COVID-19 infection inference with graph neural networks.

Infectious diseases spread rapidly, and epidemiological surveys are vital to detect high-risk transmitters and reduce transmission rates. To enhance efficiency and reduce the burden on epidemiologists, an automatic tool to assist with epidemiological surveys is necessary. This study aims to develop an automatic epidemiological survey to predict the influence of COVID-19-infected patients on future additional infections. To achieve this, the study utilized a dataset containing interaction information between confirmed cases, including contact order, contact times, and movement routes, as well as individual properties such as symptoms. Graph neural networks (GNNs) were used to incorporate interaction information and individual properties. Two variants of GNNs, graph convolutional and graph attention networks, were utilized, and the results showed that the graph-based models outperformed traditional machine learning models. For the area under the curve, the 2nd, 3rd, and 4th order spreading predictions showed higher performance by 0.200, 0.269, and 0.190, respectively. The results show that the contact information of an infected person is crucial data that can help predict whether that person will affect future infections. Our findings suggest that incorporating the relationships between an infected person and others can improve the effectiveness of an automatic epidemiological survey.

Time series analysis of meteorological factors and air pollutants and their association with hospital admissions for acute myocardial infarction in Korea.

BACKGROUND: We assessed the association between multiple meteorological factors and air pollutants and the number of acute myocardial infarction (AMI) cases using a multi-step process. METHODS: Daily AMI hospitalizations matched with 16 meteorological factors and air pollutants in 7 metropolitan provinces of the Republic of Korea from 2002 to 2017 were analyzed. We chose the best fit model after conducting the Granger causality (GC) test and examined the daily lag time effect on the orthogonalized impulse response functions. To define dose-response relationships, we performed a time series analysis using multiple generalized additive lag models based on seasons. RESULTS: A total of 196,762 cases of AMI in patients older than 20 years admitted for hospitalization were identified. The distribution of meteorological factors and air pollutants showed characteristics of a temperate climate. The GC test revealed a complex interaction between meteorological factors, including air pollutants, and AMI. The final selected factors were NO2 and temperature; these increased the incidence of AMI on lag day 4 during summer (NO2: population-attributable fraction [PAF], 3.9%; 95% confidence interval [CI], 3.6-4.0; mean temperature: PAF, 3.3%; 95% CI, 2.7-3.9). CONCLUSIONS: This multi-step time series analysis found that average temperature and NO2 are the most important factors impacting AMI hospitalizations, specifically during summer. Based on the model, we were able to visualize the effect-time association of meteorological factors and air pollutants and AMI.

The Importance of Mandatory COVID-19 Diagnostic Testing Prior to Release from Quarantine.

A 14-day quarantine is implemented in many countries in response to the coronavirus disease pandemic. Korea implemented a mandatory quarantine for those who had close contact with infected patients and those returning from abroad. The present study explored the implications of mandatory coronavirus disease 2019 testing before releasing individuals from the 14-day quarantine in Incheon, Korea. From February 11 to July 5, 2020, 19,296 people were self-quarantined, and 56 (0.3%) of them were confirmed cases of COVID-19. Twenty (35.7%) were identified through the reporting of symptoms during quarantine, and 32 (57.1%) were identified using mandatory pre-release RT-PCR tests. Among the 32, 14 (25%) individuals reported mild symptoms and 18 (32.1%) were asymptomatic. It is suggested that mandatory diagnostic testing prior to release and the symptom-based surveillance after the 14-day quarantine may help control delayed or asymptomatic COVID-19 cases.

Trends in the prevalence and treatment of bipolar affective disorder in South Korea.

This study aimed to assess trends in the prevalence of bipolar disorder (BP). We also analyzed patterns of medical use by Korean patients with BP, defined as those diagnosed with the International Classification of Diseases (ICD) F31 code who used at least one inpatient or outpatient medical service in a year. We analyzed yearly BP prevalence and inpatient hospitalization periods per year from 2008 to 2017 using National Health Insurance Service (NHIS) claims data for 52.43 million people. Overall, the BP prevalence was 0.2 %, as of 2017, with consistently higher rates in women. The BP prevalence was highest among those aged ≥60 years (0.27 %) and was lowest among those aged 0-29 years (0.12 %), as of 2017. The average annual rate of increase among those aged 0-29 years and ≥60 years was 8.48 % and 7.39 %, respectively, which exceeded the overall mean of 6.58 %. The average annual rate of increase in BP prevalence for those aged 30-59 years was 4.67 %. The proportion of inpatients who were hospitalized for longer than 180 days decreased, while the proportion of those hospitalized for 0-14 days increased. The estimated BP prevalence was higher when using the most recent NHIS data rather than in the surveys. These prevalence rates can be used to support the development of future mental health policies.

Complementing conventional infectious disease surveillance with national health insurance claims data in the Republic of Korea.

Surveillance remains an important tool for timely outbreak detection and response. Many countries, including Korea, have established national infectious disease surveillance systems with clinical notification. We aimed to evaluate the National Health Insurance Claims-based Surveillance (NHICS) compared to conventional passive report-based National Infectious Diseases Surveillance (NIDS). Reported to claimed cases ratios (R/C ratio) were evaluated from monthly notifiable disease cases captured by NIDS and NHICS. The relationships between 26 infectious diseases and each surveillance system were analysed using Pearson's correlation analysis and linear regression. There was an overall increase in R/C ratio from 2010-2017 (0.37 to 0.78). In 22 infectious diseases, there was a correlation between NIDS and NHICS. Moreover, claim-based surveillance showed less fluctuating disease incidence rates than report-based surveillance for specific infectious diseases, such as varicella, mumps, and scarlet fever. However, for infectious diseases with episodic outbreaks or low incidence, it was difficult to assess NHICS usefulness. Claim-based surveillance is less affected by limitations of conventional report-based surveillance systems, such as reporting rate. Given delays in claim systems, a claim-based surveillance is expected to be complementary to conventional systems for the detection of various infectious diseases with the advancement of bio-information technology.

Effects of interactive metronome training on postural stability and upper extremity function in Parkinson's disease: a case study.

[Purpose] The purpose of this study was to examine the effects of interactive metronome training on the postural stability and upper extremity function of an individual with Parkinson's disease. [Subject and Methods] The participant of this case study was a 75-year-old female with Parkinson's disease diagnosed 7 years prior. This study was a single-subject research with an A-B-A design. She received IM training during the treatment phase (B phase) for 40 minutes per session. She was assessed pretest and posttest using the Berg balance scale and Wolf motor function test, and at baseline and the treatment phase using the measured box-and-block test and a Tetrax system. [Results] After training, the patient's static and dynamic balance, functional activity, and performance time of the upper extremity improved. Interactive metronome therapy improved the manual dexterity of both hands. Interactive metronome therapy also improved the limit of stability of the Parkinson's disease. [Conclusion] Though a case study, the results of this study suggest that IM therapy is effective at restoring the postural stability and upper extremity function of patients with Parkinson's disease.

Erratum: Correction of Funding Source: The Burden of Cancer in Korea during 2012: Finding from a Prevalence-Based Approach.

This corrects the article on p. S168 in vol. 31, PMID: 27775254.

Health Performance and Challenges in Korea: a Review of the Global Burden of Disease Study 2013.

The global burden of disease study (GBD) provides valuable information for evaluating population health in terms of disease burden. This study collected and reviewed GBD data in Korea for the year 1990 and 2013. The burdens of cancer, cardiovascular disease, communicable disease, and injuries have decreased remarkably, thereby greatly diminishing the overall disease burden on Korea. Meanwhile, the burdens due to non-fatal chronic diseases such as neuropsychiatric and musculoskeletal disease became major burden contributors. Responding to this circumstance presents a complex challenge to the Korean health system and Korean health policy.

The Burden of Cancer in Korea during 2012: Findings from a Prevalence-Based Approach.

Cancer causes a significant deterioration in health and premature death and is a national socioeconomic burden. This study aimed to measure the burden of cancer using the disability-adjusted life year (DALY) metric based on the newly adopted methodology from the Global Burden of Disease Study in 2010. This study was conducted based on data from the Korean National Cancer Registry. The DALYs were calculated using a prevalence-based method instead of the incidence-based method used by previous studies. The total burden of cancer in 2012 was 3,470.79 DALYs per 100,000 persons. Lung cancer was the most prevalent cancer burden, followed by liver, stomach, colorectal, and breast cancer. The DALYs for lung, liver, stomach, colon and rectum, and pancreatic cancer were high in men, whereas the DALYs for breast, lung, stomach, colorectal, and liver cancer were high in women. Health loss from leukemia and cancer of the brain and nervous system was prevalent for those younger than age 20; from stomach, breast, and liver for those aged 30-50; and from lung, colon and rectum, and pancreas for a large proportion of individuals over the age of 60. The most important differences were that the DALYs were calculated by prevalence and that other components of the DALYs were measured by a population-based perspective. Thus, prevalence-based DALYs could provide more suitable data for decision making in the healthcare field.

Metabolic Risk Profile and Cancer in Korean Men and Women.

OBJECTIVES: Metabolic syndrome is a cluster of risk factors for type 2 diabetes mellitus and cardiovascular disease. Associations between metabolic syndrome and several types of cancer have recently been documented. METHODS: We analyzed the sample cohort data from the Korean National Health Insurance Service from 2002, with a follow-up period extending to 2013. The cohort data included 99 565 individuals who participated in the health examination program and whose data were therefore present in the cohort database. The metabolic risk profile of each participant was assessed based on obesity, high serum glucose and total cholesterol levels, and high blood pressure. The occurrence of cancer was identified using Korean National Health Insurance claims data. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models, adjusting for age group, smoking status, alcohol intake, and regular exercise. RESULTS: A total of 5937 cases of cancer occurred during a mean follow-up period of 10.4 years. In men with a high-risk metabolic profile, the risk of colon cancer was elevated (HR, 1.40; 95% CI, 1.14 to 1.71). In women, a high-risk metabolic profile was associated with a significantly increased risk of gallbladder and biliary tract cancer (HR, 2.05; 95% CI, 1.24 to 3.42). Non-significantly increased risks were observed in men for pharynx, larynx, rectum, and kidney cancer, and in women for colon, liver, breast, and ovarian cancer. CONCLUSIONS: The findings of this study support the previously suggested association between metabolic syndrome and the risk of several cancers. A high-risk metabolic profile may be an important risk factor for colon cancer in Korean men and gallbladder and biliary tract cancer in Korean women.

The Economic Burden of Cancers Attributable to Metabolic Syndrome in Korea.

OBJECTIVES: Metabolic syndrome is an important etiologic factor in the development of certain types of cancers. The economic cost of the treatment of cancer has been steadily increasing. We therefore estimated the economic burden of cancers attributable to metabolic syndrome in Korea. METHODS: We reviewed metabolic syndrome-related cancers and relative risk and then calculated population attributable fractions. We analyzed insurance claims data for metabolic syndrome-related cancers in 2012 in order to estimate the direct costs associated with these cancers, including hospitalization, outpatient visits, transportation costs, and caregivers' costs as well as indirect costs such as loss of productivity due to cancer treatment and premature death. RESULTS: In 2012, 18,070 patients in Korea had cancers attributable to metabolic syndrome. The economic burden was USD 199.8 million and the direct and indirect costs were USD 124.5 million and USD 75.3 million, respectively. CONCLUSIONS: We estimated the economic burden of cancers attributable to metabolic syndrome in Korea and the efforts are necessary to reduce this burden.

The burden of acute myocardial infarction after a regional cardiovascular center project in Korea.

OBJECTIVE: The aim of this study was to examine the impact of a government-directed regional cardiovascular center (RCVC) project on the length of stay (LOS) and medical costs due to acute myocardial infarction (AMI). DESIGN: A retrospective claim data review. SETTING: Forty hospitals including four RCVCs in Korea. PARTICIPANTS: A total of 1469 AMI patients who visited a RCVC in two regions between February 2009 and December 2011. INTERVENTIONS: RCVC project has been fostering specialized center by region for management of cardiovascular disease. It has built a system that could receive intensive care quickly within 3 h when disease occurred. MAIN OUTCOME MEASURES: Changes in the LOS and cost were evaluated using the difference-in-differences (DIDs) method combined with propensity score matching (1:1) and multilevel analysis with adjustment for patient's and institutional factors. RESULTS: The net effect of RCVC project implementation showed decline of LOS (-0.71 days) and total medical costs (-797 US dollars) by DID. After the RCVC project, the LOS for patients with AMI hospitalized in a RCVC was decreased by 8.9% (ß = -0.094, P = 0.041) compared with patients hospitalized in a hospital not designed as a RCVC. Compared with costs before the RCVC project, they were decreased by 11.5% (ß = -0.122, P = 0.004). CONCLUSIONS: We provided evidence regarding the change in the societal burden due to AMI after regionalization. Although there was a reduction of LOS and direct medical costs reported in limited number of regionalized hospitals, in the long term we can anticipate an expanding impact in all regionalized hospitals.

Unusual truncation of N-acylated peptoids under acidic conditions.

The terminal amino groups of peptoids have often been protected with acetyl groups to improve cell permeability and therapeutic potential, and to prevent the poisoning of the catalysts in organometallic reactions. Interestingly, the unusual truncation of the terminal peptoid unit has sometimes been encountered when the acetylated linear peptoids were treated with a TFA cleavage cocktail. In this study, we systematically investigated the electronic effects of acyl groups on the truncation of N-acylated peptoids to rationalize the formation of the deleted peptoids and to establish an appropriate strategy for preventing such undesired truncation.

The burden of nosocomial staphylococcus aureus bloodstream infection in South Korea: a prospective hospital-based nationwide study.

BACKGROUND: We estimated the nationwide burden of nosocomial S. aureus bloodstream infection (SA-BSI), a major cause of nosocomial infection, in South Korea. METHODS: To evaluate the nationwide incidence of nosocomial SA-BSI, cases of SA-BSI were prospectively collected from 22 hospitals with over 500 beds over 4?months. Data on patient-days were obtained from a national health insurance database containing the claims data for all healthcare facilities in South Korea. The additional cost of SA-BSI was estimated through a matched case?control study. The economic burden was calculated from the sum of the medical costs, the costs of caregiving and loss of productivity. RESULTS: Three hundred and thirty nine cases of nosocomial SA-BSI were included in the study: 254 cases of methicillin-resistant SA-BSI (MRSA-BSI) and 85 cases of methicillin-susceptible SA-BSI (MSSA-BSI). Death related to BSI occurred in 81 cases (31.9%) of MRSA-BSI and 12 cases (14.1%) of MSSA-BSI. The estimated incidence of nosocomial MRSA-BSI was 0.12/1,000 patient-days and that of nosocomial MSSA-BSI, 0.04/1,000 patient-days. The estimated annual cases of nosocomial BSI were 2,946 for MRSA and 986 for MSSA in South Korea. The additional economic burden per case of nosocomial SA-BSI was US $20,494 for MRSA-BSI and $6,914 for MSSA-BSI. Total additional annual cost of nosocomial SA-BSI was $67,192,559. CONCLUSION: In view of the burden of nosocomial SA-BSI, a national strategy for reducing nosocomial SA-BSI is urgently needed in South Korea.

Cross metathesis assisted solid-phase synthesis of glycopeptoids.

A solid-phase synthesis of glycopeptoids was explored through olefin cross metathesis (CM). Peptoids and sugar derivatives with appropriate olefin moieties were coupled in the presence of an olefin metathesis catalyst to afford glycopeptoids in good yields. This systematic solid-phase CM study can provide facile access to the molecular sources of glycopeptidomimetics and postchemical modifications on various molecular scaffolds.

Ethambutol-mediated cell wall modification in recombinant Corynebacterium glutamicum increases the biotransformation rates of cyclohexanone derivatives.

The effects of structural modification of cell wall on the biotransformation capability by recombinant Corynebacterium glutamicum cells, expressing the chnB gene encoding cyclohexanone monooxygenase of Acinetobacter calcoaceticus NCIMB 9871, were investigated. Baeyer-Villiger oxygenation of 2-(2'-acetoxyethyl) cyclohexanone (MW 170 Da) into R-7-(2'-acetoxyethyl)-2-oxepanone was used as a model reaction. The whole-cell biotransformation followed Michaelis-Menten kinetics. The V (max) and K (S) values were estimated as 96.8 U g(-1) of dry cells and 0.98 mM, respectively. The V (max) was comparable with that of cyclohexanone oxygenation, whereas the K (S) was almost eightfold higher. The K (S) value of 2-(2'-acetoxyethyl) cyclohexanone oxygenation was reduced by ca. 30% via altering the cell envelop structure of C. glutamicum with ethambutol, which inhibits arabinosyl transferases involved in the biosynthesis of cell wall arabinogalactan and mycolate layers. The higher whole-cell biotransformation rate was also observed in the oxygenation of ethyl 2-cyclohexanone acetate upon ethambutol treatment of the recombinant C. glutamicum. Therefore, it was assumed that the biotransformation efficiency of C. glutamicum-based biocatalysts, with respect to medium- to large-sized lipophilic organic substrates (MW > ca. 170), can be enhanced by engineering their cell wall outer layers, which are known to function as a formidable barrier to lipophilic molecules.

Ring-closing metathesis approaches for the solid-phase synthesis of cyclic peptoids.

Cyclic peptoids were efficiently synthesized on a solid phase in high yields utilizing ring-closing metathesis (RCM). This method should be a valuable tool for easy access to cyclic peptoid libraries and various cyclic compounds.

Efficient solid-phase synthesis of a series of cyclic and linear peptoid-dexamethasone conjugates for the cell permeability studies.

Cyclic peptides and their cyclic analogs have received a great deal of attention because of their numerous interesting biological activities and their challenging chemical synthesis. It has also been hypothesized that they might improve the cell permeability compared to linear molecules by providing internal hydrogen bonding and generally decreasing the conformational flexibility. In this study, a series of cyclic and linear peptoid-dexamethasone conjugates were rationally designed and efficiently synthesized on solid-phase for systematic cell permeability studies using reporter gene-based assays. These model compounds should be used to reveal how the cell permeability of cyclic molecules is affected by several physicochemical properties, especially, the reduced conformational flexibility and the ring size. In addition, the synthetic strategy that was adopted in this study can also provide a robust platform for postchemical modifications of various molecular scaffolds in solid-phase or solution-phase syntheses.