Publications by authors named "Dong Wook Kim"

1,227 Publications

  • Page 1 of 1

Factors Affecting the Survival of Early COVID-19 Patients in South Korea: An Observational Study based on the Korean National Health Insurance Big Data.

Int J Infect Dis 2021 Feb 26. Epub 2021 Feb 26.

Health Insurance Research Institute, National Health Insurance Service, Wonju, Republic of Korea.

Objectives: This study aims to identify the survival rate and to explore factors affecting survival among early COVID-19 patients in South Korea.

Methods: Data reported by the Korea Disease Control and Prevention Agency (KDCA) up to July 15, when COVID-19 was confirmed, were used as research data in connection with the National Health Insurance Service's (NHIS) national health information database. The final analysis targets were 12,646 confirmed patients and 303 deaths. The survival rate of patients with COVID-19 was estimated through Kaplan-Meier survival analysis, Cox proportional hazard regression analysis was performed to search for factors affecting survival.

Results: When looking at the survival rate by age group for men and women, the 28-day survival rate for men over 80 years old was 77% and 73% for 42 days, while 83% and 81% for women. Men had a poor survival rate than women. In chronic diseases, the highest risk of mortality was observed in malignant neoplasms of the respiratory and urogenital systems, followed by diseases of the urinary system and diabetes.

Conclusions: The number of COVID-19 deaths was highest the next day after initial diagnosis. The case fatality rate was high in males, older age, and chronic diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijid.2021.02.101DOI Listing
February 2021

Adherence to Antihypertensive Medication and Incident Cardiovascular Events in Young Adults With Hypertension.

Hypertension 2021 Mar 1:HYPERTENSIONAHA12016784. Epub 2021 Mar 1.

From the Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea (H.L., H.C.K.).

Treatment and control rates for high blood pressure are unsatisfactory in young adults. Adherence to pharmacological treatment is alarmingly low, with absence of data on its consequences in young adults with hypertension. We investigated the association of antihypertensive medication nonadherence with incident cardiovascular events among young adults initiating pharmacological treatment for hypertension. From a nationwide health insurance database, we included 123 390 participants (75.1% male) of age 20 to 44 years, free of prior cardiovascular disease (CVD), who initiated pharmacological treatment for hypertension from 2004 through 2007. Participants were categorized as either adherent (proportion of days covered ≥0.8; n=45 350) or nonadherent (proportion of days covered <0.8; n=78 040) to antihypertensive medication during the first year of treatment. The primary outcome was composite CVD events, including myocardial infarction, stroke, heart failure, and cardiovascular death. Over a median follow-up of 10 years, 3002 new CVD events occurred. CVD incidence rates per 100 000 person-years were 191.0 in the adherent group and 282.1 in the nonadherent group. Multivariable-adjusted hazard ratio for CVD events associated with nonadherence versus adherence was 1.57 (95% CI, 1.45-1.71). There was a dose-response association between medication adherence (in quartiles or continuous proportion of days covered) and CVD risk. In conclusion, among young adults who initiated pharmacological treatment for high blood pressure, poor medication adherence was associated with higher risk for future CVD events.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/HYPERTENSIONAHA.120.16784DOI Listing
March 2021

Appropriate Starting Dose of Dasatinib Based on Analyses of Dose-Limiting Toxicities and Molecular Responses in Asian Patients With Chronic Myeloid Leukemia.

Clin Lymphoma Myeloma Leuk 2021 Feb 2. Epub 2021 Feb 2.

Department of Pharmacy, College of Pharmacy, Seoul National University, Seoul, Korea; Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea. Electronic address:

Background: Dasatinib is administered at a fixed starting dosage of 100 mg once daily regardless of patient-specific factors. However, such fixed dosing may not be optimal for the treatment of Asian patients with chronic myeloid leukemia in chronic phase (CP-CML).

Patients And Methods: The dose-limiting toxicities (DLTs) and molecular responses (MRs) of dasatinib therapy were evaluated using clinical data obtained from 102 patients newly diagnosed with CP-CML at 17 hospitals in South Korea.

Results: By 36 months after the initiation of a fixed dose regimen of dasatinib 100 mg once daily as the first-line therapy, 55.9% of patients experienced at least one type of DLT. The 3 most frequent DLTs were thrombocytopenia (45.5%), pericardial or pleural effusion (30.9%), and anemia (7.3%). Patients with higher dasatinib dose adjusted for body weight (Dose/BW) had a greater rate of DLT occurrence (logit [P] = 1.58 × [Dose/BW] - 2.27, P = .03). As median Dose/BW increased from 1.23 to 2.00 mg/kg, the rate of DLT occurrence increased from 43.5% to 66.7% (P = .03). However, Dose/BW did not affect the achievement rate of major MR (60.9% to 69.6%, P = .92).

Conclusion: The starting dosage of dasatinib may need to be reduced (eg, 80 mg once daily or lower) for Asian patients with CP-CML, especially with lighter BW, to alleviate the risk of DLT occurrence without compromising the achievement of MR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clml.2021.01.020DOI Listing
February 2021

Surgical treatment of nonlesional temporal lobe epilepsy.

Seizure 2021 Feb 13;86:129-134. Epub 2021 Feb 13.

Department of Neurosurgery, College of Medicine, Seoul National University Hospital, Seoul, Republic of Korea.

Purpose: One-third of the patients with drug-resistant temporal lobe epilepsy (TLE) have a normal MRI, but there are only a few studies regarding the surgical outcomes and the efficacy of anterior temporal lobectomy (ATL) in patients with nonlesional TLE. The objective of this study is to evaluate the surgical outcomes and efficacy of ATL in patients with nonlesional TLE.

Methods: We included 77 consecutive patients without MRI-identifiable lesions who had undergone surgical resection for drug-resistant TLE. We performed univariate and multivariate logistic regression analyses to identify the predictors of surgical outcomes, and the efficacy of ATL in patients with nonlesional TLE.

Results: More than two-thirds of patients (51/76, 67.3 %) had achieved seizure freedom at the last follow-up. Presence of oroalimentary automatism, localized hypometabolism in FDG-PET, and concordant results in presurgical evaluations were associated with better surgical outcomes. Only 15 out of 77 patients (19.2 %) with nonlesional TLE were treated with ATL, and the surgically resected areas were located within the resection margin of ATL in one-third of the patients (26/77, 33.8 %). Patients with auras suggesting neocortical ictal onset and lateralizing semiological features had a higher chance that their potentially epileptogenic areas were located beyond or outside the resection margin of ATL.

Conclusion: Our study showed that the potentially epileptogenic areas were located beyond or outside the margin of the ATL in nearly two-thirds of the patients. Several clinical factors may be useful in predicting the location of an epileptogenic area, which can help optimize a surgical strategy in these patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.seizure.2021.02.012DOI Listing
February 2021

Monitoring beam-quality constancy considering uncertainties associated with ionization chambers in Daily QA3 device.

PLoS One 2021 17;16(2):e0246845. Epub 2021 Feb 17.

Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, Republic of Korea.

This study evaluates the changes occurring in the X-ray energy of a linear accelerator (LINAC) using a Daily QA3 detector system. This is accomplished by comparing the Daily QA3 results against those obtained using a water phantom. The X-energy levels of a LINAC were monitored over a duration of 1 month using the Daily QA3 system. Moreover, to account for the uncertainty, the reproducibility of the Daily QA3 ionization-chamber results was assessed by performing repeated measurements (12 per day). Subsequently, the energy-monitoring results were compared with the energy-change results calculated using the water-phantom percentage depth dose (PDD) ratio. As observed, the 6- and 10-MV beams experienced average daily energy-level changes of (-0.30 ± 0.32)% and (0.05 ± 0.38)%, respectively, during repeated measurements. The corresponding energy changes equaled (-0.30 ± 0.55)% and (-0.05 ± 0.48)%, respectively, when considering the measurement uncertainty. The Daily QA3 measurements performed at 6 MV demonstrated a variation of (2.15 ± 0.81)% (i.e., up to 3%). Meanwhile, the corresponding measurements performed using a water phantom demonstrated an increase in the PDD ratio from 0.577 to 0.580 (i.e., approximately 0.5%). At 10 MV, the energy variation in the Daily QA3 measurements equaled (-0.41 ± 0.82)% (i.e., within 1.5%), whereas the corresponding water phantom PDD ratio remained constant at 0.626. These results reveal that the Daily QA3 system can be used to monitor small energy changes occurring within radiotherapy machines. This demonstrates its potential for use as a secondary system for monitoring energy changes as part of the daily quality-assurance workflow.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0246845PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7888663PMC
February 2021

23-valent polysaccharide vaccine (PPSV23)-targeted serotype-specific identification of Streptococcus pneumoniae using the loop-mediated isothermal amplification (LAMP) method.

PLoS One 2021 16;16(2):e0246699. Epub 2021 Feb 16.

Division of Pediatric Dentistry, Department of Human Development and Fostering, Meikai University School of Dentistry, Saitama, Japan.

Reports of invasive disease due to Streptococcus pneumoniae have declined since the introduction of pneumococcal conjugate vaccines (PCV7 and PCV13). The incidence of invasive diseases due to S. pneumoniae that are not addressed by the vaccines, however, has increased in children and adults, creating a global public health problem. Previously, we established the loop-mediated isothermal amplification (LAMP) method for a PCV13 serotype-specific assay. In the current study, we developed a rapid, simple, and cost-effective assay to detect serotypes in the 23-valent pneumococcal polysaccharide vaccine (PPSV23) using the LAMP method. In this study, LAMP primer sets for serotypes 2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20, 22F, and 33F of S. pneumoniae were developed. The reactivity, specificity, and sensitivity of LAMP assays were determined and compared to those of conventional PCR. The feasibility of LAMP assays in clinical application in patients with invasive pneumococcal diseases was validated by defining the detection limit of the LAMP assay with bacterial genomic DNA-spiked blood specimens. The specificity of each LAMP assay was determined using 44 serotypes of pneumococcal strains. Their sensitivity was 100 copies per reaction versus 103 to 106 copies per reaction for PCR assays. Using DNA-spiked blood specimens, excluding the LAMP assay that targeted serotype 22F (103 copies per reaction), the limit of detection of the LAMP assay was similar to that with purified DNA as the template (102 copies per reaction), compared with 103 to >106 copies per reaction for PCR assays. In conclusion, a rapid and simple LAMP-based PPSV23-targeted serotype detection assay was developed for use in many countries. This study is the first report of a LAMP-based assay for identification of PPSV23 serotypes. Further evaluation of this assay is needed through surveillance and vaccine efficacy studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0246699PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7886117PMC
February 2021

Change of right ventricular systolic pressure can indicate dasatinib-induced pulmonary arterial hypertension in chronic myeloid leukemia.

Cancer Med 2021 Feb 15. Epub 2021 Feb 15.

Department of Hematology, Catholic Hematology Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.

Background: We investigated the feasibility of the clinical application of non-invasive transthoracic echocardiography for diagnosis of pulmonary arterial hypertension induced by dasatinib (D-PAH) in chronic myeloid leukemia (CML).

Methods: A total of 451 CML patients who were examined by 2D-echocardiography at least once at baseline and/or during dasatinib therapy as frontline (n = 196) and subsequent line (n = 255) therapies were included in this study. D-PAH was defined as right ventricular systolic pressure (RVSP) >40 mm Hg with relevant symptoms and the absence of other specific etiologies.

Results: A total of 847 echocardiographies were performed including at baseline (n = 255) and during dasatinib treatment (n = 592). During the median of 36.2 (0.1-181.8) months of dasatinib therapy, the level of RVSP gradually increased (Spearman's r = 0.2819, p < 0.001) and the mean RVSP was significantly increased after taking dasatinib therapy compared with baseline. During dasatinib therapy, 56 (12.4%) patients had RVSP >40 mm Hg without (asymptomatic, n = 27, 48.2%) or with symptoms (D-PAH, n = 29, 51.8%). All asymptomatic patients maintained dasatinib therapy without further symptoms and the D-PAH patients ultimately switched to other tyrosine kinase inhibitors. After dasatinib discontinuation, 13 (45%) and 15 (52%) patients showed RVSP normalization and gradual decrease, respectively.

Conclusions: Our large cohort study demonstrated that the gradual increment of RVSP might be induced by dasatinib and non-invasive echocardiography can be fast way for early diagnosis as well as for monitoring of D-PAH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cam4.3588DOI Listing
February 2021

Mechanism for Preserving Volatile Nitrogen Dioxide and Sustainable Redox Mediation in the Nonaqueous Lithium-Oxygen Battery.

ACS Appl Mater Interfaces 2021 Feb 15;13(7):8159-8168. Epub 2021 Feb 15.

Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, Daejeon 34114, Korea.

Excessive overpotential during charging is a major hurdle in lithium-oxygen (Li-O) battery technology. NO/NO redox mediation is an efficient way to substantially reduce the overpotential and to enhance oxygen efficiency and cycle life by suppressing parasitic reactions. Considering that nitrogen dioxide (NO) is a gas, it is quite surprising that NO/NO redox reactions can be sustained for a long cycle life in Li-O batteries with such an open structure. A detailed study with in situ differential electrochemical mass spectrometry (DEMS) elucidated that NO could follow three reaction pathways during charging: (1) oxidation of LiO to evolve oxygen, (2) vaporization, and (3) conversion into NO. Among the pathways, LiO oxidation occurs exclusively in the presence of LiO, which suggests that NO has high reactivity to LiO. At the end of the charging process, most of the volatile oxidized couple (NO) is stored by conversion to a stable third species (NO), which is then reused for producing the reduced couple (NO) in the next cycle. The dominant reaction of LiO oxidation involves the temporary storage of NO as a stable third species during charging, which is an innovative way for preserving the volatile redox couple, resulting in a sustainable redox mediation for a high-performance Li-O battery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acsami.0c17960DOI Listing
February 2021

Reliability of Skeletal Muscle Area Measurement on CT with Different Parameters: A Phantom Study.

Korean J Radiol 2021 Jan 19. Epub 2021 Jan 19.

Health Screening & Promotion Center, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.

Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters.

Materials And Methods: A phantom, simulating the L2-4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings.

Results: The skeletal muscle area (threshold, -29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30-150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0-44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used.

Conclusion: Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3348/kjr.2020.0914DOI Listing
January 2021

Combined Hepatocellular-Cholangiocarcinoma: Magnetic Resonance Imaging Features and Prognosis According to Risk Factors for Hepatocellular Carcinoma.

J Magn Reson Imaging 2021 Feb 9. Epub 2021 Feb 9.

Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.

Background: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) can develop in patients with and without risk factors for hepatocellular carcinoma (HCC).

Purpose: To compare the clinical and magnetic resonance imaging (MRI) characteristics of cHCC-CCA in patients with and without risk factors for HCC, and to assess the influence of risk factors on patient prognosis.

Study Type: Retrospective.

Population: A total of 152 patients with surgically confirmed cHCC-CCA.

Field Strength/sequence: 1.5-T and 3-T/T1-weighted dual gradient-echo in- and opposed-phase, T2-weighted turbo-spin-echo, diffusion-weighted single-shot spin-echo echo-planar, and T1-weighted three-dimensional gradient-echo contrast-enhanced sequences.

Assessment: MRI features according to the Liver Imaging Reporting and Data System (LI-RADS) and pathologic findings based on revised classification were compared between patients with and without risk factors for HCC. Overall survival (OS) and recurrence-free survival (RFS) were also compared between the two groups, and factors associated with survival were evaluated.

Statistical Tests: The clinico-pathologic and MRI features of the two groups were compared using Student's t-tests, Mann-Whitney U-tests, and chi-square tests. OS and RFS were evaluated by the Kaplan-Meier method, and factors associated with survival were evaluated by Cox proportional hazard model.

Results: cHCC-CCA in patients with risk factors were more frequently classified as LI-RADS category 4 or 5 (LR-4/5; probably or definitely HCC) (48.7%), whereas those without risk factors were more frequently classified as category M (LR-M; probably malignant, not specific for HCC) (63.6%). RFS and OS did not differ significantly according to risk factors (P = 0.63 and 0.83). Multivariable analysis showed that pathologic tumor type (hazard ratio 2.02; P < 0.05) and LI-RADS category (hazard ratio 2.19; P < 0.05) were significantly associated with RFS and OS, respectively.

Data Conclusion: Although MRI features of cHCC-CCA differed significantly between patients with and without risk factors for HCC, postsurgical prognosis did not. LI-RADS category and pathologic tumor type were independently correlated with postsurgical prognosis in patients with cHCC-CCA.

Level Of Evidence: 3 TECHNICAL EFFICACY STAGE: 2.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jmri.27528DOI Listing
February 2021

Interreader Reliability of Liver Imaging Reporting and Data System Treatment Response: A Systematic Review and Meta-Analysis.

Diagnostics (Basel) 2021 Feb 4;11(2). Epub 2021 Feb 4.

Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.

Background: For a proper management strategy in patients with locoregionally treated hepatocellular carcinoma (HCC), it is essential that the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (LR-TR) has high interreader reliability. We aimed to systematically evaluate the interreader reliability of LR-TR and sources of any study heterogeneity.

Methods: Original studies reporting the interreader reliability of LR-TR were identified in MEDLINE and EMBASE up to 20 September 2020. The pooled kappa coefficient (κ) was calculated using the DerSimonian-Laird random effects model. Subgroup analyses were performed according to imaging modality (magnetic resonance imaging (MRI) or computed tomography (CT)). Meta-regression analyses were performed to explore study heterogeneity.

Results: Eight studies with 851 HCCs were finally included. Pooled κ was 0.70 (95% CI, 0.58-0.82) for CT/MRI LR-TR, and those of MRI and CT were 0.71 (95% CI, 0.53-0.89) and 0.71 (95% CI, 0.65-0.78), respectively. Study design ( < 0.001) and type of treatment ( = 0.02) were significantly associated with substantial study heterogeneity.

Conclusion: LR-TR showed substantial interreader reliability regardless of the imaging modality. Because of substantial study heterogeneity, which was significantly associated with study design and type of treatment, published values for the interreader reliability of LR-TR should be interpreted with care.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/diagnostics11020237DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7913820PMC
February 2021

Prognosis Score System to Predict Survival for COVID-19 Cases: a Korean Nationwide Cohort Study.

J Med Internet Res 2021 02 22;23(2):e26257. Epub 2021 Feb 22.

Catholic Hematology Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.

Background: As the COVID-19 pandemic continues, an initial risk-adapted allocation is crucial for managing medical resources and providing intensive care.

Objective: In this study, we aimed to identify factors that predict the overall survival rate for COVID-19 cases and develop a COVID-19 prognosis score (COPS) system based on these factors. In addition, disease severity and the length of hospital stay for patients with COVID-19 were analyzed.

Methods: We retrospectively analyzed a nationwide cohort of laboratory-confirmed COVID-19 cases between January and April 2020 in Korea. The cohort was split randomly into a development cohort and a validation cohort with a 2:1 ratio. In the development cohort (n=3729), we tried to identify factors associated with overall survival and develop a scoring system to predict the overall survival rate by using parameters identified by the Cox proportional hazard regression model with bootstrapping methods. In the validation cohort (n=1865), we evaluated the prediction accuracy using the area under the receiver operating characteristic curve. The score of each variable in the COPS system was rounded off following the log-scaled conversion of the adjusted hazard ratio.

Results: Among the 5594 patients included in this analysis, 234 (4.2%) died after receiving a COVID-19 diagnosis. In the development cohort, six parameters were significantly related to poor overall survival: older age, dementia, chronic renal failure, dyspnea, mental disturbance, and absolute lymphocyte count <1000/mm. The following risk groups were formed: low-risk (score 0-2), intermediate-risk (score 3), high-risk (score 4), and very high-risk (score 5-7) groups. The COPS system yielded an area under the curve value of 0.918 for predicting the 14-day survival rate and 0.896 for predicting the 28-day survival rate in the validation cohort. Using the COPS system, 28-day survival rates were discriminatively estimated at 99.8%, 95.4%, 82.3%, and 55.1% in the low-risk, intermediate-risk, high-risk, and very high-risk groups, respectively, of the total cohort (P<.001). The length of hospital stay and disease severity were directly associated with overall survival (P<.001), and the hospital stay duration was significantly longer among survivors (mean 26.1, SD 10.7 days) than among nonsurvivors (mean 15.6, SD 13.3 days).

Conclusions: The newly developed predictive COPS system may assist in making risk-adapted decisions for the allocation of medical resources, including intensive care, during the COVID-19 pandemic.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2196/26257DOI Listing
February 2021

Beneficial Effect of Statins in COVID-19-Related Outcomes-Brief Report: A National Population-Based Cohort Study.

Arterioscler Thromb Vasc Biol 2021 03 4;41(3):e175-e182. Epub 2021 Feb 4.

Korean Society of Hypertension (H.-Y.L., W.B.P.).

Objective: Although statins are widely prescribed lipid-lowering drugs, there are concerns about the safety of their use in the context of coronavirus disease 2019 (COVID-19), since statins increase the expression of ACE2 (angiotensin-converting enzyme 2). This study aimed to disclose the association between statins and 60-day COVID-19 mortality. Approach and Results: All patients hospitalized with laboratory-confirmed COVID-19 were enrolled in this study from January 19 to April 16, 2020, in Korea. We evaluated the association between the use of statins and COVID-19-related mortality in the overall and the nested 1:2 propensity score-matched study. Furthermore, a comparison of the hazard ratio for death was performed between COVID-19 patients and a retrospective cohort of patients hospitalized with pneumonia between January and June 2019 in Korea. The median age of the 10 448 COVID-19 patients was 45 years. Statins were prescribed in 533 (5.1%) patients. After adjusting for age, sex, and comorbidities, Cox regression showed a significant decrease in hazard ratio associated with the use of statins (hazard ratio, 0.637 [95% CI, 0.425-0.953]; =0.0283). Moreover, on comparing the hazard ratio between COVID-19 patients and the retrospective cohort of hospitalized pneumonia patients, the use of statins showed similar benefits.

Conclusions: The use of statins correlates significantly with lower mortality in patients with COVID-19, consistent with the findings in patients with pneumonia. Graphic Abstract: A graphic abstract is available for this article.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/ATVBAHA.120.315551DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901529PMC
March 2021

Lymphopenia as a Biological Predictor of Outcomes in COVID-19 Patients: A Nationwide Cohort Study.

Cancers (Basel) 2021 Jan 26;13(3). Epub 2021 Jan 26.

Catholic Hematology Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.

We aimed to identify whether lymphopenia is a reliable prognostic marker for COVID-19. Using data derived from a Korean nationwide longitudinal cohort of 5628 COVID-19 patients, we identified propensity-matched cohorts ( = 770) with group I of severe lymphopenia (absolute lymphocyte counts [ALC]: <500/mm, = 110), group II of mild-to-moderate lymphopenia (ALC: ≥500-<1000/mm, = 330), and group III, no lymphopenia (ALC: ≥1000/mm, = 330). A significantly higher mortality rate was associated with lymphopenia severity: 40% in group I, 22.7% in group II, and 13.0% in group III ( < 0.001). At 28 days, the estimated inferior overall survival associated with intensified lymphopenia: 62.7% in group I, 79.9% in group II, and 89.0% in group III ( < 0.001). Lymphopenia contributed significantly toward a greater need for interventions in all groups but at varying degrees: requirements of invasive ventilation, intensive oxygen supply, or adequate oxygen supply, respectively ( < 0.001). The lymphopenia intensity was independently associated with higher COVID-19 mortality in multivariable analysis; adjusted odds ratios of 5.63 (95% CI, 3.0-10.72), and 2.47 (95% CI, 1.5-4.13) for group I and group II, respectively. Lymphopenia and its severity levels may serve as reliable predictive factors for COVID-19 clinical outcomes; thus, lymphopenia may provide the prognostic granularity required for clinical use in the management of patients with COVID-19.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers13030471DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7865511PMC
January 2021

Incidence and risk factors of hepatic veno-occlusive disease/sinusoidal obstruction syndrome after allogeneic hematopoietic cell transplantation in adults with prophylactic ursodiol and intravenous heparin or prostaglandin E1.

Bone Marrow Transplant 2021 Feb 1. Epub 2021 Feb 1.

Department of Hematology, Catholic Hematology Hospital and Leukemia Research Institute, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.

We attempted to identify the incidence and survival outcome of hepatic sinusoidal obstruction syndrome/veno-occlusive disease (VOD/SOS) after hematopoietic cell transplantation (HCT) under strategy of prophylactic ursodiol and intravenous heparin or prostaglandin E1 (PGE1). From 2009 to 2018, 2572 consecutive allogeneic-HCT cases were reviewed. We used oral ursodiol for all transplants, and most were administered low-dose heparin, while PGE1 in selected cases with low platelet count at the time of preconditioning. Diagnosis and severity grades were reassessed by revised EBMT criteria. The overall incidence of hepatic VOD/SOS was 3.4% (Mild 0.9%, Moderate 0.6%, Severe 0.7%, Very severe 1.2%) after allogeneic-HCT under strategy of intravenous prophylaxis. The 1-year overall survival of VOD/SOS was 41.4% which was divided into 73.9% for mild, 66.7% for moderate, 38.9% for severe, and 6.5% for very severe grade. Very high disease risk index, male gender, donor other than matched sibling donor, and busulfex > 9 mg/kg were affecting factors for development of VOD/SOS. For severe to very severe VOD/SOS, history of pre-HCT liver dysfunction was an additionally affecting factor. Allogeneic-HCT using ursodiol and intravenous prophylaxis was considered safe without significant bleeding complications and should be evaluated in future clinical trials. For those with high-risk of VOD/SOS, early intervention and management is important.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41409-021-01215-yDOI Listing
February 2021

TomoEQA: Dose verification for patient-specific quality assurance in helical tomotherapy using an exit detector.

Phys Med 2021 Jan 25;82:1-6. Epub 2021 Jan 25.

Department of Radiation Oncology, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address:

Purpose: Existing phantom-less quality assurance (QA) platforms does not provide patient-specific QA for helical tomotherapy (HT). A new system, called TomoEQA, is presented to facilitate this using the leaf open time (LOT) of a binary multi-leaf collimator, as measured by an exit detector.

Methods: TomoEQA was designed to provide measurement-based LOTs based on detector data and to generate a new digital imaging and communication in medicine (DICOM) dataset that includes the measured LOTs for use by secondary check platforms. To evaluate the system, 20 patient-specific QAs were performed using the program in Mobius3D software, and the results were compared to conventional phantom-based QA results.

Results: From our assessment, most of the differences between the planned and measured (or calculated) data, excluding one case, were within the acceptance criteria comparing with those of conventional QA. Regarding the gamma analysis, all results considered in this study were within the acceptance criteria. In addition, the developed system was performed for a failed case and showed approximately the same trends as the conventional approach.

Conclusions: TomoEQA could perform patient-specific QAs of HT using Mobius3D and provide reliable patient-specific QAs results by evaluating point dose errors and 3D gamma passing rates. TomoEQA could also distinguish whether an intensity-modulated radiation therapy plan failed or not.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejmp.2020.12.021DOI Listing
January 2021

Data resource profile: the allergic disease database of the Korean National Health Insurance Service.

Epidemiol Health 2021 21;43:e2021010. Epub 2021 Jan 21.

Big Data Department, National Health Insurance Service, Wonju, Korea.

Researchers have been interested in probing how the environmental factors associated with allergic diseases affect the use of medical services. Considering this demand, we have constructed a database, named the Allergic Disease Database, based on the National Health Insurance Database (NHID). The NHID contains information on demographic and medical service utilization for approximately 99% of the Korean population. This study targeted 3 major allergic diseases, including allergic rhinitis, atopic dermatitis, and asthma. For the target diseases, our database provides daily medical service information, including the number of daily visits from 2013 and 2017, categorized by patients' characteristics such as address, sex, age, and duration of residence. We provide additional information, including yearly population, a number of patients, and averaged geocoding coordinates by eup, myeon, and dong district code (the smallest-scale administrative units in Korea). This information enables researchers to analyze how daily changes in the environmental factors of allergic diseases (e.g., particulate matter, sulfur dioxide, and ozone) in certain regions would influence patients' behavioral patterns of medical service utilization. Moreover, researchers can analyze long-term trends in allergic diseases and the health effects caused by environmental factors such as daily climate and pollution data. The advantages of this database are easy access to data, additional levels of geographic detail, time-efficient data-refining and processing, and a de-identification process that minimizes the exposure of identifiable personal information. All datasets included in the Allergic Disease Database can be downloaded by accessing the National Health Insurance Service data sharing webpage (https://nhiss.nhis.or.kr).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4178/epih.e2021010DOI Listing
January 2021

Data resource profile: the allergic disease database of the Korean National Health Insurance Service.

Epidemiol Health 2021 21;43:e2021010. Epub 2021 Jan 21.

Big Data Department, National Health Insurance Service, Wonju, Korea.

Researchers have been interested in probing how the environmental factors associated with allergic diseases affect the use of medical services. Considering this demand, we have constructed a database, named the Allergic Disease Database, based on the National Health Insurance Database (NHID). The NHID contains information on demographic and medical service utilization for approximately 99% of the Korean population. This study targeted 3 major allergic diseases, including allergic rhinitis, atopic dermatitis, and asthma. For the target diseases, our database provides daily medical service information, including the number of daily visits from 2013 and 2017, categorized by patients' characteristics such as address, sex, age, and duration of residence. We provide additional information, including yearly population, a number of patients, and averaged geocoding coordinates by eup, myeon, and dong district code (the smallest-scale administrative units in Korea). This information enables researchers to analyze how daily changes in the environmental factors of allergic diseases (e.g., particulate matter, sulfur dioxide, and ozone) in certain regions would influence patients' behavioral patterns of medical service utilization. Moreover, researchers can analyze long-term trends in allergic diseases and the health effects caused by environmental factors such as daily climate and pollution data. The advantages of this database are easy access to data, additional levels of geographic detail, time-efficient data-refining and processing, and a de-identification process that minimizes the exposure of identifiable personal information. All datasets included in the Allergic Disease Database can be downloaded by accessing the National Health Insurance Service data sharing webpage (https://nhiss.nhis.or.kr).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4178/epih.e2021010DOI Listing
January 2021

Treatments for Convulsive and Nonconvulsive Status Epilepticus in Adults: An Expert Opinion Survey in South Korea.

J Clin Neurol 2021 Jan;17(1):20-25

Department of Neurology, Chungnam National University Hospital, Daejeon, Korea.

Background And Purpose: The aim of this study was to survey the expert opinions on treatments for convulsive status epilepticus (CSE) and nonconvulsive status epilepticus (NCSE) in adults.

Methods: Forty-two South Korean epileptologists participated in this survey. They completed an online questionnaire regarding various patient scenarios and evaluated the appropriateness of medications used to treat CSE and NCSE.

Results: Initial treatment with a benzodiazepine (BZD) followed by either a second BZD or an antiepileptic drug (AED) monotherapy was the preferred treatment strategy. More than two-thirds of the experts used a second BZD when the first one failed, and consensus was reached for 84.8% of the survey items. The preferred BZD was intravenous (IV) lorazepam for the initial treatment of status epilepticus. IV fosphenytoin and IV levetiracetam were chosen for AED monotherapy after the failure of BZD. The treatments for NCSE were similar to those for CSE. Continuous IV midazolam infusion was the treatment of choice for iatrogenic coma in refractory CSE, but other AEDs were preferred over iatrogenic coma in refractory NCSE.

Conclusions: The results of this survey are consistent with previous guidelines, and can be cautiously applied in clinical practice when treating patients with CSE or NCSE.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3988/jcn.2021.17.1.20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7840316PMC
January 2021

Antiepileptic Drug Therapy for Status Epilepticus.

J Clin Neurol 2021 Jan;17(1):11-19

Department of Neurology, Keimyung University School of Medicine, Daegu, Korea.

Status epilepticus (SE) is one of the most serious neurologic emergencies. SE is a condition that encompasses a broad range of semiologic subtypes and heterogeneous etiologies. The treatment of SE primarily involves the management of the underlying etiology and the use of antiepileptic drug therapy to rapidly terminate seizure activities. The Drug Committee of the Korean Epilepsy Society performed a review of existing guidelines and literature with the aim of providing practical recommendations for antiepileptic drug therapy. This article is one of a series of review articles by the Drug Committee and it summarizes staged antiepileptic drug therapy for SE. While evidence of good quality supports the use of benzodiazepines as the first-line treatment of SE, such evidence informing the administration of second- or third-line treatments is lacking; hence, the recommendations presented herein concerning the treatment of established and refractory SE are based on case series and expert opinions. The choice of antiepileptic drugs in each stage should consider the characteristics and circumstances of each patient, as well as their estimated benefit and risk to them. In tandem with the antiepileptic drug therapy, careful searching for and treatment of the underlying etiology are required.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3988/jcn.2021.17.1.11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7840311PMC
January 2021

Prognostic Impacts of D816V Mutation and Peri-Transplant MRD Monitoring on Acute Myeloid Leukemia with .

Cancers (Basel) 2021 Jan 18;13(2). Epub 2021 Jan 18.

Department of Hematology, Catholic Hematology Hospital, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul 06591, Korea.

The prognostic significance of mutations and optimal thresholds and time points of measurable residual disease (MRD) monitoring for acute myeloid leukemia (AML) with remain controversial in the setting of hematopoietic stem cell transplantation (HSCT). We retrospectively evaluated 166 high-risk patients who underwent allogeneic (Allo-HSCT, = 112) or autologous HSCT (Auto-HSCT, = 54). D816V mutation, a subtype of exon 17 mutations, was significantly associated with post-transplant relapse and poor survival, while other types of mutations in exons 17 and 8 were not associated with post-transplant relapse. Pre- and post-transplant MRD assessments were useful for predicting post-transplant relapse and poor survival with a higher sensitivity at later time points. Survival analysis for each stratified group by D816V mutation and pre-transplant MRD status demonstrated that Auto-HSCT was superior to Allo-HSCT in MRD-negative patients without D816V mutation, while Allo-HSCT was superior to Auto-HSCT in MRD-negative patients with D816V mutation. Very poor outcomes of pre-transplant MRD-positive patients with D816V mutation suggested that this group should be treated in clinical trials. Risk stratification by both D816V mutation and MRD status will provide a platform for decision-making or risk-adapted therapeutic approaches.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers13020336DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7831332PMC
January 2021

Diagnostic performance of ultrasonography-guided core-needle biopsy according to MRI LI-RADS diagnostic categories.

Ultrasonography 2020 Nov 3. Epub 2020 Nov 3.

Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Purpose: According to the American Association for the Study of Liver Diseases (AASLD) guidelines, biopsy is a diagnostic option for focal hepatic lesions depending on the Liver Imaging Reporting and Data System (LI-RADS) category. We evaluated the diagnostic performance of ultrasonography-guided core-needle biopsy (CNB) according to LI-RADS categories.

Methods: High-risk patients for hepatocellular carcinoma (HCC) who underwent magnetic resonance imaging (MRI) followed by CNB for a focal hepatic lesion preoperatively were retrospectively enrolled. Focal hepatic lesions on MRI were evaluated according to LI-RADS version 2018. Pathologic results were categorized into HCC, non-HCC malignancies, and benignity. The categorization was defined as correct when the CNB pathology and surgical pathology reports were identical. Nondiagnostic results were defined as inadequate CNB pathology findings for a specific diagnosis. The proportion of correct categorizations was calculated for each LI-RADS category, excluding nondiagnostic results.

Results: After excluding 16 nondiagnostic results, 131 lesions were analyzed (45 LR-5, 24 LR-4, 4 LR-3, and 58 LR-M). All LR-5 lesions were HCC, and CNB correctly categorized 97.8% (44/45) of LR-5 lesions. CNB correctly categorized all 24 LR-4 lesions, 16.7% (4/24) of which were non-HCC malignancies. All LR-M lesions were malignant, and 62.1% (36/58) were non-HCC malignancies. CNB correctly categorized 93.1% (54/58) of LR-M lesions, and 12.5% (3/24) of lesions with CNB results of HCC were confirmed as non-HCC malignancies.

Conclusion: In agreement with AASLD guidelines, CNB could be helpful for LR-4 lesions, but is unnecessary for LR-5 lesions. In LR-M lesions, CNB results of HCC did not exclude non-HCC malignancy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14366/usg.20110DOI Listing
November 2020

Complete chloroplast genomes of Thunb., Thunb., Thunb., and Thunb. (Elaeagnaceae).

Mitochondrial DNA B Resour 2020 Jun 17;5(3):2490-2492. Epub 2020 Jun 17.

Jeonnam Institute of Natural Resources Research, Jeollanam-do, Republic of Korea.

is a genus which consists about 70 species of flowering plants in the family Elaeagnaceae, and its edible fruit is a natural product used as food and in traditional medicine. In this study, we sequenced the complete chloroplast (cp) genome of four species, namely Thunb., Thunb., Thunb., and Thunb., to study their phylogenetic relationships within the Elaeagnaceae. Total lengths of the chloroplast genome were 152,261 bp, 152,267 bp, 152,224 bp, and 152,227 bp, respectively. The four genomes had representative quadripartite structures, with an LSC region (82,207 bp, 82,191 bp, 82,136 bp, and 82,139 bp) and an SSC region (18,262 bp, 18,282 bp,and 18,278 bp for both species) separated by a pair of IRs (25,896 bp, 25,897 bp, and 25,905 bp for the latter two species), respectively. Moreover, they were composed of 136-137 genes, including 88 protein-coding genes, 40-41 tRNA genes, and 8 rRNA genes. A maximum likelihood phylogenetic analysis indicated that was most closely related to , whereas was close to .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/23802359.2020.1779142DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7782260PMC
June 2020

Changes in Hepcidin Serum Levels Correlate with Clinical Improvement in Idiopathic Restless Legs Syndrome Patients.

J Clin Med 2020 Dec 20;9(12). Epub 2020 Dec 20.

Department of Neurology, School of Medicine, Konkuk University Hospital, Konkuk University, Seoul 05030, Korea.

Background: Restless legs syndrome (RLS) is a common sensory motor neurological disorder that is related to iron-dopamine dysregulation and immune system alteration. We aimed to assess the effects of serum hepcidin, an iron-regulating hormone, in drug-naive RLS patients compared to healthy controls and to evaluate its role in helping to predict clinical improvement after treatment with dopamine agonist.

Methods: Nonanemic and drug-naive RLS patients ( = 18) and healthy controls ( = 15) were enrolled. The serum hepcidin and iron-related values in the serum were measured upon the first visit in both groups and 12 weeks later after dopaminergic treatment in 12 patients. Information about sociodemographic characteristics, sleep-related profiles, mood and anxiety was obtained upon the first visit in all participants as well as after treatment in RLS patients.

Results: Serum hepcidin levels exhibited no significant differences between patients with drug-naïve RLS and healthy controls at diagnosis (7.1 ± 2.4 vs. 7.0 ± 3.2 ng/mL, = 0.357). Decreased hepcidin levels were significantly associated with decreased RLS severity (β = 0.002, 95% CI = 0.00-0.00, = 0.005) and improved quality of life (β = 0.002, 95% CI = 0.00-7.01, = 0.044) in a dose-dependent manner after 12 weeks of treatment with a dopamine agonist. This association was independent of age, sex, inflammatory markers, sleep quality, insomnia, daytime sleepiness, depression and anxiety.

Conclusions: This study demonstrates the role of hepcidin in evaluating the positive therapeutic response in RLS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/jcm9124115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7766726PMC
December 2020

Long-term outcomes with frontline nilotinib versus imatinib in newly diagnosed chronic myeloid leukemia in chronic phase: ENESTnd 10-year analysis.

Leukemia 2021 02 7;35(2):440-453. Epub 2021 Jan 7.

Universitätsklinikum Jena, Jena, Germany.

In the ENESTnd study, with ≥10 years follow-up in patients with newly diagnosed chronic myeloid leukemia (CML) in chronic phase, nilotinib demonstrated higher cumulative molecular response rates, lower rates of disease progression and CML-related death, and increased eligibility for treatment-free remission (TFR). Cumulative 10-year rates of MMR and MR were higher with nilotinib (300 mg twice daily [BID], 77.7% and 61.0%, respectively; 400 mg BID, 79.7% and 61.2%, respectively) than with imatinib (400 mg once daily [QD], 62.5% and 39.2%, respectively). Cumulative rates of TFR eligibility at 10 years were higher with nilotinib (300 mg BID, 48.6%; 400 mg BID, 47.3%) vs imatinib (29.7%). Estimated 10-year overall survival rates in nilotinib and imatinib arms were 87.6%, 90.3%, and 88.3%, respectively. Overall frequency of adverse events was similar with nilotinib and imatinib. By 10 years, higher cumulative rates of cardiovascular events were reported with nilotinib (300 mg BID, 16.5%; 400 mg BID, 23.5%) vs imatinib (3.6%), including in Framingham low-risk patients. Overall efficacy and safety results support the use of nilotinib 300 mg BID as frontline therapy for optimal long-term outcomes, especially in patients aiming for TFR. The benefit-risk profile in context of individual treatment goals should be carefully assessed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41375-020-01111-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7862065PMC
February 2021

Does Diabetes Increase the Risk of Contracting COVID-19? A Population-Based Study in Korea.

Diabetes Metab J 2020 12 23;44(6):897-907. Epub 2020 Dec 23.

Research Institute of National Health Insurance Service Ilsan Hospital, Goyang, Korea.

Background: This study aimed to determine the infection risk of coronavirus disease 2019 (COVID-19) in patients with diabetes (according to treatment method).

Methods: Claimed subjects to the Korean National Health Insurance claims database diagnosed with COVID-19 were included. Ten thousand sixty-nine patients with COVID-19 between January 28 and April 5, 2020, were included. Stratified random sampling of 1:5 was used to select the control group of COVID-19 patients. In total 50,587 subjects were selected as the control group. After deleting the missing values, 60,656 subjects were included.

Results: Adjusted odds ratio (OR) indicated that diabetic insulin users had a higher risk of COVID-19 than subjects without diabetes (OR, 1.25; 95% confidence interval [CI], 1.03 to 1.53; P=0.0278). In the subgroup analysis, infection risk was higher among diabetes male insulin users (OR, 1.42; 95% CI, 1.07 to 1.89), those between 40 and 59 years (OR, 1.66; 95% CI, 1.13 to 2.44). The infection risk was higher in diabetic insulin users with 2 to 4 years of morbidity (OR, 1.744; 95% CI, 1.003 to 3.044).

Conclusion: Some diabetic patients with certain conditions would be associated with a higher risk of acquiring COVID-19, highlighting their need for special attention. Efforts are warranted to ensure that diabetic patients have minimal exposure to the virus. It is important to establish proactive care and screening tests for diabetic patients suspected with COVID-19 for timely disease diagnosis and management.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4093/dmj.2020.0199DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7801768PMC
December 2020

New compression method for full-complex holograms using the modified zerotree algorithm with the adaptive discrete wavelet transform.

Opt Express 2020 Nov;28(24):36327-36345

In this paper, we propose a new method for coding a full complex hologram with random phase. Since holograms with random phase have very unique spatial and frequency characteristics, a new compression method suitable for such holograms is required. We analyze the frequency characteristics of holograms with random phases and propose a new adaptive discrete wavelet transform (aDWT). Next, we propose a new modified zerotree alogrithm (mZTA) suitable for the subband configuration generated by the modified wavelet transform method. The results of the compression using the proposed method showed higher efficiency than the previous method, and the reconstructed images showed visually superior results.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.406165DOI Listing
November 2020

Holographic augmented reality based on three-dimensional volumetric imaging for a photorealistic scene.

Opt Express 2020 Nov;28(24):35972-35985

In this paper, we propose a new system for a real-time holographic augmented reality (AR) video service based on a photorealistic three-dimensional (3D) object point for multiple users to use simultaneously at various locations and viewpoints. To observe the object from all viewpoints, a camera system capable of acquiring the 3D volume of a real object is developed and is used to generate a real object in real-time. Using the normal of the object point, the observable points are mapped to the viewpoint at which the user is located, and a hologram based on the object point is generated. The angle at which the reflected light from each point is incident on the hologram plane is calculated, and the intensity of the interference light is adjusted according to the angle to generate a hologram with a higher 3D effect. The generated hologram is transmitted to each user to provide a holographic AR service. The entire system consists of a camera system comprising eight RGB-D (depth) cameras and two workstations for photorealistic 3D volume and hologram generation. Using this technique, a realistic hologram was generated. Through experiments displaying holograms simultaneously from several different viewpoints, it is confirmed that multiple users can concurrently receive hologram AR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1364/OE.411141DOI Listing
November 2020

Tolerability of lacosamide rapid dose titration: A randomized, multicenter, prospective, open-label study.

Epilepsy Behav 2021 Feb 17;115:107663. Epub 2020 Dec 17.

Department of Neurology, Seoul National University Hospital, Seoul, Republic of Korea. Electronic address:

Objective: Currently recommended dosing of lacosamide often necessitates long titration periods. However, the use of a regimen consisting of initial loading dose of 200 mg followed by a maintenance dose of 200 mg/day in practice suggests tolerability of more rapid titration schedules. We aimed to clarify whether the shortened titration schedule affects tolerability of lacosamide.

Methods: We evaluated the safety of two rapid titration protocols designed to reach the target dose of 400 mg/day within 1 week, and the conventional weekly titration protocol (reaching the target dose of 400 mg/day in three weeks). The ≥50% responder rate and steady-state plasma concentration of lacosamide were also analyzed. Adverse events were assessed at 1 week and 5 weeks after reaching the target dose.

Results: Seventy-five patients with epilepsy were enrolled and evenly distributed to three titration protocols, from which 5 patients were lost to follow-up and excluded from the safety analysis. Discontinuation of lacosamide or dose reductions due to adverse events occurred in 32 patients (46%), of whom a large majority (74%) had experienced adverse events after reaching 400 mg/day, demonstrating apparent dose-dependency. There was no difference in safety outcomes among the three titration groups. Concomitant use of sodium channel blockers significantly increased the risk of adverse events.

Conclusion: Rapid titration protocols for lacosamide were not associated with an increased risk of adverse events compared to the conventional weekly titration protocol. Uptitration of lacosamide at shorter intervals to an effective target dosage may be feasible in appropriate clinical situations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.yebeh.2020.107663DOI Listing
February 2021

Statistical Analysis of Treatment Planning Parameters for Prediction of Delivery Quality Assurance Failure for Helical Tomotherapy.

Technol Cancer Res Treat 2020 Jan-Dec;19:1533033820979692

Department of Radiation Oncology, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, South Korea.

Purpose: This study aimed to investigate the parameters with a significant impact on delivery quality assurance (DQA) failure and analyze the planning parameters as possible predictors of DQA failure for helical tomotherapy.

Methods: In total, 212 patients who passed or failed DQA measurements were retrospectively included in this study. Brain (n = 43), head and neck (n = 37), spinal (n = 12), prostate (n = 36), rectal (n = 36), pelvis (n = 13), cranial spinal irradiation and a treatment field including lymph nodes (n = 24), and other types of cancer (n = 11) were selected. The correlation between DQA results and treatment planning parameters were analyzed using logistic regression analysis. Receiver operating characteristic (ROC) curves, areas under the curves (AUCs), and the Classification and Regression Tree (CART) algorithm were used to analyze treatment planning parameters as possible predictors for DQA failure.

Results: The AUC for leaf open time (LOT) was 0.70, and its cut-off point was approximately 30%. The ROC curve for the predicted probability calculated when the multivariate variable model was applied showed an AUC of 0.815. We confirmed that total monitor units, total dose, and LOT were significant predictors for DQA failure using the CART.

Conclusions: The probability of DQA failure was higher when the percentage of LOT below 100 ms was higher than 30%. The percentage of LOT below 100 ms should be considered in the treatment planning process. The findings from this study may assist in the prediction of DQA failure in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1533033820979692DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7734483PMC
December 2020