PURPOSE: Oak is the dominant tree species in Korea. Oak pollen has the highest sensitivity rate among all allergenic tree species in Korea. A deep neural network (DNN)-based estimation model was developed to determine the concentration of oak pollen and overcome the shortcomings of conventional regression models. METHODS: The DNN model proposed in this study utilized weather factors as the input and provided pollen concentrations as the output. Weather and pollen concentration data were used from 2007 to 2016 obtained from the Korea Meteorological Administration pollen observation network. Because it is difficult to prevent over-fitting and underestimation by using a DNN model alone, we developed a bootstrap aggregating-type ensemble model. Each of the 30 ensemble members was trained with random sampling at a fixed rate according to the pollen risk grade. To verify the effectiveness of the proposed model, we compared its performance with those of models of regression and support vector regression (SVR) under the same conditions, with respect to the prediction of pollen concentrations, risk levels, and season length. RESULTS: The mean absolute percentage error in the estimated pollen concentrations was 11.18%, 10.37%, and 5.04% for the regression, SVR and DNN models, respectively. The start of the pollen season was estimated to be 20, 22, and 6 days earlier than that predicted by the regression, SVR and DNN models, respectively. Similarly, the end of the pollen season was estimated to be 33, 20, and 9 days later that predicted by the regression, SVR and DNN models, respectively. CONCLUSIONS: Overall, the DNN model performed better than the other models. However, the prediction of peak pollen concentrations needs improvement. Improved observation quality with optimization of the DNN model will resolve this issue.
Korea ; Pollen ; Quercus ; Rhinitis, Allergic ; Rhinitis, Allergic, Seasonal ; Seasons ; Trees ; Weather

BACKGROUND: CDX1 and CDX2, members of the caudal-type homeobox gene family, control proliferation and differentiation of intestinal mucosal cells. Their expression is reduced commonly in colorectal cancers, but reports about the relationship between their expression and the clinicopathologic features are rare. The aim of this study was to examine CDX1 mRNA and CDX2 mRNA expression in colorectal cancers and to assess the relationship between their expression and the clinicopathologic features. METHODS: CDX1 mRNA and CDX2 mRNA expression were analyzed by real-time polymerase chain reaction in 48 colorectal cancers and their adjacent non-tumorous normal mucosas. RESULTS: CDX1 mRNA and CDX2 mRNA expression were decreased significantly in colorectal cancers than in normal mucosas (p=0.001, p=0.042, respectively). In comparison with paired normal mucosas, colorectal cancers showed decreased CDX1 mRNA expression in 64.6% (31/48) and decreased CDX2 mRNA expression in 66.7% (32/48). There was a statistically significant correlation between CDX1 mRNA and CDX2 mRNA expression in colorectal cancers (r=0.543, p<0.001). CDX1 mRNA and CDX2 mRNA expression were not related to age, sex, location of cancer, differentiation, lymphatic or vascular invasion, lymph node metastasis, stage and serum carcinoembryonic antigen level in colorectal cancers. CONCLUSION: CDX1 mRNA and CDX2 mRNA expression were decreased significantly in colorectal cancers, but were not related to the clininopathologic features.
Carcinoembryonic Antigen ; Colorectal Neoplasms* ; Genes, Homeobox ; Humans ; Lymph Nodes ; Mucous Membrane ; Neoplasm Metastasis ; Real-Time Polymerase Chain Reaction ; RNA, Messenger*

BACKGROUND: CDX1 and CDX2 are members of the caudal-type homeobox gene family and control the proliferation and differentiation of intestinal mucosal cells. Their expressions are commonly reduced in colorectal cancer, but reports about the relationships between their expressions and clinicopathologic features are rare. The aim of this study was to examine the expressions of CDX1 and CDX2 mRNAs in colorectal cancers and to assess the relationships between their expressions and clinicopathologic features. METHODS: CDX1 and CDX2 mRNA expressions were analyzed by real-time polymerase chain reaction in 48 colorectal cancers and in adjacent non-tumorous normal mucosal tissue. RESULTS: CDX1 and CDX2 mRNA expressions were significantly reduced in colorectal cancer tissues versus normal mucosal tissues (p=0.001, p=0.042, respectively). As compared with paired normal mucosal tissues, colorectal tissues showed reduced CDX1 mRNA expression in 64.6% (31/48) and reduced CDX2 mRNA expression in 66.7% (32/48) of cases. A statistically significant positive correlation was found between the expressions of CDX1 mRNA and CDX2 mRNA in colorectal cancer (r=0.543, p< 0.001). However, the expressions of CDX1 and CDX2 mRNAs were not related to age, sex, cancer location, differentiation, lymphatic or vascular invasion, lymph node metastasis, stage or serum carcinoembryonic antigen level. CONCLUSIONS: CDX1 and CDX2 mRNA expressions were found to be significantly reduced in colorectal cancers, but these expressional changes were not found to be related to clinicopathologic features.
RNA, Messenger/*metabolism ; Polymerase Chain Reaction ; Middle Aged ; Male ; Humans ; Homeodomain Proteins/*metabolism ; Female ; Colorectal Neoplasms/*metabolism

BACKGROUND: Malnutrition is associated with many adverse clinical outcomes. The present study aimed to identify the prevalence of malnutrition in hospitalized patients in Korea, evaluate the association between malnutrition and clinical outcomes, and ascertain the risk factors of malnutrition. METHODS: A multicenter cross-sectional study was performed with 300 patients recruited from among the patients admitted in 25 hospitals on January 6, 2014. Nutritional status was assessed by using the Subjective Global Assessment (SGA). Demographic characteristics and underlying diseases were compared according to nutritional status. Logistic regression analysis was performed to identify the risk factors of malnutrition. Clinical outcomes such as rate of admission in intensive care units, length of hospital stay, and survival rate were evaluated. RESULTS: The prevalence of malnutrition in the hospitalized patients was 22.0%. Old age (≥ 70 years), admission for medical treatment or diagnostic work-up, and underlying pulmonary or oncological disease were associated with malnutrition. Old age and admission for medical treatment or diagnostic work-up were identified to be risk factors of malnutrition in the multivariate analysis. Patients with malnutrition had longer hospital stay (SGA A = 7.63 ± 6.03 days, B = 9.02 ± 9.96 days, and C = 12.18 ± 7.24 days, P = 0.018) and lower 90-day survival rate (SGA A = 97.9%, B = 90.7%, and C = 58.3%, P < 0.001). CONCLUSION: Malnutrition was common in hospitalized patients, and resulted in longer hospitalization and associated lower survival rate. The rate of malnutrition tended to be higher when the patient was older than 70 years old or hospitalized for medical treatment or diagnostic work-up compared to elective surgery.
Cross-Sectional Studies ; Hospitalization ; Humans ; Intensive Care Units ; Korea ; Length of Stay ; Logistic Models ; Malnutrition ; Multivariate Analysis ; Nutrition Assessment ; Nutritional Status ; Prevalence ; Risk Factors ; Survival Rate

BACKGROUND/AIMS: The meaning of specialized intestinal metaplasia (SIM) in the diagnosis of Barrett's esophagus (BE) is not clear. This study was designed to determine the clinical significance of SIM in the diagnosis of Barrett's esophagus. MATERIALS AND METHODS: Biopsies were taken from 601 subjects with endoscopically suspected columnar-lined esophagus. Under light microscopy with Alcian-blue stain, SIM was identified. Demographic characteristics, gastroesophageal (GE) reflux symptoms and endoscopic findings were compared between the SIM-present group and the SIM-absent group. RESULTS: Among 601 subjects, 184 (30.6%) were confirmed by pathology to have SIM. Age over 40 years (P<0.001) and a medication history of proton pump inhibitor or H2 blocker were found more frequently in the SIM-present group (P=0.01) than in the SIM-absent group. Any of 7 GE reflux symptoms (heartburn, acid regurgitation, chest pain, hoarseness, globus sensation, cough and epigastric soreness) were more frequent in the SIM-present group than SIM-absent group (P<0.001). Specifically, heartburn, chest pain and cough were significantly more common in the SIM-present group. There was no clinically significant difference associated with endoscopic findings or other clinical characteristics. CONCLUSIONS: When subjects with endoscopically suspected BE are analyzed based on the presence or absence of SIM, the SIM-present group was significantly associated with GE reflux symptoms suggestive of frequent GE reflux. However, the presence of SIM did not correlate with endoscopic findings.
Barrett Esophagus ; Biopsy ; Chest Pain ; Cough ; Esophagus ; Gastroesophageal Reflux ; Heartburn ; Hoarseness ; Light ; Metaplasia ; Microscopy ; Prospective Studies ; Proton Pumps ; Sensation

BACKGROUND/AIMS: Chronic gastritis is a common finding during endoscopy and it is very important to describe it correctly. This study was designed to evaluate the distribution of endoscopic gastritis and the differences according to age, sex or area. MATERIALS AND METHODS: A clinical analysis was conducted on 25,536 subjects who had undergone an upper endoscopy for routine health check-up. Endoscopic gastritis was classified into four types, superficial gastritis, erosive gastritis, atrophic gastritis and intestinal metaplasia. The distribution of the four types of gastritis was evaluated according to sex, age and area. RESULTS: 51.6% of the patients had experienced at least one of the symptoms (epigastric pain or discomfort, soarness, dyspepsia, abdominal pain) on at least a few occasions during the previous year. The incidence of normal gastric finding was 3,593 (14.1%). 21,943 (85.9%) subjects have at least more than one of endoscopic gastritis. The number of cases with superficial gastritis was 7,983 (31.3%), erosive gastritis 6,054 (23.7%), atrophic gastritis 6,918 (27.1%), and intestinal metaplasia 1,181 (7.1%). Erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men than women (P<0.001) and in the older age group (> or =60 years) than younger age group (P<0.001). CONCLUSIONS: The prevalence of endoscopic gastritis was very common, 85.9%. In addition, erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men and in the older age group, which is similar to gastric cancer or peptic ulcer. Cautious regular endoscopic follow-up might be necessary regardless of gastrointestinal symptoms in Korea.
Dyspepsia ; Endoscopy ; Female ; Gastritis ; Gastritis, Atrophic ; Helicobacter pylori ; Humans ; Incidence ; Korea ; Male ; Metaplasia ; Peptic Ulcer ; Prevalence ; Stomach Neoplasms

BACKGROUND/AIMS: Chronic gastritis is a common finding during endoscopy and it is very important to describe it correctly. This study was designed to evaluate the distribution of endoscopic gastritis and the differences according to age, sex or area. MATERIALS AND METHODS: A clinical analysis was conducted on 25,536 subjects who had undergone an upper endoscopy for routine health check-up. Endoscopic gastritis was classified into four types, superficial gastritis, erosive gastritis, atrophic gastritis and intestinal metaplasia. The distribution of the four types of gastritis was evaluated according to sex, age and area. RESULTS: 51.6% of the patients had experienced at least one of the symptoms (epigastric pain or discomfort, soarness, dyspepsia, abdominal pain) on at least a few occasions during the previous year. The incidence of normal gastric finding was 3,593 (14.1%). 21,943 (85.9%) subjects have at least more than one of endoscopic gastritis. The number of cases with superficial gastritis was 7,983 (31.3%), erosive gastritis 6,054 (23.7%), atrophic gastritis 6,918 (27.1%), and intestinal metaplasia 1,181 (7.1%). Erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men than women (P<0.001) and in the older age group (> or =60 years) than younger age group (P<0.001). CONCLUSIONS: The prevalence of endoscopic gastritis was very common, 85.9%. In addition, erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men and in the older age group, which is similar to gastric cancer or peptic ulcer. Cautious regular endoscopic follow-up might be necessary regardless of gastrointestinal symptoms in Korea.
Dyspepsia ; Endoscopy ; Female ; Gastritis ; Gastritis, Atrophic ; Helicobacter pylori ; Humans ; Incidence ; Korea ; Male ; Metaplasia ; Peptic Ulcer ; Prevalence ; Stomach Neoplasms