like LDR. Cell survival and transformation frequencies measured after low-dose 500 MeV/n He-4, 290 MeV/n C-12 and 600 MeV/n Si-28 ion irradiations also showed an inverse dose-rate effect for transformation at SPE-like LDR. This work demonstrates the existence of inverse dose-rate effects for proton and light-ion-induced postirradiation cell survival and in vitro transformation for space mission-relevant doses and dose rates.
Occupational health research depends on the cooperation and participation of employers. The authors describe employers' reasons for non-participation in a prospective study examining risk factors for carpal tunnel syndrome (CTS) and the usefulness of preplacement, post-offer nerve conduction screening. Companies were contacted to solicit participation. Non-participation explanations were reviewed. Of 73 eligible employers, 58 declined participation (participation rate: 20.5% ). Reasons for non-participation included lack of interest (32.8%), liability concerns (awareness of CTS may increase workers' compensation claims) (22.4%), time constraints (19%), lack of direct benefit to the employer (8.6%), and company policy restraints (6.9%). Data from one employer were reviewed to determine whether workers' compensation claims for upper extremity disorders increased as a result of study participation. Claim rates showed no change in trend pre- and post-study inception. Expanding much-needed research to prevent occupational injuries and illnesses requires addressing mployers' concerns and promoting research benefits.
