Single-nucleotide polymorphism-based epidemiological analysis of Korean Mycobacterium bovis isolates.

BACKGROUND: Bovine tuberculosis (TB) is caused by Mycobacterium bovis, a well-known cause of zoonotic tuberculosis in cattle and deer, and has been investigated in many physiological and molecular studies. However, detailed genome-level studies of M. bovis have not been performed in Korea. OBJECTIVES: To survey whole genome-wide single-nucleotide polymorphism (SNP) variants in Korean M. bovis field isolates and to define M. bovis groups in Korea by comparing SNP typing with spoligotyping and variable number tandem repeat typing. METHODS: A total of 46 M. bovis field isolates, isolated from laryngopharyngeal lymph nodes and lungs of Korean cattle, wild boar, and Korean water deer, were used to identify SNPs by performing whole-genome sequencing. SNP sites were confirmed via polymerase chain reaction using 87 primer pairs. RESULTS: We identified 34 SNP sites with different frequencies across M. bovis isolates, and performed SNP typing and epidemiological analysis, which divided the 46 field isolates into 16 subtypes. CONCLUSIONS: Through SNP analysis, detailed differences in samples with identical spoligotypes could be detected. SNP analysis is, therefore, a useful epidemiological tracing tool that could enable better management of bovine TB, thus preventing further outbreaks and reducing the impact of this disease.

Introduction and Application of the Interferon-γ Assay in the National Bovine Tuberculosis Control Program in South Korea.

Bovine tuberculosis is a chronic disease impacting both public health and the livestock industry. The interferon (IFN)-γ assay has been introduced as an ancillary test for diagnosing bovine tuberculosis to overcome limitations of the skin test. The objective of this study was to assess the IFN-γ assay in terms of diagnostics and as a nationwide surveillance program in South Korea. From 2012 to 2013, cattle (n = 120) with bovine tuberculosis and cattle (n = 426) from bovine tuberculosis free herds were subjected to the IFN-γ assay to evaluate the sensitivity and specificity of the assay, respectively, depending on various cut-offs (0-3.5). When optical density of the cut-off was 0.1, the sensitivity and specificity were found to be 81.7% (74.7-88.6) and 99.5% (98.9-100.0), respectively. After introducing the IFN-γ assay as part of the national control program, the IFN-γ assay and single caudal fold skin test data were collected from 47 regional veterinary services to compare the results of these two tests. Overall, the agreement between the IFN-γ assay and the single caudal fold skin test (n = 492,068) was 98.2%, and Cohen's kappa value for the two methods was 0.47. Serial and parallel use of the IFN-γ assay and skin test for the bovine tuberculosis control program were compared using samples (n = 91) from cattle confirmed as bovine tuberculosis positive in laboratories from 2014 to 2016. Parallel screening for bTB showed much higher sensitivity (86/91, 94.5%) than the following screening approaches: serial (47.2%, 43/91), single screening using CFT (63.7%, 58/91), or the IFN-γ assay (78.0%, 71/91). These results indicate that the IFN-γ assay and single caudal fold skin test are complementary to each other; therefore, parallel use of these two tests is considered a useful approach to reduce the prevalence of bovine tuberculosis in South Korea.

Effect of adjacent bit-line cell interference on low frequency noise in NAND flash memory cell strings.

The effect of adjacent bit-line (BL) interference on low frequency in 26 nm NAND flash memory was characterized. With the program (P) and erase (E) states of adjacent cells, current fluctuation (deltaI(BL)) and corner frequency (f(c)) of Lorentzian spectrum were changed. DeltaI(BL) due to RTN ranges from approximately 67.3 nA to approximately 45.9 nA with 4 different modes (P/P, P/E, E/P, E/E) of the state of adjacent cells and f(c) ranges from 48 Hz to 89 Hz. Using measured deltaI(BL) and extracted capture (tau(c)) and emission times (tau(e)) with 4 different modes, we calculated tau and f(c), and extracted the position of a trap in the channel width direction with deltaI(BL) and simulated data. The calculated data showed excellent agreement with measured spectra. Finally, we prepared energy band diagrams in P/P and P/E modes using 3-D device simulation and clarified the effect of adjacent bit-line cell interference. The control gate bias is slightly higher in P/P mode than P/E mode, and then trap energy in P/P mode is relatively lower than that in P/E mode, resulting in shorter capture time in P/P mode.

Modification of isoflavone profiles in a fermented soy food with almond powder.

UNLABELLED: Isoflavone profiles of a fermented soy food, cheonggukjang, were modified using almond powder. Isoflavones were analyzed by high performance liquid chromatography (HPLC) with an ultraviolet detector. Malonyl derivatives of isoflavones decreased and aglycones of isoflavones increased in samples with almond powder for 48 h. As added, almond powder increased from 0%, 5%, and 10% (w/w), amounts of aglycones increased to 21.11%, 26.63%, and 32.45% for 48 h, respectively. ß-Glucosidase activity in 5% and 10% almond added samples was significantly higher than samples without addition of almond (P < 0.05). The content of succinyl daidzin and succinyl genistin, new metabolites from isoflavones, in almond-added cheonggukjang was significantly lower than control samples, implying that ß-glucosidase activity from almond affected negatively the formation of succinyl derivatives (P < 0.05). Principal component analysis (PCA) for isoflavone distribution showed that first principal component (PC1) and second principal component (PC2) expressed 64.78% and 22.26% of the data variability, respectively. Biotransformation of isoflavones in any fermented soy foods can be achieved using natural products containing high ß-glucosidase activity such as almond. PRACTICAL APPLICATION: The results of this study can help to modify the structural transformation of phytochemicals in any fermented soy foods using natural products. Adjusting the content of almond powder can achieve wanted profiles, for example, high aglycones content. Also, content of metabolites such as succinyl derivatives can be controlled using proper amounts of almond and fermentation time.

Application of solid phase-microextraction (SPME) and electronic nose techniques to differentiate volatiles of sesame oils prepared with diverse roasting conditions.

Headspace volatiles of sesame oil (SO) from sesame seeds roasted at 9 different conditions were analyzed by a combination of solid phase microextraction (SPME)-gas chromatography/mass spectrometry (GC/MS), electronic nose/metal oxide sensors (MOS), and electronic nose/MS. As roasting temperature increased from 213 to 247 °C, total headspace volatiles and pyrazines increased significantly (P < 0.05). Pyrazines were major volatiles in SO and furans, thiazoles, aldehydes, and alcohols were also detected. Roasting temperature was more discrimination factor than roasting time for the volatiles in SO through the principal component analysis (PCA) of SPME-GC/MS, electronic nose/MOS, and electronic nose/MS. Electronic nose/MS showed that ion fragment 52, 76, 53, and 51 amu played important roles in discriminating volatiles in SO from roasted sesame seeds, which are the major ion fragments from pyrazines, furans, and furfurals. SO roasted at 213, 230, and 247 °C were clearly differentiated from each other on the base of volatile distribution by SPME-GC/MS, electronic nose/MOS, and electronic nose/MS analyses. Practical Application: The results of this study are ready to apply for the discriminating samples using a combinational analysis of volatiles. Not only vegetable oils prepared from roasting process but also any food sample possessing volatiles could be targets for the SPME-GC/MS and electronic nose assays. Contents and types of pyrazines in sesame seed oil could be used as markers to track down the degree of roasting and oxidation during oil preparation.

[Clinical factors influencing liver stiffness as measured by transient elastography (Fibroscan) in patients with chronic liver disease].

BACKGROUND/AIMS: Transient elastography as performed using the Fibroscan is a useful noninvasive method for evaluating hepatic fibrosis. However, recent studies have found that liver stiffness measurement (LSM) values are inappropriately elevated in acute hepatitis or in the acute flare state of chronic hepatitis, suggesting that the LSM value obtained by the Fibroscan is not a reliable marker for fibrosis. We retrospectively evaluated the clinical factors influencing the LSM value obtained using transient elastography as performed using the Fibroscan in patients with chronic liver disease. METHODS: A total of 298 patients who were followed in Kungpook National University Hospital from November 2007 to May 2008 due to previously established liver cirrhosis or chronic liver disease were investigated using the Fibroscan, laboratory test, ultrasound, and/or abdominal computed tomography. RESULTS: The 298 patients were aged 47.8+/-12.9 years (mean+/-SD). The cut-off value for a diagnosis of liver cirrhosis was 12.5 kPa (as used in previous studies). Thirty-six patients (15%) and 202 patients (85%) with chronic liver disease without clinical manifestation of cirrhosis had LSMs of >12.5 kPa and <12.5 kPa, respectively. Multivariate analysis revealed that LSM values were unusually increased in patients with chronic liver disease who were older (P=0.007) or who had increased gamma glutamyltranspeptidase (GGT) (P=0.022), decreased albumin (P=0.015), or increased total bilirubin (P=0.009). CONCLUSIONS: This study reveals that age, GGT, and albumin are clinical factors influencing LSM values. This reinforces the need to interpret LSM values in the context of a defined diagnosis, biochemical data, radiologic examination, and other clinical findings.

Formation of succinyl genistin and succinyl daidzin by Bacillus species.

6''-O-Succinyl-4'-hydroxyisoflavone-7-O-beta-D-glucopyranoside (succinyl-beta-daidzin) and 6''-O-succinyl-6,4'-dihydroxyisoflavone-7-O-beta-D-glucopyranoside (succinyl-beta-genistin), 2 new isoflavone metabolites, are found in cheonggukjang or natto, traditional soy-based foods fermented with Bacillus species. Standard isoflavones including daidzin, genistin, daidzein, and genistein, and mixtures of isoflavones extracted from roasted soybeans were added to the medium growing Bacillus subtilis or B. subtilis natto and formation of succinyl-beta-daidzin and succinyl-beta-genistin were monitored by high-performance liquid chromatography (HPLC). Samples containing Bacillus with daidzin and genistin produced succinyl-beta-daidzin and succinyl-beta-genistin, respectively, while those with daidzein and genistein did not produce succinyl derivatives. Daidzin in samples with B. subtilis and B. subtilis natto decreased by 39.7% and 10.7%, respectively, for 4 h incubation while genistin decreased by 66.8% and 17.6%, respectively. Genistein decreased faster than daidzein during incubation with B. subtilis or B. subtilis natto without formation of succinyl derivatives. In the case of mixture of isoflavones, succinyl derivatives increased and beta-glucosides and aglycones of isoflavones decreased significantly for 8 h incubation (P < 0.05).

Comparing antioxidant effectiveness of natural and synthetic free radical scavengers in thermally-oxidized lard using DPPH method.

Antioxidant effectiveness of free radical scavengers (FRSs) of alpha-tocopherol, sesamol, butylated hydroxytoluene (BHT), and tert-butylhydroquinone (TBHQ) were evaluated in thermally-oxidized lard using methods of 2,2-diphenyl-1-picrylhydrazyl (DPPH), conjugated dienoic acid (CDA), and p-anisidine value (p-AV). Absorbance of DPPH with lard containing 2.5 micromol/g FRSs were low before oxidation while those with control lard was high due to the hydrogen atom donating ability of FRSs. During oxidation, DPPH absorbance with lard containing FRSs increased differently up to the certain point depending on the types of FRSs. DPPH absorbance of lard without FRSs started to decrease upon oxidation, which indicates that free radical scavenging compounds were generated from oxidized lipids. Results of CDA and p-AV showed that the highest antioxidant capacity was in the order of TBHQ = sesamol, BHT, and alpha-tocopherol. Antioxidant effectiveness of FRS should consider the hydrogen atom donating rates of FRS, the reactivity and stability of FRS at treatment temperature, and characteristics of radicals from FRSs, which may be predicted by the results of DPPH method.

Effects of riboflavin photosensitization on the degradation of bisphenol A (BPA) in model and real-food systems.

Effects of riboflavin photosensitizations on the stability of bisphenol A (BPA), a well-known endocrine disrupting chemical, were studied in model and real-food systems by high-performance liquid chromatography (HPLC). Concentration of BPA was significantly decreased under light exposure (P < 0.05) as the concentration of riboflavin increased while those without riboflavin under light or those with riboflavin in the dark did not change significantly (P > 0.05). Addition of 50, 100, and 200 microM sodium azide significantly increased the stability of BPA in riboflavin photosensitization with concentration dependent manner (P < 0.05), implying that a singlet oxygen or type II pathway played a role in the photodegradation of BPA. Stability of BPA in riboflavin was significantly increased in the presence of high concentration of tert-butanol, a hydroxyl radical quencher, under light storage for 80 min, indicating hydroxyl radicals were involved and contributed to the degradation of BPA, at least in part. Availability of riboflavin photosensitization on the photodegradation of BPA was tested in 2 canned tea beverages with different phenolic contents. BPA was more stable in the beverage sample with higher total phenolic contents and free radical scavenging ability. The photodegradation of BPA in riboflavin photosensitization can be an efficient way to decrease the concentration of BPA from environmental or food systems.

Preparation of a water-soluble fullerene [C70] under ultrasonic irradiation.

A water-soluble fullerene [C(70)] is prepared with fullerene [C(70)] and a mixture of concd. sulfuric acid (H(2)SO(4)) and concd. nitric acid (HNO(3)) at the ratio (v/v) of 3:1 under ultrasonic irradiation at 25-43 degrees C. The MALDI-TOF-MS spectra confirmed that the product of a water-soluble fullerene compound was C(70).