Won Young Kim

Noninvasive Coronary Vessel Wall and Plaque Imaging With Magnetic Resonance Imaging

Background—Conventional x-ray angiography frequently underestimates the true burden of atherosclerosis. Although intravascular ultrasound allows for imaging of coronary plaque, this invasive technique is inappropriate for screening or serial examinations. We therefore sought to develop a noninvasive free-breathing MR technique for coronary vessel wall imaging. We hypothesized that such an approach would allow for in vivo imaging of coronary atherosclerosis. Methods and Results—Ten subjects, including 5 healthy adult volunteers (aged 35±17 years, range 19 to 56 years) and 5 patients (aged 60±4 years, range 56 to 66 years) with x-ray–confirmed coronary artery disease (CAD), were studied with a T2-weighted, dual-inversion, fast spin-echo MR sequence. Multiple adjacent 5-mm cross-sectional images of the proximal right coronary artery were obtained with an in-plane resolution of 0.5×1.0 mm. A right hemidiaphragmatic navigator was used to facilitate free-breathing MR acquisition. Coronary vessel wall images were readily acquired in all subjects . Both coronary vessel wall thickness (1.5±0.2 versus 1.0±0.2 mm) and wall area (21.2±3.1 versus 13.7±4.2 mm2) were greater in patients with CAD (both P <0.02 versus healthy adults). Conclusions—In vivo free-breathing coronary vessel wall and plaque imaging with MR has been successfully implemented in humans. Coronary wall thickness and wall area were significantly greater in patients with angiographic CAD. The presented technique may have potential applications in patients with known or suspected atherosclerotic CAD or for serial evaluation after pharmacological intervention.

Diaphragm dysfunction assessed by ultrasonography: influence on weaning from mechanical ventilation.

Objective:To determine the prevalence of diaphragmatic dysfunction diagnosed by M-mode ultrasonography (vertical excursion <10 mm or paradoxic movements) in medical intensive care unit patients and to assess the influence of diaphragmatic dysfunction on weaning outcome. Design:Prospective, observational study. Setting:Twenty-eight-bed medical intensive care unit in a university-affiliated hospital. Patients:Eighty-eight consecutive patients in the medical intensive care unit who required mechanical ventilation over 48 hrs and met the criteria for a spontaneous breathing trial were assessed. Patients with a history of diaphragmatic or neuromuscular disease or evidence of pneumothorax or pneumomediastinum were excluded. Interventions:During spontaneous breathing trial, each hemidiaphragm was evaluated by M-mode ultrasonography using the liver and spleen as windows with the patient supine. Rapid shallow breathing index was simultaneously calculated at the bedside. Measurements and Main Results:The prevalence of ultrasonographic diaphragmatic dysfunction among the eligible 82 patients was 29% (n = 24). Patients with diaphragmatic dysfunction had longer weaning time (401 [range, 226–612] hrs vs. 90 [range, 24–309] hrs, p < .01) and total ventilation time (576 [range, 374–850] hrs vs. 203 [range, 109–408] hrs, p < .01) than patients without diaphragmatic dysfunction. Patients with diaphragmatic dysfunction also had higher rates of primary (20 of 24 vs. 34 of 58, p < .01) and secondary (ten of 20 vs. ten of 46, p = .01) weaning failures than patients without diaphragmatic dysfunction. The area under the receiver operating characteristics curve of ultrasonographic criteria in predicting weaning failure was similar to that of rapid shallow breathing index. Conclusions:Using M-mode ultrasonography, diaphragmatic dysfunction was found in a substantial number of medical intensive care unit patients without histories of diaphragmatic disease. Patients with such diaphragmatic dysfunction showed frequent early and delayed weaning failures. Ultrasonography of the diaphragm may be useful in identifying patients at high risk of difficulty weaning.

3D coronary vessel wall imaging utilizing a local inversion technique with spiral image acquisition

Current 2D black blood coronary vessel wall imaging suffers from a relatively limited coverage of the coronary artery tree. Hence, a 3D approach facilitating more extensive coverage would be desirable. The straightforward combination of a 3D‐acquisition technique together with a dual inversion prepulse can decrease the effectiveness of the black blood preparation. To minimize artifacts from insufficiently suppressed blood signal of the nearby blood pools, and to reduce residual respiratory motion artifacts from the chest wall, a novel local inversion technique was implemented. The combination of a nonselective inversion prepulse with a 2D selective local inversion prepulse allowed for suppression of unwanted signal outside a user‐defined region of interest. Among 10 subjects evaluated using a 3D‐spiral readout, the local inversion pulse effectively suppressed signal from ventricular blood, myocardium, and chest wall tissue in all cases. The coronary vessel wall could be visualized within the entire imaging volume. Magn Reson Med 46:848–854, 2001.

Blocking 4-1BB/4-1BB Ligand Interactions Prevents Herpetic Stromal Keratitis

Herpetic stromal keratitis (HSK) is a chronic inflammatory process in corneal stroma that results from recurrent HSV type 1 infection. We used the murine model of HSK to demonstrate the importance of the interaction between an inducible T cell costimulatory receptor, 4-1BB, and its ligand, 4-1BB ligand (4-1BBL), in the development of this disease. In BALB/c mice, HSK ordinarily induced by infection with the RE strain of herpes was prevented by blocking 4-1BB/4-1BBL interaction, either by deleting 4-1BB (in mutant 4-1BB−/− mice) or by introducing mAbs against 4-1BBL. The majority of T cells infiltrating the infected corneas were 4-1BB+ activated effector cells that expressed cell surface markers CD44, CD25, and/or CD62L, as well as chemokine receptors CCR1, CCR2, and CCR5, and a limited number of TCR Vβ chains (Vβ8.1/8.2, Vβ8.3, Vβ10b, and Vβ5.1/5.2, in order of abundance). Analysis of cell surface phenotypes showed that the failure to develop HSK in the 4-1BB−/− mice was associated with a reduced expression of CD62L at the time of T cell migration into the corneal stroma.

Correlation between National Influenza Surveillance Data and Google Trends in South Korea

Background In South Korea, there is currently no syndromic surveillance system using internet search data, including Google Flu Trends. The purpose of this study was to investigate the correlation between national influenza surveillance data and Google Trends in South Korea. Methods Our study was based on a publicly available search engine database, Google Trends, using 12 influenza-related queries, from September 9, 2007 to September 8, 2012. National surveillance data were obtained from the Korea Centers for Disease Control and Prevention (KCDC) influenza-like illness (ILI) and virologic surveillance system. Pearsons correlation coefficients were calculated to compare the national surveillance and the Google Trends data for the overall period and for 5 influenza seasons. Results The correlation coefficient between the KCDC ILI and virologic surveillance data was 0.72 (p<0.05). The highest correlation was between the Google Trends query of H1N1 and the ILI data, with a correlation coefficient of 0.53 (p<0.05), for the overall study period. When compared with the KCDC virologic data, the Google Trends query of bird flu had the highest correlation with a correlation coefficient of 0.93 (p<0.05) in the 2010-11 season. The following queries showed a statistically significant correlation coefficient compared with ILI data for three consecutive seasons: Tamiflu (r = 0.59, 0.86, 0.90, p<0.05), new flu (r = 0.64, 0.43, 0.70, p<0.05) and flu (r = 0.68, 0.43, 0.77, p<0.05). Conclusions In our study, we found that the Google Trends for certain queries using the survey on influenza correlated with national surveillance data in South Korea. The results of this study showed that Google Trends in the Korean language can be used as complementary data for influenza surveillance but was insufficient for the use of predictive models, such as Google Flu Trends.

Nosocomial Transmission of Severe Fever With Thrombocytopenia Syndrome in Korea

Of the 27 healthcare workers (HCWs) who had contact with a fatally ill patient with severe thrombocytopenia syndrome in Korea (SFTS), 4 who were involved in cardiopulmonary resuscitation complained of fever and were diagnosed with SFTS via seroconversion. Exposure to respiratory secretions, blood, or gowns soiled by body fluids was significantly associated with infection of HCWs.

Pulmonary Complication of Novel Influenza A (H1N1) Infection: Imaging Features in Two Patients

Novel influenza A (H1N1) virus is the pathogen of recent global outbreaks of febrile respiratory infection. We herein report the imaging findings of pulmonary complication in two patients with novel influenza A (H1N1) infection. The first patient without secondary infection showed the ill-defined ground-glass opacity nodules and patch areas of ground-glass opacities. The second patient with secondary pneumococcal pneumonia showed areas of lobar consolidation in the right middle lobe and left lower lobe and ground-glass opacities.

An Increase in Initial Shock Index Is Associated With the Requirement for Massive Transfusion in Emergency Department Patients With Primary Postpartum Hemorrhage

ABSTRACT The aim of this study was to determine whether initial shock index (SI) was independently associated with the requirement for massive transfusion (MT) in emergency department (ED) patients with primary postpartum hemorrhage (PPH). A retrospective cohort study of ED patients with primary PPH was performed at a university-affiliated, tertiary referral center between January 2004 and May 2012. Patients were classified to two groups: MT group (patients who received ≥10 U of packed red blood cells within 24 h of ED admission) and non-MT group (patients who received <10 U). Variables of the two groups were compared using univariate and multivariate analyses. A total of 126 patients were included in this study. Of these patients, 26 (20.6%) were included in MT group and 100 (79.4%) in non-MT group. Patients in MT group had significantly lower blood pressure and higher heart rate compared with patients in non-MT group (P < 0.01). Initial SI was significantly higher in MT group than in non-MT group (1.3 vs 0.8, P < 0.01). In multivariate logistic regression analysis, initial SI and heart rate were the only variables associated with the requirement for MT, with an odds ratio of 9.47 (95% confidence interval, 1.75–51.28; P < 0.01) and 1.06 (95% confidence interval, 1.02–1.09; P < 0.01), respectively. In conclusion, initial SI was independently associated with the requirement for MT in ED patients with primary PPH. Routine calculation of initial SI can help clinicians to identify patients who may benefit from timely and appropriate use of MT to improve clinical outcomes.

Neurologic outcome in comatose patients resuscitated from out-of-hospital cardiac arrest with prolonged downtime and treated with therapeutic hypothermia

BACKGROUND Previous reports have shown that prolonged duration of resuscitation efforts in out-of-hospital cardiac arrest (OHCA) is associated with poor neurologic outcome. This concept has recently been questioned with advancements in post-cardiac arrest care including the use of therapeutic hypothermia (TH). The aim of this study was to determine the rate of good neurologic outcome based on the duration of resuscitation efforts in OHCA patients treated with TH. METHODS This prospective, observational, study was conducted between January 2008 and September 2012. Inclusion criteria consisted of adult non-traumatic OHCA patients who were comatose after return of spontaneous circulation (ROSC) and received TH. The primary endpoint was good neurologic outcome defined as a cerebral performance category score of 1 or 2. Downtime was calculated as the length of time between the patient being recognized as pulseless and ROSC. RESULTS 105 patients were treated with TH and 19 were excluded due to unknown downtime, leaving 86 patients for analysis. The median downtime was 18.5 (10.0-32.3)min and 33 patients (38.0%) had a good neurologic outcome. When downtime was divided into four groups (≤10min, 11-20min, 21-30min, >30min), good neurologic outcomes were 62.5%, 37%, 25%, and 21.7%, respectively (p=0.02). However, even with downtime >20min, 22.9% had a good neurologic outcome, and this percentage increased to 37.5% in patients with an initial shockable rhythm. CONCLUSIONS Although longer downtime is associated with worse outcome in OHCA patients, we found that comatose patients who have been successfully resuscitated and treated with TH have neurologically intact survival rates of 23% even with downtime >20min.

Role of procalcitonin and C‐reactive protein in differentiation of mixed bacterial infection from 2009 H1N1 viral pneumonia

Please cite this paper as: Ahn et al. (2011) Role of procalcitonin and C‐reactive protein in differentiation of mixed bacterial infection from 2009 H1N1 viral pneumonia. Influenza and Other Respiratory Viruses 5(6), 398–403.