Antimicrobial activity of epsilon-polylysine against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in various food extracts

This study compared the antimicrobial effects of epsilon-polylysine (epsilon-PL) against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in 6 food extracts and in broth. The food extracts (10% (w/w) in distilled water) evaluated were fat-free and whole fat milk, beef, bologna, rice, and vegetables (50:50 ratio of broccoli and cauliflower). epsilon-PL was tested at 0.005% and 0.02% (w/v) against E. coli O157:H7 and L. monocytogenes, and 0.02% and 0.04% (w/v) against S. Typhimurium. The substrates were inoculated (5 log CFU/mL) and periodically analyzed for surviving populations during storage at 12 degrees C for 6 d. In general, all 3 pathogens reached 7 to 9 log CFU/mL within 2 d in control substrates (no epsilon-PL). Immediate bactericidal effects (P < 0.05) following exposure to epsilon-PL were obtained in the rice (all pathogens) and vegetable (E. coli O157:H7 and S. Typhimurium) extracts. During storage, antimicrobial effects of epsilon-PL were more pronounced in the food extracts than in the broth medium. The greatest antimicrobial activity for all 3 pathogens was obtained in the rice and vegetable extracts, where counts were reduced (P < 0.05) to below the detection limit (0.0 log CFU/mL) by one or both epsilon-PL concentrations tested. In the other food extracts (fat-free milk, whole fat milk, beef, and bologna), both epsilon-PL concentrations tested generally resulted in lower (P < 0.05) pathogen levels at the end of storage compared to initial counts, with better bactericidal effects exerted by the higher of the 2 epsilon-PL concentrations. Additional research is needed to explore the potential antimicrobial effects of epsilon-PL in real food systems.

Probing the microscopic structure of bound states in quantum point contacts

Using an approach that allows us to probe the electronic structure of strongly pinched-off quantum point contacts (QPCs), we provide evidence for the formation of self-consistently realized bound states (BSs) in these structures. Our approach exploits the resonant interaction between closely coupled QPCs, and demonstrates that the BSs may give rise to a robust confinement of single spins, which show clear Zeeman splitting in a magnetic field.

CEBPG regulates ERCC5/XPG expression in human bronchial epithelial cells and this regulation is modified by E2F1/YY1 interactions

Marked inter-individual variation in lung cancer risk cannot be accounted for solely by cigarette smoke and other environmental exposures. Evidence suggests that variation in bronchial epithelial cell expression of key DNA repair genes plays a role. Variation in these genes correlates with variation in expression of CEBPG and E2F1 transcription factors. Here, we investigated the mechanistic basis for correlation of the DNA repair gene ERCC5 (previously known as XPG) with CEBPG and E2F1. CEBPG expression vector transfected into H23 or H460 cell lines up-regulated endogenous ERCC5 and also luciferase from a reporter construct containing 589 bp of ERCC5 5' regulatory region. A recognition site for CEBPG and a region containing sites for YY1 on the sense strand and E2F1 on the anti-sense strand participated in CEBPG up-regulation of ERCC5. CEBPG, E2F1 and YY1 binding to their respective sites were confirmed by electrophoretic mobility shift assay. Thus, we conclude that CEBPG regulates ERCC5 expression and this regulation is modified by E2F1/YY1 interactions. Several polymorphisms have been identified in these regions and, based on the data presented here, it is reasonable to hypothesize that they may contribute to risk for bronchogenic carcinoma.

Oxidation of corn oil during frying of soy-flour-added flour dough

Oxidation of corn oil during frying of soy-flour-added dough was studied. Flour dough containing soy flour at 0%, 10%, 20%, and 30% was fried in corn oil at 180 degrees C for 2.5 min, and a total of 60 fryings were performed every 30 min. The oxidation of oil was determined by contents of free fatty acids (FFA), conjugated dienoic acids (CDA), polar compounds, and p-anisidine values (PAV). Tocopherols and phospholipids (PLs) in the oil were determined by HPLC. Tocopherols were present in corn oil at 1000 ppm before frying and increased after the first frying of dough containing soy flour due to tocopherol transfer from soy-flour-added dough to the oil during frying. However, as the oil repeated frying, tocopherol contents decreased and its degradation rate was higher in the oil that fried soy-flour-added dough than in the oil that fried the dough without soy flour. PL was not detected in corn oil before and after frying. As the oil repeated frying, FFA, CDA, and polar compounds contents, and PAV of frying oil increased due to the oil oxidation. The values were higher in the oil which fried soy-flour-added dough than in the oil fried the dough without soy flour, indicating the acceleration of oil oxidation by soy flour added to dough. Increase in the oil oxidation by soy flour added to the dough was highly correlated with fast decomposition of tocopherol in the oil.

Phase II study of induction chemotherapy with fixed dose rate (FDR) gemcitabine and cisplatin followed by concurrent chemoradiation with capecitabine for locally advanced pancreatic cancer (LAPC)

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Background: Despite the use of 5-FU based chemoradiotherapy (CRT) over the past decades, prognosis of patients with LAPC remains dismal. To deliver more efficient systemic treatment earlier and reduce toxicity of CRT, we designed a treatment protocol consisting of induction (IND) chemotherapy with FDR gemcitabine (GEM) and cisplatin (CDDP), followed by CRT with capecitabine (CAP) in LAPC. Methods: Eligible patients had unresectable, histologically confirmed adenocarcinoma of pancreas, ECOG PS of 0–2, and no prior chemo- or radiotherapy for this phase II study. Patients received FDR GEM 1000 mg/m2 (D1,8) and CDDP 60 mg/m2 (D1) every 3 weeks for 3 cycles. Patients without disease progression subsequently received CRT of 55.8 Gy in 31 fractions concurrently with CAP, 650 mg/m2 given twice daily without drug holidays. Four weeks after CRT, FDR GEM 1000 mg/m2 was given on day 1, 8 every 3 weeks for 3 cycles. Time to progression was the primary endpoint. Results: Between Jan 2005 and Nov 2006, 21 patients were enrolled (median age 59, M/F: 13/8, ECOG PS 0/1: 3/18). Two patients withdrew consent after 1st and 2nd cycle and remaining 19 patients completed all three cycles of IND chemotherapy, with three (15.8%) out of 19 evaluable patients achieving partial response (0 CR, 3 PR, 14 SD, 2 PD). All 17 patients completed CRT with mean radiation dose of 55.4 Gy. Further four patients progressed during CRT, while one additional patient achieved partial response. As of Jan 2007, 5 patients died and 12 patients showed tumor progression. Median TTP was 12.5 mo (95% CI: 4.2–20.8) and median survival was not reached with median follow up duration of 9.7 months. Grade III/IV toxicities included neutropenia (38.1%/9.5%), thrombocytopenia (4.8%/0%), and anemia (14.3%/0%) during IND phase. Toxicites were generally mild during CRT phase with grade III neutropenia and diarrhea occurring in one and two patients, respectively. One patient died of neutropenic sepsis after 3rd cycle of IND chemotherapy. Conclusions: FDR GEM-CDDP induction chemotherapy followed by CAP-RT and maintenance FDR GEM is feasible and active with promising TTP of 12.5 months. Enrollment continues till reaching target accrual of 37 patients.

No significant financial relationships to disclose.

Imaging of pericardial diseases

Traditionally echocardiography has been the method of choice for the evaluation of pericardial and cardiac lesions. However, computed tomography (CT) and magnetic resonance imaging (MRI) provide a large field of view and excellent images of anatomy not available with echocardiography. In addition, CT and MRI demonstrate high soft-tissue contrast as well as the exact localization of a lesion. Currently, CT and MRI are the preferred techniques for the recognition and characterization of pericardial disorders. In this review, the characteristic imaging appearances of a variety of pericardial diseases are discussed.

Utilization of an alternative Communication Device using the Anal Sphincter (CDAS)

The purpose of this study was to invent a new communication system for terminal amyotrophic lateral sclerosis (ALS) patients who are in a state of complete motor paralysis with intact sensory and cognitive functions whose speech are disrupted due to the weakness of muscles involved in speaking and/ or to tracheostomy and ventilator dependence.

Automated Individual Prescription of Exercise with an XML-based Expert System

Continuously motivating people to exercise regularly is more important than finding a barriers such as lack of time, cost of equipment or gym membership, lack of nearby facilities and poor weather or night-time lighting. Our proposed system presents practicable methods of motivation through a web-based exercise prescription service. Users are instructed to exercise according to their physical ability by means of an automated individual prescription of exercise checked and approved by a personal trainer or exercise specialist after being tested with the HIMS, fitness assessment system. Furthermore, utilizing BIOFIT exercise prescriptions scheduled by an expert system can help users exercise systematically. Automated individual prescriptions are built in XML based documents because the data needs to be flexible, expansible and convertible structures to process diverse exercise templates. Web-based exercise prescription service makes users stay interested in exercise even if they live in many different environments.

Implementation of a transcutaneous charger for fully implantable middle ear hearing device

A transcutaneous charger for the fully implantable middle ear hearing device (F-IMEHD), which can monitor the charging level of battery, has been designed and implemented. In order to recharge the battery of F-IMEHD, the electromagnetic coupling between primary coil at outer body and secondary coil at inner body has been used. Considering the implant condition of the F-IMEHD, the primary coil and the secondary coil have been designed. Using the resonance of LC tank circuit at each coil, transmission efficiency was increased. Since the primary and the secondary coil are magnetically coupled, the current variation of the primary coil is related with the impedance of internal resonant circuit. Using the principle mentioned above, the implanted module could transmit outward the information about charging state of battery or coupling between two coils by the changing internal impedance. As in the demonstrated results of experiment, the implemented charger has supplied the sufficient operating voltage for the implanted battery within about 10 mm distance. And also, it has been confirmed that the implanted module can transmit information outward by control of internal impedance.

Analysis of relation between coronary perfusion pressure and the extracted parameters from a ventricular fibrillation ECG signal

This work presents an alternative return of spontaneous circulation (ROSC) estimate using indirectly induced presumption that coronary perfusion pressure (CPP) correlates with the extracted parameter from the ventricular fibrillation (VF) ECG signal. In past studies, it is revealed that successful cardiopulmonary resuscitation (CPR) needs at least 30 approximately 40 mmHg CPP during the aortic diastolic period. In 360 segments derived from 18 test dogs with experimental cardiac arrest of cardiac cause, we analyzed the ability of 4 spectral features of VF before countershock to discriminate or not between segments that correspond to CPP. The median frequency (MF), peak frequency (PF), average segment amplitude (ASA) and maximum segment amplitude (MSA) were studied. After preprocessing the raw data acquired from the specific experimental setup and protocol, we verified CPP is a serious estimate of ROSC, and then we analyzed the extracted parameters corresponding to CPP by multiple regression. In the specific conditional frequency domain (MF: 9.42 approximately 12.42 Hz, PF: 8.71 approximately 13.08 Hz, ASA: > 0.19 mV), CPP is correlated to the extracted parameter with 0.71 +/- 0.05 coefficient of multiple determination (R(2)). The combination of MF, PF, and ASA achieved a 79.47 +/- 3% sensitivity and 41.67 +/- 4% specificity in testing.

Reduction of Listeria monocytogenes populations during exposure to a simulated gastric fluid following storage of inoculated frankfurters formulated and treated with preservatives

The effect of a simulated gastric fluid (adjusted to pH 1.0 with HCl) on Listeria monocytogenes, inoculated postprocessing on pork frankfurters formulated with sodium lactate (SL) and sodium diacetate (SD) and not dipped or dipped in solutions of lactic acid or acetic acid, was evaluated during storage of the frankfurters at 10 degrees C for 40 days. Pork frankfurters containing 1.8% SL, 0.25% SD, 1.8% SL+0.125% SD, or 1.8% SL+0.25% SD were inoculated with 10(2)-10(3) CFU/cm2 of a 10-strain preparation of L. monocytogenes and were not dipped or dipped for 2 min in solutions of 2.5% lactic or acetic acid before they were vacuum-packaged and stored. Survival of L. monocytogenes was determined after exposure of frankfurters for 0, 20, 40, and 60 min to the simulated gastric fluid after storage for 0, 10, 20, 30, or 40 days. Growth of L. monocytogenes on frankfurters formulated with antimicrobials was inhibited in the order control <SL<0.25% SD<SL+0.125% SD<SL+0.25% SD. Survival of L. monocytogenes during exposure to simulated gastric fluid was higher on those frankfurters on which there had been extensive growth of the pathogen than on frankfurters on which growth had been inhibited. Inclusion of single antimicrobials in the formulation of not dipped frankfurters appeared to increase resistance of L. monocytogenes to simulated gastric fluid provided the initial level of the pathogen exposed to the simulated gastric fluid was higher than 5 log CFU/cm2. Although the combinations of SL and SD used in the formulation of not dipped frankfurters inhibited growth of L. monocytogenes, prolonged (40 days) storage of such frankfurters induced slight resistance to simulated gastric fluid. The frankfurter formulation of 0.25% SD and dipping in 2.5% lactic acid appeared to increase resistance of L. monocytogenes to simulated gastric fluid following growth during prolonged (days 20 to 40) storage. Use of 2.5% acetic acid dipping combined with antimicrobials in the formulation inhibited growth of L. monocytogenes on frankfurters and subsequent detectable survival after exposure to simulated gastric fluid.

Transport of target anions, chromate (Cr (VI)), arsenate (As (V)), and perchlorate (ClO4-), through RO, NF, and UF membranes

Rejection and transport of chromate (Cr (VI)), arsenate (As (V)), and perchlorate (ClO4-) by and through reverse osmosis, nanofiltration, and ultrafiltration were found to be affected by solution pH and ionic strength. In this study, the rejection of these target ionic contaminants increased with increasing pH at the same conductivity (ionic strength) for the tested membranes, regardless of salt type. General trends showed that the rejection followed the order: CaCl2 < KCl < or = K2SO4, at the same pH and conductivity condition. The rejection also significantly decreased as conductivity was increased regardless of the salt type. These results support the notion that a more negative surface charge due to increasing pH and/or decreasing ionic strength (conductivity) enhances rejection; lower molecular weight cut-off also enhances rejection. Measured values of hindered diffusion coefficient through the membrane pores (Dp) for the target contaminants significantly decreased as pH was increased, regardless of salt type at the same conductivity. At the same pH and conductivity, the Dp of the target contaminants follows the order: CaCl2 > KCl > K2SO4, in the presence of different types of salts. The Dp of the target contaminants significantly increased as conductivity was increased regardless of the salt type. The rejection data were modeled by application of a non-equilibrium thermodynamic model. The rejection model has five transport parameters: the molecular transport coefficient (omega), osmotic pressure gradient (deltaII), molecular reflection coefficient (sigma), the average bulk fluid interfacial concentration between the feed and permeate side (C(avg)), and the solvent flux (Jv). The transport parameters were determined by independent measurements (and calculation with minimum assumptions.) Measurements and predictions of the target contaminant transport were in good agreement.

Effect of simulated spray chilling with chemical solutions on acid-habituated and non-acid-habituated Escherichia coli O157:H7 cells attached to beef carcass tissue

Samples (10 by 20 by 2.5 cm) of beef carcass tissue were inoculated (10(4) to 10(5) CFU/cm2) with Escherichia coli O157: H7 that was either non-acid habituated (prepared by incubating at 15 degrees C for 48 h in inoculated filter-sterilized composite [1:1] of hot and cold water meat decontamination runoff fluids, pH 6.05) or acid habituated (prepared in inoculated water fluids mixed with filter-sterilized 2% lactic acid [LA] runoff fluids in a proportion of 1/99 [vol/vol], pH 4.12). The inoculated surfaces were exposed to conditions simulating carcass chilling (- 3 degrees C for 10 h followed by 38 h at 1 degree C). Treatments applied to samples (between 0 and 10 h) during chilling included the following: (i) no spraying (NT) or spraying (for 30 s every 30 min) with (ii) water, (iii) cetylpyridinium chloride (CPC; 0.1 or 0.5%), (iv) ammonium hydroxide (AH; 0.05%), (v) lactic acid (LA; 2%), (vi) acidified sodium chlorite (ASC; 0.12%), (vii) peroxyacetic acid (PAA; 0.02%), (viii) sodium hydroxide (SH; 0.01%), or (ix) sodium hypochlorite (SC; 0.005%) solutions of 4 degrees C. Samples were taken at 0, 10, 24, 36, and 48 h of the chilling process to determine changes in E. coli O157:H7 populations. Phase 1 tested water, SH, PAA, LA, and 0.5% CPC on meat inoculated with non-acid-habituated pathogen populations, whereas phase 2 tested water, SC, AH, ASC, LA, and 0.1% CPC on meat inoculated with acid- and non-acid-habituated populations. Reductions in non-acid-habituated E. coli O157:H7 populations from phase 1 increased in the order NT = water = SH < PAA < LA < CPC. Reductions from phase 2 for acid-habituated cells increased in the order NT = water = SC < ASC = LA = AH < CPC, whereas on non-acid-habituated cells the order observed was NT = water = SC < AH = ASC < LA < CPC. Previous acid habituation of E. coli O157:H7 inocula rendered the cells more resistant to the effects of spray chilling, especially with acid; however, the trend of reduction remained spray chilling with water = non-spray chilling < spray chilling with chemical solutions.

Characterization of Nutty Flavor in Cheddar Cheese

The objectives of this study were to determine the volatile components responsible for the sensory perception of nutty flavor in Cheddar cheese. Cheddar cheeses with and without nutty flavors were selected by descriptive sensory analysis. Volatile aroma components from Cheddar cheeses with and without nutty flavors were isolated and characterized using solvent extraction with high vacuum distillation, dynamic headspace analysis, gas chromatography-olfactometry, and gas chromatography-mass spectrometry. More than 50 aroma-active compounds were detected in Cheddar cheeses. Consistent differences were observed between nutty and not nutty Cheddar cheeses. Strecker aldehydes were detected in higher amounts in Cheddar cheeses with nutty flavors compared with Cheddar cheeses without nutty flavors. Strecker aldehydes, dimethyl sulfide, and propionic acid were evaluated in young and aged Cheddar cheese models for nutty flavor by descriptive sensory analysis. Dimethyl sulfide and propionic acid did not contribute to nutty flavor in Cheddar cheese. The addition of Strecker aldehydes to young (<4 mo old) Cheddar cheese models resulted in nutty/malty flavor perceived by sensory analysis. When Strecker aldehydes were incorporated into aged (>9 mo old) Cheddar cheese models, nutty flavor perception increased. Strecker aldehydes contribute to nutty flavor in aged Cheddar cheese.

Agricultural recycling of the by-product concentrate of livestock wastewater treatment plant processed with VSEP RO and bio-ceramic SBR

One of the problems in a reverse osmosis process for livestock wastewater treatment is disposal of the by-product concentrate. The agricultural recycling of the concentrate is more cost saving than a further treatment. Application of the concentrate reduces the chemical fertilizer amendment. The agricultural recycling of the concentrate from the Kimhae livestock wastewater treatment plant, processed with the VSEP RO and bio-ceramic SBR, was studied. The concentrate includes non-biodegradable humic ubstance and residual inorganic ions (NH4+, NO3-, PO4(3-), K+, etc.). The contents of N, P and K were 1,650, 382 and 2,059 mg L(-1), respectively. The total acidity of humic acids extracted from the concentrate was 5.17 cmol(+) g(-1), composed of 2.38 cmol(+) g(-1) of carboxylic group and 2.79 cmol(+) g(-1) of phenolic hydroxyl group. Coliforms and E. coli were not detected in the concentrate. The yield of rice plant with the concentrate applied to it resulted in similar production to that with chemical fertilizer applied. The water extractable nitrate content of the concentrate-applied land did not exceed that of chemical fertilizer applied, at soil depths of 30 and 60 cm. The percolated amount of nitrate into the water table in arable land with the concentrate applied showed a similar level to that treated with the chemical fertilizer.

A Web-based interactive education programme on vaccination for public health officials

Health and Welfare Training Center of Korean National Institute of Health (KNIH) has developed various education curricula for officials who are involved in the public health or welfare sectors. Still almost all education programmes are off-line based. In off-line settings, both the lecturers and the students should come to NIH from their counties to join the education programmes, and it is impossible for the students to review or to re-practice the education contents. We developed a prototype on-line setting education programmes to provide a more convenient and more effective service to the officials. This web-based interactive education programme consisted of the specific objectives on vaccination for the public health officials who were working for the national immunization programmes. It became a prototype of web-based education and was evaluated by the participants in April, 2001. From the evaluation, we improved the contents and tried to develop more subjects for the officials' training.