Circuit Training Improves the Levels of ß-Amyloid and Brain-Derived Neurotrophic Factor Related to Cognitive Impairment Risk Factors in Obese Elderly Korean Women.

Background: The purpose of this study was to investigate the effect of circuit training on ß-amyloid, BDNF, and cognitive function in untrained obese elderly Korean women. Methods: The subjects for the study were aged 65-70 years and were each assigned to a circuit training group (EG, n = 12) or a control group (CG, n = 11). The 60 min combined exercise was performed 3 times per week for 16 weeks. The exercise intensity was progressively increased from a 40% heart rate reserve to a 70% heart rate reserve. The test data were analyzed using a paired t-test, an independent t-test, and a two-way repeated measures ANOVA, and an alpha level of 0.05 was set for all tests of significance. Results: Group-by-time interaction effects were observed for ß-amyloid (p < 0.05), brain-derived neurotrophic factor (p < 0.01), and cognitive function (p < 0.05). Within the exercise group, significant differences were found in ß-amyloid (p < 0.05), brain-derived neurotrophic factor (p < 0.001), and cognitive function (p < 0.05) when comparing across different time points. Additionally, there were statistically significant differences between groups in post-exercise ß-amyloid (p < 0.05), change in ß-amyloid (p < 0.05), brain-derived neurotrophic factor (p < 0.01), and cognitive function (p < 0.05). Conclusions: Therefore, it is suggested that the circuit training used in this study could be an effective exercise method for improving the risk factors of cognitive impairment in obese elderly Korean women.

Effectiveness of Regular Aerobic Exercise in Improving Vascular Stiffness in Elderly Korean Women.

The purpose of this study was to determine the effects of aerobic exercise on carotid to femoral pulse wave velocity (cf-PWV), cell adhesion molecules (intracellular adhesion molecules (ICAM-1), vascular cell adhesion molecules (VCAM-1), endothelial selectin (E-selectin), and oxidized LDL in elderly women aged 70-85 years, and to identify the effect of and correlation with vascular stiffness. Forty participants were recruited and divided into three groups; vascular stiffness (VSG, n = 14), obesity (OG, n = 14), and normal (NG, n = 12). All groups were given a 16-week intervention of aerobic exercise, and the data collected before and after exercise were analyzed using SPSS Ver. 23.0. Two-way repeated-measures ANOVA was used to evaluate between-group and time-dependent interaction effects. One-way ANOVA was used to evaluate between-group variations. In addition, the significance was tested using a post hoc test (Scheffe). The within-group variations by time before and after exercise were examined using a paired t-test, and correlation analysis was performed using Pearson correlation coefficients. Simple regression analysis was performed for variables showing significant differences. The results indicate interaction effects for cf-PWV (p < 0.001), VCAM-1 (p < 0.01), E-selectin (p < 0.05), and oxidized LDL (p < 0.001). The rate of change of cf-PWV was positively correlated with that of VCAM-1 (r = 0.352, p < 0.05) and that of oxidized LDL (r = 0.325, p < 0.05) with statistical significance. To determine the effect of the rate of change of cf-PWV on the rate of change of VCAM-1, the variables were tested, and the coefficient of determination in the regression analysis was 0.124, indicating that 12.4% of the tested variables fit the standard regression line. The variables for the effect of the rate of change of cf-PWV on the rate of change of oxidized LDL were also tested, and the coefficient of determination in the regression analysis was 0.106, indicating that 10.6% of the tested variables fit the standard regression line. Thus, the 16-week regular and consistent aerobic exercise program had significant effects on the cf-PWV, ICAM-1, VCAM-1, E-selectin, and oxidized LDL in elderly Korean women with vascular stiffness, suggesting improvements in vascular stiffness, based on which the intervention is predicted to contribute to the prevention of vascular dysfunction by lowering the risk of cardiovascular disease due to atherosclerosis, as well as having a positive effect in the prevention of impairment of vascular endothelial cells.

Gleditsiae fructus regulates osteoclastogenesis by inhibiting the c­Fos/NFATc1 pathway and alleviating bone loss in an ovariectomy model.

Medical and economic developments have allowed the human lifespan to extend and, as a result, the elderly population has increased worldwide. Osteoporosis is a common geriatric disease that has no symptoms and even a small impact can cause fractures in patients, leading to a serious deterioration in the quality of life. Osteoporosis treatment typically involves bisphosphonates and selective estrogen receptor modulators. However, these treatments are known to cause severe side effects, such as mandibular osteonecrosis and breast cancer, if used for an extended period of time. Therefore, it is essential to develop therapeutic agents from natural products that have fewer side effects. Gleditsiae fructus (GF) is a dried or immature fruit of Gleditsia sinensis Lam. and is composed of various triterpenoid saponins. The anti­inflammatory effect of GF has been confirmed in various diseases, and since the anti­inflammatory effect plays a major role in inhibiting osteoclast differentiation, GF was expected to be effective in osteoclast differentiation and menopausal osteoporosis; however, to the best of our knowledge, it has not yet been studied. Therefore, the present study was designed to examine the effect of GF on osteoclastogenesis and to investigate the mechanism underlying inhibition of osteoclast differentiation. The effects of GF on osteoclastogenesis were determined in vitro by tartrate­resistant acid phosphatase (TRAP) staining, pit formation assays, filamentous actin (F­actin) ring formation assays, western blotting and reverse transcription­quantitative PCR analyses. Furthermore, the administration of GF to an animal model exhibiting menopausal osteoporosis allowed for the analysis of alterations in the bone microstructure of the femur using micro­CT. Additionally, assessments of femoral tissue and serum were conducted. The present study revealed that the administration of GF resulted in a reduction in osteoclast levels, F­actin rings, TRAP activity and pit area. Furthermore, GF showed a dose­dependent suppression of nuclear factor of activated T­cells cytoplasmic, c­Fos and other osteoclastogenesis­related markers.

Ambient air pollution and the risk of neurological diseases in residential areas near multi-purposed industrial complexes of korea: A population-based cohort study.

Emerging evidence suggest that long-term exposure to air pollution may induce adverse effects on the central nervous system. However, no study explored the associations in large industrial complex (IC) areas which are one of the major contributors to air pollution. Therefore, we aimed to investigate the pollution status and the association between residential proximity and incidence of neurological diseases near two major ICs characterized as multi-purposed ICs in Korea. A retrospective cohort of residents near the ICs was constructed using Korea's health insurance data and monitored from 2008 to 2019. Emission amounts of the ICs and the air pollution status in the nearby (exposed) and remote (control) area were evaluated using data from national regulatory networks, and hazard ratios (HRs) and 95% confidence intervals (CIs) for neurological diseases of the exposed group compared to the control group were calculated using Cox proportional regression models. Overall, the complexes emitted large amounts of VOCs, CO, NOx, and PM10, and annual levels of ambient PM (2.5, 10), gaseous substances (NO2, SO2), VOCs and PAHs were higher in the exposed area compared to the control and/or the national average. The risk of inflammatory disease of the CNS (G00-09) and extrapyramidal and movement disorders (G20-26) were higher in the exposed area with a HR (95% CI) of 1.36 (1.10-1.68) and 1.33 (1.27-1.39) respectively. Among the subclasses, other extrapyramidal and movement disorders (G25) and epilepsy (G40) were associated with higher risks in the exposed area (HR (95%CI): 1.11 (1.04-1.18), 1.08 (1.00-1.16)) after adjusting for potential confounders. These results suggest that people living near ICs are more likely to be exposed to higher air pollution levels and have higher risks of developing several neurological disorders. However, further epidemiological studies in these industrial areas supplemented with other indicators of environmental exposure and control of other diverse factors are warranted.

National Monitoring of Mosquito Populations and Molecular Analysis of Flavivirus in the Republic of Korea in 2020.

The Korea Disease Control and Prevention Agency has established centers at 16 locations to screen vector populations and pathogens. The aims of this study were to determine the relative spatiotemporal distributions of mosquitoes that are flavivirus vectors, and to correlate them with instances of flaviviral disease in the Republic of Korea (ROK). We collected 67,203 mosquitoes in traps at 36 collection sites in 30 urban regions and migratory bird habitats in 2020. The trap index was 36.6, and the predominant mosquito species were the Culex pipiens complex, Armigeres subalbatus, Aedes albopictus, Aedes vexans, and Culex tritaeniorhynchus. The mosquitoes were pooled into 4953 pools to monitor flavivirus infection. We determined that the minimum infection rate of flavivirus was 0.01%. Japanese encephalitis virus (JEV) was detected in only seven pools of Culex orientalis from Sangju, and we isolated JVE from two pools. All detected JEV was found to be genotype V by phylogenetic analysis. To the best of our knowledge, this is the first study to isolate genotype V JVE from Culex orientalis in the ROK. Subsequent geographical and ecological studies on mosquitoes will help improve our understanding of the relative risk of flavivirus infection. Future studies should analyze mosquito species distribution and improve flavivirus monitoring and long-term surveillance.

Molecular evidence of zoonotic Babesia species, other than B. microti, in ixodid ticks collected from small mammals in the Republic of Korea.

The occurrence of tick-borne infectious diseases, including zoonotic babesiosis, has become a serious concern in recent years. In this study, we detected Babesia spp. using polymerase chain reaction (PCR) amplification of the 18S rRNA of the parasites isolated from ixodid ticks collected from small mammals in the Republic of Korea (ROK). Sequence analysis of the PCR amplicon revealed the presence of B. duncani, B. venatorum, B. capreoli/divergens, and, the most prevalent, B. microti in the ticks. The molecular phylogenetic analysis showed that the four species-specific18S rRNA sequences clustered in four distinct clades. This is the first study to provide molecular evidence for the presence of zoonotic Babesia spp. other than B. microti in ticks in the ROK.

Nationwide Incidence of Chigger Mite Populations and Molecular Detection of Orientia tsutsugamushi in the Republic of Korea, 2020.

The Korea Disease Control and Prevention Agency has established regional centers at 16 locations to monitor vectors and pathogens. We investigated the geographical and temporal distribution of chigger mite populations to understand tsutsugamushi disease epidemiology in 2020. To monitor weekly chigger mite populations, 3637 chigger mites were collected from sticky chigger mite traps in autumn. Chigger mites appeared from the first week of October to the third week of December, peaking in the fourth week of October. The predominant species were Leptotrombidium scutellare, Leptotrombidium palpale, Neotrombicula kwangneungensis, Neotrombicula tamiyai, and Leptotrombidium pallidum. To monitor Orientia tsutsugamushi infection in chigger mites, 50,153 chigger mites were collected from 499 trapped wild rodents in spring and autumn, with a chigger index of 100.5. Approximately 50% of chigger mites were pooled into 998 pools, and the minimum infection rate (MIR) of O. tsutsugamushi was 0.1%. Jeongeup had the highest MIR for O. tsutsugamushi (0.7%). The Kato-related genotype was the most common (52.2%), followed by the Karp-related (17.4%), Boryong (13.0%), JG-related (8.7%), Shimokoshi (4.3%), and Kawasaki (4.3%) genotypes. Ecological and geographical studies focusing on the basic ecology and pathology of mites will improve our understanding of tsutsugamushi disease risks in the Republic of Korea.

Nationwide Temporal and Geographical Distribution of Tick Populations and Phylogenetic Analysis of Severe Fever with Thrombocytopenia Syndrome Virus in Ticks in Korea, 2020.

Since 2010, the Korea Disease Control and Prevention Agency has established centers at 16 locations to monitor disease vectors and pathogens. Here, we examined tick populations to understand the geographical and temporal distribution of severe fever with thrombocytopenia syndrome virus (SFTSV) vectors in 2020. From April to November, 63,376 ticks were collected from traps to monitor tick populations, with a trap index of 41.3. Tick incidence varied from April to October, with population peaks observed for nymphs in May, adults in July, and larvae in September. The predominant tick species were Haemaphysalis longicornis, Haemaphysalis spp., H. flava, Ixodes spp., Amblyomma testudinarium, and Ixodes nipponensis. Approximately 50% of the collected ticks were pooled into 2973 groups to detect the rate of SFTSV infection in ticks. The minimum infection rate (MIR) of SFTSV was 0.2%, and Andong had the highest MIR for SFTSV (4.0%). The B3 genotype was the most prevalent (52.2%) followed by B2 (28.6%), B5 (15.9%), B4 (1.6%), and B6 (1.6%). We identified widely distributed tick species and a high degree of diversity in SFTSV strains in ticks from different geographical regions. The results may provide a basis for future epidemiological studies and risk assessments for tick-borne diseases.

Geographical Distribution of Borrelia burgdorferi sensu lato in Ticks Collected from Wild Rodents in the Republic of Korea.

Lyme disease is a tick-borne zoonotic disease caused by Borrelia burgdorferi sensu lato (s. l.) via transmission cycles involving competent tick vectors and vertebrate reservoirs. Here, we determined the prevalence and distribution of Borrelia genospecies in 738 ticks of at least three species from wild rodents in nine regions of the Republic of Korea (ROK). Ticks were analyzed using nested PCR targeting partial flagellin B gene sequences, followed by sequence analysis. The prevalence of Borrelia infection was 33.6%, and the most common genospecies were B. afzelii (62.5%), B. valaisiana (31.9%), B. yangtzensis (2.4%), B. garinii (1.6%), and B. tanukii (1.6%). Borrelia afzelii was found in all regions except Jeju Island; this predominant genospecies was found in the northern and central sampling regions. Borrelia valaisiana, B. yangtzensis, and B. tanukii were found only in the southern regions with B. valaisiana being the most common, whereas B. yangtzensis and B. tanukii were only found on Jeju Island. Our study is the first to describe the nationwide prevalence of B. burgdorferi s. l. in ticks from wild rodents in the ROK. Continuous surveillance in ticks, animals, humans, and different regions is required to avoid disease distribution and possible transmission to humans in the ROK.

The influence of surrounding land cover on wetland habitat conditions: a case study of inland wetlands in South Korea.

Wetland ecosystems have been globally degraded and lost due to rapid urbanization and climate change. An assessment of national scale inventory, including wetland types and conditions, is urgently required to understand the big picture of endangered wetlands, such as where they are and how they look like. We analyzed the spatial patterns of each inland wetland type (brackish wetland was included) in South Korea and the relative importance of land cover categories on wetland conditions. The wetlands were grouped into four dominant types (riverine, lake, mountain, and human-made) according to their topography. Riverine wetlands constituted the largest area (71.3%). The relative ratio of wetlands in a well-conserved condition (i.e., "A" rank) was highest in riverine wetlands (23.8%), followed by mountain wetlands (22.1%). The higher proportion of grasslands was related to a better condition ranking, but the increasing bareland area had a negative impact on wetland conditions. We also found that wetlands located near wetland protected areas tend to be in a better condition compared to remote sites. Our results further support the importance of the condition of surrounding areas for wetland conservation.

Geographical Genetic Variation and Sources of Korean Aedes albopictus (Diptera: Culicidae) Populations.

Aedes albopictus (Skuse, 1894) is a mosquito vector raising global health concerns owing to its transmission of dengue, Zika, and chikungunya viruses. This vector accounts for a large proportion of the Korean mosquito community; however, autochthonous clinical cases resulting from this species remain unreported in South Korea. This study aimed to examine the geographical genetic variations and sources of Ae. albopictus populations in South Korea exclusively on the basis of COI gene analysis from 292 samples collected from 37 localities in 2016-2018 and 290 reference sequences from GenBank. Thirty-eight haplotypes were identified among the 292 Ae. albopictus samples, with H1 (n = 190, 65.1%), H29 (n = 24, 8.22%), and H32 (n = 24, 8.22%) being the most common and widely distributed haplotypes in the mainland, southern coastal region, and Jeju Island, respectively. In general, high haplotype (≥0.5; 44.7%) and low nucleotide (≤0.00148 max.) diversity were observed in these populations. Based on eight regional groups, results of neutral tests and a mismatch analysis supported demographic expansions after bottlenecks. Furthermore, analysis of molecular variance, FST, and K2P distance showed that Gyeongsangnam-do, Jeju Island, and mainland groups were genetically differentiated. Haplotype network and phylogenetic analyses revealed that the sources of the main haplotypes are related to strains from other countries. The current findings need to be validated with additional sampling from heterogeneous habitats and different genetic markers. However, our results suggest that haplotype changes should be closely monitored for efficient vector surveillance and control.

Racial and Ethnic Disparities in Diagnosis of Chronic Medical Conditions in the USA.

BACKGROUND: There exist racial and ethnic disparities in the prevalence of chronic medical illnesses. However, it is unclear if the disparities arise from patients' self-reported estimates on these diseases and whether there is an association between healthcare utilization and diagnosis. OBJECTIVE: To estimate national racial/ethnic prevalence of undiagnosed hypertension, diabetes, high cholesterol, and kidney disease and identify characteristics associated with undiagnosed diseases. DESIGN: Retrospective analysis of multi-year survey data. PARTICIPANTS: Adults 18 years and older who participated in the National Health and Nutrition Examination Survey during 2011-2014 (n = 10,403). MAIN OUTCOMES: Undiagnosed hypertension (SBP ≥ 140 or DBP ≥ 90 on physical examination with no history of hypertension), undiagnosed diabetes (hgba1c ≥ 6.5% with no history of diabetes), undiagnosed high cholesterol (LDL ≥ 160 mg/dL with no history of high cholesterol), and undiagnosed kidney disease (eGFR ≤ 30 with no history of kidney disease). RESULTS: The study sample was categorized into Whites, Blacks, Hispanics, Asians, and Other. After adjusting for sociodemographic characteristics, Asians had increased odds of undiagnosed hypertension (OR = 1.41 [1.06-1.86]) and diabetes (OR = 6.16 [3.76-10.08]) compared to Whites. Blacks (OR = 2.53 [1.71-3.73]) and Hispanics (OR = 1.88 [1.19-2.99]) had increased odds of undiagnosed diabetes compared to Whites. Multivariate logistic regression analysis indicated that not having any health insurance was associated with increased odds of undiagnosed diabetes and hyperlipidemia (OR = 1.56 [1.00-2.44] and OR = 2.08 [1.44-3.00], respectively). A recent healthcare visit was associated with a lower likelihood of having undiagnosed hypertension (OR = 0.58 [0.41-0.83]) and diabetes (OR = 0.35 [0.18-0.69]). CONCLUSIONS: In a nationally representative cohort, Asians had higher rates of undiagnosed hypertension and diabetes, and all minorities were more likely to have undiagnosed diabetes compared to Whites. Healthcare utilization was associated with undiagnosed medical conditions. Our study showed that reliance on self-reported data may systemically underestimate the prevalence of chronic illnesses among minorities and further research is needed to understand the significance of healthcare utilization in health outcomes.

Disparities in Hypertension Associated with Limited English Proficiency.

BACKGROUND: Limited English proficiency (LEP) is associated with poor health status and worse outcomes. OBJECTIVE: To examine disparities in hypertension between National Health and Nutrition Examination Survey (NHANES) respondents with LEP versus adequate English proficiency. DESIGN: Retrospective analysis of multi-year survey data. PARTICIPANTS: Adults 18 years of age and older who participated in the NHANES survey during the period 2003-2012. MAIN MEASURES: We defined participants with LEP as anyone who completed the NHANES survey in a language other than English or with the support of an interpreter. Using logistic regression, we estimated the odds ratio for undiagnosed or uncontrolled hypertension (systolic blood pressure (SBP) > 140 mmHg or diastolic blood pressure (DBP) > 90 mmHg) among LEP participants relative to those with adequate English proficiency. We adjusted for sociodemographic, acculturation-related, and hypertension-related variables. KEY RESULTS: Fourteen percent (n = 3,269) of the participants had limited English proficiency: 12.4% (n = 2906) used a Spanish questionnaire and 1.6% (n = 363) used an interpreter to complete the survey in another language. Those with LEP had higher odds of elevated blood pressure on physical examination (adjusted odds ratio [AOR] = 1.47 [1.07-2.03]). This finding persisted among participants using an interpreter (AOR = 1.88 [1.15-3.06]) but not among those using the Spanish questionnaire (AOR = 1.32 [0.98-1.80]). In a subgroup analysis, we found that the majority of uncontrolled hypertension was concentrated among individuals with a known diagnosis of hypertension (AOR = 1.80 [1.16-2.81]) rather than those with undiagnosed hypertension (AOR = 1.14 [0.74-1.75]). Interpreter use was associated with increased odds of uncontrolled hypertension, especially among patients who were not being medically managed for hypertension (AOR = 6.56 [1.30-33.12]). CONCLUSIONS: In a nationally representative sample, participants with LEP were more likely to have poorly controlled hypertension than those with adequate English proficiency. LEP is an important driver of disparities in hypertension management and outcomes.

In Silico Design and Experimental Validation of siRNAs Targeting Conserved Regions of Multiple Hepatitis C Virus Genotypes.

RNA interference (RNAi) is a post-transcriptional gene silencing mechanism that mediates the sequence-specific degradation of targeted RNA and thus provides a tremendous opportunity for development of oligonucleotide-based drugs. Here, we report on the design and validation of small interfering RNAs (siRNAs) targeting highly conserved regions of the hepatitis C virus (HCV) genome. To aim for therapeutic applications by optimizing the RNAi efficacy and reducing potential side effects, we considered different factors such as target RNA variations, thermodynamics and accessibility of the siRNA and target RNA, and off-target effects. This aim was achieved using an in silico design and selection protocol complemented by an automated MysiRNA-Designer pipeline. The protocol included the design and filtration of siRNAs targeting highly conserved and accessible regions within the HCV internal ribosome entry site, and adjacent core sequences of the viral genome with high-ranking efficacy scores. Off-target analysis excluded siRNAs with potential binding to human mRNAs. Under this strict selection process, two siRNAs (HCV353 and HCV258) were selected based on their predicted high specificity and potency. These siRNAs were tested for antiviral efficacy in HCV genotype 1 and 2 replicon cell lines. Both in silico-designed siRNAs efficiently inhibited HCV RNA replication, even at low concentrations and for short exposure times (24h); they also exceeded the antiviral potencies of reference siRNAs targeting HCV. Furthermore, HCV353 and HCV258 siRNAs also inhibited replication of patient-derived HCV genotype 4 isolates in infected Huh-7 cells. Prolonged treatment of HCV replicon cells with HCV353 did not result in the appearance of escape mutant viruses. Taken together, these results reveal the accuracy and strength of our integrated siRNA design and selection protocols. These protocols could be used to design highly potent and specific RNAi-based therapeutic oligonucleotide interventions.

A molecular phylogenetic study on South Korean Tettigonia species (Orthoptera: Tettigoniidae) using five genetic loci: The possibility of multiple allopatric speciation.

In Korea, members of the genus Tettigonia have been known as two species, T. ussuriana and T. dolichoptera dolichoptera. However, the taxonomic status of the Jeju Island population of T. ussuriana (JJ-TU) is in question, relative to the mainland population (ML-TU), because of their different body sizes and ratios of wing length. To clarify the relatedness of JJ-TU and ML-TU, we examined the genetic variation and phylogenetic relationships within and between T. ussuriana and related species collected in South Korea, using five genetic loci: three mitochondrial genes (cytochrome c oxidase subunit 1 [CO1], cytochrome c oxidase subunit 2 [CO2], NADH dehydrogenase 1 [ND1]) and two nuclear loci (second internal transcribed spacer [ITS2], and tubulin alpha-1 [TA1]). Unexpectedly, the JJ-TU population is explicitly sister to T. d. dolichoptera, with low genetic distance (0.76-1.22% in CO1), indicating no direct connection with the ML-TU population; this finding suggests a recent divergence involving rapid morphological change without gene flow between JJ-TU and mainland T. d. dolichoptera. The separation of these populations from their common ancestor was caused by geographical isolation during last glacial age. This finding indicates that the JJ-TU population should be elevated to the rank of subspecies, at the very least. Furthermore, the ML-TU population was also revealed to have four genetically divided groups (group A-D) from four localized populations, but no significant morphological differences exist among them. The genetic difference (range 3.19-4.10% in CO1) between group A + B and C + D was especially large, suggesting that cryptic speciation has widely occurred within the mainland areas, caused by allopatric isolations resulting from mountain barriers.

Automated high-throughput siRNA transfection in raw 264.7 macrophages: a case study for optimization procedure.

RNAi using siRNA is a very powerful tool for functional genomics to identify new drug targets and biological pathways. Although their use in epithelial cells is relatively easy and straightforward, transfection in other cell types is still challenging. The authors report the optimization of transfection conditions for Raw 267.4 macrophage cells. The herein described procedure makes use of automated confocal microscopy, enhanced green fluorescent protein (EGFP)-expressing macrophages, and fluorescently labeled siRNAs to simultaneously quantify both siRNA uptake and silencing efficiency. A comparison of 10 commercial transfectants was performed, leading to the selection of the transfectant giving the highest reproducible knock-down effect without inducing cell toxicity or cell activation. Several buffers used for siRNA/lipid complex assembly were tested, and such a study revealed the crucial importance of this parameter. In addition, a kinetics study led to the determination of the optimal siRNA concentration and the best time window for the assay. In an original approach aimed at simultaneously optimizing both the high-throughput screening process and biological factors, optimal reagent volumes and a process flowchart were defined to ensure robust silencing efficiencies during screening. Such an account should pave the way for future genome-wide RNAi research in macrophages and present an optimization procedure for other "hard-totransfect" cell lines.

Furan in commercially processed foods: four-year field monitoring and risk assessment study in Korea.

The aim of this study was to monitor and assess the risk associated with the presence of furan in various food products consumed in Korea. An optimized analytical method was used for the analysis of furan levels. The optimized solid-phase microextraction (SPME) fiber exposure conditions as follows for temperature, time, and amount of sample were 50 degrees C, 20 min, and 5 g (ml), respectively. Furan was detected in all food samples tested, at levels ranging from 0.4 ng/g in canned crab to 814 ng/g in ground roasted coffee powder. The furan levels in coffee, canned fish, canned meats, sauce, soup, retort, canned vegetables, baby foods, nutritional/diet drinks, confectionary and biscuits and snacks, juice, jams, and canned fruit were (ng/g) 169, 56.1, 30.1, 21.1, 18.1, 15.6, 10.9, 10.6, 7.1, 5.4, 3.7, 3.2, and 2.9, respectively. Furan concentrations in baby food products were between 1 and 102.5 ng/g. The total exposure estimate of furan was determined to be 10.6 ng/kg/d (maximum, 20 ng/kg/d) for adults, and 17.4 ng/kg/d (maximum. 84.9 ng/kg/d) for babies. Exposure estimates found in this study are lower than those prescribed by the U.S. Food and Drug Administration (FDA).