Biomedical subjects

Young Woo Sohn

Publications and source records attributed to Young Woo Sohn.

5 recordsLinked to original sources

PubMed2006

Effects of ranitidine for exercise induced gastric mucosal changes and bleeding.

AIM: To evaluate the effect of ranitidine on gastric mucosal changes and on GI bleeding in long distance runners. METHODS: Twenty-four long distance runners (M: 16, F: 8, age: 18.2 +/- 1.5 years) participated in this study. A symptom questionnaire, stool hemoccult test, and upper gastrointestinal (GI) endoscopy were performed on the subjects prior to the study. The subjects took oral ranitidine (150 mg, b.i.d.) for two weeks. The upper GI endoscopy and stool Hemoccult tests were repeated after the treatment. RESULTS: Twenty-two of the 24 runners had at least one upper GI mucosal lesion before the medication. The Endoscopic improvements were seen in eleven of the 14 cases of erosive gastritis and four of the 5 cases of esophagitis. Six subjects were Heme occult positive prior to the study, but only one was positive after the medication. CONCLUSION: Gastric mucosal lesions and GI bleeding in long distance runners seem to be associated to acid-related factors mediated by the high level of regular running. Ranitidine seems to be and effective prophylaxis to prevent gastric mucosal lesions and GI bleeding.

Adolescent↗

PubMed2005

[A case of spontaneous biloma complicated with choledocholithiasis and chronic cholecystitis].

A biloma is an encapsulated bile collection outside the biliary tree. Most cases of biloma are caused by iatrogenic injury or trauma. Intrahepatic rupture of the biliary tree due to nontraumatic cause is a rare event. A 68- year-old man was admitted because of abdominal pain and fever. He had no past history of abdominal surgery, instrumentation or trauma. Computed tomography (CT) scan and magnetic resonance cholangiopancreatography (MRCP) demonstrated a large subcapsular fluid collection in the right liver associated with choledocholithiasis and cholecystitis. Biloma was confirmed by sono-guided percutaneous needle aspiration and was drained through a pigtail catheter. After the successful treatment by percutaneous drainage and endoscopic sphincterotomy, the patient recovered. Here, we report an uncommon case of spontaneous biloma formation in association with choledocholithiasis with a review of literatures.

Aged↗

PubMed2004

Pilot ability to anticipate the consequences of flight actions as a function of expertise.

The study offers insights into pilot ability to anticipate consequences of actions and how this ability changes with experience. Novice and expert pilots completed trials in which 3 screens depicted a control movement (or control movements), a cockpit flight situation, or a change in flight situation. Changes depicted in the 3rd screen of each trial were consistent, inconsistent with the mental model of the effect of the control movement or movements, or inconsistent with the application of the control movement(s) to the current flight situation. Pilots indicated whether the depicted change was inconsistent or consistent with their expectations, and accuracy of consistency judgments was greater for mental-model than for situation-model inconsistent statements. Experts are more accurate than novices, particularly for trials that involve multiple, meaningfully related control movements. Expert ability to organize information into meaningful units appears to facilitate future flight state projections, and projection failures appear to result from situation- rather than mental-model failures. Actual or potential applications of this research include analysis of flight situation awareness and flight performance errors.

Accidents, Aviation↗

PubMed2004

Memory processes of flight situation awareness: interactive roles of working memory capacity, long-term working memory, and expertise.

This research examined the role of working memory (WM) capacity and long-term working memory (LT-WM) in flight situation awareness (SA). We developed spatial and verbal measures of WM capacity and LT-WM skill and then determined the ability of these measures to predict pilot performance on SA tasks. Although both spatial measures of WM capacity and LT-WM skills were important predictors of SA performance, their importance varied as a function of pilot expertise. Spatial WM capacity was most predictive of SA performance for novices, whereas spatial LT-WM skill based on configurations of control flight elements (attitude and power) was most predictive for experts. Furthermore, evidence for an interactive role of WM and LT-WM mechanisms was indicated. Actual or potential applications of this research include cognitive analysis of pilot expertise and aviation training.

Acceleration↗

PubMed2003

Roles of working memory capacity and long-term working memory skill in complex task performance.

In the present research, we examined the relative roles of domain-general and domain-specific individual difference characteristics in complex cognitive task performance. Specifically, we examined the impact both of working memory (WM) capacity and of acquired skills used to encode presented information in an accessible form in long-term working memory (LTWM) on performance in a complex aviation task environment. Measures of WM capacity and LTWM skill served as performance predictors. A criterion measure of task performance was related to the predictor measures. The results indicated that an increase in LTWM skill decreases the role of WM capacity as the determinant of complex task performance, although both measures are important performance predictors. We discuss how the two distinct WM constructs coexist and interact to support complex task performance.

Cognition↗