To evaluate effect of empirical combination of a β-lactam to vancomycin and vancomycin monotherapy in Staphylococcus aureus bacteremia (MSSA-B), we conducted a retrospective cohort study. Electronic medical records of individuals who were diagnosed with MSSA-B between January 2005 and February 2015 at a tertiary care center were reviewed. Patients were classified into three groups according to empirical antibiotic regimen (BL group, β-lactam; VAN group, vancomycin; BV group, combination of β-lactam and vancomycin), and 30-day all-cause mortality of each group was compared. During the study period, 561 patients with MSSA-B were identified. After exclusion of 198 patients (36 with poly-microbial infection, 114 expired within 2 days, and 48 already received parenteral antibiotics) and a matching process, 46 patients for each group were included. Baseline characteristics were similar except for severity and comorbidity scores. The 30-day mortality for all three groups were not significantly different (BL 4.3%, VAN 6.5%, BV 8.7%; P = 0.909). In a multivariate analysis, type of empirical antibiotic regimen was not statistically associated with 30-day all-cause mortality. In comparison with the VAN group, the BV group yielded a HR of 0.579 (95% CI = 0.086–3.890, P = 0.574). Pitt bacteremia score was the only significant factor for mortality. The empirical combination of a β-lactam to vancomycin was not associated with lower mortality in treating MSSA-B, compared to vancomycin monotherapy.

To provide optimal cut-off values of anti-Middle East respiratory syndrome coronavirus (MERS-CoV) serologic tests, we evaluated performance of ELISA IgG, ELISA IgA, IFA IgM, and IFA IgG using 138 serum samples of 49 MERS-CoV-infected patients and 219 serum samples of 219 rRT-PCR-negative MERS-CoV-exposed healthcare personnel and patients. The performance analysis was conducted for two different purposes: (1) prediction of neutralization activity in MERS-CoV-infected patients, and (2) epidemiologic surveillance of MERS-CoV infections among MERS-CoV-exposed individuals. To evaluate performance according to serum collection time, we used ‘days post onset of illness (dpoi)’ and ‘days post exposure (dpex)’ assessing neutralization activity and infection diagnosis, respectively. Performance of serologic tests improved with delayed sampling time, being maximized after a seroconversion period. In predicting neutralization activity, ELISA IgG tests showed optimal performance using sera collected after 21 dpoi at cut-off values of OD ratio 0.4 (sensitivity 100% and specificity 100%), and ELISA IgA showed optimal performance using sera collected after 14 dpoi at cut-off value of OD ratio 0.2 (sensitivity 85.2% and specificity 100%). In diagnosis of MERS-CoV infection, ELISA IgG exhibited optimal performance using sera collected after 28 dpex, at a cut-off value of OD ratio 0.2 (sensitivity 97.3% and specificity 92.9%). These new breakpoints are markedly lower than previously suggested values (ELISA IgG OD ratio 1.1, sensitivity 34.8% and specificity 100% in the present data set), and the performance data help serologic tests to be practically used in the field of MERS management.

Objective Narcolepsy is characterized by excessive daytime somnolence associated with sleep paralysis, hallucinations during falling asleep or awakening, and cataplexy. Early onset of narcolepsy is very rare and has significant clinical implication such as development and growth. We experienced a case of narcolepsy in a 3-year-old girl presenting with excessive sleepiness and cataplexy. Methods The patient underwent brain MRI and 24 hr-video electroencephalogram (EEG) monitoring. Polysomnography (PSG) with multiple sleep latency test (MSLT) and human leukocyte antigen (HLA) DQ typing were performed. Results Long-term video-EEG monitoring revealed no abnormal slow or epileptiform discharge during tongue thrusting, dropping head with laughter, or flopping down while standing up, which were consistent with cataplexy associated with narcolepsy. Mean sleep latency was 2.5 min and 4 episodes of sleep-onset REM periods in 5 naps were observed in PSG with MSLT. She was positive in HLA-DQB1*0602. Based on these findings, she was diagnosed as narcolepsy with cataplexy. Conclusion The history, combined with PSG and MSLT are helpful in the diagnosis of narcolepsy. We report a case of early-onset narcolepsy presenting with excessive sleepiness and narcolepsy. Narcolepsy is characterized by excessive daytime somnolence associated with sleep paralysis, hallucinations during falling asleep or awakening, and cataplexy. Early onset of narcolepsy is very rare and has significant clinical implication such as development and growth. We experienced a case of narcolepsy in a 3-year-old girl presenting with excessive sleepiness and cataplexy. The patient underwent brain MRI and 24 hr-video electroencephalogram (EEG) monitoring. Polysomnography (PSG) with multiple sleep latency test (MSLT) and human leukocyte antigen (HLA) DQ typing were performed. Long-term video-EEG monitoring revealed no abnormal slow or epileptiform discharge during tongue thrusting, dropping head with laughter, or flopping down while standing up, which were consistent with cataplexy associated with narcolepsy. Mean sleep latency was 2.5 min and 4 episodes of sleep-onset REM periods in 5 naps were observed in PSG with MSLT. She was positive in HLA-DQB1*0602. Based on these findings, she was diagnosed as narcolepsy with cataplexy. The history, combined with PSG and MSLT are helpful in the diagnosis of narcolepsy. We report a case of early-onset narcolepsy presenting with excessive sleepiness and narcolepsy.

Objective Paroxysmal nonepileptic events (PNEs) are frequently encountered in children. Although the frequencies and types of PNEs have been extensively studied in the adult population, the data available for children and adolescents are limited. In this study, we evaluate and compare the characteristics of PNEs between the age groups and the patients with or without neurologic deficits to enable early detection and diagnosis of PNEs. Methods We retrospectively reviewed 887 pediatric patients who were admitted to epilepsy monitoring unit at Samsung Medical Center between December 2001 and July 2014. One hundred forty one patients (15.9%) were diagnosed as having PNEs on the basis of clinical history and long-term video-EEG monitoring (VEM). Results Children with PNEs were divided into 3 groups by age as follows; 1) infant, toddler, and preschool group (<6 years, N=50, 35.5%); 2) school-age group (6–<12 years, N=30, 21.3%); 3) adolescent group (12–<18 years, N=61, 43.3%). Physiologic disorders such as normal infant behavior, sleep movement, and staring were more common in patients younger than 6 years of age, whereas conversion disorder predominated in patients older than 6 years. Vasogenic syncope was also frequently observed in adolescent group and was confirmed by tilt test. There was no significant difference of specific PNE types between the groups of patients with or without neurologic deficits. Conclusion In this study, physiologic symptoms predominated in younger age group, while conversion disorder was more often observed in older age groups. Clinical pattern recognition by age plays an important role in clinical practice in that pediatric patients present with various types of PNEs showing age-specific patterns. Considering inconsistent manifestation of conversion disorder, long-term VEM can be helpful in diagnosing normal infant behavior and conversion disorder. Paroxysmal nonepileptic events (PNEs) are frequently encountered in children. Although the frequencies and types of PNEs have been extensively studied in the adult population, the data available for children and adolescents are limited. In this study, we evaluate and compare the characteristics of PNEs between the age groups and the patients with or without neurologic deficits to enable early detection and diagnosis of PNEs. We retrospectively reviewed 887 pediatric patients who were admitted to epilepsy monitoring unit at Samsung Medical Center between December 2001 and July 2014. One hundred forty one patients (15.9%) were diagnosed as having PNEs on the basis of clinical history and long-term video-EEG monitoring (VEM). Children with PNEs were divided into 3 groups by age as follows; 1) infant, toddler, and preschool group (<6 years, N=50, 35.5%); 2) school-age group (6–<12 years, N=30, 21.3%); 3) adolescent group (12–<18 years, N=61, 43.3%). Physiologic disorders such as normal infant behavior, sleep movement, and staring were more common in patients younger than 6 years of age, whereas conversion disorder predominated in patients older than 6 years. Vasogenic syncope was also frequently observed in adolescent group and was confirmed by tilt test. There was no significant difference of specific PNE types between the groups of patients with or without neurologic deficits. In this study, physiologic symptoms predominated in younger age group, while conversion disorder was more often observed in older age groups. Clinical pattern recognition by age plays an important role in clinical practice in that pediatric patients present with various types of PNEs showing age-specific patterns. Considering inconsistent manifestation of conversion disorder, long-term VEM can be helpful in diagnosing normal infant behavior and conversion disorder.

In this study, we investigated the feasibility of TCE source zone flow reduction using chemical oxidant of KMnO4. The flow reduction by the induced mineral formation at the source zone has been studied through numerical case studies so far. By considering actual flow and transport condition of fields, low concentration of permanganate is applied and pseudo-multidimensional setting of parallel column connection is utilized in the experiments. The combined effects of mass reduction and flow change are quantified based on lab experiments in which low concentration of potassium permanganate within limited time is introduced into the experiments. The observations indicate that partial source mass reduction due to chemical oxidation is effective for mass flux decrement even for lower concentration of permanganate. The water flux was decreased only for the period of KMnO4 flushing due to MnO2 precipitation but rebounded right after the finish of the flushing. It is suspected that 1) reduced aqueous TCE concentration during the flushing period accelerate TCE mass transfer and cause relative permeability increase; 2) initially small amount of MnO2 formed or Mn2+ ions formed under very low pH during KMnO4 flushing time.