Animal studies indicate that a combination of kanamycin (KM) and noise produces a synergistic effect, whereby the threshold shift from the combination is greater than the sum of the shifts caused by either agent alone. Most such studies have focused on adult animals, and it has remained unclear whether younger, presumably more susceptible, animals show an even greater synergistic effect. The present study tested the hypothesis that young CBA/J mice receiving a low dose of KM (300 mg/kg, 2×/day, s.c.) from 20 to 30 days post-gestational age followed by brief noise exposure (110 dB SPL; 4-45 kHz, 30 s) would show greater noise-induced permanent threshold shifts (NIPTS) than mice receiving either treatment alone. Noise exposure produced 30-40 dB of NIPTS and moderate hair cell loss in young saline-treated mice. KM alone at this dose had no effect on thresholds. Surprisingly, mice receiving KM plus noise were protected from NIPTS, showing ABR thresholds not significantly different from unexposed controls. Mice receiving KM prior to noise exposure also showed significantly less outer hair cell loss than saline-treated mice. Additional experiments indicated protection by KM when the noise was applied either 24 or 48 h after the last KM injection. Our results demonstrate a powerful protective effect of subchronic low-dose kanamycin against NIPTS in young CBA/J mice. Repeated kanamycin exposure may establish a preconditioned protective state, the molecular bases of which remain to be determined.

Objectives: Implicit bias contributes to both health care disparities and professional limitations, and it exists among physicians. Prior literature has described physician weight bias (WB) toward patients, but little research has investigated interphysician WB. This study describes the prevalence of interphysician implicit WB and investigates the relationships between implicit, explicit, and professional biases. The authors hypothesized that the majority of physicians possess interphysician implicit WB and that the degree of implicit bias has a direct relationship with explicit and professional WB. Methods:In this cross-sectional study, a survey was used to measure interphysician implicit, explicit, and professional WB. It included adaptations of two previously validated measures (the Implicit Association Test and the Crandall Anti-fat Attitudes Questionnaire) and an investigator developed and tested Professional Weight Bias Scale. The survey was distributed electronically via medical society message boards, email lists, and social media groups.Results: A total of 620 physicians and medical students participated. Fifty-eight percent were female, ages ranged from 22 to 83 years (mean = 44 years), and body mass index (BMI) ranged from 16 to 59 (mean = 26). Descriptive analyses revealed that 87% had some degree of implicit interphysician antifat bias, with 31% and 34% categorized as moderate and severe, respectively. Correlation and multiple regression analyses revealed that male sex, increased age, and decreased BMI were related to increased implicit bias, controlling for all other factors. Furthermore, implicit, explicit, and professional bias all had significant, direct relationships with each other.