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Abstract Unique characteristics of the naked mole-rat (NMR) have made it increasingly popular as a laboratory animal model. These rodents are used to study many fields of research including longevity and aging, cancer, circadian rhythm, pain, and metabolism. Currently, the analgesic dosing regimens used in the NMR mirror those used in other rodent species. However, there is no pharmacokinetic (PK) data supporting the use of injectable analgesics in the NMR. Therefore, we conducted 2 independent PK studies to evaluate 2 commonly used analgesics in the NMR: meloxicam (2 mg/kg SC) and buprenorphine (0.1 mg/kg SC). In each study, blood was collected at 8 time points after subcutaneous injection of meloxicam or buprenorphine (0 [predose], 0.25, 0.5, 1, 2, 4, 8, and 24 h). Three NMRs were used per time point for a total of 24 animals per PK study. Plasma concentrations of meloxicam were highest between 0.5 and 1 h postinjection. Levels remained above the extrapolated dog and cat therapeutic threshold levels (390 to 911 ng/mL) for at least 24 h. Plasma concentrations of buprenorphine were highest between 0.25 and 0.5 h postinjection. Levels remained above the human therapeutic threshold (1 ng/mL) for up to 21 h. No skin reactions were seen in association with injection of either drug. In summary, these data support dosing meloxicam (2 mg/kg SC) once every 24 h and buprenorphine (0.1 mg/kg SC) once every 8 to 12 h in the NMR. Further studies should be performed to evaluate the clinical efficacy of these drugs by correlating plasma concentrations with postoperative pain assessments. 

Objectives:Hearing loss affects the emotional well-being of adults and is sometimes associated with clinical depression. Chronic tinnitus is highly comorbid with hearing loss and separately linked with depression. In this article, the authors investigated the combined effects of hearing loss and tinnitus on depression in the presence of other moderating influences such as demographic, lifestyle, and health factors. Design:The authors used the National Health and Nutrition Examination Survey data (2011–2012 and 2015–2016) to determine the effects of hearing loss and tinnitus on depression in a population of US adults (20 to 69 years). The dataset included the Patient Health Questionnaire-9 for depression screening, hearing testing using pure-tone audiometry, and information related to multiple demographic, lifestyle, and health factors (n = 5845). Results:The statistical analysis showed moderate to high associations between depression and hearing loss, tinnitus, and demographic, lifestyle, and health factors, separately. Results of logistic regression analysis revealed that depression was significantly influenced by hearing loss (adjusted odds ratios [OR] = 3.0), the functional impact of tinnitus (adjusted OR = 2.4), and their interaction, both in the absence or presence of the moderating influences. The effect of bothersome tinnitus on depression was amplified in the presence of hearing loss (adjusted OR = 2.4 in the absence of hearing loss to adjusted OR = 14.9 in the presence of hearing loss). Conversely, the effect of hearing loss on depression decreased when bothersome tinnitus was present (adjusted OR = 3.0 when no tinnitus problem was present to adjusted OR = 0.7 in the presence of bothersome tinnitus). Conclusions:Together, hearing loss and bothersome tinnitus had a significant effect on self-reported depression symptoms, but their relative effect when comorbid differed. Tinnitus remained more salient than hearing loss and the latter’s contribution to depression was reduced in the presence of tinnitus, but the presence of hearing loss significantly increased the effects of tinnitus on depression, even when the effects of the relevant demographic, lifestyle, or health factors were controlled. Treatment strategies that target depression should screen for hearing loss and bothersome tinnitus and provide management options for the conditions.