• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.817-825
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• 2021

Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) characterized by an inhaled inciting antigen that leads to the inflammation of the lung parenchyma and small airway with immunologic reactions. Over the last decades, the most effective therapeutic option for HP has been limited to antigen avoidance. The differential diagnosis of HP from other ILDs is the beginning of treatment as well as diagnosis. However, the presence of several overlapping clinical and radiologic features makes differentiating HP from other ILDs particularly challenging. In 2020, a multidisciplinary committee of experts from the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax suggested a new clinical practice guideline classifying HP into nonfibrotic and fibrotic phenotypes on the basis of chest high-resolution CT (HRCT) findings. Therefore, we introduced a new diagnostic algorithm based on chest HRCT in the clinical practice guideline for the diagnosis of HP.

• Pediatric Infection and Vaccine
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• v.30 no.1
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• pp.20-32
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• 2023

Purpose: This study aimed to identify the etiology and risk factors of community-acquired pneumonia (CAP) requiring hospitalization in Korean children during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Clinical information of children admitted with CAP to Seoul National University Children's Hospital (SNUCH) between January 1, 2021, and February 28, 2022, was retrospectively collected and analyzed. In addition, the etiologic diagnosis and demographic data of children with CAP who were discharged at the other seven hospitals between January and February 2022 were collected. Pneumonia was diagnosed using strict criteria comprising clinical symptoms, physical examination findings, and chest radiographic findings. Results: Among 91 children hospitalized with CAP at SNUCH during the 14-month period, 68.4% were aged <5 years and 79.1% had underlying diseases. Among the 95 CAP cases, respiratory assistance was required in 70.5%, and the use of a ventilator was required in 20.0%. A total of five patients expired, all of whom were either immunocompromised or had underlying neurological diseases. Neurological diseases and immunosuppression were significantly correlated with respiratory assistance (P=0.003) and death (P=0.014). A total of 55% of the detected respiratory pathogens were viruses, the most common of which was rhinovirus at 35.9%. Among the 169 children hospitalized for CAP at the eight institutions, ≥1 respiratory virus was detected in 92.3%, among which respiratory syncytial virus (79.8%) was the most prevalent. Conclusions: Even during the COVID-19 pandemic, Korean children were hospitalized with CAP caused by seasonal respiratory viral pathogens. Although atypical and pyogenic bacteria were not detected, continuous clinical monitoring and further prospective studies should be conducted.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.298-303
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• 2023

Electronic cigarette or vaping-associated lung injury (EVALI) is a disease defined by lung injuries caused by e-cigarette use. It predominantly manifests in forms of organized pneumonia or diffuse alveolar damage but rarely as acute eosinophilic pneumonia (AEP). This report describes a 34-year-old male with acute respiratory symptoms and a vaping history of only nicotine. Chest CT revealed peripheral distributing multiple patchy consolidations and ground-glass opacities dominant in both lower lobes, bilateral diffuse interlobular septal thickening, and bilateral pleural effusion without cardiomegaly. Bronchoalveolar lavage fluids showed increased eosinophilia levels, while infectious laboratory results were all negative, enabling the diagnosis of both AEP and EVALI. Herein, we report a rare case of only-nicotine vaping EVALI manifested as AEP.

• Journal of Digital Convergence
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• v.21 no.1
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• pp.19-27
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• 2023

This is an implementation study towards the development of a strategy to improve the pneumonia adequacy evaluation index of regional public hospital and to confirm its effectiveness. One physician, eight nurses, one computer room staff, and one nursing professor working at a regional base public hospital located in N city participated in this study from March to October 2021. An implementation study was conducted based on the conceptual model of Zuber-Skerritt & Fletcher. The stages of planning, implementation, evaluation, and reflection were operated in two cycles, and the effectiveness was evaluated in the second and third quarters. Compared to the pneumonia adequacy evaluation index in 2019, all indicators reached 100% of the standard target in 2021. The results of this study therefore infer that to provide higher quality medical services in the future, it is necessary to apply medical quality improvement activities through practical research under multidisciplinary participation and cooperation and to review the applicability of clinical sites.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.218-223
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• 2022

Although the typical CT findings of Pneumocystis jiroveci pneumonia (PJP) include diffuse or multifocal areas of ground-glass opacities in both lungs, it can also rarely manifest as multiple pulmonary nodules. We report a rare case of atypical PJP in an immunocompromised patient with multiple myeloma, presenting as widespread ground-glass opacities and multiple necrotic subpleural nodules in both lungs on CT, which proved to be granulomatous PJP on percutaneous transthoracic needle biopsy.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.256-256
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• 1994

폐렴균(Streptococcus pneuminiae)은 그람양성균으로 병원성을 갖는 것은 협막을 갖는 S type이며 협박다당류의 항원성에 의해 84가지의 serotype으로 분류되어 있다. 미국에서는 이중 23가지 type이 폐렴환자의 90%이상에서 발견되는 것을 최근 보고하였다. 본 연구의 목적은 polyvalent vaccine을 구성하는 23가지 type의 폐럼균주로부터 협막다당류를 분리, 정제하고 각 성분함량이 각 type에 대한 vaccine기준 함량에 적합한지 여부를 판정함으로써 한국형 vaccine개발의 기초로 활용하고자 한다.

• Tuberculosis and Respiratory Diseases
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• v.42 no.1
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• pp.67-75
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• 1995

Background: Although we gain new knowledge, the problem of pneumonia will not be eliminated. We should understand who is at risk, why these people develop this problem, what causes the pneumonia, and how to manage and prevent respiratory infection. To clarify the alterations of the etiologies of bacterial pneumonia we analysed the recent causative organisms and evaluated the therapeutic implications. Methods: A retrospective four-year study of bacterial pneumonia was conducted in Soon Chun Hyang University Hospital. 190 episodes of bacterial pneumonia was investigated. Results: 1) The causative organisms were isolated in 173 cases on the sputum culture: 154 cases (89%) were gram negative bacilli and 19 cases(11%) were gram positive cocci. The major organisms were Pseudomonas species 49 cases(28%), Klebsiella pneumoniae 29 cases(17%), Enterobacter species 25 cases(14%), and Acinetobacter species 20 cases(12%) in decreasing order. Pseudomonas species(13 cases, 34%) were frequently found in nosocomial pneumonia. 2) The causative organisms were isolated in 16 cases on the blood culture: 7 cases(43%) were gram negative bacilli and 9 cases(57%) were gram positive cocci. The major organisms were Staphylococcus aureus(6 cases, 38%), Pseudomonas species(3 cases, 19%) in decreasing order. 3) In the susceptibility test of causative organisms to antimicrobial drugs, Pseudomonas was susceptible to amikacin, ciprofloxacin, aztreonam, ceftazidime(more than 50%) and resistant to piperacillin, gentamicin, carbenicillin(more than 60%). Klebsiella was susceptible to chloramphenicol, gentamicin, cefotetan(more than 70%) and resistant to carbenicillin, ampicillin(more than 70%). Staphylococcus was susceptible to methicillin(64%), and Streptococcus pneumoniae was susceptible to oxacillin(94%). 4) The response rate after antibiotics therapy was 81% and the mortality rate was 19%. Conclusion: As considering the changes of causative organisms and antibiotic resistance, it behooves us to exercise caution in dispending antibiotics in order to maximize their continued efficacy and to do appropiate antibiotics therapy based on cultures and susceptibility test.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.391-400
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• 2011

Pneumonia is an infection of the lungs and respiratory system and can be classified by a variety of factors such as infectious agents, etiology, infection area, and other criteria. From a 46-year-old male, who was suspected of being infected with atypical pathogen pneumonia and underwent such tests as serological testing, examination of sputum, urine examination, parasite examination, bronchoscopy, needle biopsy and so on, no significant abnormality was found. This patient also showed no specific symptoms like auscultatory abnormalities, high fever, nonproductive cough, muscle stiffness, sputum production, dyspnea. Prescription of broad-spectrum oral antibiotics and ant-parasitic didn't seem to be effective against bacterial and atypical pathogen. The patient's condition alternately repeated between natural cure and recurrence. The average healing process during which scarring, nodule recurrence and disappearance on the lungs happened was about 20 days. Chest radiography and chest high resolution computerized tomographic scans(HRCT scan) was performed to depict parenchymal aberrations and demarcate the extent and distribution of atypical pathogen pneumonia. As a result, chest radiography did not show the specific symptoms, whereas areas of opacity (seen as white) which represent consolidation were revealed in chest HRCT scan. This indicates that only chest radiography is not that useful for early diagnosis of atypical pathogen pneumonia in patients, since it can't show exactly what the symptom is because of the barriers such as diaphragm, liver, and spine. Therefore, it is desirable that chest HRCT should be used in the diagnosis to compare with the results of chest radiography. Here, report with literature investigations the case of recurrent atypical pathogen pneumonia.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.289-298
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• 1994

Background: Most studies of Mycoplasma pneumonia involve a group of admitted patients in hospital, usually with major medical illness. So we investigated the epidemiologic and radiologic features during the course of outbreak of pneumonia in Chunnam coastal area. Methods: We retrospectively studied the epidemiologic and clinical feature of 105 patients with serologically proven Mycoplasma pneumonia treated at Kwang-Yang Hospital during a epidemic period of Jun.1993 to Dec.1993. All cases of pneumonia developed in this period were also reviewed and compared with serologically proven group. Results: 1) There were 63 males and 42 females. 2) More than half(57%) of cases belonged to 5-9 years of age group, and mean age was 6.5 years old. Mean age was steadily decreased as prevalence of Mycoplasma pneumonia had been subsided. 3) A major determinant of the outbreak seemed to be the population density rather than the population size. 4) The common radiologic features were interstitial in type, and 67 cases was restricted to one lobe. Lobar types are more common in late childhood, and interstitial or diffuse types in early childhood. Conclusion: These epidemiologic and radiographic characteristics would contribute to the diagnosis of Mycoplasma pneumonia.

• Pediatric Infection and Vaccine
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• v.30 no.3
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• pp.121-128
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• 2023

Purpose: This study aimed to investigate the recent age distribution of Mycoplasma pneumoniae in patients with respiratory infections and the differences in diagnostic usefulness according to the methods used in these patients. Methods: We retrospectively reviewed the medical records of patients aged ≤18 years with respiratory infectious diseases who underwent polymerase chain reaction (PCR) or a specific immunoglobulin M (IgM) test between July 2016 and February 2019. The diagnosis of M. pneumoniae infection was confirmed by a positive result in the PCR or IgM test. Results: Of the 2,721 patients tested for M. pneumoniae, 2,197 underwent IgM, and 1,144 underwent PCR, with positivity rates of 17% and 20%, respectively. Among the 620 patients tested for both IgM and PCR tests simultaneously, 35% had M. pneumoniae infection, with 14% under 1 year old and 13% under 1-2 years old. The positive rate increased with age in both tests. Higher positive rates were observed in the IgM test before 3 years of age and in the PCR test after 3 years of age. The agreement rate between the two tests was 77.9% (Cohen's kappa 0.402). Conclusions: As age increased, the rates of M. pneumoniae infection also increased. In patients under 2 years of age, 4¬-14% of infections were confirmed depending on the method used. The moderate agreement between the PCR and IgM tests suggests that the simultaneous use of PCR and the IgM test for the early diagnosis should be approached with caution.