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This chapter examines the founding of Chosŏn Korea in 1392 in relation to Ming China, offering an understanding of how the tribute system worked at times of conflicting interests between China and its neighboring powers.
Lipid metabolism and inflammation contribute to CVD development. This study investigated whether the consumption of cranberries (CR; Vaccinium macrocarpon) can alter HDL metabolism and prevent inflammation in mice expressing human apo A-I transgene (hApoAITg), which have similar HDL profiles to those of humans. Male hApoAITg mice were fed a modified American Institute of Nutrition-93M high-fat/high-cholesterol diet (16 % fat, 0·25 % cholesterol, w/w; n 15) or the high-fat/high-cholesterol diet containing CR (5 % dried CR powder, w/w, n 16) for 8 weeks. There were no significant differences in body weight between the groups. Serum total cholesterol, non-HDL-cholesterol and TAG concentrations were significantly lower in the control than CR group with no significant differences in serum HDL-cholesterol and apoA-I. Mice fed CR showed significantly lower serum lecithin–cholesterol acyltransferase activity than the control. Liver weight and steatosis were not significantly different between the groups, but hepatic expression of genes involved in cholesterol metabolism was significantly lower in the CR group. In the epididymal white adipose tissue (eWAT), the CR group showed higher weights with decreased expression of genes for lipogenesis and fatty acid oxidation. The mRNA abundance of F4/80, a macrophage marker and the numbers of crown-like structures were less in the CR group. In the soleus muscle, the CR group also demonstrated higher expression of genes for fatty acid β-oxidation and mitochondrial biogenesis than those of the control. In conclusion, although CR consumption elicited minor effects on HDL metabolism, it prevented obesity-induced inflammation in eWAT with concomitant alterations in soleus muscle energy metabolism.
Background: The Korean National Healthcare-Associated Infections Surveillance System (KONIS) was established to conduct nationwide surveillance of device-associated healthcare-associated infections (HAIs) and surgical site infections annually in 2006. However, no surveillance on overall HAIs has been conducted. Objective: We conducted a point-prevalence survey of total HAIs to estimate the incidence rate of HAIs in acute-care hospitals in South Korea. Methods: We defined HAIs according to KONIS and NHSN criteria. In total, 29 acute-care hospitals including 9 tertiary-care hospitals (TCHs) and 20 secondary-care hospitals (SCHs) were recruited as representing the population of every metropolitan city and province in South Korea. Patients who stayed at the hospitals on August 1, 2018, were randomly selected: 100 for SCHs and 200 for TCHs. Their medical records were retrospectively reviewed for HAIs according to the NHSN criteria by the infection control nurses (ICNs) from each hospital. A web-based data collection and analysis program was developed, and participating ICNs were educated in a 1-day training course with pre- and postevaluations. They received continuous feedback of input data and questions through the web-based system during the study. To generate estimates of the incidence rate of HAIs, we converted prevalence to incidence using the formula of Rhame and Sudderth. Results: Of 4,296 patients, 133 had ≥1 HAI (3.1%). In total, 141 HAIs were identified: gastrointestinal infections (n = 30, 21.3%), bloodstream infections (n = 30, 21.3%), pneumonia (n = 29, 20.6%), urinary tract infection (n =26, 18.4%). Among the gastrointestinal infections, C. difficile infections were the most common (17.7%). Device-associated infections accounted for 34.8% of all HAIs. The overall incidence of HAIs in TCHs was 4.39%, which was a higher incidence than SCHs (3.76%). Intensive care units had 12.6% of HAIs, whereas general wards had 3.4%. HAI incidences were 5.7%, 2.8%, and 2.3%, respectively, for each of the medical wards, surgical wards, and pediatric wards. The 3 most common pathogens were Escherichia coli, Acinetobacter baumannii, and Enterococcus faecium. Conclusions: The prevalence of HAI in Korea is lower than in most Western countries. The HAI burden of Clostridium difficile infection is surprisingly high, which calls for prompt control at the national level. To obtain national-level data on HAI burdens, ongoing surveillance is needed.
Background: Recently, healthcare-associated infections (HAIs) in long-term care hospitals (LTCHs) have markedly increased, but no infection control policy has been established in South Korea. We investigated the current HAI surveillance system and executed a point-prevalence pilot study in LTCHs. Methods: HAIs were defined by newly established surveillance manual based on McGeer criteria revised in 2012. Three LTCHs in Seoul and Gyeonggi province were voluntarily recruited, and data were collected from up to 50 patients who were hospitalized on August 1. The medical records from September to November 2018 were retrospectively reviewed by a charge nurse for infection control per each hospitals after 1 day of training specific for LTCH surveillance. All data were reviewed by a senior researcher visiting onsite. Results: The participating hospitals had 272.33 ± 111.01 beds. Only 1 hospital had an onsite microbiological laboratory. In total, 156 patients were enrolled and 5 HAIs were detected, for a prevalence rate of 3.2%. The average patient age was 79.04 ± 9.92 years. The HAIs included 2 urinary tract infections, skin and soft-tissue infection, low respiratory infection, and conjunctivitis. Conclusions: This is the first survey of HAI in LTCHs in South Korea. The 3.2% prevalence rate is lower than those from previous reports from the European Union or the United States. This study supports the development of a national HAI surveillance and infection control system in LTCHs, although implementation may be limited due to the lack of laboratory support and infection control infrastructure in Korea.
Shared decision-making (SDM) is a critical component of delivering patient-centered care. Members of vulnerable populations may play a passive role in clinical decision-making; therefore, understanding their prior decision-making experiences is a key step to engaging them in SDM.
To understand the previous healthcare experiences and current expectations of vulnerable populations on clinical decision-making regarding therapeutic options.
Clients of a local food bank were recruited to participate in focus groups. Participants were asked to share prior health decision experiences, explain difficulties they faced when making a therapeutic decision, describe features of previous satisfactory decision-making processes, share factors under consideration when choosing between treatment options, and suggest tools that would help them to communicate with healthcare providers. We used the inductive content analysis to interpret data gathered from the focus groups.
Twenty-six food bank clients participated in four focus groups. All participants lived in areas of socioeconomic disadvantage. Four themes emerged: prior negative clinical decision-making experience with providers, patients preparing to engage in SDM, challenges encountered during the decision-making process, and patients’ expectations of decision aids. Participants also reported they were unable to discuss therapeutic options at the time of decision-making. They also expressed financial concerns and the need for sufficiently detailed information to evaluate risks.
Our findings suggest the necessity of developing decision aids that would improve the engagement of vulnerable populations in the SDM process, including consideration of affordability, use of patient-friendly language, and incorporation of drug–drug and drug–food interactions information.
We report our experience with an emergency room (ER) shutdown related to an accidental exposure to a patient with coronavirus disease 2019 (COVID-19) who had not been isolated.
A 635-bed, tertiary-care hospital in Daegu, South Korea.
To prevent nosocomial transmission of the disease, we subsequently isolated patients with suspected symptoms, relevant radiographic findings, or epidemiology. Severe acute respiratory coronavirus 2 (SARS-CoV-2) reverse-transcriptase polymerase chain reaction assays (RT-PCR) were performed for most patients requiring hospitalization. A universal mask policy and comprehensive use of personal protective equipment (PPE) were implemented. We analyzed effects of these interventions.
From the pre-shutdown period (February 10–25, 2020) to the post-shutdown period (February 28 to March 16, 2020), the mean hourly turnaround time decreased from 23:31 ±6:43 hours to 9:27 ±3:41 hours (P < .001). As a result, the proportion of the patients tested increased from 5.8% (N=1,037) to 64.6% (N=690) (P < .001) and the average number of tests per day increased from 3.8±4.3 to 24.7±5.0 (P < .001). All 23 patients with COVID-19 in the post-shutdown period were isolated in the ER without any problematic accidental exposure or nosocomial transmission. After the shutdown, several metrics increased. The median duration of stay in the ER among hospitalized patients increased from 4:30 hours (interquartile range [IQR], 2:17–9:48) to 14:33 hours (IQR, 6:55–24:50) (P < .001). Rates of intensive care unit admissions increased from 1.4% to 2.9% (P = .023), and mortality increased from 0.9% to 3.0% (P = .001).
Problematic accidental exposure and nosocomial transmission of COVID-19 can be successfully prevented through active isolation and surveillance policies and comprehensive PPE use despite longer ER stays and the presence of more severely ill patients during a severe COVID-19 outbreak.
Predicting the isotopic modification of ice by melting processes is important for improving the accuracy in paleoclimate reconstruction. To this end, we present results from cold room laboratory observations of changes in the isotopic ratio (D/H and 18O/16O) of ice cubes by isotopic exchange between liquid water and ice in nearly isothermal conditions. A 1-D model was fit to the isotopic results by adjusting the values of two parameters, the isotopic exchange rate constant (kr) and the fraction of ice participating in the exchange (f). We found that the rate constant for hydrogen isotopic exchange between liquid water and ice may be greater (up to 40%) than that for the oxygen isotopic exchange. The range of the rate constant obtained from four melt experiments is from 0.21 to 0.82 h–1. The model results also suggest that f decreases with the increasing wetness of the ice. This is because with increasing water saturation in ice, water may be present only in the small pores or some of the water that was exchanged with ice may be bypassed, decreasing the effective surface area over which the isotopic exchange can occur. The relationship between the two water isotopes (δ18O vs δD) was observed and modeled and the slope was <8, which is significantly different from the slope of the meteoric waterline. We note that these slopes were obtained without considering the sublimation process.
In the Republic of Korea, despite the introduction of one-dose universal varicella vaccination in 2005 and achieving a high coverage rate of 98.9% in 2012, the incidence rate has been increased sevenfold. This study aimed to investigate time trends of varicella incidence rate, assessing the age, period and birth cohort effects. We used national data on the annual number of reported cases from 2006 to 2017. A log-linear Poisson regression model was used to estimate age–period–cohort effects on varicella incidence rate. From 2006 to 2017, the incidence of varicella increased from 22.5 cases to more than 154.8 cases per 100 000. Peak incidence has shifted from 4 to 6 years old. The estimated period and cohort effects showed significant upward patterns, with a linear increasing trend by net drift. There has been an increase in the incidence among the Korean population regarding period and cohort despite the universal vaccination of varicella vaccine. Our data suggest the need for additional studies to address the current gap in herd immunity.
Treatment of liver fibrosis is very limited as there is currently no effective anti-fibrotic therapy. Spirulina platensis (SP) is a blue-green alga that is widely supplemented in healthy foods. The objective of this study was to determine whether SP supplementation can prevent obesity-induced liver fibrosis in vivo. Male C57BL/6J mice were randomly assigned to a low-fat or a high-fat (HF)/high-sucrose/high-cholesterol diet or an HF diet supplemented with 2·5 % SP (w/w) (HF/SP) for 16 or 20 weeks. There were no significant differences in body weight, activity, energy expenditure, serum lipids or glucose tolerance between mice on HF and HF/SP diets. However, plasma alanine aminotransferase level was significantly reduced by SP at 16 weeks. Expression of fibrotic markers and trichrome stains showed no differences between HF and HF/SP. Splenocytes isolated from HF/SP fed mice had lower inflammatory gene expression and cytokine secretion compared with splenocytes from HF-fed mice. SP supplementation did not attenuate HF-induced liver fibrosis. However, the expression and secretion of inflammatory genes in splenocytes were significantly reduced by SP supplementation, demonstrating the anti-inflammatory effects of SP in vivo. Although SP did not show appreciable effect on the prevention of liver fibrosis in this mouse model, it may be beneficial for other inflammatory conditions.
Given its diverse disease courses and symptom presentations, multiple phenotype dimensions with different biological underpinnings are expected with bipolar disorders (BPs). In this study, we aimed to identify lifetime BP psychopathology dimensions. We also explored the differing associations with bipolar I (BP-I) and bipolar II (BP-II) disorders.
We included a total of 307 subjects with BPs in the analysis. For the factor analysis, we chose six variables related to clinical courses, 29 indicators covering lifetime symptoms of mood episodes, and 6 specific comorbid conditions. To determine the relationships among the identified phenotypic dimensions and their effects on differentiating BP subtypes, we applied structural equation modeling.
We selected a six-factor solution through scree plot, Velicer's minimum average partial test, and face validity evaluations; the six factors were cyclicity, depression, atypical vegetative symptoms, elation, psychotic/irritable mania, and comorbidity. In the path analysis, five factors excluding atypical vegetative symptoms were associated with one another. Cyclicity, depression, and comorbidity had positive associations, and they correlated negatively with psychotic/irritable mania; elation showed positive correlations with cyclicity and psychotic/irritable mania. Depression, cyclicity, and comorbidity were stronger in BP-II than in BP-I, and they contributed significantly to the distinction between the two disorders.
We identified six phenotype dimensions; in addition to symptom features of manic and depressive episodes, various comorbidities and high cyclicity constructed separate dimensions. Except for atypical vegetative symptoms, all factors showed a complex interdependency and played roles in discriminating BP-II from BP-I.
The submarine channel-fill system of the Cambrian Spurs Formation exhibits unique metre-scale cycles of breccia and diamictite. The studied sections, Eureka Spurs, are located at the Mariner Glacier in the central-eastern part of northern Victoria Land, Antarctica. A facies analysis of the channel-fill deposit has led to the recognition of four main lithofacies: breccia, diamictite, thin-bedded sandstone and mudstone. The channel-fill deposit consists of two architectural elements: hollow-fill (HF) and sheet-like (SL) elements. The SL has wide convex-up geometry and consists solely of a very thick bed of diamictite, and is interpreted as a submarine channel lobe. The HF has a concave-up erosional base and flat upper surface. The HF consists of nine cyclic alternations of underlying breccia (cohesionless debris flow) and overlying diamictite (cohesive debris flow). The deposition of breccia is interpreted to have been controlled by repeated allogenic processes such as earthquakes. In contrast, the abrupt vertical transition from breccia to diamictite in each cycle is interpreted to have resulted from an autogenic, slope instability-related process. The interaction of the allogenic and autogenic factors recorded in the metre-scale unique cyclic deposits provides new criteria to interpret cycles of submarine debris flow.
Objectives: Rotator cuff tear is the leading cause of the decline in quality of life for older adults, but comparative evidence on treatment effectiveness is lacking. This study systematically reviewed the effects of various rotator cuff tear treatments through a Bayesian meta-analysis of the related randomized clinical trials (RCTs).
Methods: We searched nine electronic databases for RCTs evaluating rotator cuff tear treatments from their inception through June 2017. A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the National Institute for Health and Care Excellence-Decision Support Unit guidelines (Supplementary Table 1). Outcomes included functional improvement, pain one year after surgical treatment, and tendon structural integrity. The Bayesian network meta-analysis was applied for functional improvement and pain, based on an assumption of consistency and similarity. Tendon integrity was reported descriptively.
Results: Fifteen RCTs were selected. Patients undergoing physiotherapy after open surgery showed statistically significant functional improvements compared with those undergoing physiotherapy only (mean differences, 9.1 [credible interval, 0.9–17.4]). Open surgery with physiotherapy was associated with a decrease in pain 1 year after treatment compared with when physiotherapy was combined with arthroscopic rotator cuff surgery, mini open surgery, platelet-rich plasma therapy, or physiotherapy alone (absolute value of mean difference 1.2 to 1.4). The tendon integrity results were inconsistent.
Conclusions: Some surgical treatments were associated with significant improvement in function and pain, but evidence regarding their comparative effectiveness is still lacking. A well-designed RCT discussing functional and structural treatment outcomes is needed in future.
To evaluate the appropriateness of the screening strategy for healthcare personnel (HCP) during a hospital-associated Middle East Respiratory Syndrome (MERS) outbreak, we performed a serologic investigation in 189 rRT-PCR–negative HCP exposed and assigned to MERS patients. Although 20%–25% of HCP experienced MERS-like symptoms, none of them showed seroconversion by plaque reduction neutralization test (PRNT).
To examine the hypothesis that the association between vitamin D deficiency and depressive symptoms is dependent upon total cholesterol level in a representative national sample of the South Korean population.
This was a population-based cross-sectional study.
The Fifth Korean National Health and Nutrition Examination Survey (KNHANES V, 2010–2012).
We included 7198 adults aged 20–88 years.
The incidence of depressive symptoms in individuals with vitamin D deficiency (serum 25-hydroxyvitamin D<20 ng/ml) was 1·54-fold (95 % CI 1·20, 1·98) greater than in individuals without vitamin D deficiency (serum 25-hydroxyvitamin D ≥20 ng/ml). The relationship was stronger in individuals with normal-to-borderline serum total cholesterol (serum total cholesterol<240 mg/dl; OR=1·60; 95 % CI 1·23, 2·08) and non-significant in individuals with high serum total cholesterol (OR=0·97; 95 % CI 0·52, 1·81) after adjustment for confounding variables (age, sex, BMI, alcohol consumption, smoking status, regular exercise, income level, education level, marital status, changes in body weight, perceived body shape, season of examination date and cholesterol profiles).
The association between vitamin D deficiency and depressive symptoms was weakened by high serum total cholesterol status. These findings suggest that both vitamin D and total cholesterol are important targets for the prevention and treatment of depression.
Polycyclic aromatic hydrocarbons (PAH) are common dietary exposures that cross the human placenta and are classified as a probable human carcinogen. The aim of the present study was to investigate the potential impact of exposure to PAH-containing meat consumed during pregnancy on birth outcomes.
Prospective birth cohort study. Only non-smoking women with singleton pregnancies, who were free from chronic disease such as diabetes and hypertension, were included in the study. Maternal consumption of PAH-rich meat was estimated through FFQ. Multiple linear regression was used to assess factors related to higher intake and the association between dietary PAH and birth outcomes.
Republic of Korea, 2006–2011.
Pregnant women (n 778) at 12–28 weeks of gestation enrolled in the Mothers and Children’s Environmental Health (MOCEH) study.
The multivariable regression model showed a significant reduction in birth weight associated with higher consumption level of foods rich in PAH, such as grilled or roasted meat, during pregnancy (β=−17·48 g, P<0·05 for every 1 point higher in meat score). Further adjusting for biomarkers of airborne PAH did not alter this association. There was no evidence that higher consumption level of PAH-rich meat shortens the duration of gestation (P=0·561). Regression models performed for birth length and head circumference produced negative effects that were not statistically significant.
Consumption of higher levels of barbecued, fried, roasted and smoked meats during pregnancy was associated with reduced birth weight. Dietary risk of PAH exposure in Korean women is of concern.
Cerebral white matter hyperintensities (WMH) are prevalent incident findings on brain MRI scans among elderly people and have been consistently implicated in cognitive dysfunction. However, differential roles of WMH by region in cognitive function are still unclear. The aim of this study was to ascertain the differential role of regional WMH in predicting progression from mild cognitive impairment (MCI) to different subtypes of dementia.
Participants were recruited from the Clinical Research Center for Dementia of South Korea (CREDOS) study. A total of 622 participants with MCI diagnoses at baseline and follow-up evaluations were included for the analysis. Initial MRI scans were rated for WMH on a visual rating scale developed for the CREDOS. Differential effects of regional WMH in predicting incident dementia were evaluated using the Cox proportional hazards model.
Of the 622 participants with MCI at baseline, 139 patients (22.3%) converted to all-cause dementia over a median of 14.3 (range 6.0–36.5) months. Severe periventricular WMH (PWMH) predicted incident all-cause dementia (Hazard ratio (HR) 2.22; 95% confidence interval (CI) 1.43–3.43) and Alzheimer's disease (AD) (HR 1.86; 95% CI 1.12–3.07). Subcortical vascular dementia (SVD) was predicted by both PWMH (HR 16.14; 95% CI 1.97–132.06) and DWMH (HR 8.77; 95% CI 1.77–43.49) in more severe form (≥ 10 mm).
WMH differentially predict dementia by region and severity. Our findings suggest that PWMH may play an independent role in the pathogenesis of dementia, especially in AD.
Many transgenic domestic animals have been developed to produce therapeutic proteins in the mammary gland, and this approach is one of the most important methods for agricultural and biomedical applications. However, expression and secretion of a protein varies because transgenes are integrated at random sites in the genome. In addition, distal enhancers are very important for transcriptional gene regulation and tissue-specific gene expression. Development of a vector system regulated accurately in the genome is needed to improve production of therapeutic proteins. The objective of this study was to develop a knock-in system for expression of human fibroblast growth factor 2 (FGF2) in the bovine β-casein gene locus. The F2A sequence was fused to the human FGF2 gene and inserted into exon 3 of the β-casein gene. We detected expression of human FGF2 mRNA in the HC11 mouse mammary epithelial cells by RT-PCR and human FGF2 protein in the culture media using western blot analysis when the knock-in vector was introduced. We transfected the knock-in vector into bovine ear fibroblasts and produced knock-in fibroblasts using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system. Moreover, the CRISPR/Cas9 system was more efficient than conventional methods. In addition, we produced knock-in blastocysts by somatic cell nuclear transfer using the knock-in fibroblasts. Our knock-in fibroblasts may help to create cloned embryos for development of transgenic dairy cattle expressing human FGF2 protein in the mammary gland via the expression system of the bovine β-casein gene.