Preliminary experiments on proposals for the spread of droplets due to tooth brushing in schools / 대한구강보건학회지

Objectives@#Coronavirus (COVID-19) has recently emerged as a major public health problem around the world. There is a high demand for health promotion programs that allow schools and local children’s centers to brush their teeth and wash their hands compared to others after lunch; and furthermore, the demand for schools with brushing facilities is twice that of schools without brushing facilities. However, students are returning home without brushing their teeth after lunch at kindergartens and schools, where face-to-face classes are conducted. This situation can be further understood by examining the education office’s official letter that considers the risk of “droplet infection” at kindergartens and schools. Thus, this pilot study is interested in identifying the relationship between brushing teeth and the spread of droplets, and proposing proper brushing guidelines for students in schools. @*Methods@#The droplet diffusion test was conducted in three ways: during conversation, when brushing teeth, and when brushing teeth with the mouth closed. A Mie Scattering technique using a continuous wave (CW) laser was performed to observe and compare the distribution of droplets ejected from the oral cavity in this experiment. @*Results@#As a result, it was confirmed that the droplets that spread, while brushing the lingual surface of the maxillary anterior region, were significantly reduced when brushing the teeth with the mouth closed. @*Conclusions@#Based on the results of this study, personal hygiene education such as the school group tooth brushing project and hand washing should be continuously conducted and monitored by installing transparent partitions, and the tooth brushing technique to prevent the spread of droplets in schools.

Preliminary experiments on proposals for the spread of droplets due to tooth brushing in schools / 대한구강보건학회지

Objectives@#Coronavirus (COVID-19) has recently emerged as a major public health problem around the world. There is a high demand for health promotion programs that allow schools and local children’s centers to brush their teeth and wash their hands compared to others after lunch; and furthermore, the demand for schools with brushing facilities is twice that of schools without brushing facilities. However, students are returning home without brushing their teeth after lunch at kindergartens and schools, where face-to-face classes are conducted. This situation can be further understood by examining the education office’s official letter that considers the risk of “droplet infection” at kindergartens and schools. Thus, this pilot study is interested in identifying the relationship between brushing teeth and the spread of droplets, and proposing proper brushing guidelines for students in schools. @*Methods@#The droplet diffusion test was conducted in three ways: during conversation, when brushing teeth, and when brushing teeth with the mouth closed. A Mie Scattering technique using a continuous wave (CW) laser was performed to observe and compare the distribution of droplets ejected from the oral cavity in this experiment. @*Results@#As a result, it was confirmed that the droplets that spread, while brushing the lingual surface of the maxillary anterior region, were significantly reduced when brushing the teeth with the mouth closed. @*Conclusions@#Based on the results of this study, personal hygiene education such as the school group tooth brushing project and hand washing should be continuously conducted and monitored by installing transparent partitions, and the tooth brushing technique to prevent the spread of droplets in schools.

Experiences with Establishing and Implementing Learning Management System and Computer-Based Test System in Medical College / 한국의학교육

PURPOSE: The purpose of this study was to establish an e-learning system to support learning in medical education and identify solutions for improving the system. METHODS: A learning management system (LMS) and computer-based test (CBT) system were established to support e-learning for medical students. A survey of 219 first- and second-grade medical students was administered. The questionnaire included 9 forced choice questions about the usability of system and 2 open-ended questions about necessary improvements to the system. RESULTS: The LMS consisted of a class management, class evaluation, and class attendance system. CBT consisted of a test management, item bank, and authoring tool system. The results of the survey showed a high level of satisfaction in all system usability items except for stability. Further, the advantages of the e-learning system were ensuring information accessibility, providing constant feedback, and designing an intuitive interface. Necessary improvements to the system were stability, user control, readability, and diverse device usage. CONCLUSION: Based on the findings, suggestions for developing an e-learning system to improve usability by medical students and support learning effectively are recommended.

A Case of Prothionamide Induced Hepatitis on Patient with Multi-Drug Resistant Pulmonary Tuberculosis / 결핵및호흡기질환

The prevalence of multi-drug resistant tuberculosis (MDR-TB), which is resistant to isoniazid and rifampin, has been increasing in Korea. And the side effects of 2nd line anti-tuberculosis medications, including drug-induced hepatitis, are well known. Although prothionamide (PTH) is one of the most useful anti-TB medications and although TB medication-induced acute hepatitis is a severe complication, there are only a few published case reports about prothionamide induced hepatitis. In this case report, a 22 year old male was diagnosed with pulmonary MDR-TB and was administered 2nd line anti-TB mediations, including PTH. Afterwards, he had a spiking fever and his liver enzymes were more than 5 times greater than the upper limit of the normal range. He was then diagnosed with drug-induced hepatitis by liver biopsy. His symptoms and liver enzyme elevation were improved after stopping PTH. Accordingly, we report this case of an association between PTH and acute hepatitis.

Influence of root canal curvature on the screw-in effect of nickel-titanium rotary files in simulated resin root canal / 대한치과보존학회지

OBJECTIVES: Nickel-titanium (Ni-Ti) rotary instruments have some unexpected disadvantages including the tendency to screw-in to the canal. The purpose of this study was to evaluate the influence of root canal curvatures on the screw-in effect of Ni-Ti rotary files. MATERIALS AND METHODS: A total of 80 simulated root canals in clear resin blocks were used in the study. Canals with curvature of 0, 10, 20 and 30 degrees were instrumented with ProTaper instruments SX, S1, S2 and a ProFile of #25/0.06 to 1.0-2.0 mm beyond the initial point of root curvature. The screw-in force was measured with a specially designed device while canal was instrumented with a ProFile of #30/0.06 at a constant speed of 300 rpm. The data were subjected to one-way ANOVA and Scheffe multiple range test for post-hoc test. RESULTS: Larger degree of canal curvature generated significantly lesser screw-in forces in all groups (p < 0.001). CONCLUSIONS: More attention needs to be paid when using rotary instruments in canals with less curvature than canals with more curvatures to prevent or reduce any accidental overinstrumentation.

Breast Examination Instruction by a Standardized Patient Instructor / 한국의학교육

PURPOSE: The purpose of this research was to identify the effectiveness of a standardized patient (SP) instructor. The study was performed to compare the effects of two types of instruction on breast examination skills by an SP instructor and a professor. METHODS: Fifty-four medical students in the third year and 4 SPs participated in the study. In a pretest, each student was judged by the SP individually in performing a breast examination and completed a questionnaire about perception. Next, students were randomly assigned to 2 experimental groups (small-group instruction by an SP instructor or professor). A posttest of performance and perception was administered using the same procedures as in the pretest. To identify the effectiveness of the SP instructor, differences in student scores between the groups were analyzed by t-test. RESULTS: In the posttest of student performance on the breast examination, there was no significant difference between the groups (p=0.270). With regard to student perception, scores on self-confidence in the breast examination were significantly different (p=0.026) between the groups, of which students who received instruction from the professor showed a higher level. Additionally, there was a significant effect on students' perceived reliability of instruction by the SP instructor (p=0.011), and students who were instructed by the SP demonstrated higher reliability compared with professor-taught students. CONCLUSION: Instruction by an SP instructor has the same effectiveness as instruction by a professor. SP instructors have very powerful effects on student performance and perception.

Bilioptysis Caused by Bronchobiliary Fistula Secondary to Sclerosing Therapy of Liver Cyst / 결핵및호흡기질환

Bronchobiliary fistula is a rare disorder consisting of an abnormal communication between the bronchial tree and the biliary duct. In Western countries, trauma, postoperative biliary stenosis, and biliary lithiasis are the predominant causative factors of bronchobiliary fistula. Bilioptysis (bile stained sputum) is a pathognomic finding for bronchobiliary fistula. To date, there are just a few reported cases of bronchobiliary fistula after sclerosis of a liver cyst. We describe the case of a 74-year-old woman who developed bronchobiliary fistula after sclerosing therapy of a liver cyst. The diagnosis was confirmed by the presence of bilioptysis and the chest and dynamic liver CT findings. The patient was successfully treated with antibiotics and percutaneous transhepatic catheter drainage.

A Case of Pneumonia with Septic Shock Due to Nocardia farcinia in Liver Transplant Patient / 결핵및호흡기질환

Nocardia farcinia, an aerobic, gram-positive bacilli actinomycetes of the genus Nocardia, is an uncommon pathogen found in humans. The most common Nocardia infection sites are the lung, central nervous system, and skin. Even though hematogenous dissemination can occur, isolation of the organism from blood cultures is very rare. We report a case of Nocardia infection that was isolated on blood cultures. A 59-year-old male with a medical history that includes a liver transplantation 6-years prior due to hepatocellular carcinoma secondary to chronic hepatitis B, developed pneumonia and was transferred to Severance Hospital. At the time of admission, the patient's initial exam showed hypothermia, tachypnea, and hypotension. His chest radiograph showed severe pneumonia and a large abscess on left upper lobe. Under the presumptive diagnosis of bacterial pneumonia or other opportunistic infection, we started broad spectrum antibiotics. However, he developed Nocardia sepsis, rapidly deteriorated, and subsequently died.

A Review on Usage and Effectiveness of e-Learning in Medical Education / 한국의학교육

E-learning is recently considered as a critical strategy to improve the effectiveness and efficiency of education. Although the use of e-learning has been growing rapidly in medical education, there are not sufficient data applying e-learning and evidence of the effectiveness. The purpose of the study is to review the recent literatures on applying e-learning in medical education settings and to identify usage types and educational effectiveness appeared in the research. The results demonstrated the types applying e-learning in medical education were categorized into the blended learning, online education, and virtual learning environment. The educational effectiveness of e-learning were the improvements of knowledge, clinical skill, attitude, and satisfaction. The study suggested the recommendations based on the results in order to apply e-learning effectively to medical education.

Non-tuberculous Mycobacterial Lung Disease Presenting as a Solitary Pulmonary Nodule / 결핵및호흡기질환

We report a case of Mycobacterium intracellulare pulmonary infection presenting as a solitary pulmonary nodule (SPN). A 35-year-old male was admitted due to a SPN in the right upper lobe which was detected on the chest radiography being examed due to recurrent cough for 1 year. The computed tomography (CT) revealed a spiculated nodule containing air-bronchogram, which was suspicious of malignancy. We performed transbronchial biopsy and the pathology showed granulomatous inflammation with caseous necrosis. Under the presumptive diagnosis of pulmonary tuberculosis, we started anti-tuberculous medication including isoniazid, rifampin, ethambutol, and pyrazinamide. In one month, however, the sputum culture was positive for Mycobacterium intracellulare. The follow-up chest CT showed slight aggravation of the previous lesions. Under the final diagnosis of Mycobacterium intracellulare pulmonary infection presenting as a solitary pulmonary nodule, we changed the regimen to rifampin, ethambutol, and clarithromycin. The follow-up chest CT after the completion of treatment, revealed resolution of the previous lesions.

Non-tuberculous Mycobacterial Lung Disease Presenting as a Solitary Pulmonary Nodule / 결핵및호흡기질환

We report a case of Mycobacterium intracellulare pulmonary infection presenting as a solitary pulmonary nodule (SPN). A 35-year-old male was admitted due to a SPN in the right upper lobe which was detected on the chest radiography being examed due to recurrent cough for 1 year. The computed tomography (CT) revealed a spiculated nodule containing air-bronchogram, which was suspicious of malignancy. We performed transbronchial biopsy and the pathology showed granulomatous inflammation with caseous necrosis. Under the presumptive diagnosis of pulmonary tuberculosis, we started anti-tuberculous medication including isoniazid, rifampin, ethambutol, and pyrazinamide. In one month, however, the sputum culture was positive for Mycobacterium intracellulare. The follow-up chest CT showed slight aggravation of the previous lesions. Under the final diagnosis of Mycobacterium intracellulare pulmonary infection presenting as a solitary pulmonary nodule, we changed the regimen to rifampin, ethambutol, and clarithromycin. The follow-up chest CT after the completion of treatment, revealed resolution of the previous lesions.

A Case of Bronchilolitis Obliterans Organizing Pneumonia in a Patient with Ulcerative Colitis / 결핵및호흡기질환

The ulcerative colitis is a chronic inflammatory bowel disease with an unknown etiology. The major symptoms of ulcerative colitis are diarrhea, abdominal pain and hematochezia. However, arthritis, skin disorders, hepatobiliary inflammation and uveitis are occasionally recognized as systemic complications. Although there are few reports of coexistent pulmonary and inflammatory bowel disease, the lung is not generally considered to be a target organ in ulcerative colitis. We report a patient with ulcerative colitis-related bronchilolitis obliterans organizing pneumonia confirmed by video-assisted thoracoscopic surgery, who responded to corticosteroid therapy.

A Case of Prolonged Extracorporeal Membrane Oxygenation Support for Severe Acute Respiratory Distress Syndrome: A Case Report / 대한구급학회지

When all the conventional treatments have failed for patients with acute respiratory distress syndrome (ARDS), extracorporeal membrane oxygenation (ECMO) can offer these patients a chance to survive. We report here on a case of successful treatment with prolonged ECMO support for a patient with severe ARDS. A 41-year-old female patient with acute A-viral hepatitis developed pneumonia and progressive ARDS. After tracheostomy, her clinical condition deteriorated despite proper antibiotic administration and other conventional treatments, including the recruitment maneuver and steroid use. Venoarterial ECMO was given for the management of refractory hypoxemia that developed 14 days after the initiation of mechanical ventilation. The duration of ECMO support was 4 weeks, and she was successfully weaned off ECMO and mechanical ventilation.

Effect of air pollution on acute exacerbation of adult asthma in Seoul, Korea: A case-crossover study / 대한내과학회지

BACKGROUND/AIMS: Outdoor air pollution is an important risk factor for developing asthma and acute exacerbation. Although some epidemiologic studies have shown that increased levels of air pollutants are linked with acute exacerbations of asthma, few have estimated the effects of individual air pollutant on the exacerbation of asthma in adult patients in Korea. METHODS: We evaluated the relative risk of acute exacerbation of asthma due to an increase in air pollutant levels. We enrolled patients with asthma who were living in Seoul, and who had visited the emergency department (ED) of three University Hospitals in Seoul, Korea, for aggravated asthmatic symptoms over 12 months. The daily average levels of air pollutants were retrieved from data collected by routine monitoring for gaseous air pollutants (sulfur dioxide [SO2], nitrogen dioxide [NO2], ozone [O3], carbon monoxide [CO]) and for airborne particles less than or equal to 10 micrometer in diameter (PM10)]. A case-crossover analysis was performed using levels of air pollutants at 2 weeks before and after ED visits of controls. RESULTS: For the 1 year study period, 297 ED visits were made by 237 adult patients with asthma. There were no significant increases in the relative risk for ED visits for air pollutants including SO2, NO2, O3, CO, and PM10. CONCLUSIONS: These findings suggest that there was no significant impact of air pollution on ED visits for acute exacerbation of asthma in adult patients living in Seoul. Further large scale studies are needed to confirm the effects of these air pollutants on the exacerbation of asthma.

Dietary Intake of Calcium and Distal Colorectal Adenomatous Polyps in Korean Adults / 가정의학회지

BACKGROUND: Colorectal cancer is fourth in prevalence of carcinoma and fourth most cause of death from malignant neoplasm, which has been increasing in Korea. In this study, we tried to investigate the association of dietary intake of calcium and distal colorectal adenomatous polyps known as precursors of colorectal cancer. METHODS: A total of 2,456 subjects who visited a health promotion center in one university hospital in Seoul, Korea, from June 2003 to June 2006 underwent sigmoidoscopy and completed a 24-hour dietary recall. RESULTS: Among the selected 2,408 subjects, the prevalence of distal colorectal adenoma found in sigmoidoscopy was 12.54%. After adjusting for age and total serum cholesterol by multiple logistic regression, the odds ratio of the male subjects who had the highest quintile of dietary intake of calcium was 0.512 (95% CI: 0.305-0.859; P = 0.011) compared with the lowest. CONCLUSION: In male subjects with the highest quintile of dietary calcium density was associated with a low risk of distal colorectal adenomatous polyps.

The Effect of Lifestyle Modification Program for Medical Students' Personal Health Practices / 가정의학회지

BACKGROUND: Lifestyle is an important risk factor for many diseases. We need to educate medical students for advocating health promoting behaviors to their patients. Teaching knowledge, however, was not enough for medical students to change their health-related lifestyle. In this study, we investigated health promoting behaviors of medical students, and the improvement of their health behaviors after competitive lifestyle modification program. METHODS: All sophomores of medical college in Seoul National University were included in this study. We performed lifestyle modification program consisting of lecture, group competition, and feedback. We focused on reforming health behaviors like smoking, drinking, exercise, stress management and eating habits. And we also checked common symptoms of functional diseases, medication frequency for relieving these symptoms and general life satisfaction. RESULTS: After 2 months of lifestyle modification program, the obese (P = 0.0455) and the average value of BMI (P < 0.001) were decreased and two of smokers quitted smoking. Numbers of medical students with health related habits such as regular exerciser (P = 0.027), frequent user of symptom-relief medication (P < 0.001), breakfast skipper (P = 0.005) were signifi cantly changed in positive way, and the average value of general life satisfaction score (P = 0.003) was improved. CONCLUSION: Lifestyle modification program improved medical students' health habits and enhanced general life satisfaction.

A Case of Squamous Cell Carcinomatous Lung Abscess with Multiple Metastatic Abscesses / 결핵및호흡기질환

Among the bronchogenic carcinomas, especially squamous cell carcinoma and large cell carcinoma frequently present with cavitation, which may result from tumor necrosis. Cavitary lesions of the tumor are occasionally associated with infection and misdiagnosed as benign lung abscess owing to the partial responsiveness to antibiotics. It is very difficult to distinguish the carcinomatous abscess from the benign lung abscess, because of their similar clinical and radiologic features. Delay in diagnosis of underlying lung cancer may result in poor outcome. Therefore, clinicians should remember that the patients with highly suspicious carcinoma of the lung should undergo further precise examinations to find out malignant cells.

The Importance of the Simple Chest X-ray Tend to Make Careless Interpretation: with a Case of Mediastinal Tumor / 결핵및호흡기질환

The middle mediastinum contains several important organs and pluripotent cells. It is difficult to make a definitive diagnosis in patients with middle mediastinal tumors due to a wide range of diseases. The likelihood of malignancy is influenced primarily by the following factors: patient age, size, tumor location, and the presence or absence of symptoms. We describe a case of a middle mediastinal tumor, which was suspected on chest x-ray; chest computed tomography revealed the eccentric mass of distal esophagus. This case emphasizes the diagnostic importance of the chest x-ray to the physicians. The possible differential diagnoses are reviewed.

A Case of Henoch-Shonlein Purpura Caused by Rifampin / 결핵및호흡기질환

Rifampin is one of the first line drugs for treating tuberculosis, but it might be associated with serious adverse effects, including renal failure. We report here on a case of a 57-year-old patient who developed Henoch-Shonlein purpura during antituberculosis therapy that included rifampin. The patient converted to negative on the AFB smear for tuberculosis two weeks after the initial administration of antituberculosis medication. After treatment for 60 days, this patient was diagnosed with Henoch-Shonlein purpura by the purpura lesion on the lower legs, the leukocytoclastic vasculitis, the renal impairment and the pathological examination. After stopping rifampin, the skin lesions disappeared in about 10 days and his renal function gradually improved. This case study showed that Henoch-Schonlein purpura can be caused by rifampin during antituberculosis therapy and we recommend that the use of rifampin should be restrained when clinical symptoms of Henoch-Shonlein purpura are observed.

A Case of Endobronchial Lipoma Causing Right Middle and Lower Lobes Collapse and Bronchiolitis Obliterans-organizing Pneumonia / 결핵및호흡기질환

Lipoma is a common neoplasm in soft tissues. However, an intrapulmonary lipoma is a rare benign tumor. Patients with a bronchial lipoma might have a malignant potential related to their smoking history due to the case reports of lung cancer accompanied with lipoma. Endobronchial lipoma can cause irreversible parenchymal lung damage if not diagnosed and treated early. Therefore, it should initially be treated by fiberoptic bronchoscopy or surgery depending on the status of distal parenchymal lung damage. Bronchiolitis obliterans with organizing pneumonia (BOOP) is a pathological syndrome that is defined by the presence of buds of granulation tissue consisting of fibroblasts and collagen within the lumen of the distal air spaces. BOOP is caused by drug intoxication, connective tissue disease, infection, obstructive pneumonia, tumors, or an unknown etiology. We encountered a 58 year-old male patient with endobronchial lipoma, causing the collapse of the right middle and lower lobes, and BOOP due to obstructive pneumonia.