Browsing by Author "Johnson, Joshua"

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    A Dose Monitoring Program for Computed Radiography
    (2012) Johnson, Joshua

    Recently, there has been a lot of effort placed on monitoring patient dose from medical procedures. The majority of people's concern has been focused on computed tomography because of the higher amounts of patient dose associated with CT exams. Our institution currently has dose monitoring programs for CT, nuclear medicine, and digital projection radiography. However, there is currently no established way to track patient dose for computed radiography. The current method of tracking computed radiography is to track exposure indicators which are not directly meaningful to patient dose. In order to address this issue, I have expanded on the exposure indicator tracking by adding a conversion for estimated patient effective dose in computed radiography.

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    Chronic infusions of mecamylamine into the medial habenula: Effects on nicotine self-administration in rats.
    (Behavioural brain research, 2022-01) Levin, Edward D; Wells, Corinne; Slade, Susan; Johnson, Joshua; Petro, Ann; Rezvani, Amir H; Rose, Jed E
    The habenula is an epithalamic structure through which descending connections go from the telencephalon to the brainstem, putting it in a key location to provide feedback control over the ascending projections from the brainstem to the telencephalon. The medial habenula has a high concentration of nicotinic receptors. We assessed the role of medial habenular nicotinic receptors for nicotine self-administration (SA) in female young adult Sprague-Dawley rats. The rats had bilateral chronic infusion cannulae placed into the medial habenula nucleus. Each cannula was connected to a slow delivery osmotic minipump to chronically infuse mecamylamine (100 µg/side/day) or vehicle for four consecutive weeks. The rats were tested for nicotine SA for the first two weeks of mecamylamine infusion. Then, they had one week of enforced abstinence, during which they had no access to the nicotine SA. Finally, they had one week of resumed nicotine SA access. There was a significantly differential mecamylamine effects in animals with lower and higher pretreatment baseline nicotine SA. Rats with lower baseline nicotine SA levels showed a nearly significant mecamylamine-induced reduction in SA while those with higher baseline levels of SA showed a significant mecamylamine-induced increase in nicotine SA. This study determined that medial habenular nicotinic receptors are important for nicotine reinforcement. Baseline level of performance makes a crucial difference for the involvement of habenular mechanisms in nicotine reinforcement with nicotinic activation being important for maintaining nicotine self-administration for those with lower levels of baseline self-administration and the opposite effect with subjects with higher levels of baseline self-administration.
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    The Association between Patients’ Physical Function in the Hospital and Their Outcomes in Skilled Nursing Facilities
    (Phys Ther Policy Admin Leadership, 2019-11-01) Johnson, Joshua; Fritz, Julie; Brooke, Benjamin; LaStayo, Paul; Thackeray, Anne; Stoddard, Gregory; Marcus, Robin
    Study Design. Retrospective observational study. Background. Shifting policies incentivize the appropriate use of skilled nursing facilities (SNFs) by linking reimbursement to patient outcomes. An appropriate recommendation for SNF care following hospitalization is limited by inadequate knowledge of the relationships between clinical presentation in the hospital and the expected outcomes in the SNF. Objectives. The primary objective was to test for relationships between physical function (PF) in the hospital and outcomes in a SNF. Methods and Measures. Data were collected from one academic medical center, five SNFs, and a state all-payer claims database. Primary predictor variables, tested in separate multivariate regression analyses, were PF at hospital admission or discharge. SNF outcomes were PF change, length of stay (LOS), discharge to community, and hospital events occurring within 30 days of hospital discharge. Results. Higher PF at hospital discharge was associated with a 2.3% decrease in SNF LOS (95% confidence interval [CI]=-4.2, -0.3; p=0.025). Trends indicate that those with higher levels of PF at hospital discharge had attenuated PF gains in the SNF (b=-0.13; 95% CI=-0.29, 0.02; p=0.091). No associations were observed between hospital PF and SNF discharge to the community or 30day hospital events. Conclusions. Patients with higher PF in the hospital may expect shorter LOS and potentially attenuated PF gains in the SNF and therefore may not benefit from care in that setting. In larger samples, similar analyses and prospective studies should further explore the associations observed in this study and inform future clinical application.