• Journal of radiological science and technology
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• v.35 no.2
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• pp.165-172
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• 2012

We investigated the vascular characteristics of tumors and normal tissue using perfusion CT in the rabbit brain tumor model. The VX2 carcinoma concentration of $1{\times}10^7$ cells/ml(0.1ml) was implanted in the brain of nine New Zealand white rabbits (weight: 2.4kg-3.0kg, mean: 2.6kg). The perfusion CT was scanned when the tumors were grown up to 5mm. The tumor volume and perfusion value were quantitatively analyzed by using commercial workstation (advantage windows workstation, AW, version 4.2, GE, USA). The mean volume of implanted tumors was $316{\pm}181mm^3$, and the biggest and smallest volumes of tumor were 497 $mm^3$ and 195 $mm^3$, respectively. All the implanted tumors in rabbits are single-nodular tumors, and intracranial metastasis was not observed. In the perfusion CT, cerebral blood volume (CBV) were $74.40{\pm}9.63$, $16.08{\pm}0.64$, $15.24{\pm}3.23$ ml/100g in the tumor core, ipsilateral normal brain, and contralateral normal brain, respectively ($p{\leqq}0.05$). In the cerebral blood flow (CBF), there were significant differences between the tumor core and both normal brains ($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($962.91{\pm}75.96$ vs. $357.82{\pm}12.82$ vs. $323.19{\pm}83.24$ ml/100g/min). In the mean transit time (MTT), there were significant differences between the tumor core and both normal brains ($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($4.37{\pm}0.19$ vs. $3.02{\pm}0.41$ vs. $2.86{\pm}0.22$ sec). In the permeability surface (PS), there were significant differences among the tumor core, ipsilateral and contralateral normal brains ($47.23{\pm}25.45$ vs. $14.54{\pm}1.60$ vs. $6.81{\pm}4.20$ ml/100g/min)($p{\leqq}0.05$). In the time to peak (TTP) were no significant differences among the tumor core, ipsilateral and contralateral normal brains. In the positive enhancement integral (PEI), there were significant differences among the tumor core, ipsilateral and contralateral brains ($61.56{\pm}16.07$ vs. $12.58{\pm}2.61$ vs. $8.26{\pm}5.55$ ml/100g). ($p{\leqq}0.05$). In the maximum slope of increase (MSI), there were significant differences between the tumor core and both normal brain($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($13.18{\pm}2.81$ vs. $6.99{\pm}1.73$ vs. $6.41{\pm}1.39$ HU/sec). Additionally, in the maximum slope of decrease (MSD), there were significant differences between the tumor core and contralateral normal brain($p{\leqq}0.05$), but no significant differences between the tumor core and ipsilateral normal brain($4.02{\pm}1.37$ vs. $4.66{\pm}0.83$ vs. $6.47{\pm}1.53$ HU/sec). In conclusion, the VX2 tumors were implanted in the rabbit brain successfully, and stereotactic inoculation method make single-nodular type of tumor that was no metastasis in intracranial, suitable for comparative study between tumors and normal tissues. Therefore, perfusion CT would be a useful diagnostic tool capable of reflecting the vascularity of the tumors.

• Tuberculosis and Respiratory Diseases
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• v.56 no.3
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• pp.261-268
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• 2004

Background : The resurgence of tuberculosis and outbreaks of multidrug resistant (MDR) tuberculosis have increased the emphasis for the development of new susceptibility testing of the Mycobacterium tuberculosis for the effective treatment and control of the disease. Conventional drug susceptibility testings, such as those using egg-based or agar-based media have some limits, such as the time required and difficulties in determining critical inhibitory concentrations, but these are still being used in many diagnostic laboratories because of no better lternatives, considering cost and accuracy. To overcome these limits, a rapid and simple method for new susceptibility testing, using live and dead assays, was applied for a bacterial cell viability assay to distinguish dead from live bacterial cells based on two-color fluorescence. Materials and Methods Strains : Forty strains were used in this study, 20 susceptible to all antituberculosis drugs and the other 20 resistant to the four first line antituberculosis drugs isoniazid, rifampicin, streptomycin and ethambutol. Antibiotics : The four antibiotics were dissolved in 7H9 broth to make the following solutions: $0.1{\mu}g\;isoniazid(INH)/m{\ell}$, $0.4{\mu}g\;rifampicin(RMP)/m{\ell}$, $4.0{\mu}g\;streptomycin(SM)/m{\ell}$ and $4.0{\mu}g\;ethambutol(EMB)/m{\ell}$. Results : Live and dead Mycobacterium tuberculosis cells fluoresced green and red with the acridin (Syto 9) and propidium treatments, respectively. These results are very well accorded with conventional drug susceptibility testing by proportional method on Lowensen-Jensen media (L-J) containing 4 drugs (INH, RMP, EMB and SM), showing a 93.7 % accordance rate in susceptible strains and 95% in resistant strains. Conclusion : The results of the drug susceptibility testing using the live and dead bacterial cell assay showed high accordance rates compared with the conventional proportion method on L-J. This finding suggests that the live and dead bacterial cell assay can be used as an alternative to conventional drug susceptibility testing for M. tuberculosis strains.

• Korean Journal of Psychosomatic Medicine
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• v.17 no.2
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• pp.68-74
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• 2009

Objectives : Illness behavior is defined as the persistence of an adaptive/maladaptive mode of perceiving, evaluating and responding to health status and symptoms according to the status. In a cognitive aspect, somatizing symptoms are regarded as being originated from distortions, including magnification and/or amplification, of perceiving, evaluating and responding to symptoms such as bodily sensations. That is somatization may be explained by maladaptive illness behavior. In this study, we tried to investigate differences of illness behavior in depressive patient according to the presence of somatization. Methods : We divided 45 patients who were diagnosed as depression with ICD-10 diagnostic criteria into two groups(somatizing and non-somatizing group) according to the somatization subscale of Korean Depression Scale and compared two groups in the differences of illness behavior using the Illness Behavior Questionnaire. Results : Somatizing group showed significantly higher scores than non-somatizing group on the disease affirmation subscale($6.79{\pm}2.08$ vs. 4.76, p=0.003) and the denial subscale($3.25{\pm}1.22$ vs. $2.10{\pm}1.41$, p=0.006). There were no significant differences between two groups on the general hypochondriasis subscale and the affective unstability subscale. In a logistic regression analysis, somatizing group also showed higher odds ratio (OR) scores on the disease affirmation subscale(OR=1.418, p=0.089) and the denial subscale(OR=1.880, p=0.083). Conclusion : The disease affirmation and denial may be a discriminative mechanism of somatization in depressive patients. These subscales of Illness Behavior Questionnare could be useful markers, and psychiatric illnesses with somatizing and depressive symptoms may be differentially diagnosed and be predicted through these subscales.

• Korean Journal of Psychosomatic Medicine
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• v.22 no.2
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• pp.121-129
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• 2014

Objectives : This study was to assess the prevalence and its correlates of restless legs syndrome(RLS) in outpatients with bipolar disorder. Methods : A total of 100 clinical stabilized bipolar outpatients were examined. The presence of RLS and its severity were assessed using the International Restless Legs Sydrome Study Group(IRLSSG) diagnostic criteria. Beck's Depression Inventory(BDI), Spielberg's State Anxiety Inventory(STAI-X-1), Pittsburgh Sleep Quality Index(PSQI), Korean version Drug Attitude Inventory(KDAI-10), Subjective Well-Beings under Neuroleptic Treatment Scale-Short Form(SWN-K) and Barnes Akathisia Rating Scale(BARS) were used to evaluate the depressive symptomatology, level of anxiety, subjective quality of sleep, subjective feeling of well-being, drug attitude, presence of akathisia, respectively. Results : Of the 100 bipolar outpatients, 7(7%) were met to full criteria of IRLSSG and 36(36%) have at least one of the 4 IRLSSG criterion. Because of relatively small sample size, non-parametric analysis were done to compare the characteristics among 3 groups(full-RLS, 1 ${\geq}$positive RLS-symptom and Non-RLS). There were no significant differences in sex, age, and other sociodemographic and clinical data among 3 groups. BDI, STAI-X-1 and PSQI are tended to be impaired in RLS and 1 ${\geq}$positive RLS-symptom groups. Conclusions : This is the first preliminary study for studying the prevalence and its correlates of RLS in bipolar disorder. The results shows that relatively small proportion of RLS was present in bipolar disorder patients when compared to patients with schizophrenia. Same tendencies shown in schizophrenic patients were found that bipolar patients with RLS had more depressive symptoms, state anxiety and poor subjective sleep quality. Further systematic studies may be needed to find the characteristics of RLS in bipolar patients.

• Journal of Environmental Health Sciences
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• v.43 no.1
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• pp.1-22
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• 2017

'The worstest environment disaster', 'World's first biocide massacre', 'Home-based Sewol ferry disaster' are all phrases attached to the recent humidifier disinfectant disaster. In the spring of 2011, four of 8 pregnant women including 1 adult man passed away at a university hospital in Seoul due to breathing failure. Epidemiologic investigation conducted by the Korean CDC soon revealed the inhalation of humidifier disinfectant, which had been widely used in Korea during the winter, to be responsible for the disease. As well as lung fibrosis hardening of the lungs, other diseases including asthma, rhinitis, skin disease, liver disease, fetal disease or cancers have been researched for their relation with exposure to the products. By February 9, 2017, 5,342 cases had registered for health problems and 1,131 of them were already dead (20.8% mortality rate). Based on studies by government agencies and a telephone survey of the general population by Seoul National University and civic groups, around 20% of the general public of Korea has used these products. Since the market release of the first product by SK Chemical in 1994, over 7.1 million items from around 20 brands were sold up to 2011. Most of the products were manufactured by well-known large conglomerates such as SK, Lotte, Samsung, Shinsegye, LG, and GS, as well as some European companies including UK-based Reckitt Benckiser and TESCO, the German firm Henkel, the Danish firm KeTox, and an Irish company. Even though this disaster was unveiled in 2011 by the Korean government, the issue of the victims was neglected for over five years. In 2016, an unexpected but intensive investigation by prosecutors found that Reckitt Benckiser manipulated and concealed animal tests for its own brand and brought several university experts and company employees to court. The matter was an intense social issue in Korea from May to June with a surge in media coverage. The prosecutor's investigation and a nationwide boycott campaign organized by victims and environmental groups against Reckitt Benckiser, whose product had been used by more than 70% of victims, led to the producer's official apology and a compensation scheme. A legislative investigation organized after the April 2016 national election revealed the producers' faults and the government's responsibility, but failed to meet expectations. A special law for the victims passed the National Assembly in January 2017 and a punitive system together with a massive environmental epidemiology investigation are expected to be the only solutions for this tragedy. Sciences of medicine, toxicology and environmental health have provided decisive evidence so far, but for the remaining problems the perspectives of social sciences such as sociology and jurisprudence are highly necessary, similar to with the Minamata disease and Wonjin Rayon events. It may not be easy to follow this issue using unfamiliar terminology from medical and chemical science and the long, complicated history of the event. For these reasons the author has attempted to write this article in a question and answer format to render it easier to follow. The 17 questions are: Q1 What is humidifier disinfectant? Q2 What kind of health problems are caused by humidifier disinfectant? Q3 How many victims are there? Q4 What is the analysis of the 1,112 cases of death? Q5 What is the problem with the government's diagnostic criteria and the solution? Q6 Who made what brands? Q7 Has there been a recall? What is still on sale? Q8 Was safety not checked by any producers? Q9 What are the government's responsibilities? Q10 Is it true that these products were sold only in Korea? Q11 Why and how was it unveiled only in 2011 after 17 years of sales? Q12 What delayed the resolution of the victim issue? Q13 What is the background of the prosecutor's investigation in early 2016? Q14 Is it possible to report new victim cases without evidence of product purchase? Q15 What is happening with the victim issue? Q16 How does it compare with the cases of Minamata disease and Wonjin Rayon? Q17 Are there prevention measures and lessons?

• Journal of the Korean Society of Radiology
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• v.5 no.4
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• pp.195-200
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• 2011

The purpose of this study is to investigate the dose of radiation exposure to radiation-related workers in a hospital setting, thus increasing awareness of the health risk to the radiation-related workers. The result of the analysis showed the average dose of radiation exposure to radiation-related workers in hospital K was $0.75{\pm}0.26mSv$ in 2008, $0.67{\pm}0.30mSv$ in 2009, and $0.92{\pm}0.33mSv$ in 2010. The average dose of radiation exposure in hospital P was $0.43{\pm}0.13mSv$ in 2008, $0.43{\pm}0.20mSv$ in 2009, and $0.33{\pm}0.85mSv$ in 2010. The average dose of radiation exposure in hospital K by age group was 13.39mSv for age 20 to 29, 8.37mSv for age 30 to 39, 1.19mSv for age 40 to 49, 0.28mSv for age 50 to 59, and 0.32mSv for age 60 to 69 The average dose of radiation exposure in hospital P by age group was 0.33mSv for age 20 to 29, 1.41mSv for age 30 to 39, 0.83mSv for age 40 to 49, 1.66mSv for age 50 to 59, and 1.12mSv for age 60 to 69. Moreover, the average radiation exposure to radiation-related workers over 3 year period by gender group in hospital K was $2.92{\pm}1.03mSv$ for male group and $0.94{\pm}0.93mSv$ for female group. The average radiation exposure over 3 year period by gender group in hospital P was $0.66{\pm}0.18mSv$ for male group and $1.80{\pm}0.60mSv$ for female group. Persons working in diagnostic radiology department received mean of $1.65{\pm}1.54mSv/year$, mean $1.17{\pm}0.82mSv/year$ in radiation oncology, mean $1.79{\pm}1.42mSv/year$ at nuclear medicine department and mean $0.99{\pm}0.51mSv/year$ at other departments. Radiation exposure was higher than that of other departments(p<0.05). Doctors and technologists received higher radiation exposure (mean $1.75{\pm}1.17mSv/year$, $1.60{\pm}1.39mSv/year$ each) than other workers(p<0.05). Measurement and evaluation of radiation exposure in radiation-related workers should be widely conducted accurately and consistently in the radiation-related occupational setting so that people in these occupational settings are more aware of the risk from radiation exposure, and thus give more attention and caution to decrease radiation exposure. It would be essential to minimize accumulated radiation dose in the radiation-related occupational setting in order to maintain and improve the health of radiation-related workers.

• Journal of the Korean Society of Radiology
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• v.5 no.5
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• pp.303-308
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• 2011

Background/Aims : The increasing use of diagnostic and therapeutic interventional radiology calls for greater consideration of radiation exposure risk to radiologist and radiological technician, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a protective grass shield. Methods : A protective grass was following data depth, 0.8 cm; width, 100 cm; length, 100 cm, lead equivalent, 1.6 mmPb. The protective shield was located between the patient and the radiologist. Thirty patients (13 male and 17 female) undergoing interventional radiology between September 2010 and December 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective grass shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. Results : The mean patient age was 69 years. The mean patient height and weight was $159.7{\pm}6.7$ cm and $60.3{\pm}5.9$ kg, respectively. The mean body mass index (BMI) was $20.5{\pm}3.0$ kg/m2. radiologists received $1530.2{\pm}550.0$ mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to $50.3{\pm}85.2$ mR/hr with the protective lead shield (p-value<0.0001). The radiation exposure to radiologist and radiological technician was significantly reduced by the use of a protective lead shield (p value <0.0001). The amount of radiation exposure during interventional radiology was related to the patient' BMI (r=0.749, p=0.001). Conclusions : This protective shield grass is effective in protecting radiologist and radiological technician from radiation exposure.

• Korean Journal of Psychosomatic Medicine
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• v.28 no.1
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• pp.8-19
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• 2020

Objectives : The purpose of this study was to examine whether the MMPI-2-RF serves as a useful tool to differentiate between the subtypes of high risk of suicide among psychiatric outpatients. Methods : Patients were recruited from the department of psychiatry of university hospital. Participants were diagnosed using DSM-5 criteria by board certified psychiatrists. Their medical records were reviewed retrospectively. And participants were put into 4 groups (Suicide ideation, Suicide attempt, Non-suicidal self-injury, and general psychiatric diagnosis as a control group). For statistical comparison, the MANCOVA with gender as a covariate was used. Results : The results indicated that as previous research with non-clinical sample suggested, psychiatric outpatients with high suicide risk also have significantly higher Emotional/Internalizing Dysfunction, Helplessness/Hopelessness, Suicidal/Death Ideation, Demoralization, Cognitive complaints, Cynicism, Dysfunctional negative thoughts than general psychiatric patients group. But group differences within the high suicide risk patients have not been observed. However, suicide attempt group and NSSI group has higher Behavioral/Externalizing Dysfunction, RC4, AGG than general psychiatric patients group. But there was no difference between suicidal idea group and general psychiatric patients group. Conclusions : There was no group difference observed between all three subtypes, which mean the MMPI2-RF may not be the useful diagnostic tool to navigate high suicide risk subtypes. Even though there was no difference observed in the suicide ideation group, suicide attempt group and NSSI group have higher aggression and externalization. So those indexes could serve as a useful marker to investigate riskiness of suicide related symptoms.

• Journal of Korean Public Health Nursing
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• v.15 no.2
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• pp.239-248
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• 2001

The purpose of this study was to analyze risk factors for nosocomial pneumonia in patients admitted to NS ICU, and to provide a basic data to decrease respiratory nosocomial infection rate engendered from medical environments in NS ICU. The study site was the NS ICU at a university hospital located in Seoul, Korea. The subjects were 31 patients diagnosed with nosocomial pneumonia, who were selected from the initial list of 300 potential subjects who had been a) admitted between September 1999 and January 2000, and September 2000 and January 2001, b) resided at the NS ICU over 72 hours. The diagnostic standard of nosocomial pneumonia was based on the nosocomial infection guides of C university hospital. The data were analyzed using frequencies and logistic regression analysis. The sputums obtained from the subjects were cultivated and causal viruses were separated. The results were as follows: 1. The nosocomial pneumonia rate was $10.3\%$. There were 7 types of causal viruses separated from the sputum. and the most prevalent type of virus was MRSA as $62.2\%$. 2. The factors significantly influencing the incidence of nosocomial pneumonia included age, the residential duration at the NS ICU, GCS scores, diabetes mellitus, insertion of tracheal tube and its duration, tracheostomy and its length of insertion, the use of artificial ventilator and the length of its use, and the insertion of naso-gastic tube. The most significant risk factor among these was the insertion of tracheal tube (odds ratio=18.684. $95\%$ CI=6.849-50.974), followed by the use of tracheostomy (odds ratio=15.419, $95\%$ CI=6.615-35.942), the insertion of naso-gastric tube (odds ratio=14.875, $95\%$ CI=6.396-34.595), and the use of artificial ventilator (odds ratio=13.000. $95\%$ CI=5.633­30.001). 3. Regarding the use of the mechanical aids, the insertion of tracheal tube resulted in 12.968 times increase of the nosocomial pneumonia rate, and the use of artificial ventilator lead 6.714 times increase of the nosocomial pneumonia rate. One point increase of the GCS score resulted in the 1.210 times increase of the nosocomial pneumonia rate. For patients who had tracheal tube, tracheostomy, and artificial ventilator, one day increase of their residential duration at NS ICU lead 1.073 times increase of the nosocomial pneumonia rate. 4. In terms of duration of the mechanical aid usage, one day increase in the use of artificial ventilator engendered 1.080 times increase in the nosocomial pneumonia rate. One day increase of the residential duration at the NS ICU lead 1.604 times increase in the nosocomial pneumonia rate. As one point of the GCS score increased, 0.876 times decrease of the nosocomial pneumonia rate was reported. These study findings show that the risk factors significantly influencing the incidence of nosocomial pneumonia include the use of tracheal tube, tracheostomy, naso-gastic tube, and artificial ventilator. It is recommended that nurses working at NS ICU should pay more attention to the patients with these factors as the risky group for the nosocomial pneumonia, and thus make more active efforts to provide nosocomial pneumonia prevention strategies for them. In further studies patients admitted to the different types of ICUs such as internal medicine or surgery unit ICU will be also included, and more wide investigation of nosocomial pneumonia risk factors will be conducted through one-year longitudinal follow up.

• Journal of the Korean Society of Radiology
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• v.14 no.6
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• pp.773-780
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• 2020

With the development of the 4th industrial, research is being conducted to prevent diseases and reduce damage in various fields of science and technology such as medicine, health, and bio. As a result, artificial intelligence technology has been introduced and researched for image analysis of radiological examinations. In this paper, we will directly apply a deep learning model for classification and detection of pneumonia using chest X-ray images, and evaluate whether the deep learning model of the Inception series is a useful model for detecting pneumonia. As the experimental material, a chest X-ray image data set provided and shared free of charge by Kaggle was used, and out of the total 3,470 chest X-ray image data, it was classified into 1,870 training data sets, 1,100 validation data sets, and 500 test data sets. I did. As a result of the experiment, the result of metric evaluation of the Inception V3 deep learning model was 94.80% for accuracy, 97.24% for precision, 94.00% for recall, and 95.59 for F1 score. In addition, the accuracy of the final epoch for Inception V3 deep learning modeling was 94.91% for learning modeling and 89.68% for verification modeling for pneumonia detection and classification of chest X-ray images. For the evaluation of the loss function value, the learning modeling was 1.127% and the validation modeling was 4.603%. As a result, it was evaluated that the Inception V3 deep learning model is a very excellent deep learning model in extracting and classifying features of chest image data, and its learning state is also very good. As a result of matrix accuracy evaluation for test modeling, the accuracy of 96% for normal chest X-ray image data and 97% for pneumonia chest X-ray image data was proven. The deep learning model of the Inception series is considered to be a useful deep learning model for classification of chest diseases, and it is expected that it can also play an auxiliary role of human resources, so it is considered that it will be a solution to the problem of insufficient medical personnel. In the future, this study is expected to be presented as basic data for similar studies in the case of similar studies on the diagnosis of pneumonia using deep learning.