Humans with a patent foramen ovale (PFO) have a higher esophageal temperature (T) than humans without a PFO (PFO-). Thus the presence of a PFO might also be associated with differences in thermal responsiveness to passive cooling and heating such as shivering and hyperpnea, respectively. The purpose of this study was to determine whether thermal responses to passive cooling and heating are different between PFO- subjects and subjects with a PFO (PFO+). We hypothesized that compared with PFO- subjects PFO+ subjects would cool down more rapidly and heat up slower and that PFO+ subjects who experienced thermal hyperpnea would have a blunted increase in ventilation. Twenty-seven men (13 PFO+) completed two trials separated by >48 h: ) 60 min of cold water immersion (19.5 ± 0.9°C) and) 30 min of hot water immersion (40.5 ± 0.2°C). PFO+ subjects had a higher T before and during cold water and hot water immersion ( < 0.05). However, the rate of temperature change was similar between groups for each condition. Within a subset of 18 subjects (8 PFO+) who experienced thermal hyperpnea, PFO+ subjects experienced thermal hyperpnea at a higher absolute T but with a blunted magnitude compared with PFO- subjects. These data suggest that PFO+ subjects have a higher T at rest and have blunted thermal hyperpnea during passive heating. Patent foramen ovale (PFO) is found in ~25-40% of the population. The presence of a PFO appears to be associated with a greater core body temperature and blunted ventilatory responses during passive heating. The reason for this blunted ventilatory response to passive heating is unknown but may suggest differences in thermal sensitivity in PFO+ subjects compared with PFO- subjects.
Drug-induced uveitis is an uncommon but important cause of ocular inflammation. Uveitis can be seen in association with various systemic, topical, and intraocular medications. In this article, we review common medications associated with uveitis. Most cases of drug-induced uveitis resolve with termination of the suspected medication with or without administration of topical or systemic steroids. It is important for clinicians to readily identify medications that may cause uveitis in order to provide rapid treatment, avoid consequences of longstanding inflammation, and prevent costly and excessive laboratory testing.
Approximately 35% of the general healthy population has a patent foramen ovale (PFO). People without a PFO (PFO−) have a lower esophageal temperature (Tesoph) under resting conditions and during exercise. Additionally, while breathing super cooled (−2.0 °C) air at the end of a 10‐minute exercise bout (2:30 stages at 25, 50, 75 and 90% of VO2MAX), PFO− subjects did not increase Tesoph as much as subjects with a PFO (PFO+). These data suggest blunted respiratory system cooling in PFO+ subjects. Taken together, these data suggest differences between PFO− and PFO+ subjects in thermoregulatory and ventilatory responses at rest and during exercise. However, to our knowledge it has not been prospectively determined if a PFO has any role on thermoregulatory and ventilatory responses to passive cooling.Fourteen males matched for height, weight and age participated in this study (9 PFO−; age: 26 ± 6 yrs, height: 180.1 ± 7.2 cm, weight: 83.3 ± 12.3 kg, BSA: 2.0 ± 0.2 m2; 5 PFO+; age: 28 ± 6 yrs, height: 175.8 ± 7.3 cm, weight: 77.7 ± 6.0 kg, BSA: 2.0 ± 0.1 m2). Subjects came to the lab at the same time each morning and laid in a reclined position, immersed to the nipple line in a water bath (19.6 ± 0.7 °C) until 1) 60 minutes elapsed, 2) Tesoph decreased to 35.5 °C, 3) sustained shivering occurred (oxygen uptake [VO2] > 25% of resting values for 5 consecutive minutes), or 4) subjects asked to get out of the water.We measured Tesoph, VO2 and minute ventilation (VE) every 5 minutes. At rest before immersion PFO− subjects had a lower Tesoph than PFO+ subjects (PFO−: 36.5 ± 0.2, PFO+: 36.8 ± 0.2, p = .04). At the end of immersion PFO− subjects also had a lower Tesoph than PFO+ subjects (PFO− : 36.0 ± 0.4, PFO+: 36.5 ± 0.3, p = .04). There were no differences in VO2 or VE at any time point. Furthermore, after the initial increase in Tesoph upon immersion, PFO− subjects decreased Tesoph throughout the remainder of the trial; while PFO+ subjects drop in Tesoph plateaued after 50 minutes of immersion. These data suggest that PFO− subjects are unable to retain heat as effectively as PFO+ subjects during passive cooling. This may be due to the possibility that PFO− subjects have greater respiratory system heat loss than PFO+ subjects.Support or Funding Information2015 Eugene and Clarissa Evonuk Memorial Graduate Fellowship
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