Multiple-electrode radiofrequency ablations using Octopus® electrodes in an in vivo porcine liver model

OBJECTIVES

The objective of this study was to determine the in vivo efficacy of radiofrequency ablation (RFA) in porcine liver using Octopus® electrodes for creating a large coagulation compared with RFA using clustered electrodes.

METHODS

A total of 39 coagulations were created using a 200-W generator and clustered electrodes or Octopus electrodes during laparotomy in 19 pigs. Radiofrequency was applied to the livers using four protocols: (1) Group A-1, monopolar mode using a clustered electrode (n=11); (2) Group A-2, monopolar mode using an Octopus electrode (n=11); (3) Group B-1, consecutive monopolar mode using three, clustered electrodes (n=8); and (4) Group B-2, switching monopolar mode using two Octopus electrodes (n=9). The energy efficiency, shape, diameters (D) and volume (V) of the coagulation volume were compared in each of the two groups.

RESULTS

The mean maximum D and V of the coagulations in Group A-2 (4.7 cm and 33.1 cm(3), respectively) were significantly larger than those in Group A-1 (4.1 cm and 20.3 cm(3), respectively) (p<0.05). Furthermore, the mean minimum D, maximum D and V of the coagulations in Group B-2 were significantly larger than those in Group B-1, i.e. 5.3 vs 4.0 cm, 6.6 vs 4.9 cm and 66.9 vs 30.2 cm(3), respectively (p<0.05). The energy efficiencies were also significantly higher in Groups A-2 and B-2 than in Groups A-1 and B-1 (p<0.05).

CONCLUSION

The Octopus electrodes were more efficient for creating a large ablation zone than clustered electrodes, and the efficacy of RFA with Octopus electrodes can be amplified in the switching monopolar mode.

1,3-Diphenylpropenone ameliorates TNBS-induced rat colitis through suppression of NF-κB activation and IL-8 induction

In the present study, we examined whether newly synthesized phenylpropenone derivatives, by inhibiting NF-κB activity, would inhibit IL-8 expression, inflammation and abnormal angiogenesis, resulting in amelioration of disease conditions. The phenylpropenone derivatives inhibited NF-κB transcriptional activity, which correlated with their suppressive activity against TNF-α-induced adhesion of U937 human monocytic cells to HT-29 human colonic epithelial cells, an in vitro model of IBD. Among the derivatives, 1,3-diphenylpropenone (DPhP) was most efficacious, and it significantly suppressed TNF-α-induced production of IL-8 which is a proinflammatory and proangiogenic cytokine. The anti-inflammatory activity of DPhP was also confirmed in the trinitrobenzene sulfonic acid (TNBS)-induced rat colitis model. DPhP was protective against the TNBS-induced inflammatory responses, which included weight loss, increased myeloperoxidase activity and mucosal damage. In the colon tissue, DPhP inhibited TNBS-induced NF-κB nuclear translocation, IL-8 and TNF-α expressions, and abnormal angiogenesis. In addition, DPhP also suppressed IL-8-induced angiogenesis, which was revealed by an in vivo assay using chick chorioallantoic membrane. Furthermore, the level of IL-6, a pleiotropic cytokine which is implicated in the pathogenesis of IBD and colitis-associated cancer, was suppressed by DPhP in rat colon tissue and serum. In conclusion, the results suggest that DPhP is a potential dual-acting IBD drug candidate targeting both inflammation and abnormal angiogenesis, possibly through the NF-κB and IL-8 signaling pathway.

P1-01-07: ErbB-2 Peptide Vaccination Suppresses Spontaneous Tumorigenesis and Tumor Stem Cell Expansion in MMTV-PyVT Transgenic Mouse

Immunization targeting ErbB-2 could have considerable therapeutic potential by controlling growth and metastasis of highly aggressive tumor cells in the earlier preclinical and clinical studies. Just a few studies have examined preventive potential of ErbB-2 vaccines in preclinical studies. However, animal model systems used in the previous studies were tumor transplantation or neu-transgenic mouse, which were not relevant to human HER-2 positive breast tumorigenesis. In this study, active immunotherapy against tumor antigen ErbB-2/neu for primary prevention of breast cancer was tested using FVB/N-Tg (MMTV-PyVT) transgenic mice model. Mice were grouped to receive either ErbB-2 peptide vaccine, immune adjuvant only, tetanus toxoid, or PBS every 2 weeks for 3 times and monthly thereafter. The MMTV-PyVT transgenic mice in control groups (PBS, immune adjuvant only, or tetanus toxoid peptide) developed spontaneous mammary adenocarcinomas in 12 to 15 weeks, but vaccination against ErbB-2 strongly suppressed tumor formation by 30 weeks of observation. Further pathologic examination showed complete prevention of tumorigenesis was observed in ErbB-2 vaccinated mice, whereas the mice in control groups developed highly aggressive ErbB-2 overexpressing tumors similar to human breast cancer. The tumor protective effect of peptide vaccination was associated with induction of ErbB-2-specific humoral immune responses as well as T cell responses. Additionally, role of signal through ErbB-2 pathway and the relationship with stemness of cancer cells were determined by Aldefluor assay, mammosphere formation assay using Mouse mammary carcinoma (MMC) cells in vitro, and level of nestin expression determined by Western blot analysis. Further analysis of mammosphere formation capacity of MMC cells using immune sera showed that sera from ErbB2 vaccinated mice had a significant inhibitory effect on mammosphere formation in ErbB-2 overexpressing MMC cells. These results suggest that ErbB-2 targeting by cancer vaccination might be useful adjuvant to standard therapy, helping to prevent relapse in patients with ErbB-2-overexpressing tumors by suppressing stem/progenitor cell population.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-01-07.

Small bowel carcinoma in young patient detected by double-balloon enteroscopy

A 17-year old female presented with a chief complaint of melena and epigastric pain. She had a family history of colon cancer, her mother having been diagnosed with hereditary nonpolyposis colorectal carcinoma (HNPCC). After close examination including double-balloon enteroscopy, the patient was diagnosed with small bowel carcinoma, in spite of her young age. Here we report this rare case of small bowel carcinoma in a young patient with a family history of HNPCC.

Stress as an influencing factor in psoriasis

Emotional stress may influence the development and exacerbation of psoriasis. The proportion of psoriasis patients who believe stress affects their skin condition (i.e., "stress responders") is considerably high, ranging from 37% to 78%. Stress may worsen psoriasis severity and may even lengthen the time to disease clearance. Although a pathogenic association appears likely, additional well-controlled studies are necessary to confirm such a causal relationship. Dysregulation of the hypothalamus-pituitary-adrenal and sympathetic adrenomedullary systems has been proposed as one possible underlying cause of stress-induced flares of psoriasis. While stress may be an exacerbating factor, psoriasis itself may contribute to significant adverse psychological sequelae. Breaking this stress cycle may be an important part of any therapeutic approach. Thus, stress reduction through psychotherapy and pharmacotherapy may be useful in treating psoriatic patients who are stress responders.

Feasibility of hydrogen production from ripened fruits by a combined two-stage (dark/dark) fermentation system

Anaerobic fermentation for hydrogen (H2) production was studied in a two-stage fermentation system fed with different ripened fruit feedstocks (apple, pear, and grape). Among the feedstocks, ripened apple was the most efficient substrate for cumulative H2 production (4463.7 mL-H2 L(-1)-culture) with a maximum H2 yield (2.2 mol H2 mol(-1) glucose) in the first stage at a hydraulic retention time (HRT) of 18 h. The additional cumulative biohydrogen (3337.4 mL-H2 L(-1)-culture) was produced in the second stage with the reused residual substrate from the first stage. The major byproducts in this study were butyrate, acetate, and ethanol, and butyrate was dominant among them in all test runs. During the two-stage system, the energy efficiency (H(2) conversion) obtained from mixed ripened fruits (RF) increased from 4.6% (in the first stage) to 15.5% (in the second stage), which indicated the energy efficiency can be improved by combined hydrogen production process. The RF could be used as substrates for biohydrogen fermentation in a two-stage (dark/dark) fermentation system.

Negative refraction power causes underestimation of peripapillary retinal nerve fibre layer thickness in spectral-domain optical coherence tomography

BACKGROUND/AIMS

Although studies using optical coherence tomography (OCT) reported that the retinal nerve fibre layer (RNFL) thickness of myopic eyes was thinner than those of normal controls, it was unclear if this finding indicated the difference in actual structural thickness or that created by sources affecting accuracy of OCT measurement. This study's aim was to evaluate the effect of refraction power on the measurement of the RNFL thickness using spectral-domain OCT.

METHODS

OCT scans to measure RNFL thickness were repeated in 15 cycloplegic eyes of 15 participants, while different refraction powers were induced by wearing soft contact lenses of eight different dioptres (-6 to +8).

RESULTS

Measured RNFL thicknesses decreased significantly with soft contact lenses of higher plus dioptres and increased with those of more minus dioptres. This finding was consistent with or without controlling factors including the signal strength and test-retest variability of the machine. Measurement of peripapillary RNFL thicknesses was not varied between scans performed with and without plano contact lenses.

CONCLUSIONS

In spectral-domain OCT, RNFL thickness was underestimated in eyes with increasing negative refraction power and overestimated with increasing positive refraction power.

The effect of 1-furan-2-yl-3-pyridine-2-yl-propenone on pharmacokinetic parameters of theophylline

The pharmacokinetic parameters of theophylline in rats did not change significantly when the drug was intravenously administered after three consecutive days of pretreatment with 17 mg/kg, orally, of 1-furan-2-yl-3-pyridine-2-yl-propenone (FPP-3), an investigatory drug having dual inhibitory action on cyclooxygenase (COX) and 5-lipoxygenase (5-LOX). However, significant changes were found in the pharmacokinetic parameters of the drug at doses of 34 mg/kg and more of FPP-3. Results of cytochrome P450 activity test indicated that the alteration in pharmacokinetic parameters of the drug appears to be due to the inhibitory effect of FPP-3 on cytochrome P450 1A which is responsible for the metabolism of theophylline. Methoxyresorufin-O-demethylase (MROD) and ethoxyresorufin-O-deethylase (EROD) activity assays revealed that the relative activities of cytochrome P450 1A1 and 1A2 were dose-dependently reduced in the presence of 1, 5, and 10 microM FPP-3 concentrations. Taking into consideration that FPP-3 is intended to be primarily used by geriatric patients with chronic diseases and therefore may be used in long-term basis, the investigatory drug needs to be assessed thoroughly in terms of drug interaction with other commonly prescribed medications.

Characteristics of permanganate oxidation of TCE at low reagent concentrations

A controlled-release technique using potassium permanganate (KMnO4) has been recently developed as a long-term and semi-passive remediation scheme for dilute groundwater plumes of chlorinated solvents such as trichloroethylene (TCE) and perchloroethylene. Batch experiments were performed to evaluate TCE removal efficiencies of a low concentration of permanganate (MnO4-) solution and to estimate the optimum dose of permanganate required to remove low levels of TCE from groundwater plumes without leaving intermediate organic forms. Experimental results indicated that when the molar ratio of [MnO4-]0/[TCE]0 was about 10, 95% of the TCE in the plume was removed within less than 90 min, and about 90% of the chloride in the organic forms was converted into inorganic ions, while the TCE removal rates and the chloride conversion rates were considerably lower when the [TCE]0/ [MnO4-]0 values were lower. These data suggested that the [MnO4-]0 and the [MnO4-]0/[TCE]0 values would have strong effects on the efficiency and completeness of TCE oxidation. Further detailed investigations of the effect of [MnO4-]0 and [MnO4-]0/[TCE]0 values on the removal efficiencies and completeness of the TCE oxidation are warranted for successful application of the controlled-release KMnO4 technique in practice.

Mac-2 binding protein and galectin-3 expression in mucinous tumours of the ovary: an annealing control primer system and immunohistochemical study

AIM

We used a new differential display method, the annealing control primer (ACP) system, to analyse the differentially expressed genes in mucinous ovarian tumours. To verify the corresponding target gene, immunohistochemical staining was performed on various epithelial tumours of the ovary.

METHODS AND RESULTS

The ACP-based reverse transcriptase-polymerase chain reaction revealed that 21 genes were upregulated in the mucinous ovarian adenoma and 14 genes were upregulated in the mucinous ovarian carcinoma. Among them, we selected one upregulated gene, the Mac-2 binding protein (Mac-2 BP), and verified the expression of the Mac-2 BP and its ligand, galectin-3, in a variety of epithelial ovarian tumours by immunohistochemistry. Positive expression of the Mac-2 BP was significantly higher in the mucinous ovarian tumours compared to the other epithelial tumours. Mac-2 BP expression was significantly increased in the borderline and malignant tumours compared to the benign tumours. Galectin-3 expression was more frequent in clear cell carcinomas, serous tumours and mucinous tumours than in endometrioid and transitional tumours. However, there were no differences in galectin-3 expression in comparisons among benign, borderline and malignant mucinous and serous tumours.

CONCLUSION

These data indicate that the Mac-2 BP may play a role in the development and progression of mucinous ovarian tumours.

Comparison of risk factors and clinical responses to proton pump inhibitors in patients with erosive oesophagitis and non-erosive reflux disease

BACKGROUND

There has been no report on the response to proton pump inhibitor (PPI) therapy and on-demand or the relapse rate of non-erosive reflux disease (NERD) and erosive oesophagitis in Korea.

AIM

To compare the risk factors, clinical symptoms and PPI responses between patients with erosive oesophagitis and NERD patients.

METHODS

A survey was performed prospectively in the erosive oesophagitis (205 patients) and NERD group (200 patients). Clinical symptoms, risk factors and PPI responses were analysed. On-demand therapy and the relapse rate of GERD symptoms were investigated during a one-year follow-up.

RESULTS

BMI > or = 25 (OR 3.0, 95% CI 1.1-8.3), alcohol use (OR 2.9, 95% CI 1.0-8.3), hiatal hernia (OR 5.0, 95% CI 1.2-20) and triglyceride > or =150 mg/dL (OR 4.0, 95% CI 1.7-10) were more common in the erosive oesophagitis group than in the NERD group by multivariate analysis. The ratio of oesophageal to extra-oesophageal symptoms was higher in the erosive oesophagitis group compared with the NERD group (P < 0.001). The PPI response rates at 8 weeks were different (P = 0.02); refractory rates were higher in the NERD group (16.7%) compared with the erosive oesophagitis group (6.0%). However, there was no significant difference between the two groups in on-demand therapy or the relapse rate.

CONCLUSION

These results suggest that the underlying pathogenic mechanisms of erosive oesophagitis and NERD are distinct.

Characteristics for electrochemical machining with nanoscale voltage pulses

Electrochemical machining has traditionally been used in highly specialized fields, such as those of the aerospace and defense industries. It is now increasingly being applied in other industries, where parts with difficult-to-cut material, complex geometry and tribology, and devices of nanoscale and microscale are required. Electric characteristic plays a principal function role in and chemical characteristic plays an assistant function role in electrochemical machining. Therefore, essential parameters in electrochemical machining can be described current density, machining time, inter-electrode gap size, electrolyte, electrode shape etc. Electrochemical machining provides an economical and effective method for machining high strength, high tension and heat-resistant materials into complex shapes such as turbine blades of titanium and aluminum alloys. The application of nanoscale voltage pulses between a tool electrode and a workpiece in an electrochemical environment allows the three-dimensional machining of conducting materials with sub-micrometer precision. In this study, micro probe are developed by electrochemical etching and micro holes are manufactured using these micro probe as tool electrodes. Micro holes and microgroove can be accurately achieved by using nanoscale voltages pulses.

Asiatic Acid Derivatives Protect Primary Cultures of Rat Hepatocytes against Carbon Tetrachloride-Induced Injury via the Cellular Antioxidant System

We attempted to elucidate the hepatoprotective mechanism of two asiatic acid (AS) derivatives, 3β,23-dihydroxyurs-2-oxo-12-ene-28-oic acid (AS-10) and 3β,23-dihydroxyurs-12-ene-28-oic acid (AS-14), which exhibited significant protective activity against carbon tetrachloride (CCl4)-induced hepatotoxicity in primary cultures of rat hepatocytes. Our findings showed that AS-10 and AS-14 preserved the level of glutathione and the activities of antioxidant enzymes such as glutathione reductase, glutathione peroxidase, superoxide dismutase and catalase. In addition, these compounds ameliorated lipid peroxidation, as demonstrated by a reduction in the production of malondialdehyde. Furthermore, AS-10 and AS-14 did not restore the reduced total GSH level by BSO, indicating that the hepatoprotective activities of these compounds may be involved, in part, by regulating GSH synthesis. From these results, we suggest that both AS-10 and AS-14 exerted their hepatoprotective activities against CCl4-induced injury by preserving the cellular antioxidative defense system.

Asiatic acid derivatives protect primary cultures of rat hepatocytes against carbon tetrachloride-induced injury via the cellular antioxidant system

We attempted to elucidate the hepatoprotective mechanism of two asiatic acid (AS) derivatives, 3beta,23-dihydroxyurs-2-oxo-12-ene-28-oic acid (AS-10) and 3beta,23-dihydroxyurs-12-ene-28-oic acid (AS-14), which exhibited significant protective activity against carbon tetrachloride (CCl4)-induced hepatotoxicity in primary cultures of rat hepatocytes. Our findings showed that AS-10 and AS-14 preserved the level of glutathione and the activities of antioxidant enzymes such as glutathione reductase, glutathione peroxidase, superoxide dismutase and catalase. In addition, these compounds ameliorated lipid peroxidation, as demonstrated by a reduction in the production of malondialdehyde. Furthermore, AS-10 and AS-14 did not restore the reduced total GSH level by BSO, indicating that the hepatoprotective activities of these compounds may be involved, in part, by regulating GSH synthesis. From these results, we suggest that both AS-10 and AS-14 exerted their hepatoprotective activities against CCl4-induced injury by preserving the cellular antioxidative defense system.

Metabolic syndrome and quality of life (QOL) using generalised and obesity-specific QOL scales

OBJECTIVES

We investigated the association between metabolic syndrome (MS) and health-related quality of life (HRQOL) assessed using generalised and obesity-specific QOL instruments.

METHODS

We recruited 456 outpatients [age: 19-81 years, body mass index (BMI): 16.3-36.7 kg/m2] in the primary care division from 12 general hospitals in Korea. HRQOL was measured using EuroQol comprising the health states descriptive system (EQ-5D) and visual analogue scale (EQ-VAS) as a general instrument. The Korean Obesity-related QOL scale (KOQOL) composed of six domains was used as a disease-specific QOL instrument. MS was defined on the basis of International Diabetes Federation (IDF) criteria with Korean-specific waist circumference cutoffs (men: 90 cm, women: 85 cm).

RESULTS

Subjects with MS displayed significantly higher impairment of EQ-5D and KOQOL. Binary logistic regression analysis of MS patients with controls for age, gender, smoking, alcohol, exercise, education, income, marital status and medication history disclosed odds ratio (OR) values of 2.13 (1.33-3.41) for impaired total KOQOL, 2.07 (1.31-3.27) for impaired physical health, 1.63 (1.03-2.60) for impaired work-related health, 2.42 (1.45-4.04) for impaired routine life, 2.08 (1.27-3.40) for impaired sexual life and 2.56 (1.59-4.11) for diet distress. Among the EQ-5D dimensions, only pain/discomfort displayed a significantly increased OR of 1.60 (1.01-2.56) in MS group.

CONCLUSIONS

Subjects with MS displayed a significantly impaired HRQOL compared with those without MS. MS and HRQOL were more strongly associated in obesity-specific QOL than in generalised QOL.

Efficacy of controlled-release KMnO4 (CRP) for controlling dissolved TCE plume in groundwater: a large flow-tank study

A well-based, reactive barrier system using controlled-release potassium permanganate (CRP system) was recently developed as a long-term treatment option for dilute plumes of chlorinated solvents in groundwater. In this study, we performed large-scale (L x W x D = 8 m x 4 m x 2 m) flow-tank experiments to examine remedial efficacy of the CRP system. A total of 110 CRP rods (OD x L=5 cm x 150 cm) were used to construct a well-based CRP system (L x W x D = 3 m x 4 m x 1.5 m) comprising three discrete barriers installed at 1-m interval downstream. Natural sands having oxidant demand of 3.7 g MnO(4)(-)kg(-1) for 500 mg L(-1)MnO(4)(-) were used as porous media. After MnO(4)(-) concentrations were somewhat stabilized (0.5-6.0 mg L(-1)), trichloroethylene (TCE) plume was flowed through the flow-tank for 53 d by supplying 1.19 m(3)d(-1) of TCE solution. Mean initial TCE concentrations were 87 microg L(-1) for first 20 d and 172 microg L(-1) for the next 33 d. During TCE treatment, flow velocity (0.60md(-1)), pH (7.0-8.2), and concentrations of dissolved metals ([Al]=0.7 mg L(-1), [Fe]=0.01 mg L(-1)) showed little variations. The MnO(2)(s) contents in the sandy media measured after the TCE treatment ranged from 21 to 26 mg kg(-1), slightly increased from mean baseline value of 17 mg kg(-1). Strengths of the TCE plume considerably diminished by the CRP system. For the 87 microg L(-1) plume, TCE concentrations decreased by 38% (53), 67% (29), and 74% (23 microg L(-1)) after 1st, 2nd, and 3rd barriers, respectively. For the 172 microg L(-1) plume, TCE concentrations decreased by 27% (125), 46% (93), and 65% (61 microg L(-1)) after 1st, 2nd, and 3rd barriers, respectively. Incomplete destruction of TCE plume was attributed to the lack of lateral dispersion in the unpumped well-based barrier system. Development of delivery systems that can facilitate lateral spreading and mixing of permanganate with contaminant plume is warranted.

Identification of glutathione conjugates and mercapturic acids of 1,2-dibromopropane in female BALB/c mice by liquid chromatography-electrospray ionization tandem mass spectrometry

Based on recent results that 1,2-dibromopropane (1,2-DBP) causes hepatotoxicity and immunotoxicity in female BALB/c mice as well as a reduction of hepatic glutathione levels, the possible formation of glutathione conjugates and mercapturic acids of 1,2-DBP was investigated in vivo in the present studies. The following four metabolites were identified in the liver at 12 h after treatment with 1,2-DBP, by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS): M1, 2-hydroxypropylglutathione; M2, 2-oxopropylglutathione; M3, N-acetyl-S-(2-hydroxypropyl)-L-cysteine; and M4, N-acetyl-S-(2-oxopropyl)-L-cysteine. Ions of individual conjugates were observed at m/z 366, 364, 222 and 220, respectively. Characteristic product ions at m/z 237, 217, 204 and 202 for the identification of M1, M2, M3 and M4 were observed, respectively. In the sera isolated from the same animals, only mercapturic acids (M3 and M4) were observed by LC-ESI/MS. When female BALB/c mice were treated orally with 1,2-DBP at doses of 150, 300 and 600 mg kg(-1) once for 12 h, the production of glutathione conjugates and mercapturic acids in liver was apparently dose dependent, as were the concentrations of them in sera. When the production of metabolites from 1,2-DBP was investigated in liver following oral treatment with 600 mg kg(-1) 1,2-DBP for 6, 12, 24 and 48 h, metabolite concentrations were greatest at the first time point (6 h). The results explain the authors' previous studies that oral treatment with 1,2-DBP reduces the hepatic content of glutathione.

Antibiogram and coagulase diversity in staphylococcal enterotoxin-producing Staphylococcus aureus from bovine mastitis

We investigated antibiogram and coagulase gene diversity in staphylococcal enterotoxin (StE)-producing Staphylococcus aureus isolated from raw milk samples of cows infected with mastitis from 140 dairy farms in Korea between 1997 and 2004. Of the 696 Staph. aureus isolates collected in this study, 164 isolates (23.6%) produced one or more staphylococcal enterotoxins (A to D), and 19 isolates (2.7%) were methicillin-resistant. The percentage of StE-producing Staph. aureus (SES) isolates resistant to methicillin, kanamycin, neomycin, amikacin, and tetracycline was greater than that of non-SES. Ten coagulase genotype patterns were observed, including 4 main types comprising I (25.4%), II (13.9%), VII (13.2%), and VIII (17.8%). More than 4 Staph. aureus types were isolated from each of 82 dairy farms in different geographic locations, and only 1 coagulase genotype pattern was observed in 39 of the herds (47.6%). There was no significant correlation between coagulase genotypes harbored by Staph. aureus and their specific StE type. The percentage of isolates producing major StE types (A, B, AC, and ABCD) and being resistant to cephalothin and methicillin was greater among the Staph. aureus isolates with the 4 predominant coagulase genotypes (I, II, VII, and VIII) than among the isolates harboring the 6 rare coagulase types (III, IV, V, VI, IX, and X). Based on coagulase gene polymorphisms, our data indicate that a broad distribution of identical or closely related enterotoxin-producing Staph. aureus strains seem to contribute to bovine mastitis in the Republic of Korea.

In vitro characterization of the enzymes involved in the metabolism of 1-furan-2-yl-3-pyridin-2-yl-propenone, an anti-inflammatory propenone compound

Carbonyl reduction is a significant step in the phase I biotransformation of a great variety of aromatic, alicyclic and aliphatic carbonyl compounds. 1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) has been shown to have anti-inflammatory activity as it inhibits the production of nitric oxide and tumor necrosis factor-beta. In the present study, the metabolic fate and possible involvement of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) and carbonyl reductase (CBR) in the metabolism of FPP-3 were investigated in rat liver subcellular fractions. When FPP-3 was incubated with rat liver subcellular fractions in the presence of beta-NADPH, two major peaks were detected by reduction on the propenone: M1 (1-furan-2-yl-3-pyridin-2-yl-propan-1-one) and M2 (1-furan-2-yl-3-pyridin-2-yl-propan-1-ol). Inhibitors of CBR, such as quercitrin, ethacrynic acid and menadione, significantly increased the formation of M1, but effectively inhibited the formation of M2 in subcellular fractions. Meanwhile, 18beta-glycyrrhetinic acid, a selective inhibitor of 11beta-HSD, marginally inhibited the reduction of FPP-3 in microsomes. A good correlation was observed between the formation of M2 and CBR activity with either 4-pyridine carboxaldehyde (r=0.72) or D,L-glyceraldehyde (r=0.63) as substrates in the cytosol. These results indicated that FPP-3 might be metabolized by cytosolic CBR and uncharacterized microsomal reductase(s) in rat liver.

Model-based evaluation of controlled-release systems in the remediation of dissolved plumes in groundwater

Controlled-release, semi-passive reactive barrier systems have been recently developed as a long-term treatment option for controlling the spread of contaminant plumes in groundwater. This paper describes a new computer code, and applies it to study coupled processes of solute release, reaction, and mass transport in an in situ remediation scheme using the controlled release of potassium permanganate. Confidence with the modeling approach was developed by model verifications and simulating results of a pilot-scale test-cell experiment. Sensitivity analyses indicated the possibilities of treatment inefficiencies due to inability of transverse dispersion to mix the permanganate (MnO(4)(-)) within the zone of reaction, fluctuations in source strength due to variations in flow velocity, and the small length of treatment zone due to strong soil utilization of MnO(4)(-). Although problems associated with the fluctuating source strength and strong soil utilization can be addressed by optimizing the release rate, the inefficiency of transverse dispersion to create mixing could pose a serious limitation. Through a series of model simulations, a system of injection/withdrawal wells in a doublet arrangement was developed to facilitate lateral spreading and mixing of MnO(4)(-). A well-mixed, stable MnO(4)(-) zone with predetermined size (DxL=8m x 2m) and concentration ranges (1.5-20 mg l(-1)) was created by four 1-day injection/withdrawal pumping periods over 24 d. This type of mixing zone may persist for many years with periodic well mixing and replacements of exhausted controlled-release forms. Coupled use of the generalized code with field hydrologic data will help to optimize the design and operation of controlled-release systems in practice.