Does Objective Structured Clinical Examinations Score Reflect the Clinical Reasoning Ability of Medical Students?

Abstract:BackgroundClinical reasoning ability is an important factor in a physician's competence and thus should be taught and tested in medical schools. Medical schools generally use objective structured clinical examinations (OSCE) to measure the clinical competency of medical students. However, it is unknown whether OSCE can also evaluate clinical reasoning ability. In this study, the authors investigated whether OSCE scores reflected students' clinical reasoning abilities.MethodsSixty-five fourth-year medical students participated in this study. Medical students completed the OSCE with 4 cases using standardized patients. For assessment of clinical reasoning, students were asked to list differential diagnoses and the findings that were compatible or not compatible with each diagnosis. The OSCE score (score of patient encounter), diagnostic accuracy score, clinical reasoning score, clinical knowledge score and grade point average (GPA) were obtained for each student, and correlation analysis was performed.ResultsClinical reasoning score was significantly correlated with diagnostic accuracy and GPA (correlation coefficient = 0.258 and 0.380; P = 0.038 and 0.002, respectively) but not with OSCE score or clinical knowledge score (correlation coefficient = 0.137 and 0.242; P = 0.276 and 0.052, respectively). Total OSCE score was not significantly correlated with clinical knowledge test score, clinical reasoning score, diagnostic accuracy score or GPA.ConclusionsOSCE score from patient encounters did not reflect the clinical reasoning abilities of the medical students in this study. The evaluation of medical students' clinical reasoning abilities through OSCE should be strengthened

"Water-cycle" mechanism for writing and erasing nanostructures at the LaAlO3/SrTiO3 interface

Nanoscale control of the metal-insulator transition in LaAlO3/ SrTiO3 heterostructures can be achieved using local voltages applied by a conductive atomic-force microscope probe. One proposed mechanism for the writing and erasing process involves an adsorbed H2O layer at the top LaAlO3 surface. In this picture, water molecules dissociates into OH- and H+ which are then selectively removed by a biased AFM probe. To test this mechanism, writing and erasing experiments are performed in a vacuum AFM using various gas mixtures. Writing ability is suppressed in those environments where H2O is not present. The stability of written nanostructures is found to be strongly associated with the ambient environment. The self-erasure process in air can be strongly suppressed by creating a modest vacuum or replacing the humid air with dry inert gas. These experiments provide strong constraints for theories of both the writing process as well as the origin of interfacial conductance.Comment: 11 pages, 3 figure

Clinical outcomes of spontaneous bacterial peritonitis due to extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella species: A retrospective matched case-control study

<p>Abstract</p> <p>Background</p> <p>Clinical outcomes of spontaneous bacterial peritonitis (SBP) due to extended-spectrum β-lactamase-producing <it>Escherichia coli </it>and <it>Klebsiella </it>species (ESBL-EK) have not been adequately investigated.</p> <p>Methods</p> <p>We conducted a retrospective matched case-control study to evaluate the outcomes of SBP due to ESBL-EK compared with those due to non-ESBL-EK. Cases were defined as patients with liver cirrhosis and SBP due to ESBL-EK isolated from ascites. Control patients with liver cirrhosis and SBP due to non-ESBL-EK were matched in a 3:1 ratio to cases according to the following five variables: age (± 5 years); gender; species of infecting organism; Child-Pugh score (± 2); Acute Physiological and Chronic Health Evaluation II score (± 2). 'Effective initial therapy' was defined as less than 72 hours elapsing between the time of obtaining a sample for culture and the start of treatment with an antimicrobial agent to which the EK was susceptible. Cephalosporin use for ESBL-EK was considered 'ineffective', irrespective of the minimum inhibitory concentration. ESBL production was determined according to the Clinical and Laboratory Standards Institute guidelines on stored isolates.</p> <p>Results</p> <p>Of 1026 episodes of SBP in 958 patients from Jan 2000 through Dec 2006, 368 (35.9%) episodes in 346 patients were caused by SBP due to EK, isolated from ascites. Of these 346 patients, twenty-six (7.5%) patients with SBP due to ESBL-EK were compared with 78 matched controls. Treatment failure, evaluated at 72 hours after initial antimicrobial therapy, was greater among the cases (15/26, 58% <it>vs</it>. 10/78, 13%, <it>P </it>= .006); 30-day mortality rate was also higher than in the controls (12/26, 46% <it>vs</it>. 11/78, 15%, <it>P </it>= .001). When the case were classified according to the effectiveness of the initial therapy, 'ineffective initial therapy' was associated with higher 30-day mortality rate (11/18, 61% <it>vs</it>. 1/8, 13%, <it>P </it>= .036).</p> <p>Conclusion</p> <p>SBP due to ESBL-EK had poorer outcomes than SBP due to non-ESBL-EK. Ineffective initial therapy seems to be responsible for the higher rate of treatment failure and mortality in SBP due to ESBL-EK.</p

Highly-Sensitive Textile Pressure Sensors Enabled by Suspended-Type All Carbon Nanotube Fiber Transistor Architecture.

Among various wearable health-monitoring electronics, electronic textiles (e-textiles) have been considered as an appropriate alternative for a convenient self-diagnosis approach. However, for the realization of the wearable e-textiles capable of detecting subtle human physiological signals, the low-sensing performances still remain as a challenge. In this study, a fiber transistor-type ultra-sensitive pressure sensor (FTPS) with a new architecture that is thread-like suspended dry-spun carbon nanotube (CNT) fiber source (S)/drain (D) electrodes is proposed as the first proof of concept for the detection of very low-pressure stimuli. As a result, the pressure sensor shows an ultra-high sensitivity of ~3050 Pa-1 and a response/recovery time of 258/114 ms in the very low-pressure range of <300 Pa as the fiber transistor was operated in the linear region (VDS = -0.1 V). Also, it was observed that the pressure-sensing characteristics are highly dependent on the contact pressure between the top CNT fiber S/D electrodes and the single-walled carbon nanotubes (SWCNTs) channel layer due to the air-gap made by the suspended S/D electrode fibers on the channel layers of fiber transistors. Furthermore, due to their remarkable sensitivity in the low-pressure range, an acoustic wave that has a very tiny pressure could be detected using the FTPS

Posttraumatic stress disorder and depression of survivors 12 months after the outbreak of Middle East respiratory syndrome in South Korea

The 2015 outbreak of Middle East Respiratory Syndrome (MERS) in the Republic of Korea is a recent and representative occurrence of nationwide outbreaks of Emerging Infectious Diseases (EIDs). In addition to physical symptoms, posttraumatic stress disorder (PTSD) and depression are common following outbreaks of EID. The present study investigated the long-term mental health outcomes and related risk factors in survivors of MERS. A prospective nationwide cohort study was conducted 12 months after the MERS outbreak at multi-centers throughout Korea. PTSD and depression as the main mental health outcomes were assessed with the Impact of Event Scale-Revised Korean version (IES-R-K) and the Patient Health Questionnaire-9 (PHQ-9) respectively. 42.9% of survivors reported PTSD (IES-R-K ≥ 25) and 27.0% reported depression (PHQ-9 ≥ 10) at 12 months post-MERS. A multivariate analysis revealed that anxiety (adjusted odds ratio [aOR], 5.76; 95%CI, 1.29–25.58; P = 0.021), and a greater recognition of stigma (aOR, 11.09, 95%CI, 2.28–53.90; P = 0.003) during the MERS-affected period were independent predictors of PTSD at 12 months after the MERS outbreak. Having a family member who died from MERS predicted the development of depression (aOR, 12.08, 95%CI, 1.47–99.19; P = 0.020). This finding implies that psychosocial factors, particularly during the outbreak phase, influenced the mental health of patients over a long-term period. Mental health support among the infected subjects and efforts to reduce stigma may improve recovery from psychological distress in an EID outbreak.The study was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea (HI15C3227) and a grant from the Korean Mental Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (HL19C0007). The funding bodies were not involved in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript

Estimating contact-adjusted immunity levels against measles in South Korea and prospects for maintaining elimination status.

Measles has been reemerging in South Korea since December 2018 resulting in 185 cases by September 2019. We calculated contact-adjusted immunity levels against measles in South Korea using national seroprevalence data in 2014, vaccination uptake rates, and an age-specific contact matrix. We further explored options to achieve a contact-adjusted immunity level of 93% for herd immunity. The assessed contact-adjusted immunity level has increased from 86% in 2014 to 92% in 2018. Herd immunity could be achieved with immunizing 50% of susceptibles among birth cohorts 1999-2003 in 2018. Contact-adjusted immunity levels against measles have increased recently in South Korea, although they might not yet be high enough to guarantee herd immunity

Staphylococcus aureus Colonization of the Mouse Gastrointestinal Tract Is Modulated by Wall Teichoic Acid, Capsule, and Surface Proteins

Staphylococcus aureus colonizes the nose, throat, skin, and gastrointestinal (GI) tract of humans. GI carriage of S. aureus is difficult to eradicate and has been shown to facilitate the transmission of the bacterium among individuals. Although staphylococcal colonization of the GI tract is asymptomatic, it increases the likelihood of infection, particularly skin and soft tissue infections caused by USA300 isolates. We established a mouse model of persistent S. aureus GI colonization and characterized the impact of selected surface antigens on colonization. In competition experiments, an acapsular mutant colonized better than the parental strain Newman, whereas mutants defective in sortase A and clumping factor A showed impaired ability to colonize the GI tract. Mutants lacking protein A, clumping factor B, poly-N-acetyl glucosamine, or SdrCDE showed no defect in colonization. An S. aureus wall teichoic acid (WTA) mutant (ΔtagO) failed to colonize the mouse nose or GI tract, and the tagO and clfA mutants showed reduced adherence in vitro to intestinal epithelial cells. The tagO mutant was recovered in lower numbers than the wild type strain in the murine stomach and duodenum 1 h after inoculation. This reduced fitness correlated with the in vitro susceptibility of the tagO mutant to bile salts, proteases, and a gut-associated defensin. Newman ΔtagO showed enhanced susceptibility to autolysis, and an autolysin (atl) tagO double mutant abrogated this phenotype. However, the atl tagO mutant did not survive better in the mouse GI tract than the tagO mutant. Our results indicate that the failure of the tagO mutant to colonize the GI tract correlates with its poor adherence and susceptibility to bactericidal factors within the mouse gut, but not to enhanced activity of its major autolysin

Should HLA-B*5701 Screening Be Performed in Every Ethnic Group before Starting Abacavir?

Human leukocyte antigen allele (HLA)-B*5701 is associated with abacavir hypersensitivity. However, the carriage rate of HLA-B*5701 has rarely been studied in Asians. In 534 Korean patients with human immunodeficiency virus infection, HLA-B*5701 status was determined by polymerase chain reaction with HLA-B*5701-specific primers. No patients had the HLA-B*5701 allele (95% confidence interval, 0%-0.7%). This explains the paucity of immunologically confirmed cases of abacavir hypersensitivity in Koreans.Saag M, 2008, CLIN INFECT DIS, V46, P1111, DOI 10.1086/529382Mallal S, 2008, NEW ENGL J MED, V358, P568*PAN ANT GUID AD A, 2008, GUID US ANT AG HIV 1Waters LJ, 2007, AIDS, V21, P2533Sun HY, 2007, J ANTIMICROB CHEMOTH, V60, P599, DOI 10.1093/jac/dkm243Rauch A, 2006, CLIN INFECT DIS, V43, P99Phillips EJ, 2006, CLIN INFECT DIS, V43, P103Martin AM, 2005, TISSUE ANTIGENS, V65, P571, DOI 10.1111/j.1399-0039.2005.00401.xLee KW, 2005, TISSUE ANTIGENS, V65, P437, DOI 10.1111/j.1399-0039.2005.00386.xMiddleton D, 2004, TISSUE ANTIGENS, V63, P555Phillips EJ, 2002, AIDS, V16, P2223Saito S, 2000, TISSUE ANTIGENS, V56, P522Park MH, 1999, TISSUE ANTIGENS, V53, P3861