Purpose: Mycoplasma pneumoniae pneumonia (MP) is a major cause of community-acquired pneumonia (CAP) in children and is associated with extrapulmonary manifestations (EPM). The incidence and risk factors for EPM in children are unknown. Methods: This was a retrospective study involving 65,243 pediatric patients with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Medical records were reviewed to collect information regarding the clinical characteristics, radiological results, and laboratory findings. Logistic regression with multivariate analysis was performed to evaluate the risk factors associated with EPM in MP. Results: The incidence of EPM was 23.9%, including elevation of liver enzymes (18.1%), mucocutaneous manifestations (4.4%), proteinuria (4.1%), cardiovascular and neurological manifestations (0.4%), hematologic manifestations (0.2%), and arthritis (0.2%). Statistical analysis showed that mucocutaneous manifestations significantly increased with elevated alanine aminotransferase (adjusted odds ratio [aOR], 3.623; 95% confidence interval [CI], 1.933-6.790) and atopic sensitization (aOR, 2.973; 95% CI, 1.615–5.475) and decreased with respiratory virus coinfection (aOR, 0.273; 95% CI, 0.084–0.887). Elevated liver enzymes were significantly associated with elevated lactate dehydrogenase (aOR, 3.055; 95% CI, 2.257–4.137), presence of pleural effusion (aOR, 2.635; 95% CI, 1.767–3.930), and proteinuria with respiratory virus coinfection (aOR, 2.245; 95% CI, 1.113–4.527). Conclusion Approximately 24% of pediatric patients with MP had various EPM. As the risk factors associated with each EPM were different, it is necessary to evaluate the various clinical aspects and findings of MP to predict and prepare for the occurrence of EPM.

Purpose: As cone-beam computed tomography (CBCT) has become the most widely used 3-dimensional (3D) imaging modality in the dental field, storage space and costs for large-capacity data have become an important issue. Therefore, if 3D data can be stored at a clinically acceptable compression rate, the burden in terms of storage space and cost can be reduced and data can be managed more efficiently. In this study, a deep learning network for super-resolution was tested to restore compressed virtual CBCT images. Materials and Methods: Virtual CBCT image data were created with a publicly available online dataset (CQ500) of multidetector computed tomography images using CBCT reconstruction software (TIGRE). A very deep superresolution (VDSR) network was trained to restore high-resolution virtual CBCT images from the low-resolution virtual CBCT images. Results: The images reconstructed by VDSR showed better image quality than bicubic interpolation in restored images at various scale ratios. The highest scale ratio with clinically acceptable reconstruction accuracy using VDSR was 2.1. Conclusion VDSR showed promising restoration accuracy in this study. In the future, it will be necessary to experiment with new deep learning algorithms and large-scale data for clinical application of this technology.

PURPOSE: Artificial intelligence (AI), represented by deep learning, can be used for real-life problems and is applied across all sectors of society including medical and dental field. The purpose of this study is to review articles about deep learning that were applied to the field of oral and maxillofacial radiology. MATERIALS AND METHODS: A systematic review was performed using Pubmed, Scopus, and IEEE explore databases to identify articles using deep learning in English literature. The variables from 25 articles included network architecture, number of training data, evaluation result, pros and cons, study object and imaging modality. RESULTS: Convolutional Neural network (CNN) was used as a main network component. The number of published paper and training datasets tended to increase, dealing with various field of dentistry. CONCLUSION: Dental public datasets need to be constructed and data standardization is necessary for clinical application of deep learning in dental field.
Artificial Intelligence ; Dataset ; Dentistry ; Learning

PURPOSE: Croup is known to have epidemics in seasonal and biennial trends, and to be strongly associated with epidemics of parainfluenza virus. However, seasonal and annual epidemics of croup have not been clearly reported in Korea. This study aimed to examine the seasonal/annual patterns and etiologies of childhood croup in Korea during a consecutive 6-year period. METHODS: Pediatric croup data were collected from 23 centers in Korea from 1 January 2010 to 31 December 2015. Electronic medical records, including multiplex reverse transcription polymerase chain reaction (RT-PCR) results, demographics and clinical information were cross-sectionally reviewed and analyzed. RESULTS: Overall, 2,598 childhood croup patients requiring hospitalization were identified during the study period. Among them, a total of 927 who underwent RT-PCR were included in the analysis. Males (61.5%) predominated, and most (63.0%) of them were younger than 2 years of age (median, 19 months; interquartile range, 11–31 months). Peak hospitalization occurred in 2010 and 2012 in even-numbered years, and parainfluenza virus (PIV, 39.7%) was the most common cause of childhood croup requiring hospitalization, followed by respiratory syncytial virus (14.9%), human rhinovirus (12.5%), Mycoplasma pneumonaie (10.6%), and human coronavirus (7.3%). CONCLUSION: It is concluded that croup hospitalization has a biennial pattern in even-numbered years. PIV may be the most common cause of childhood croup; however, croup epidemics could be attributed to other viruses.
Child ; Coronavirus ; Croup ; Demography ; Electronic Health Records ; Hospitalization ; Humans ; Korea ; Male ; Mycoplasma ; Paramyxoviridae Infections ; Polymerase Chain Reaction ; Respiratory Syncytial Viruses ; Retrospective Studies ; Reverse Transcription ; Rhinovirus ; Seasons

In the published article, the Figure 4 was published with incorrect y-axis and legend.

BACKGROUND/AIMS: Colorectal cancer is associated with different anatomical, biological, and clinical characteristics. We determined the impact of the primary tumor location in patients with metastatic colorectal cancer (mCRC). METHODS: Demographic data and clinical information were collected from 1,115 patients from the Republic of Korea, who presented with mCRC between January 2009 and December 2011, using web-based electronic case report forms. Associations between the primary tumor location and the patient's clinical characteristics were assessed, and factors inf luencing overall survival were analyzed using Cox proportional hazards regression models. RESULTS: Of the 1,115 patients recruited to the study, 244 (21.9%) had right colon cancer, 483 (43.3%) had left colon cancer, and 388 (34.8%) had rectal cancer. Liver and lung metastases occurred more frequently in patients with left colon and rectal cancer (p = 0.005 and p = 0.006, respectively), while peritoneal and ovarian metastases occurred more frequently in patients with right and left colon cancer (p < 0.001 and p = 0.031, respectively). The median overall survival of patients with tumors originating in the right colon was significantly shorter than that of patients whose tumors had originated in the left colon or rectum (13.7 months [95% confidence interval (CI), 12.0 to 15.5] vs. 18.0 months [95% CI, 16.3 to 19.7] or 19.9 months [95% CI, 18.5 to 21.3], respectively; p = 0.003). Tumor resection, the number of metastatic sites, and primary tumor location correlated with overall survival in the univariate and multivariate analyses. CONCLUSIONS: Primary tumor location influences the metastatic sites and prognosis of patients with mCRC.
Colon ; Colonic Neoplasms ; Colorectal Neoplasms* ; Humans ; Liver ; Lung ; Multivariate Analysis ; Neoplasm Metastasis ; Prognosis ; Rectal Neoplasms ; Rectum ; Republic of Korea

Procalcitonin (PCT) is a predictive marker for the occurrence of bacterial infection and the decision to terminate antibiotic treatment in critically ill patients. An unusual increase in PCT, regardless of infection, has been observed during extracorporeal membrane oxygenation (ECMO) support. We evaluated trends and the predictive value of PCT levels in adult cardiogenic shock during treatment with ECMO. We reviewed the clinical records of 38 adult cardiogenic shock patients undergoing veno-arterial ECMO support between January 2014 and December 2016. The exclusion criteria were age < 18 years, pre-ECMO infection, and less than 48 hours of support. The mean patient age was 56.7±14.7 years and 12 (31.6%) patients were female. The mean duration of ECMO support was 9.0±7.6 days. The rates of successful ECMO weaning and survival to discharge were 55.3% (n=21) and 52.6% (n=20), respectively. There were 17 nosocomial infections in 16 (42.1%) patients. Peak PCT levels (mean 25.6±9.4 ng/mL) were reached within 48 hours after initiation of ECMO support and decreased to ≤5 ng/mL within one week. The change in PCT levels was not useful in predicting the occurrence of new nosocomial infections during the ECMO run. However, a PCT level >10 ng/mL during the first week of ECMO support was significantly associated with mortality (p < 0.01). The change in PCT level was not useful in predicting new infection during ECMO support. However, higher PCT levels within the first week of the ECMO run are associated with significantly higher mortality.
Adult ; Bacterial Infections ; Calcitonin ; Critical Illness ; Cross Infection ; Extracorporeal Membrane Oxygenation ; Female ; Humans ; Mortality ; Shock ; Shock, Cardiogenic ; Weaning

BACKGROUND: Several injectable hydrogels have been developed extensively for a broad range of biomedical applications. Injectable hydrogels forming in situ through the change in external stimuli have the distinct properties of easy management and minimal invasiveness, and thus provide the advantage of bypassing surgical procedures for administration resulting in better patient compliance. METHODS: The injectable in situ-forming hydrogels can be formed irreversibly or reversibly under physiological stimuli. Among several external stimuli that induce formation of hydrogels in situ, in this review, we focused on the electrostatic interactions as the most simple and interesting stimulus. RESULTS: Currently, numerous polyelectrolytes have been reported as potential electrostatically interactive in situ-forming hydrogels. In this review, a comprehensive overview of the rapidly developing electrostatically interactive in situ-forming hydrogels, which are produced by various anionic and cationic polyelectrolytes such as chitosan, celluloses, and alginates, has been outlined and summarized. Further, their biomedical applications have also been discussed. CONCLUSION: The review concludes with perspectives on the future of electrostatically interactive in situ-forming hydrogels.
Alginates ; Chitosan ; Hydrogel* ; Hydrogels* ; Patient Compliance ; Regenerative Medicine

BACKGROUND: The shortage of human hearts for allotransplantation makes xenotransplantation a possible option for controllable organ providers. To detect acute xenograft rejection, invasive biopsy seems inevitable; however, this occasionally results in poor incision wound healing or infection. To date, no method of noninvasive imaging for early detection of xenograft rejection has been established. We hypothesized that ultrasound speckle tracking would better detect xenograft failure than routine left ventricular ejection fractions (EF). METHODS: From August 2013 to July 2015, a total of six cardiac heterotopic xenotransplants (α 1, 3-galactosyltransferase gene-knockout porcine heart) into cynomolgus monkeys were monitored with echocardiography every 3 to 7 days. M-mode and two-dimensional (2D)-EF measurements and myocardial strain analyses were performed. Cardiac xenograft pathology was reviewed from the immediate postoperative biopsy, as well as the necropsy. RESULTS: Myocardial speckle tracking analysis was feasible in all six cases. The longest survival was 43 days. Only one pathology-proven immunologic rejection occurred. Cardiac xenograft failure appeared as two types: a dilated pattern with decreased EF or a myocardial-thickening pattern with preserved EF. Both antibody-mediated rejection (n=1) and sepsis-induced myocardial dysfunction (n=2) revealed decreased radial or circumferential strains, but normal-range EF. Xenograft functional decline was significant with respect to radial or circumferential strain (P=0.028), but not to conventional M-mode or 2D-EFs (P=0.600, P=0.340, respectively). CONCLUSIONS: Radial and circumferential strains were significantly decreased in both types of xenograft failure, regardless of EF. Further studies are warranted to correlate the strain analysis and immunopathological details.
Biopsy ; Echocardiography ; Heart ; Heart Transplantation ; Heterografts ; Humans ; Macaca fascicularis ; Methods ; Pathology ; Stroke Volume ; Transplantation, Heterologous* ; Transplants* ; Ultrasonography ; Wound Healing