DNA microarrays on a dendron-modified surface improve significantly the detection of single nucleotide variations in the p53 gene

Selectivity and sensitivity in the detection of single nucleotide polymorphisms (SNPs) are among most important attributes to determine the performance of DNA microarrays. We previously reported the generation of a novel mesospaced surface prepared by applying dendron molecules on the solid surface. DNA microarrays that were fabricated on the dendron-modified surface exhibited outstanding performance for the detection of single nucleotide variation in the synthetic oligonucleotide DNA. DNA microarrays on the dendron-modified surface were subjected to the detection of single nucleotide variations in the exons 5–8 of the p53 gene in genomic DNAs from cancer cell lines. DNA microarrays on the dendron-modified surface clearly discriminated single nucleotide variations in hotspot codons with high selectivity and sensitivity. The ratio between the fluorescence intensity of perfectly matched duplexes and that of single nucleotide mismatched duplexes was >5–100 without sacrificing signal intensity. Our results showed that the outstanding performance of DNA microarrays fabricated on the dendron-modified surface is strongly related to novel properties of the dendron molecule, which has the conical structure allowing mesospacing between the capture probes. Our microarrays on the dendron-modified surface can reduce the steric hindrance not only between the solid surface and target DNA, but also among immobilized capture probes enabling the hybridization process on the surface to be very effective. Our DNA microarrays on the dendron-modified surface could be applied to various analyses that require accurate detection of SNPs

Emergency department utilization in elderly patients: a report from the National Emergency Department Information System (NEDIS) of Korea, 2018-2022

Objective With general aging of the population, emergency department (ED) utilization by elderly patients is increasing. In this study, we analyzed data on ED visits of patients aged 65 years and older in Korea. Methods The study is a retrospective analysis of National Emergency Department Information System (NEDIS) data from 2018–2022, focusing on patients aged 65 years and older who visited EDs across Korea. ED utilization data were analyzed using Korean Triage and Acuity Scale (KTAS) scores. The patients were divided into three age groups, and common chief complaints and diagnoses were identified. Age- and sex-standardized ED visits per 100,000 population and outcomes were also analyzed. Results During the study period, there was a total of 9,803,065 elderly patient ED visits. The mean patient age was 76.4±7.6 years, and 47.6% were men. The ED mortality rate and in-hospital mortality rate were 1.8% and 4.6%, respectively. The KTAS scores 1–2 group accounted for 11.0% of patients, KTAS score 3 group for 42.5%, KTAS scores 4–5 group for 37.2%, and KTAS score unknown group for 9.4%. When patients were categorized into three age groups, the oldest group exhibited the highest rates of KTAS score 1, severe illness diagnoses, and mortality. The most frequently reported chief complaint was abdominal pain, and the most common diagnosis was light headedness. When analyzing the data by year, the COVID-19 outbreak had a discernible impact on ED visits and clinical outcomes. Conclusion Over the past 5 years, ED visits for elderly patients have averaged 26,050 per 100,000 population per year, with a temporary decline during the COVID-19 pandemic and a subsequent upward trend

Operation of national coordinating service for interhospital transfer from emergency departments: experience and implications from Korea

Background Since 2014, Korea has been operating the National Emergency Medical Situation Room (NEMSR) to provide regional emergency departments (EDs) with coordination services for the interhospital transfer of critically ill patients. The present study aimed to describe the NEMSRs experience and interhospital transfer pattern from EDs nationwide, and investigate the factors related to delayed transfers or transfers that could not be arranged by the NEMSR. Methods This study was a retrospective cross-sectional analysis of the NEMSRs coordination registry from 2017 to 2019. The demographic and hospital characteristics related to emergency transfers were analyzed with hierarchical logistic models. Results The NEMSR received a total of 14,003 requests for the arrangement of the interhospital transfers of critically ill patients from 2017 to 2019. Of 10,222 requests included in the analysis, 8297 (81.17%) successful transfers were coordinated by the NEMSR. Transfers were requested mainly due to a shortage of medical staff (59.79%) and ICU beds (30.80%). Delayed transfers were significantly associated with insufficient hospital resources. The larger the bed capacity of the sending hospital, the more difficult it was to coordinate the transfer (odds ratio [OR] for transfer not arranged = 2.04; 95% confidence interval [CI]: 1.48–2.82, ≥ 1000 beds vs. < 300 beds) and the longer the transfer was delayed (OR for delays of more than 44 minutes = 2.08; 95% CI: 1.57–2.76, ≥ 1000 beds vs. < 300 beds). Conclusions The operation of the NEMSR has clinical importance in that it could efficiently coordinate interhospital transfers through a protocolized process and resource information system. The coordination role is significant as information technology in emergency care develops while regional gaps in the distribution of medical resources widen

Characteristics of pediatric emergency department visits before and during the COVID-19 pandemic: a report from the National Emergency Department Information System (NEDIS) of Korea, 2018–2022

Objective As of 2018, approximately 1.2 million pediatric patients visited emergency departments (EDs) in Korea, showing a steady increase. Given the distinct differences between children and adults, it is vital to examine the epidemiological characteristics of pediatric patients visiting the ED. Methods This study retrospectively analyzed the ED use patterns of pediatric patients <18 years old in Korea from January 1, 2018, to December 31, 2022, using data from the National Emergency Department Information System (NEDIS). Results Most pediatric ED patients were boys, with an average age of 6.6±5.3 years. Patients younger than 1 year and those in critical condition had longer ED stays and more frequently required hospital admission and used the 119-ambulance service. The primary symptom was fever, and the most common discharge diagnosis was gastroenteritis. Following the declaration of the COVID-19 pandemic in 2020, ED visits decreased by 49%. Meanwhile, there was an increase in in-hospital mortality rate/age- and sex-standardized mortality rate per 100,000 ED visits, Admission and transfer rates remained similar between before and after the start of the pandemic. Conclusion Through this analysis, we identified the characteristics of pediatric patients visiting EDs in Korea. We observed a sharp decline in ED visits after the start of the COVID-19 pandemic. From there, ED visits slowly increased but remained below prepandemic levels for 3 years. This research will serve as a foundational resource for appropriately allocating and preparing pediatric ED resources

Effectiveness of regdanvimab on mortality in COVID-19 infected patients on hemodialysis

Background Although several therapeutic agents have been evaluated for the treatment of coronavirus disease 2019 (COVID-19), there are lack of effective and proven treatments for end-stage renal disease (ESRD). The present study aims to evaluate the effectiveness of regdanvimab on mortality in COVID-19–infected patients on hemodialysis (HD). Methods We conducted an observational retrospective study in 230 COVID-19–infected patients on HD, of whom 77 (33.5%) were administered regdanvimab alone or in combination with dexamethasone or remdesivir during hospitalization (regdanvimab group) and 153 patients (66.5%) were not (no regdanvimab group). The primary outcome was in-hospital mortality. We compared mortality rates according to the use of regdanvimab and investigated the factors associated with mortality. Results Fifty-nine deaths occurred during hospitalization, 49 in the no regdanvimab group (32.0%) and 10 in the regdanvimab group (13.0%), and the mortality rate was significantly higher in the no regdanvimab group than that in the regdanvimab group (p = 0.001). Multivariate Cox regression analysis showed that malignancy (p = 0.001), SPO2 of <95% at admission (p = 0.003), and administration of antibiotics and regdanvimab (p = 0.007 and p = 0.002, respectively) were significantly associated factors with mortality. Conclusion Regdanvimab administration is beneficial in improving prognosis in hospitalized COVID-19 patients on HD. Considering the vulnerability to infection and high mortality of ESRD patients, regdanvimab may be considered as a therapeutic option in COVID-19 patients on HD

Epidemiologic trends of patients who visited nationwide emergency departments: a report from the National Emergency Department Information System (NEDIS) of Korea, 2018–2022

Objective This study analyzed trends in emergency department (ED) visits in Korea using the National Emergency Department Information System (NEDIS) data from 2018 to 2022. Methods This was a retrospective observational study using data from the NEDIS database from 2018 to 2022. Age- and sex-standardized ED visits per 100,000 population, as well as age- and sex-standardized rates for mortality, admission, and transfer, were calculated. Results The standardized ED visits per 100,000 population was approximately 20,000 from 2018 to 2019 and decreased to about 18,000 in 2022. The standardized mortality rate ranged from 1.4% to 1.7%. The admission rate (18.4%–19.4%) and the transfer rates (1.6%–1.8%) were similar during the study period. Approximately 5.5% of patients were triaged as Korean Triage and Acuity Scale score 1 or 2. About 91% of patients visited the ED directly and 21.7% of patients visited the ED with an ambulance. The ED length of stay was less than 6 hours in 90.3% of patients and the ED mortality rate was 0.6%. Acute gastroenteritis was the most common diagnosis. Respiratory virus symptoms, such as fever and sore throat, were also common chief complaints. Conclusion ED visits decreased during the 5-year period, while admission, transfer, and death rates remained relatively stable

The structure of procaspase 6 is similar to that of active mature caspase 6.

To investigate the structural characteristics and activation mechanism of the precursor caspase, genes encoding the inactive pro-form and the active mature form of caspase 6 were expressed in Escherichia coli and the proteins of both forms were purified to homogeneity. The structure of each protein was characterized by chemical cross-linking, size-exclusion chromatography, CD and fluorescence spectroscopies. The pro-form caspase 6 exhibits a dimeric structure and its overall secondary structure was found to be similar to that of the mature caspase 6. Upon the maturation of procaspase 6, the maximum fluorescence wavelength lambda(max) was red-shifted from 330 to 337 nm and the fluorescence intensity of lambda(max) was increased. This fluorescence spectral change indicates that the environment of a tryptophan residue in the substrate-binding site can be changed to a more polar one when the procaspase 6 is processed. Taken together, our results strongly demonstrate that precursor caspase 6 exists as a dimer and its overall structure is similar to that of the active caspase 6. Our results also suggest that the local conformational change at the substrate-binding site, with no drastic change in the overall structure, seems to enable precursor caspase 6 to become the active mature enzyme

Game Transport Protocol: A Reliable Lightweight Transport Protocol for Massively Multiplayer On-line Games” Internal Report, 2001, Korea. Available at: http://mmlab.snu.ac.kr/publications/docs/itcom(shpack).pdf

With the advent of high-speed access network technologies such as ADSL, increasing numbers of Internet users are participating in various interactive multimedia applications. Among these, the most popular are the massively interactive on-line games, or MMPOGs. In MMPOGs, a large amount of event data is associated with various control objects. This event data has different characteristics from that which is generally used on the Internet. Namely, events occur very frequently with short inter-arrival times and their size is quite small, because they only contain control information. Most commercial MMPOGs use TCP or UDP as the transport protocol for the event data. However, since TCP is such a heavy protocol, due to its complex congestion control algorithm and byte-oriented window scheme, it is difficult to support many concurrent users. On the other hand, UDP is a relatively lightweight protocol, but there are no functions available which permit reliable transmission and session management. In this paper, we propose a new transport protocol, Game Transport Protocol (GTP), which is designed for the transmission of the event data used by MMPOGs. GTP supports several functions designed to meet the various requirements of MMPOGs. Firstly, GTP uses a packet-based window scheme not a byte-based window scheme as in the case of TCP. This scheme is quite simple and suitable for the small size of the event data. Also, GTP performs session management and retransmission using GTP control blocks, and supports an adaptive retransmission scheme that controls the maximum number of retransmission