Biomedical subjects
P R Sullivan
Publications and source records attributed to P R Sullivan.
Diagnosis of acute thoracic aortic dissection in the emergency department.
In this article we try to determine how frequently emergency physicians (EPs) suspected the diagnosis in acute aortic dissection (AD). In this retrospective descriptive study, we identified all patients with the final diagnosis of AD initially evaluated in 1 of 3 emergency departments (EDs) over a 5-year period. Patients were included if AD was not suspected before ED evaluation. Patients undergoing thoracic aorta imaging as the initial ED study were defined as suspected AD. Forty-three patients totaling 44 presentations were identified. EPs suspected AD in 19 of 44 presentations. EPs suspected AD in 12 of 14 (86%) cases of chest and back pain and in 5 of 11 (45%) of chest pain. Thirteen of 39 (33%) painful presentations involved abdominal pain; EPs suspected AD in 1 of 13 (8%). EPs suspected the diagnosis in 43% of acute AD; location of pain was most predictive of a suspected diagnosis.
Optical density changes of Gafchromic MD-55 film resulting from laser light exposure at wavelengths of 671 nm and 633 nm.
Laser-based scanners provide a sensitive means for measuring optical density (OD) of Gafchromic films. Such instruments were reviewed in a recent AAPM report (task group 55) which provided recommendations and information on OD measurements (effect of wavelength, temperature, etc.). The present article reports that variable rate scanners and spot densitometers using laser diodes (671 nm) and HeNe lasers (633 nm) can cause polymerization of Gafchromic film. The light induced polymerization depends on light power, wavelength, beam spot size, dwell time, and prior radiation dose of the film. Measurements were made with a custom built scanner that provided accurate control of light power, light polarization, dwell time, and film position in relation to the beam focus. The results demonstrate that lasers operating with powers of 0.1, 0.5, 1.0, and 1.5 mW produce a nonlinear increase in OD of Gafchromic film. The measured change in OD after 1 min of exposure ranges from 0.150 to 0.244 for a laser diode operating at 0.5 and 1.5 mW, respectively. Tables are included that tabulate the increase in OD for laser power, dwell time, and prior dose. Laser light induced polymerization can have a significant impact on dosimetry measurements acquired using these laser-based systems.
Transient hyperprolactinemia and hyperthyroidism in autoimmune thyroiditis.
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A critique of the Massachusetts determination of need program.
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Influence of personal values on psychiatric judgment: a military example.
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Learning theories and supportive psychotherapy.
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The role of human conscience in therapeutic abortion.
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