Radon, the primary constituent of natural radiation, is the second leading environmental cause of lung cancer after smoking. To confirm a relationship between indoor radon exposure and lung cancer, estimating cumulative levels of exposure to indoor radon for an individual or population is necessary. This study sought to develop a model for estimate indoor radon concentrations in Korea. Especially, our model and method may have wider application to other residences, not to specific site, and can be used in situations where actual measurements for input variables are lacking. In order to develop a model, indoor radon concentrations were measured at 196 ground floor residences using passive alpha-track detectors between January and April 2016. The arithmetic mean (AM) and geometric mean (GM) means of indoor radon concentrations were 117.86±72.03 and 95.13±2.02 Bq/m³, respectively. Questionnaires were administered to assess the characteristics of each residence, the environment around the measuring equipment, and lifestyles of the residents. Also, national data on indoor radon concentrations at 7643 detached houses for 2011-2014 were reviewed to determine radon concentrations in the soil, and meteorological data on temperature and wind speed were utilized to approximate ventilation rates. The estimated ventilation rates and radon exhalation rates from the soil varied from 0.18 to 0.98/hr (AM, 0.59±0.17/hr) and 326.33 to 1392.77 Bq/m²/hr (AM, 777.45±257.39; GM, 735.67±1.40 Bq/m²/hr), respectively. With these results, the developed model was applied to estimate indoor radon concentrations for 157 residences (80% of all 196 residences), which were randomly sampled. The results were in better agreement for Gyeonggi and Seoul than for other regions of Korea. Overall, the actual and estimated radon concentrations were in better agreement, except for a few low-concentration residences.
Background Radiation ; Exhalation ; Gyeonggi-do ; Korea ; Life Style ; Lung Neoplasms ; Methods ; Models, Theoretical ; Radon* ; Seoul ; Smoke ; Smoking ; Soil ; Ventilation ; Wind

Radon, the primary constituent of natural radiation, is the second leading environmental cause of lung cancer after smoking. To confirm a relationship between indoor radon exposure and lung cancer, estimating cumulative levels of exposure to indoor radon for an individual or population is necessary. This study sought to develop a model for estimate indoor radon concentrations in Korea. Especially, our model and method may have wider application to other residences, not to specific site, and can be used in situations where actual measurements for input variables are lacking. In order to develop a model, indoor radon concentrations were measured at 196 ground floor residences using passive alpha-track detectors between January and April 2016. The arithmetic mean (AM) and geometric mean (GM) means of indoor radon concentrations were 117.86±72.03 and 95.13±2.02 Bq/m³, respectively. Questionnaires were administered to assess the characteristics of each residence, the environment around the measuring equipment, and lifestyles of the residents. Also, national data on indoor radon concentrations at 7643 detached houses for 2011-2014 were reviewed to determine radon concentrations in the soil, and meteorological data on temperature and wind speed were utilized to approximate ventilation rates. The estimated ventilation rates and radon exhalation rates from the soil varied from 0.18 to 0.98/hr (AM, 0.59±0.17/hr) and 326.33 to 1392.77 Bq/m²/hr (AM, 777.45±257.39; GM, 735.67±1.40 Bq/m²/hr), respectively. With these results, the developed model was applied to estimate indoor radon concentrations for 157 residences (80% of all 196 residences), which were randomly sampled. The results were in better agreement for Gyeonggi and Seoul than for other regions of Korea. Overall, the actual and estimated radon concentrations were in better agreement, except for a few low-concentration residences.
Background Radiation ; Exhalation ; Gyeonggi-do ; Korea ; Life Style ; Lung Neoplasms ; Methods ; Models, Theoretical ; Radon ; Seoul ; Smoke ; Smoking ; Soil ; Ventilation ; Wind

Background/Aims: The risk of herpes zoster (HZ) is increased in patients with autoimmune diseases (AID), probably due to immunosuppressive therapy. Methods: This prospective cross-sectional study investigated varicella zoster virus (VZV)-specific immunity in relation to subclinical VZV reactivation in 48 AID patients and 48 healthy controls (HCs). We assessed humoral immunity (serum VZV immunoglobulin g [IgG], IgA, and IgM) and cell-mediated immunity (interferon-γ [IFNγ]-releasing assay) to VZV as well as salivary VZV DNA status. Subclinical VZV reactivation was confirmed by detecting VZV DNA in saliva or VZV IgM in serum in the absence of typical HZ symptoms. Results: Median IgA levels were higher in the AID group than in the HC group, while VZV IgG and IgM levels were comparable between the groups. AID patients showed fewer IFNγ spot-forming cells (SFCs) upon VZV stimulation than HCs (58.2 vs. 122.0 SFCs/106 peripheral blood mononuclear cells [PBMCs], p < 0.0001). Subclinical VZV reactivation was more frequent in AID patients than in HCs (12.5% vs. 0%, p = 0.01). AID patients with VZV reactivation received prednisolone more frequently and at a higher dose than AID patients without reactivation. VZV-specific IFNγ SFCs were significantly lower in patients with VZV reactivation among AID patients (26.3 vs. 62.6 SFCs/106 PBMCs, p < 0.0001). Conclusions Results suggest that poor cellular response against VZV might cause clinical and subclinical reactivation of VZV in AID patients.

Background/Aims: The risk of herpes zoster (HZ) is increased in patients with autoimmune diseases (AID), probably due to immunosuppressive therapy. Methods: This prospective cross-sectional study investigated varicella zoster virus (VZV)-specific immunity in relation to subclinical VZV reactivation in 48 AID patients and 48 healthy controls (HCs). We assessed humoral immunity (serum VZV immunoglobulin g [IgG], IgA, and IgM) and cell-mediated immunity (interferon-γ [IFNγ]-releasing assay) to VZV as well as salivary VZV DNA status. Subclinical VZV reactivation was confirmed by detecting VZV DNA in saliva or VZV IgM in serum in the absence of typical HZ symptoms. Results: Median IgA levels were higher in the AID group than in the HC group, while VZV IgG and IgM levels were comparable between the groups. AID patients showed fewer IFNγ spot-forming cells (SFCs) upon VZV stimulation than HCs (58.2 vs. 122.0 SFCs/106 peripheral blood mononuclear cells [PBMCs], p < 0.0001). Subclinical VZV reactivation was more frequent in AID patients than in HCs (12.5% vs. 0%, p = 0.01). AID patients with VZV reactivation received prednisolone more frequently and at a higher dose than AID patients without reactivation. VZV-specific IFNγ SFCs were significantly lower in patients with VZV reactivation among AID patients (26.3 vs. 62.6 SFCs/106 PBMCs, p < 0.0001). Conclusions Results suggest that poor cellular response against VZV might cause clinical and subclinical reactivation of VZV in AID patients.

Invasive fungal infection remains a major cause of morbidity and mortality in immunocompromised patients. Invasive fungal sinusitis can present as a Tolosa-Hunt syndrome (THS) or orbital apex, leading to frequent misdiagnosis. Accurate diagnosis of fungal infection invading the cavernous sinus or orbital apex is essential to reduce mortality through early antifungal treatment and reduce the risk of worsening with steroid treatment due to misdiagnosis of THS. Herein, we report a case of invasive fungal sinusitis mimicking THS.

Clustered occurrences of ankylosing spondylitis (AS) in family have been noticed. We evaluated patients with AS confirmed by the modified New York criteria for familial history of AS (one or more first to third degree relatives). The clinical characteristics and the recurrence risks (number of AS patients/number of familial members) of the familial AS compared to sporadic AS were investigated. Out of a total of 204 AS patients, 38 patients (18.6%) reported that they had a familial history of AS. The recurrence risks in the familial AS patients for first, second and third degree family members were 14.5%, 5.2%, and 4.4% respectively. Erythrocyte sedimentation rate (ESR) (22.6+/-22.2 vs 35.4+/-34.4, P=0.029) and C-reactive protein (CRP) (1.24+/-1.7 vs 2.43+/-3.3, P=0.003) at diagnosis, body mass index (21.9+/-2.7 vs 23.7+/-3.3, P=0.002) and frequency of oligoarthritis (13.2% vs 33.7%, P=0.021) were significantly lower in the familial form. The presence of HLA-B27 (97.4% vs 83.1%, P=0.044) was significantly higher in familial AS. In conclusion, Korean familial AS patients show a lower frequency of oligoarthritis, lower BMI, lower ESR and CRP at diagnosis and higher presence of HLA-B27.
Adult ; Age Factors ; Arthritis, Juvenile/diagnosis/epidemiology ; Blood Sedimentation ; Body Mass Index ; C-Reactive Protein/analysis ; Demography ; Family ; Female ; HLA-B27 Antigen/metabolism ; Humans ; Interviews as Topic ; Male ; Middle Aged ; Phenotype ; Recurrence ; Republic of Korea ; Risk Factors ; Severity of Illness Index ; Sex Factors ; Spondylitis, Ankylosing/*diagnosis

A gastrocolocutaneous fistula is a rare complication of percutaneous endoscopic gastrostomy (PEG). We report a case of a gastrocolocutaneous fistula presenting with intractable diarrhea and gastrostomy tube malfunction. A 62-year-old woman with a history of multiple system atrophy was referred to us because of PEG tube malfunction. Twenty days prior to presentation, the patient started developing sudden diarrhea within minutes after starting PEG feeding. Fluoroscopy revealed that the balloon of the PEG tube was located in the lumen of the transverse colon with the contrast material filling the colon. Subsequently, the PEG tube was removed and the opening of the gastric site was endoscopically closed using hemoclips. Clinicians should be aware of gastrocolocutaneous fistula as one of the complications of PEG insertion. Sudden onset of diarrhea, immediately after PEG feedings, might suggest this complication, which can be effectively treated with endoscopic closure.
Colon ; Colon, Transverse ; Diarrhea* ; Female ; Fistula* ; Fluoroscopy ; Gastrostomy* ; Humans ; Middle Aged ; Multiple System Atrophy

Behçet's disease is a systemic vasculitis of unknown etiology characterized by recurrent oral and genital ulcers and uveitis. The vascular involvement of Behçet's disease affects arteries, veins, and blood vessels of all sizes, and it can include venous or arterial thrombosis and arterial aneurysms. There are only a few reports of an aortic aneurysm invading a vertebral body in a patient with Behçet's disease. Here, we report the case of a 45-year-old man who was initially diagnosed with vertebral invasion of a mycotic aneurysm. He underwent vascular surgery and received empirical antibiotics, but all cultures were negative. However, he had persistent, recurrent deep vein thrombosis and elevated inflammatory markers. After reviewing the pathology, a final diagnosis of Behçet's disease was made. He was successfully treated with corticosteroids. This report presents a rare case of Behçet's disease mimicking vertebral invasion of a mycotic aneurysm.
Adrenal Cortex Hormones ; Aneurysm ; Aneurysm, Infected* ; Anti-Bacterial Agents ; Aortic Aneurysm ; Arteries ; Behcet Syndrome ; Blood Vessels ; Diagnosis ; Humans ; Middle Aged ; Osteomyelitis ; Pathology ; Systemic Vasculitis ; Thrombosis ; Ulcer ; Uveitis ; Veins ; Venous Thrombosis

Background/Aims: While most cancer patients with end-of-life (EOL) care receive antibiotic treatments, antibiotic use should be decided appropriately considering the benefits, side effects, resistance, and cost effects. Antimicrobial stewardship programs (ASP) are important for patients with EOL care, but there is limited study analyzing actual antibiotic use in EOL care and the perceptions of Korean medical staff. Methods: Electronic medical records of 149 deceased cancer patients hospitalized in the medical hospitalist units at Asan Medical Center in Seoul from May 2019 to September 2021 were reviewed. Basic information, antibiotic use, duration, and changes were investigated. We surveyed medical staff’s perceptions of antibiotics in cancer patients with EOL. Results: Of the 149 cancer patients with EOL care, 146 (98.0%) agreed with physician orders for life-sustaining treatment (POLST). In total, 143 (95.9%) received antibiotics, 110 (76.9%) received combination antibiotic treatment, and 116 (81.1%) were given antibiotics until the day of death. In a survey of 60 medical staff, 42 (70.0%) did not know about ASP, and 24 (40.0%) thought ASP was important in EOL care. Nineteen doctors (31.7%) discussed the use or discontinuation of antibiotics with patients or caregivers when writing POLST, but only 8 patients (5.6%) stopped antibiotics after POLST. Conclusions Most cancer patients with EOL care continue to receive antibiotics until just before their death. A careful approach is needed, considering the benefits and side effects of antibiotic use, and the patient’s right to self-decision. It is necessary to actively improve awareness of ASP and its importance for medical staff.

Background: Tuberculous meningitis (TBM) is the most severe form of tuberculosis, but differentiating between the diagnosis of TBM and viral meningitis (VM) is difficult. Thus, we have developed machine-learning modules for differentiating TBM from VM.Material and Methods: For the training data, confirmed or probable TBM and confirmed VM cases were retrospectively collected from five teaching hospitals in Korea between January 2000 - July 2018. Various machine-learning algorithms were used for training. The machinelearning algorithms were tested by the leave-one-out cross-validation. Four residents and two infectious disease specialists were tested using the summarized medical information. Results: The training study comprised data from 60 patients with confirmed or probable TBM and 143 patients with confirmed VM. Older age, longer symptom duration before the visit, lower serum sodium, lower cerebrospinal fluid (CSF) glucose, higher CSF protein, and CSF adenosine deaminase were found in the TBM patients. Among the various machinelearning algorithms, the area under the curve (AUC) of the receiver operating characteristics of artificial neural network (ANN) with ImperativeImputer for matrix completion (0.85; 95% confidence interval 0.79 - 0.89) was found to be the highest. The AUC of the ANN model was statistically higher than those of all the residents (range 0.67 - 0.72, P <0.001) and an infectious disease specialist (AUC 0.76; P = 0.03). Conclusion The machine-learning techniques may play a role in differentiating between TBM and VM. Specifically, the ANN model seems to have better diagnostic performance than the non-expert clinician.