• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.723-730
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• 2005

Purpose : This study was performed to characterize the etiology and clinical features of acute viral lower-respiratory tract infections(LRI). Methods : Etiologic agents and clinical features of acute viral LRI were studied from October. 2003 through March. 2004 in hospitalized children with LRI(253 cases) at Samsung Cheil Hospital. The viruses were identified by indirect immunofluorescent method. Medical records of patients with proven viral LRI were reviewed retrospectively. Results : Ninety two cases(36.4%) were confirmed as viral infections. The identified pathogens were respiratory syncytial virus(RSV, 76.0%), adenovirus(ADV, 12.0%), influenza virus type A(INFA, 9.8 %), influenza virus type B(INFB, 1.1%) and parainfluenza virus(PIV, 1.1%). Eight four point eight% of patients were younger than 2 years of age. Clinical diagnosis of LRI were pneumonia(56.5%), bronchiolitis(35.9%), tracheobronchitis(4.3%) and croup(3.3%). The clinical symptoms and signs were cough(98.8%), rhinorrhea(82.6%), fever(70.7%), rale(67.4%), wheezing(29.3%), chest retraction(28.3%) and cyanosis(4.3%). The severe respiratory symptoms and signs were more common in RSV-infected patients, even cyanosis could be observed. Seventeen point four percent of patient had fever of $38.5^{\circ}C$ or higher and their most common etiologic agent was INFA(66.7%). Twenty three point nine percent had fever more than 5 days and common etiologic agent was INFA(77.8%). The elevated WBC count($>14{\times}10^3/{\mu}L$) was in 14.1%, and common etiologic agents were INFA(22.2%) and ADV(18.2%). C-reactive protein(CRP >4.0 mg/dL) was increased in 13.0%, and common in ADV(63.6 %). Increased aspartate aminotransferase(AST)/alanine aminotransferase(ALT) was detected in 10.9%, and the most common etiologic agent was RSV(12.9%). Conclusion : The common agents of acute viral LRI were RSV, ADV and INF, respectively. Because the etiologic agents present variable clinical features, it may be helpful to treat and to evaluate acute viral LRI that we should understand their etiologic variability.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.570-578
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• 2003

Background : Ambient particles during Asian dust events are usually sized less than $10{\mu}m$, known to be associated with the adverse effects on the general populations. But, there has been no considerable evidence linking these particles to the adverse effects on airways. The objectives of this study was to investigate the possible adverse effects of Asian dust events on respiratory function and symptoms in subjects with bronchial asthma. Patients and Methods : From march to June 2002, Asthmatic patients who were diagnosed with bronchial challenge test or bronchodilator response were enrolled. We divided them into three groups; mild, moderate, and severe, according to the severity. Subjects with other organ insufficiency such as heart, kidney, liver, and malignancy were excluded. All patients completed twice daily diaries and recorded peak flow rate, respiratory symptom, and daily activity. Daily and hourly mean pollutant levels of particulate matter < $10{\mu}m$ in diameter($PM_{10}$), nitrogen dioxide($NO_2$), sulphur dioxide($SO_2$), ozone($O_3$) and carbon monoxide(CO) were measured at the 10 different monitoring sites. Results : Dust events occured 14 times during the study period. Daily averages of 4 air pollutant were measured with an increased level of $PM_{10}$, decreased level of $NO_2$ and $SO_2$, and no change in CO during dust days compared to those during control days. An increase in $PM_{10}$ concentration was associated with an increase of subjects with PEF variability of >20% (p<0.05), night time symptom(p<0.05), and a decrease in mean PEF (p<0.05), which were calculated by the longitudinal data analysis. Otherwise, there was no association between $PM_{10}$ level and bronchodialtor inhaler, and daytime respiratory symptoms. Conclusion : This study shows evidence that ambient air pollution, especially $PM_{10}$, during Asian dust events, could be one of the many aggravating factors at least in patients with airway diseases. This data can be used as a primary source to set up a new policy on air environmental control and to evaluate the safety of air pollution index. We also expect that this research will help identify precise components of dust, which are more linked to the adverse effects.

• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.172-177
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• 2015

Purpose: This study aimed to analyze the epidemic period of RSV infection and evaluate the appropriate time of palivizumab immunoprophylaxis. Methods: From January 1991 to July 2012, nasopharyngeal (NP) aspirates were obtained from patients who visited Seoul National University Children's Hospital for respiratory symptoms. NP samples were used to detect respiratory viruses. Among them, we analyzed the positive number and detection rate of RSV infection in two-week interval. The beginning of RSV season was defined when RSV positive number was more than 4 and RSV detection rate was over 10%. From January 2007 to March 2014, we analyzed the starting time of palivizumab immunoprophylaxis for the infants at high risk. Results: The RSV detection rate was 2,013/21,698 (9.69%) over 22 years. The median RSV season was from $2^{nd}-3^{rd}$ week of October to $1^{st}-2^{nd}$ week of February. The earliest starting week was the 3rd week of July in year 2001, and the latest end week was the 3rd week of May in year 1990. Palivizumab immunoprophylaxis was initiated most frequently at the 3rd week of October (18.7%). However, the percentage of starting palivizumab on the 1st week of September has increased from 3.8% in the year 2007 to 14.1% in 2013. Conclusions: The year to year variability of RSV season exists. The starting time of palivizumab immunoprophylaxis should be adjusted based on the season of RSV epidemic.

• Progress in Medical Physics
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• v.26 no.3
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• pp.127-136
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• 2015

The purpose of this study is to perform a dosimetric evaluation of amplitude-based respiratory gating for the delivery of volumetric modulated arc therapy (VMAT). We selected two types of breathing patterns, subjectively among patients with respiratory-gated treatment log files. For patients that showed consistent breathing patterns (CBP) relative to the 4D CT respiration patterns, the variability of the breath-holding position during treatment was observed within the thresholds. However, patients with inconsistent breathing patterns (IBP) show differences relative to those with CBP. The relative isodose distribution was evaluated using an EBT3 film by comparing gated delivery to static delivery, and an absolute dose measurement was performed with a $0.6cm^3$ Farmer-type ion chamber. The passing rate percentages under the 3%/3 mm gamma analysis for Patients 1, 2 and 3 were respectively 93.18%, 91.16%, and 95.46% for CBP, and 66.77%, 48.79%, and 40.36% for IBP. Under the more stringent criteria of 2%/2 mm, passing rates for Patients 1, 2 and 3 were respectively 73.05%, 67.14%, and 86.85% for CBP, and 46.53%, 32.73%, and 36.51% for IBP. The ion chamber measurements were within 3.5%, on average, of those calculated by the TPS and within 2.0%, on average, when compared to the static-point dose measurements for all cases of CBP. Inconsistent breathing patterns between 4D CT simulation and treatment may cause considerable dosimetric differences. Therefore, patient training is important to maintain consistent breathing amplitude during CT scan acquisition and treatment delivery.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1075-1081
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• 2007

We investigated whether 1) capsaicin ingestion (100 mg) enhances autonomic nervous system (ANS) activities associated with thermogenic sympathetic activity as energy metabolic modulator, 2) UCP1 and ${\beta}_{3}$-AR variants of each subjects influence with ANS activity. Eight healthy males (24.7 ${\pm}$ 1.8 yr) volunteered for this study. The cardiac autonomic nervous activities evaluated by means of heart rate variability of power spectral analysis and energy metabolism were continuously measured during 5-min rest for total 90-min resting condition with placebo or capsaicin oral administration chosen at random. The results indicated that there were no significant differences in heart rate during rest between both trials. Autonomic nervous activity increased in capsaicin tablet trial, but the difference did not reach the statistical significance. Capsaicin, however, induced significantly lower respiratory gas exchange ratio at Test3 (CAP: 0.80 ${\pm}$ 0.02 vs. 0.85 ${\pm}$ 0.02), means ${\pm}$ SE, p<0.05). In conclusion, it may be suggested the capsaicin consumption as a valuable supplement for the treatment of individual with hyperlipidemia and/or obesity by improving lipolysis. Further studies will also be considered genetic variants such as UCP1 and/or ${\beta}_{3}$-AR associated with obesity.

• Korean Journal of Remote Sensing
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• v.32 no.5
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• pp.499-509
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• 2016

The occurrence of sand dust has been steadily increased since 1990 and the amount of damage was also increased. In most of previous studies, ground based observations were used for sand dust analyses, but its high spatio-temporal variability has not been well understood. In this study, satellite aerosol observations were used to overcome current limitations of the sand dust variability in space and time and to estimate associations with morbidity of respiratory and cardiovascular ailments. In general, high AODs were observed in the west part of the Koran peninsula in spring. The reasonable associations between the morbidity and sand dust were observed from April to July with highest positive correlation (~0.6) at three month lags (lag 3). Based on the results, we found a utility of the satellite aerosol observations for sand dust analyses by considering of morbidity effects. In addition, health effect against the sand dust is proved to be examined and smooth medical supplies and prevention of undesired medical expenses would be possible.

• Journal of Environmental Health Sciences
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• v.30 no.2
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• pp.140-148
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• 2004

To evaluate the acute effects of fine particles on pulmonary function, a longitudinal study was conducted. This study was carried out for the schoolchildren (3rd and 6th grades) living in Beijing, China. Each child was provided with a mini-Wright peak flow meter and a preformatted health symptom diary for 40 days, and was trained on their proper use. Participants were instructed to perform the peak flow test three times in standing position, three times a day (9 am, 12 pm, and 8 pm), and to record all the readings along with the symptoms (cold, cough, and asthmatic symptoms) experienced on that day. Daily measurement of fine particles (PM$_{10}$ and PM$_{2.5}$) was obtained in the comer of the playground of the participating elementary school for the same period of this longitudinal study. The relationship between daily peak expiratory flow rate (PEFR) and fine particle levels was analyzed using a mixed linear regression models including gender, height, the presence of respiratory symptoms, and daily average temperature and relative humidity as extraneous variables. The total number of students participating in this longitudinal study was 87. The range of daily measured PEFR was 253-501$\ell$/min. In general, the PEFR measured in the morning was lower than the PEFR measured in the evening (or afternoon) on the same day. The daily mean concentrations of PM$_{10}$ and PM$_{2.5}$ over the study period were 180.2$\mu\textrm{g}$/㎥ and 103.2$\mu\textrm{g}$/㎥, respectively. The IQR (inter-quartile range) of PM$_{10}$ and PM$_{2.5}$ were 91.8$\mu\textrm{g}$/㎥ and 58.0$\mu\textrm{g}$/㎥. During the study period, the national ambient air quality standard of 150$\mu\textrm{g}$/㎥ (for PM$_{10}$) was exceeded in 23 days (57.5%). The analysis showed that an increase of 1$\mu\textrm{g}$/㎥ of PM$_{10}$ corresponded to 0.59$\mu\textrm{g}$/㎥ increment of PM$_{2.5}$. Daily mean PEFR was regressed with the 24-hour average PM$_{10}$ (or PM$_{2.5}$) levels, weather information such as air temperature and relative humidity, and individual characteristics including gender, height, and respiratory symptoms. The analysis showed that the increase of fine particle concentrations was negatively associated with the variability in PEFR. The IQR increments of PM$_{10}$ or PM$_{2.5}$ (at 1-day time lag) were also shown to be related with 1.54 $\ell$/min (95% Confidence intervals: 0.94-2.14) and 1.56$\ell$/min (95% CI: 0.95-2.16) decline in PEFR.R.ine in PEFR.ine in PEFR.

• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.315-320
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• 2015

Background: The efficacy of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy can be measured based on the rate of treatment response, based on the Response Evaluation Criteria in Solid Tumors (RECIST) criteria or progression-free survival (PFS). However, there are some patients harboring sensitive EGFR mutations who responded poorly to EGFR-TKI therapy. In addition, there is variability in the PFS after EGFR-TKI treatment. Methods: We performed a retrospective analysis of the medical records of 85 patients with non-small cell lung cancer, who had achieved a stable disease or better response at the first evaluation of treatment response, after receiving a 2-month course of gefitinib. We calculated the tumor shrinkage rate (TSR) by measuring the longest and perpendicular diameter of the main mass on computed tomography before, and 2 months after, gefitinib therapy. Results: There was a significant positive correlation between the TSR and PFS (R=0.373, p=0.010). In addition, a simple linear regression analysis showed that the TSR might be an indicator for the PFS ($B{\pm}standard$ error, $244.54{\pm}66.79$; p=0.001). On univariate analysis, the sex, histologic type, smoking history and the number of prior chemotherapy regimens, were significant prognostic factors. On multivariate regression analysis, both the TSR (${\beta}$=0.257, p=0.029) and adenocarcinoma (${\beta}$=0.323, p=0.005) were independent prognostic factors for PFS. Conclusion: Our results showed that the TSR might be an early prognostic indicator for PFS in patients receiving EGFRTKI therapy.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.39-50
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• 2001

Background: Power spectrum analysis method is a powerful noninvasive tool for quantifying autonomic nervous system activity. In this paper, we developed a data acquistion system for estimating the activity of the autonomic nervous system by the analysis of heart rate and respiratory rate variability using power spectrum analysis. Materials and methods: For the detection of QRS peak and measurement of respiratory rate from patient's ECG, we used low-pass filter and impedence method respectively. This system adopt an isolated power for patient's safety. In this system, two output signals can be obtained: R-R interval heart rate) and respiration rate time series. Experimental ranges are 30-240 BPM for ECG and 15-80 BPM for respiration. Results: The system can acquire two signals accurately both in the experimental test using simulator and in real clinical setting. Conclusion: The system developed in this paper is efficient for the acquisition of heart rate and respiration signals. This system will play a role in research area for improving our understanding of the pathophysiologic involvement of the autonomic nervous system in various disease states.

• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.139-142
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• 2013

X-linked recessive myotubular myopathy (XLMTM) is a severe congenital muscle disorder caused by mutations in the MTM1 gene and characterized by severe hypotonia and generalized muscle weakness in affected males. It is generally a fatal disorder during the neonatal period and early infancy. The diagnosis is based on typical histopathological findings on muscle biopsy, combined with suggestive clinical features. We experienced a case of a newborn who required intubation and ventilator care because of profound hypotonia and respiratory difficulty. The preliminary diagnosis at the time of request for retrieval was hypoxic ischemic encephalopathy, but the infant was clinically reevaluated for generalized weakness and muscle atrophy. Muscle biopsies showed variability in fiber size and centrally located nuclei in nearly all the fibers. We detected an MTM1 gene mutation of c.1261-1C>A in the intron 10 region, and diagnosed the neonate with myotubular myopathy. The same mutation was detected in his mother.