Influence of coffee characteristics on tooth discoloration.

PURPOSE: To evaluate the impact of coffee attributes on tooth discoloration, emphasizing the importance of potential factors such as serving temperature, bean variety, and chlorogenic acid (CGA) content. METHODS: Coffee preparation involved the extraction of espresso from four types of roasted beans (Vietnam Robusta, Uganda Robusta, Ethiopia Yirgacheffe Arabica, and Colombia Supremo Arabica), followed by chlorogenic content analysis using high-performance liquid chromatography. Bovine tooth enamel specimens were carefully prepared and stained with coffee (hot and iced), with a color assessment conducted at different time intervals (3, 9, 24, 48, and 72 hours). The Vickers hardness tester was employed to ensure specimen quality, while spectrophotometry aided in color analysis using the CIEDE2000 formula. RESULTS: The results revealed varying effects of serving temperature, bean type, and CGA content on tooth discoloration. It was demonstrated that perceptible color differences occur after a 3-hour immersion in coffee, with hot coffee showing higher staining potential compared to iced variations. Furthermore, chlorogenic acid content and bean type significantly affected tooth discoloration, with higher chlorogenic acid levels associated with increased staining. Notably, Robusta coffee showed less discoloration compared to Arabica, potentially due to differences in pH levels. CLINICAL SIGNIFICANCE: The findings provide valuable insights for both dental practitioners and coffee consumers, assisting in making informed decisions regarding coffee intake and oral hygiene.

Assessing the Feasibility and Efficacy of Pre-Sleep Dim Light Therapy for Adults with Insomnia: A Pilot Study.

Background: Insomnia is increasingly recognized for its marked impact on public health and is often associated with various adverse health outcomes, including cardiovascular diseases and mental health disorders. The aim of this study was to investigate the efficacy of pre-sleep dim light therapy (LT) as a non-pharmacological intervention for insomnia in adults, assessing its influence on sleep parameters and circadian rhythms. Methods: A randomized, open-label, two-arm clinical trial was conducted over two weeks with 40 participants aged 20-60 years, all of whom had sleep disorders (CRIS, KCT0008501). They were allocated into control and LT groups. The LT group received exposure to warm-colored light, minimizing the blue spectrum, before bedtime. The study combined subjective evaluation via validated, sleep-related questionnaires, objective sleep assessments via actigraphy, and molecular analyses of circadian clock gene expression in peripheral blood mononuclear cells. Baseline characteristics between the two groups were compared using an independent t-test for continuous variables and the chi-squared test for categorical variables. Within-group differences were assessed using the paired t-test. Changes between groups were analyzed using linear regression, adjusting for each baseline value and body mass index. The patterns of changes in sleep parameters were calculated using a linear mixed model. Results: The LT group exhibited significant improvements in sleep quality (difference in difference [95% CI]; -2.00 [-3.58, -0.43], and sleep efficiency (LT: 84.98 vs. control: 82.11, p = 0.032), and an advanced Dim Light Melatonin Onset compared to the control group (approximately 30 min). Molecular analysis indicated a significant reduction in CRY1 gene expression after LT, suggesting an influence on circadian signals for sleep regulation. Conclusions: This study provides evidence for the efficacy of LT in improving sleep quality and circadian rhythm alignment in adults with insomnia. Despite limitations, such as a small sample size and short study duration, the results underscore the potential of LT as a viable non-pharmacological approach for insomnia. Future research should expand on these results with larger and more diverse cohorts followed over a longer period to validate and further elucidate the value of LT in sleep medicine. Trial registration: The trial was registered with the Clinical Research Information Service (KCT0008501).

Feasibility and Efficacy of Morning Light Therapy for Adults with Insomnia: A Pilot, Randomized, Open-Label, Two-Arm Study.

Background and Objectives: Light therapy (LT) is used as an adjunctive treatment for sleep problems. This study evaluates the impact of LT on sleep quality and sleep-related parameters in patients with sleep disorders. Materials and Methods: We performed a pilot, randomized, open-label clinical trial. Fourteen patients aged 20-60 years with insomnia were randomized into the control and LT groups (1:1 ratio). The LT group was instructed to use a device that provides bright LT (6000 K, 380 lux, wavelength 480 nm) for at least 25 min before 09:00 a.m. for two weeks. A self-reported questionnaire was used to evaluate circadian preference, mood, and sleep-related parameters. We analyzed serum cortisol levels and clock genes' expression. Results: The Epworth Sleepiness Scale (ESS), insomnia severity index(ISI), and Pittsburgh Sleep Quality index(PSQI) were significantly improved within the LT group only after the two-week period. When comparing the two groups, only the change in ESS was significant (mean difference, control: -0.14 vs. LT: -1.43, p = 0.021) after adjusting for the baseline characteristics. There were no significant differences in serum cortisol or clock genes' expression. Conclusions: LT can improve daytime sleepiness in patients with sleep disorders; however, further well-designed studies are warranted to confirm its efficacy.

Fabrication of a Highly Stretchable, Wrinkle-Free Electrode with Switchable Transparency Using a Free-Standing Silver Nanofiber Network and Shape Memory Polymer Substrate.

Transparent and stretchable electrodes (TSEs) are a key technology for the next generation of stretchable electronics and optoelectronics. Metallic nanofibers are widely used because of their good optoelectrical properties, but they demonstrate low stretchability. To enhance stretchability, fabricating in-plane buckled nanofibers with the aid of a prestrained substrate has become crucial in this research field. Here, a composite comprising shape memory polymer-TSE (SMP-TSE) using crosslinked polycyclooctene as a substrate, which shows wrinkle-free deformation and switchable optical transparency, is fabricated. Because of its considerable elongation without residual strain and the shape memory behavior of polycyclooctene, in-plane buckled nanofibers are formed effectively. For fabrication of SMP-TSE, continuous and thin metallic nanofiber that can maintain its structural integrity is required; therefore, electrospinning and an ultraviolet reduction process to create a free-standing, conductive, nanofiber network are used. Because of its in-plane buckled nanofibers, the electrode maintained its resistance during 3000 cycles of a bending test and 900 cycles of a tensile test. Furthermore, SMP-TSE is able to electrically control its temperature, optical transparency, elastic modulus, and shape memory behavior. Finally, the use of SMP-TSE in a smart display that can control its optical and mechanical properties is demonstrated.

Binary Structure of Amyloid Beta Oligomers Revealed by Dual Recognition Mapping.

Amyloid beta (Aß) oligomers are widely considered to be the causative agent of Alzheimer's disease (AD), a progressive neurodegenerative disorder. Determining the structure of oligomers is, therefore, important for understanding the disease and developing therapeutic agents; however, elucidating the structure has been proven difficult due to heterogeneity, noncrystallinity, and variability. Herein, we investigated homo- and hetero-oligomers of Aß40 and Aß42 using atomic force microscopy (AFM) and revealed characteristics of the molecular structure. By examining the surface of individual oligomers with sequential N- and C-terminus specific antibody-tethered tips, we simultaneously mapped the N- and C-terminus distributions and the elastic modulus. Interestingly, both the N- and C-termini of Aß peptides were recognized on the oligomer surface, and the termini detected pixel regions exhibited a lower elastic modulus than silent pixel regions. These two types of regions were randomly distributed on the oligomer surface.

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.

Effect of TV food advertising restriction on food environment for children in South Korea.

Summary: This study attempted to determine the effects of restrictions on television (TV) food advertising on children's food environments in South Korea. It examined changes that occurred in the marketing mix of food companies following enactment of those restrictions. An on-line survey was conducted with marketers or R&D managers of 108 food companies. A questionnaire was used to inquire about changes that occurred in Product, Place, Price and Promotion as a result of the restrictions placed on TV food advertising. Analysis was performed on the data collected from the responding 63 food companies (58.3%). The results of their answers showed that among the four marketing mix components the restrictions exerted relatively stronger effects on Product. Effects were stronger on companies that produced foods within the product categories of Energy-Dense and Nutrient-Poor foods (EDNP companies) in comparison with companies that did not (non-EDNP companies). The restrictions exerted positive effects on EDNP companies with respect to compliance with labeling requirements and reinforcement of nutritional contents examination, as well as changes to products such as reducing unhealthy ingredients and fortifying nutrients. Overall, the results revealed the possibility that restrictions on TV food advertising could improve children's food environments by encouraging EDNP companies to make favorable product changes. On the one hand, the results also found that some food companies attempted to bypass the regulations by changing marketing channels from TV to others and by reducing product serving sizes. Thus, future measures should be implemented to prevent food companies from bypassing regulations and to control children's exposure to marketing channels other than TV.

Quantifying Burden of Disease to Measure Population Health in Korea.

Quantitative assessments of the health status of a population are essential to make decisions and set priorities in the field of public health. Changing epidemiologic patterns increase the demand for comprehensive estimates of population health across the full health spectrum, including non-communicable diseases and injuries. Burden of disease (BoD) analysis has helped meet this need. With the success of the Global Burden of Disease (GBD) Study, the BoD technique has become predominantly associated with the GBD approach and its methodology using disability-adjusted life year (DALY) has been rapidly disseminated and generally accepted over the last several years. The first Korean BoD study using the DALY metric was presented in 2002. Various BoD studies have since been conducted, but the DALY concept has remained primarily academic and has not yet been actively utilized in the health policy arena. Here, we review the DALY metric and population-based Korean BoD studies using national health data, with the intent of increasing the understanding of their value and their potential role in strengthening future assessments of the Korean population's health status.

The Non-Communicable Disease Burden in Korea: Findings from the 2012 Korean Burden of Disease Study.

In recognition of Korea's rising burden of non-communicable diseases (NCDs), we investigated the nation's NCD status and extracted detailed information from the 2012 Korean Burden of Disease study. Consistent with that study, we used disability-adjusted life year (DALY) as a metric. Using national data sources and disability weights specific to the Korean population, we analyzed 116 disaggregated NCDs from the study's four-level disease and injury hierarchy for both sexes and nine age groups. Per 100,000 population, 21,019 DALYs were lost to 116 NCDs. Of those, 13.97% were due to premature death (death prior to the standard life expectancy for a subject's age) and 86.03% to non-fatal health outcomes. Based on traditional statistics, the main causes of health loss were mortality of neoplasms; cardiovascular and circulatory diseases; diabetes, urogenital, blood, and endocrine diseases; and chronic respiratory diseases. When combined with analyses of premature death and non-fatal outcomes, however, a substantially different view emerged: the main causes of health loss were diabetes mellitus, low back pain, chronic obstructive pulmonary disease, ischemic heart disease, ischemic stroke, cirrhosis of the liver, osteoarthritis, asthma, gastritis and duodenitis, and periodontal disease (in that order), collectively causing 49.20% of DALYs. Thus, burden of disease data using DALYs rather than traditional statistics brings a new perspective to characterization of the population's health that provides practical information useful for developing and targeting national NCD control programs to better meet national needs.

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.

Disability-adjusted Life Years for 313 Diseases and Injuries: the 2012 Korean Burden of Disease Study.

This study is part of a 5-year research project on the national burden of diseases, injuries, and risk factors in Korea. Using disability-adjusted life years (DALYs), a metric introduced by the 1990 Global Burden of Disease (GBD) project, we performed a comprehensive and detailed assessment of the magnitude and distribution of both fatal and non-fatal health problems in the Korean population. The concept and general approach were consistent with the original GBD study, with some methodological modifications to make the study more suitable for Korea. We computed DALYs for 313 causes in both sexes and nine age groups using the entire population's medical records and newly generated Korean disability weights. In 2012, the dominant disease burden was non-communicable diseases, which accounted for 85.21% of total DALYs, while injuries accounted for 7.77% and communicable, maternal, neonatal, and nutritional disorders for 7.02%. Of the total DALYs, 88.67% were from years lived with disability and 11.32% were from years of life lost due to premature mortality. Diabetes mellitus was the leading cause of DALYs, followed by low back pain, chronic obstructive pulmonary disease, ischemic heart disease, ischemic stroke, cirrhosis of the liver, falls, osteoarthritis, motorized vehicle with three or more wheels, and self-harm. The results reported here identify key health challenges and opportunities for future health interventions and policy changes, and provide information that will help assess the major public health issues in Korea, a nation faced with one of the world's most rapidly ageing populations.

Children's exposure to food advertising on free-to-air television: an Asia-Pacific perspective.

There is an established link between food promotions and children's food purchase and consumption. Children in developing countries may be more vulnerable to food promotions given the relative novelty of advertising in these markets. This study aimed to determine the scope of television food advertising to children across the Asia-Pacific to inform policies to restrict this marketing. Six sites were sampled, including from China, Indonesia, Malaysia and South Korea. At each site, 192 h of television were recorded (4 days, 16 h/day, three channels) from May to October 2012. Advertised foods were categorized as core/healthy, non-core/unhealthy or miscellaneous, and by product type. Twenty-seven percent of advertisements were for food/beverages, and the most frequently advertised product was sugar-sweetened drinks. Rates of non-core food advertising were highest during viewing times most popular with children, when between 3 (South Korea) and 15 (Indonesia) non-core food advertisements were broadcast each hour. Children in the Asia-Pacific are exposed to high volumes of unhealthy food/beverage television advertising. Different policy arrangements for food advertising are likely to contribute to regional variations in advertising patterns. Cities with the lowest advertising rates can be identified as exemplars of good policy practice.

Different contribution of extent of myocardial injury to left ventricular systolic and diastolic function in early reperfused acute myocardial infarction.

BACKGROUND: We sought to investigate the influence of the extent of myocardial injury on left ventricular (LV) systolic and diastolic function in patients after reperfused acute myocardial infarction (AMI). METHODS: Thirty-eight reperfused AMI patients underwent cardiac magnetic resonance (CMR) imaging after percutaneous coronary revascularization. The extent of myocardial edema and scarring were assessed by T2 weighted imaging and late gadolinium enhancement (LGE) imaging, respectively. Within a day of CMR, echocardiography was done. Using 2D speckle tracking analysis, LV longitudinal, circumferential strain, and twist were measured. RESULTS: Extent of LGE were significantly correlated with LV systolic functional indices such as ejection fraction (r = -0.57, p < 0.001), regional wall motion score index (r = 0.52, p = 0.001), and global longitudinal strain (r = 0.56, p < 0.001). The diastolic functional indices significantly correlated with age (r = -0.64, p < 0.001), LV twist (r = -0.39, p = 0.02), average non-infarcted myocardial circumferential strain (r = -0.52, p = 0.001), and LV end-diastolic wall stress index (r = -0.47, p = 0.003 with e') but not or weakly with extent of LGE. In multivariate analysis, age and non-infarcted myocardial circumferential strain independently correlated with diastolic functional indices rather than extent of injury. CONCLUSIONS: In patients with timely reperfused AMI, not only extent of myocardial injury but also age and non-infarcted myocardial function were more significantly related to LV chamber diastolic function.

Effects of exposure to television advertising for energy-dense/nutrient-poor food on children's food intake and obesity in South Korea.

The aim of this study was to determine the effect of television food advertising on participant food intake and risk of obesity. A total of 2419 children aged 11-13 years were selected from 118 elementary schools in South Korea. All participants completed a self-administered questionnaire with questions about height, weight, television viewing times, food preferences, and food intakes. To estimate actual exposure to food advertising, we asked participants to specify the times at which they usually watched television. We then collected data on the various types of food advertisement broadcast on five different television networks during those viewing times over the course of the previous 7 months. The amount of television watched and exposure to energy-dense/nutrient-poor (EDNP) food advertising were associated with an increased risk of being overweight or obese. Exposure to television advertising for EDNP food was also significantly associated with higher EDNP food preference and intake and lower fruit and vegetable intake. However, these relationships disappeared for all foods after adjusting for the overall amount of television watched. Although it was not possible to conclude that exposure to television advertising for EDNP food was associated with an increased risk of obesity, preference for EDNP foods, or overall food intake due to the strong comprehensive effects of television viewing time, there was a reason to believe the evidence of the effects of advertising in this study. Future longitudinal studies are needed to determine the exclusive effects of exposure to television advertising for EDNP food.

Syringaresinol Attenuates α-Melanocyte-Stimulating Hormone-Induced Reactive Oxygen Species Generation and Melanogenesis.

Ginseng has been utilized for centuries in both the medicinal and cosmetic realms. Recent studies have actively investigated the biological activity of ginseng berry and its constituents. (+)-Syringaresinol [(+)-SYR], an active component of ginseng berry, has been demonstrated to have beneficial effects on the skin, but its potential impact on skin pigmentation has not been fully explored. Here, the antioxidant and anti-pigmentary activity of (+)-SYR were evaluated in B16F10 murine melanoma cells and in an artificial human pigmented skin model, Melanoderm™. A real-time PCR, Western blotting, immunofluorescence staining, and histochemistry staining were conducted to confirm the effects of (+)-SYR on pigmentation. (+)-SYR reduced melanogenesis and dendrite elongation in α-melanocyte-stimulating hormone (α-MSH)-primed B16F10 cells with low cytotoxicity. (+)-SYR suppressed the expression of melanogenic genes, namely tyrosinase (TYR), tyrosinase-related protein 1 (TRP-1), and tyrosinase-related protein 2 (TRP-2). Notably, (+)-SYR attenuated α-MSH-induced cytosolic and mitochondrial reactive oxygen species (ROS) generation, which was attributable at least in part to the suppression of NADPH oxidase-4 (NOX 4) expression. Finally, the brightening activities of (+)-SYR were verified using Melanoderm™, underscoring the potential of ginseng berry and (+)-SYR as functional ingredients in skin-brightening cosmetics.

Comprehensive assessment of the combined impact of dyslipidemia and inflammation on chronic kidney disease development: A prospective cohort study.

BACKGROUND: There remains a limited comprehensive understanding of how dyslipidemia and chronic inflammation collectively contribute to the development of chronic kidney disease (CKD). OBJECTIVE: We aimed to identify clusters of individuals with five variables, including lipid profiles and C-reactive protein (CRP) levels, and to assess whether the clusters were associated with incident CKD risk. METHODS: We used the Korean Genome and Epidemiology Study-Ansan and Ansung data. K-means clustering analysis was performed to identify distinct clusters based on total cholesterol, triglyceride, non-high-density lipoprotein (HDL)-C, HDL-C, and CRP levels. Cox proportional hazards models were used to examine the association between incident CKD risk and the different clusters. RESULTS: During the mean 10-year follow-up period, CKD developed in 1,645 participants (690 men and 955 women) among a total of 8,053 participants with a mean age of 51.8 years. Four distinct clusters were identified: C1, low cholesterol group (LC); C2, high-density lipoprotein cholesterol group (HC); C3, insulin resistance and inflammation group (IIC); and C4, dyslipidemia and inflammation group (DIC). Cluster 4 had a significantly higher risk of incident CKD compared to clusters 2 (hazard ratio (HR) 1.455 [95% confidence interval (CI) 1.234-1.715]; p < 0.001) and cluster 1 (HR 1.264 [95% CI 1.067-1.498]; p = 0.007) after adjusting for confounders. Cluster 3 had a significantly higher risk of incident CKD compared to clusters 2 and 1. CONCLUSION: Clusters 4 and 3 had higher risk of incident CKD compared to clusters 2 and 1. The combination of dyslipidemia with inflammation or insulin resistance with inflammation appears to be pivotal in the development of incident CKD.

The Human Genetic Differences in the Outcomes of mRNA Vaccination against COVID-19: A Prospective Cohort Study.

BACKGROUND: This study aimed to explore how genetic variations in individuals impact neutralization activity post-mRNA vaccination, recognizing the critical role vaccination plays in curbing COVID-19 spread and the necessity of ensuring vaccine efficacy amidst genetic diversity. METHODS: In a 4-week clinical pilot study, 534 healthy subjects received their first COVID vaccine dose, followed by the second dose. Antibody levels were evaluated thrice. From this pool, 120 participants were selected and divided into high- and low-antibody groups based on their levels. Genomic DNA was isolated from peripheral blood mononuclear cells for pilot genome-wide association studies (GWAS) conducted on a single platform. Real-time PCR was used to confirm differences in gene expression identified via GWAS analysis. RESULTS: Three SNPs exceeded the level of p < 1.0 × 10-3. The rs7795433 SNP of the HDAC9 gene (7q21.1) showed the strongest association with COVID-19 vaccination under the additive model (OR = 5.63; p = 3 × 10-5). In the PCR experiments, the AA genotype group showed that the gene expression level of HDAC9 was likely to be decreased in the low-antibody-formation group at the time of vaccination. CONCLUSION: We found that AA genotype holders (rs7795433 SNP of the HDAC9 gene) have a high probability of having a higher antibody count when vaccinated, and GG type holders have a high probability of the opposite. These findings show that the genetic characteristics of vaccinated people may affect antibody production after COVID vaccination.

Statistical Analysis of the Role of Cavity Flexibility in Thermostability of Proteins.

Conventional statistical investigations have primarily focused on the comparison of the simple one-dimensional characteristics of protein cavities, such as number, surface area, and volume. These studies have failed to discern the crucial distinctions in cavity properties between thermophilic and mesophilic proteins that contribute to protein thermostability. In this study, the significance of cavity properties, i.e., flexibility and location, in protein thermostability was investigated by comparing structural differences between homologous thermophilic and mesophilic proteins. Three dimensions of protein structure were categorized into three regions (core, boundary, and surface) and a comparative analysis of cavity properties using this structural index was conducted. The statistical analysis revealed that cavity flexibility is closely related to protein thermostability. The core cavities of thermophilic proteins were less flexible than those of mesophilic proteins (averaged B' factor values, -0.6484 and -0.5111), which might be less deleterious to protein thermostability. Thermophilic proteins exhibited fewer cavities in the boundary and surface regions. Notably, cavities in mesophilic proteins, across all regions, exhibited greater flexibility than those in thermophilic proteins (>95% probability). The increased flexibility of cavities in the boundary and surface regions of mesophilic proteins, as opposed to thermophilic proteins, may compromise stability. Recent protein engineering investigations involving mesophilic xylanase and protease showed results consistent with the findings of this study, suggesting that the manipulation of flexible cavities in the surface region can enhance thermostability. Consequently, our findings suggest that a rational or computational approach to the design of flexible cavities in surface or boundary regions could serve as an effective strategy to enhance the thermostability of mesophilic proteins.

Correction with blood T1 is essential when measuring post-contrast myocardial T1 value in patients with acute myocardial infarction.

BACKGROUND: Post-contrast T1 mapping by modified Look-Locker inversion recovery (MOLLI) sequence has been introduced as a promising means to assess an expansion of the extra-cellular space. However, T1 value in the myocardium can be affected by scanning time after bolus contrast injection. In this study, we investigated the changes of the T1 values according to multiple slicing over scanning time at 15 minutes after contrast injection and usefulness of blood T1 correction. METHODS: Eighteen reperfused acute myocardial infarction (AMI) patients, 13 cardiomyopathy patients and 8 healthy volunteers underwent cardiovascular magnetic resonance with 15 minute-post contrast MOLLI to generate T1 maps. In 10 cardiomyopathy cases, pre- and post-contrast MOLLI techniques were performed to generate extracellular volume fraction (Ve). Six slices of T1 maps according to the left ventricular (LV) short axis, from apex to base, were consecutively obtained. Each T1 value was measured in the whole myocardium, infarcted myocardium, non-infarcted myocardium and LV blood cavity. RESULTS: The mean T1 value of infarcted myocardium was significantly lower than that of non-infarcted myocardium (425.4 ± 68.1 ms vs. 540.5 ± 88.0 ms, respectively, p < 0.001). T1 values of non-infarcted myocardium increased significantly from apex to base (from 523.1 ± 99.5 ms to 561.1 ± 81.1 ms, p = 0.001), and were accompanied by a similar increase in blood T1 value in LV cavity (from 442.1 ± 120.7 ms to 456.8 ± 97.5 ms, p < 0.001) over time. This phenomenon was applied to both left anterior descending (LAD) territory (from 545.1 ± 74.5 ms to 575.7 ± 84.0 ms, p < 0.001) and non-LAD territory AMI cases (from 501.2 ± 124.5 ms to 549.5 ± 81.3 ms, p < 0.001). It was similarly applied to cardiomyopathy patients and healthy volunteers. After the myocardial T1 values, however, were adjusted by the blood T1 values, they were consistent throughout the slices from apex to base (from 1.17 ± 0.18 to 1.25 ± 0.13, p > 0.05). The Ve did not show significant differences from apical to basal slices. CONCLUSION: Post-contrast myocardial T1 corrected by blood T1 or Ve, provide more stable measurement of degree of fibrosis in non-infarcted myocardium in short- axis multiple slicing.

Serum cystatin C is a major predictor of vancomycin clearance in a population pharmacokinetic analysis of patients with normal serum creatinine concentrations.

We developed a population pharmacokinetic model of vancomycin by integrating the effects of cystatin C and other demographic factors in a large population of Korean patients with normal serum creatinine concentrations to elucidate the precise role of serum cystatin C concentrations in the prediction of vancomycin clearance. A population pharmacokinetic model of vancomycin was developed using NONMEM software from a total of 1,373 vancomycin concentration measurements in 678 patients whose serum creatinine concentrations were lower than 1.2 mg/dL. Covariate selection revealed that cystatin C was the most influential factor and had negative influence ((-0.78)) in the relationship. Total body weight, sex, age, and serum creatinine were also significantly correlated with the clearance. The estimated intersubject variabilities of clearance and volume of distribution were 24.7% and 25.1%, respectively. A 14-fold difference in predicted trough concentrations was observed according to only cystatin C concentrations in a population of simulated individuals with median demographic characteristics. The use of serum cystatin C as marker of vancomycin clearance for more accurate predictions of serum vancomycin concentrations could be useful, particularly among patients with normal serum creatinine concentrations.