In vivo nicotine is associated with Alzheimer's, Parkinson's and lung cancer. Diagnostic assays of these diseases depend on very low analytical detection limits. In this study, a sensitive analytical method was examined using a voltammetric graphite pencil electrode (GPE) and a modified carbon nanotube paste electrode (CNE). The optimum analytical conditions for both electrodes were compared using square wave anodic stripping voltammetry (SW) and cyclic voltammetry (CV) obtaining 400 sec accumulation time and oxidation peak. Under optimum parameters, the stripping working range of GPE was 5.0-40.0μg/L, CNE: 0.1-0.8 and 5-50μg/L. Quantification limits were 5.0μg/L for GPE and 0.1μg/L for CNE, while detection limits were 0.6μg/L for GPE and 0.07μg/L for CNE. A standard deviation of 10.0μg/L was observed for 0.064 GPE and 0.095 CNE (n = 12) using 400 sec accumulation time. The results obtained can be applied to non.treated urine and ex vivo biological diagnostics.

A rapid, simple and reliable LC-MS/MS method, which can be used on a routine basis, was developed for the simultaneous detection of 8 penicillin antibiotics (amoxicillin, ampicillin, penicillin-G, penicillin-V, oxacillin, cloxacillin, nafcillin and dicloxacillin) in swine muscle and kidney. The antibiotics were extracted from samples with water and methanol. The extract was centrifuged, filtered and analyzed by liquid chromatography coupled with a tandem mass spectrometer (LC-MS/MS), using a C18 reversed phase column with water/acetonitrile gradient containing 0.05 % formic acid. Mass spectral acquisition was achieved in an electrospray positive ion mode by applying multiple reaction monitoring (MRM) of 2 fragment ion transitions to provide a high degree of sensitivity and specificity. The ion rations were consistent and could be used for confirmation of identity of the penicillin antibiotics. Recoveries of eight penicillins at three fortification levels (10, 20 and 40㎍/㎏) ranged from 79.8 to 102.4% and 72.8 to 103.4% in swine muscle and kidney, respectively. The coefficient of variation was than 9% in all samples. The estimated limits of quantification (LOQs) ranged from 1.0 to 3.2㎍/㎏ in swine muscle and kidney, respectively. The LOQs of this method are below the MRLs of penicillin antibiotics in animal tissues established in Korea and other countries.

The purpose of this investigation was to evaluate anti-tumor activity and detect what compounds affect its activity form Alpinia officinarum Hance. Two fractions, methanol and ethylacetate, were isolated by Amberlite XAD-2 resin column chromatography from methanol extract of the rhizomes of Alpinia officinarum. In hollow fiber assay, the methanol extract and methanol fraction were found to inhibit the tumor growth against colon tumor cell lines such as Colo-320, HCT116 and WiDr. Three diarylheptanoids [5-hydroxy-1, 7-diphenyl-3-heptanone, 5-hydroxy-7-(4``-hydroxy-3``-methoxyphenyl)-1-phenyl- 3-heptanone and 3, 5-dihydroxy-1, 7-diphenylheptane] and two flavonoids [galangin and kaempheride] were isolated and identified from the methanol fraction, which is higher activity than ethylacetate fraction. Among these diarylheptanoids and flavonoids, 3, 5-dihydroxy-1, 7-diphenylheptane, galangin and kaempheride as active components on anti-tumor activity were mainly posited in methanol fraction.

Antimicrobial peptides are widely found in living organisms and are known to play a critical role in innate immunity. Numerous antimicrobial peptides from diverse species appear to be effective against pathogenic microorganisms of bacteria, fungi, protozoa, and viruses. Because antibiotic resistance is a global health issue in the fight against pathogenic microorganisms, there has been an urgent need for development of new antibiotic substances. In the current study, we performed yeast two hybrid screening using Beclin1 bait in order to find new peptide antibiotics from a random peptide library. Two candidate peptides from the screening were expressed in a yeast secretory system of Pichia pastoris and tested for any antimicrobial activity against Staphylococcus aureus, MRSA, MRSA2242, MRSA2250, Lactobacillus casei, and Lactobacillus acidophilus. Disc clear zone assay and spectrophotometric analysis revealed that the two peptides exert a decent activity against the pathogenic bacteria, in contrast to minimal effect on the commensal Lactobacillus strains. Taken together, this study presents novel peptides with antibacterial activity against the pathogenic forms of Staphylococcus aureus and suggests the possibility that these peptides, upon further characterization, may be developed as clinically useful antibiotics.

A voltammetric assay of phenol ions was investigated using three electrode systems of graphite pencil working, reference and counter electrodes. Under optimum analytical parameters, square wave stripping working ranges were attained at a mili range of 10~80 mg/L and a micro range of 20~90 ug/L using seawater electrolyte. The developed sensor was applied to tap water and the human body system of a smoker. It was found that the methods can be applied to in vivo fluid or medicinal diagnosis.

In this study, two duplex real-time PCR approach with melting curve analysis is presented for the detection of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella spp. and Staphylococcus aureus, which are important food-borne bacterial pathogens usually present in fresh and/or minimally processed vegetables. Reaction conditions were adjusted for the simultaneous amplification and detection of specific fragments in the β-glucuronidase (uidA, E. coli), thermonuclease (nuc, S. aureus), hemolycin (hly, L. monocytogenes) and tetrathionate reductase (ttr, Salmonella spp.) genes. Melting curve analysis using a SYBR Green I real-time PCR approach showed characteristic Tm values demonstrating the specific and efficient amplification of the four pathogens; 80.6 ± 0.9 ℃,86.9 ± 0.5 ℃, 80.4 ± 0.6 ℃ and 88.1 ± 0.11 ℃ for S. aureus, E. coli O157:H7, L. monocytogenes and Salmonella spp.,respectively. For all the pathogens, the two duplex, real-time PCR was equally sensitive to uniplex real-time PCR,using same amounts of purified DNA, and allowed detection of 10 genome equivalents. When our established duplex real-time PCR assay was applied to artificially inoculated fresh lettuce, the detection limit was 10³ CFU/g for each of these pathogens without enrichment. The results from this study showed that the developed duplex real-time PCR with melting curve analysis is promising as a rapid and cost-effective test method for improving food safety.

In this study, the Comet assay (evaluation of DNA damage) used the fish hepatocellular carinoma cell, PLHC-1, was tried to the sediment extract obtained from freshwater to understand its applicability as a tool for monitoring sediment toxicity. In paralle

Threelectrodes systems were used in stripping voltammetry (SW) and cyclic voltammetry (CV) instead of the expensive platinum and Ag/AgCl reference electrodes. Moreover, the electrolyte solution was used with deep seawater, which can reduce water pollution, is more eco-friendly, and has a lower cost. The analytical optimum parameters measured via CV and SW and with working ranges were obtained from 10 to 80 ug/L using fluorine immobilized on a graphite pencil electrode (FE). Under the optimum conditions, the analytical detection limit of 6.30 ug/LAu was obtained. The results of the study can be applied to diagnostic assay for natural minerals and human finger tissue.

The MTT assay is one of superior evaluation methods widely used to analyze the viability of metabolically active cell. It can be used to determine the percentage of viable sperm through measurement of the reduction of MTT granules at mitochondria in sperm tail. The purpose of this study is to determine the optimal condition of a simple and easy MTT assay to validate boar sperm viability and compare the accuracy of this test with microscopic examination. The MTT reduction rate for sperm viability were analyzed in microtiter plates (96 well) from 1 hr to 5 hr incubation periods at using spectrophotometer (microplate reader) at 550 nm wavelength. The remainder of semen sample was simultaneously examined to compare the correlation of accuracy between MTT assay and other sperm parameters. Those sperm parameters were included the motility, survival rates, membrane integrity, mitochondria activity and acrosome integrity. The OD values of MTT assay (MTT reduction rates) did not greatly change at 1 hr to 5 hr incubation periods in different proportion of live and freeze-killed sperms (dead sperm). The MTT reduction rates or survival rates were decreased according to the different concentration of live and dead sperm. The linear regression at 1 hr and 4 hr incubation periods in sperm MTT assay was y=291.55x-72.176 and y= 180.64x-44.569, respectively. There are high correlation between 1 hr and 4 hr incubation periods (p<0.001). The results of MTT assay and other sperm parameters has a positive correlation (p<0.01 or 0.05). The correlation coefficients for MTT assay was 0.88115 for motility, 0.89868 for survival rates, 0.91722 for membrane integrity and 0.77372 for acrosome integrity, respectively. In conclusion, the MTT assay can be used as a reliable and efficient evaluation method for boar sperm viability. It can be use practical means to evaluate the quality of boar sperm by a fast, inexpensive and easy method.

Recently, studies on natural source antioxidants have become increasingly active in various fields. Among analytical methods for assessment of antioxidant activity, the DPPH, ABTS, and TBA assays have become quite popular in natural antioxidant studies. One of the reasons is that these methods are simple to use and highly sensitive. In particular, DPPH and ABTS assays are based on the theory that a hydrogen donor is an antioxidant. The antioxidant effect can be easily evaluated by following the decrease of specific UV absorption and the results are usually expressed in terms of Trolox equivalent antioxidant capacity (TEAC). The TBA assay has been commonly used for measurement of lipid oxidation in some foods and biological systems. Because the colored complex is formed by the TBA-malonaldehyde interaction, the TBA value can be evaluated using a UV spectrophotometer or HPLC. However, the TBA-malonaldehyde complex is very unstable and often is either not detected in many oxidized lipids or is a minor product of secondary oxidation. As a result of these defects, numerous studies are ongoing.

Currently food-borne disease is being increased at outdoor food services including hotels and restaurants. Speedy and convenient practical monitoring techniques to determine hygienic conditions are needed. This study was designed to verify correlation of direct ATP (Adenosine Tri-Phosphate) examination method using ATP bioluminescence and surveillance with check-list by inspector. Hygienic status of personal hygiene (hands), kitchen utensils (knives, chopping boards, kitchen towels, cap openers, food storage containers, and blade of slice machines), facilities and equipments (refrigerator handles, worktables, and sinks) in five major hotels in Seoul were examined. The result of personal hygiene of hotels was relatively better than other inspection items (46.6 points in personal hygiene, 40.2 points in kitchen utensils, 40.3 points in facilities & equipments). In ATP inspection, kitchen utensils and facilities & equipments were relatively clean comparing with personal hands data (40.8 ± 6.77 RLU/cm²). After correlation analysis of surveillance in hygienic status points and ATP value, all results showed negative and high correlation. The surveillance data and ATP results investigating personal hygiene, kitchen utensils and facilities & equipments were highly correlated. The ATP examination method which shows real-time identification could be considered as an appropriate method to alternate current check-list dependent safety management in food services including hotels.

The aim of this study is to evaluate the estrogenic activity of Cucurbita pepo seed extract which includes β-sitosterol and other phytosterols. Sample was extracted from Cucurbita pepo seed by supercritical carbondioxide method and resuspended with ethanol. Estrogenic activity was measured by recombinant yeast assay which detects estrogenic activity using recombinant yeast with high level of estrogenic receptor. However, estrogenic activity of pumpkin seed extract was not found in this study. Based on this data, pumpkin seed extract will not cause estrogenic disturbance.