• Journal of Microbiology and Biotechnology
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• v.34 no.2
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• pp.340-348
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• 2024

Salmonella, a major contributor to foodborne infections, typically causes self-limiting gastroenteritis. However, it is frequently invasive and disseminates across the intestinal epithelium, leading to deadly bacteremia. Although the genus is subdivided into >2,600 serotypes based on their antigenic determinants, only few serotypes are responsible for most human infections. In this study, a rapid dot-blot immunoassay was developed to diagnose multiple Salmonella enterica serotypes with high incidence rates in humans. The feasibility of 10 commercial antibodies (four polyclonal and six monoclonal antibodies) was tested using the 18 serotypes associated with 67.5% Salmonella infection cases in the United States of America (U.S.A) in 2016. Ab 3 (polyclonal; eight of 18 serotypes), Ab 8 (monoclonal; 13 of 18 serotypes), and Ab 9 (monoclonal; 10 of 18 serotypes) antibodies exhibited high detection rates in western blotting and combinations of two antibodies (Ab 3+8, Ab 3+9, and Ab 8+9) were applied to dot-blot assays. The combination of Ab 3+8 identified 15 of the tested 18 serotypes in 3 h, i.e., S. Enteritidis, S. Typhimurium, S. Javiana, S. I 4,[5],12:i:-, S. Infantis, S. Montevideo, S. Braenderup, S. Thompson, S. Saintpaul, S. Heidelberg, S. Oranienburg, S. Bareilly, S. Berta, S. Agona, and S. Anatum, which were responsible for 53.7% Salmonella infections in the U.S. in 2016. This cost-effective and rapid method can be utilized as an on-site colorimetric method for Salmonella detection.

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.894-905
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• 1992

Dioxygen binding and homogeneous catalytic oxidation of hydrazobenzene were investigated by employing tetradentate Schiff base Cobalt(II) complexes such as Co(II)(SED)$(Py)_2$, Co(II)(SOPD)$(Py)_2$ and Co(II)(SND)$(Py)_2$ in saturated oxygen methanol solvent. The major product of hydrazobenzene ($H_2$AB) oxidation by catalysts of superoxo type [Co(III)(SED)(Py)$O_2$] and [Co(III)(SOPD)(Py)$O_2$] complexes are trans-azobenzene (t-AB) and rate constants k for oxidation reaction was 7.692 ${\times}$ $10^{-2}$ M/sec for [Co(III)(SED)(Py)$O_2$] and 5.076 ${\times}$ $10^{-2}$ M/sec for [Co(III)(SOPD)(Py)$O_2$]. But cis-azobenzene (c-AB) are obtained as a major product with ${\mu}$-peroxo type [Co(III)(SED)(Py)]$_2O_2$ catalyst, and rate constant k is 1.266 ${\times}$ $10^{-2}$ M/sec. The rate constants of oxidation reaction has been studied spectrophotometrically and the rate law established. A mechanism involving a intermediate activated complexes of catalyst, hydrazobenzene and oxygen has been proposed. $H_2$AB + Co(II)(Schiff base)$(Py)_2$ + $O_2$ ${\rightleftharpoons}_{MeOH}^K$ Co(III)(Schiff base)(Py)$O_2$${\cdot}$$H_2$AB + Py $\longrightarrow^k$ Co(II)(Schiff base)$(Py)_2$ + t-AB + $H_2O_2$(Scchiff base : SED and SOPD). $H_2$AB + 2Co(II)(SND)$(Py)_2$ + $O_2$ ${\rightleftharpoons}_{MeOH}^K$ [Co(III)(SND)(Py)]$_2O_2$${\cdot}$H_2$AB + 2Py ${\longrightarrow}^k$ (Co(II)(SND)$(Py)_2$ + c-AB + $H_2O_2$.

• BMB Reports
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• v.38 no.6
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• pp.683-689
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• 2005

Antibody to hepatitis B surface antigen (HBsAb) is the important serological marker of the hepatitis B virus (HBV) infection. Conventionally, the hepatitis B surface antigen (HBsAg) obtained from the plasma of HBV carriers is used as the diagnostic antigen for detection of HBsAb. This blood-origin antigen has some disadvantages involved in high cost, over-elaborate preparation, risk of infection, et al. In an attempt to explore the suitable recombinant HBsAg for the diagnostic purpose, the HBV S gene was expressed in Pichia pastoris and the product was applied for detection of HBsAb. Hepatitis B virus S gene was inserted into the yeast vector and the expressed product was analyzed by sodium dodecyl sulphate polyacrolamide gel electrophoresis (SDS-PAGE), immunoblot, electronic microscope and enzyme linked immunosorbent assay (ELISA). The preparations of synthesized S protein were applied to detect HBsAb by sandwich ELISA. The S gene encoding the 226 amino acid of HBsAg carrying ahexa-histidine tag at C terminus was successfully expressed in Pichia pastoris. The His-Tagged S protein in this strain was expressed at a level of about 14.5% of total cell protein. Immunoblot showed the recombinant HBsAg recognized by monoclonal HBsAb and there was no cross reaction between all proteins from the host and normal sera. HBsAb detection indicated that the sensitivity reached 10 mIu (micro international unit)/ml and the specificity was 100% with HBsAb standard of National Center for Clinical Laboratories. A total of 293 random sera were assayed using recombinant S protein and a commercial HBsAb ELISA kit (produced by blood-origin HBsAg), 35 HBsAb positive sera and 258 HBsAb negative sera were examined. The same results were obtained with two different reagents and there was no significant difference in the value of S/CO between the two reagents. The recombinant HBV S protein with good immunoreactivity and specificity was successfully expressed in Pichia pastoris. The reagent for HBsAb detection prepared by Pichia pastoris-derived S protein showed high sensitivity and specificity for detection of HBsAb standard. And a good correlation was obtained between the reagent produced by recombinant S protein and commercial kit produced by blood-origin HBsAg in random samples.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.78-81
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• 2008

Purpose: In this study, we evaluated unstable serum data of HBe antigen (HBeAg) or HBe antibody (HBeAb) in patients who experienced HBeAg seroconversion. This study have been performed to assist a medical technologist in the recognition of patients who were chronically infected with the hepatitis B virus (HBV). Materials and Methods: A total number of 3 patients were enrolled in this study. All patients experienced HBeAg seroconversion. Serum data of HBeAg and HBeAb were measured by radioimmunoassay. Results: The data of HBeAg or HBeAb showed an unstable change during seroconversion from HBeAg to HBeAb in chronic type B hepatitis (CBH). Conclusions: Serum data of HBeAg or HBeAb can change during HBe seroconversion. These data suggest that patients with HBe seroconversion can experience an unstable oscillation of HBeAg or HBeAb value from positive to negative. Unstable data can appear naturally due to the seroconversion process.

• Clean Technology
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• v.27 no.3
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• pp.261-268
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• 2021

Equilibrium, kinetics, and thermodynamics of adsorption of acid black 1 (AB1) by coal-based granular activated carbon (CGAC) were investigated with the adsorption variables of initial concentration of dye, contact time, temperature, and pH. The adsorption reaction of AB1 by activated carbon was caused by electrostatic attraction between the surface (H⁺) of activated carbon and the sulfite ions (SO₃^-) and nitrite ions (NO₂^-) possessed by AB1, and the degree of reaction was highest at pH 3 (97.7%). The isothermal data of AB1 were best fitted with Freundlich isotherm model. From the calculated separation factor (1/n) of Freundlich, it was confirmed that adsorption of AB1 by activated carbon could be very effective. The heat of adsorption in the Temkin model suggested a physical adsorption process (< 20 J mol^-1). The kinetic experiment favored the pseudo second order model, and the equilibrium adsorption amount estimated from the model agreed to that given by the experiments (error < 9.73% ). Intraparticle diffusion was a rate controlling step in this adsorption process. From the activation energy and enthalpy change, it was confirmed that the adsorption reaction is an endothermic reaction proceeding with physical adsorption. The entropy change was positive because of an active reaction at the solid-liquid interface during adsorption of AB1 on the activated carbon surface. The free energy change indicated that the spontaneity of the adsorption reaction increased as the temperature increased.

• Archives of Pharmacal Research
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• v.17 no.4
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• pp.249-255
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• 1994

An efficient synthetic method for 11-deoxyanthracycline AB synthons is described. A verstile key intemediate vinyl bromide 3 was prepared from 5- methodxy-1-tetralone in three steps, and then was converted to the allylic alcohols 4 and 8 which, in tum, fumished highly fuctionalized AB synthons 7 and 12, respectively, via sequential epoxidation-reduction-protection processes.

• Communications for Statistical Applications and Methods
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• v.10 no.1
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• pp.115-123
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• 2003

In this paper, we discuss the usefulness of AB/BA/AA/BB crossover design sense of sample size. The result is that the AB/BA/AA/BB crossover design is more economical than AB/BA one if large carryover effect exists and so is it in the comparison with completely randomized design within-subject correlation is large.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.6 no.1
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• pp.32-38
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• 2003

Purpose: Hepatic allografts from donors with hepatitis B core antibody have been demonstrated to transmit hepatitis B virus (HBV) infection to recipients after liver transplantation (LT). The efficacy of hepatitis B immune globulin (HBIg) to prevent de novo hepatitis B was investigated by comparing active immunization in the early phase to HBIg monotherapy in the late phase of pediatric liver transplants at Samsung Medical Center. Methods: Among pediatric liver transplants, from May, 1996 to June, 2002, 15 recipients who were hepatitis B surface antigen (HBsAg) (-) received an allograft from a donor with hepatitis B core antibody (HBcAb) (+). Except two who died from unrelated causes, eleven of 13 recipients were HBsAb (+), and 2 were naive (HBsAb(-), HBcAb(-)). All patients were vaccinated for HBV before LT. In the early phase (January, 1997~November, 1997, 3 patients), HBsAb (+) recipients received booster vaccination after LT. In the late phase (December, 1997~, 10 patients), all recipients were given booster vaccination and received HBIg therapy in order to maintain HBsAb titer greater than 200 IU/L. Lamivudine was given in one case because of severe side effect of HBIg. We retrospectively analyzed the effect of the preventive therapy for de novo hepatitis B through medical records. Results: De novo hepatitis B developed in three of 13 recipients (23.1%). All of 3 patients who received active immunization in the early phase became HBsAg (+) at 7~19 months after transplantation. One of them was naive before LT and the other two were HBsAb (+). All of 10 recipients who were given HBIg in the late phase remained HBsAg (-) at 7~55 months' follow-up. Conclusion: Passive immunization with HBIg was effective for prevention of de novo hepatitis B in HBsAg (-) recipients of hepatic allografts from HBcAb (+) donors.

• Journal of Life Science
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• v.18 no.6
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• pp.858-864
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• 2008

In the greenhouse fields for fruits and vegetables during the winter in Korea, there are serious damages by the sclerotium diseases due to the low temperature and humidity. This study was carried out to select an antagonic agent for the biological control of the sclerotium diseases. The 55 antagonic agents were selected from the rhizosphere in soil where the fruits and vegetables were cultivated in the green house fields, and strain AB02 among the tested isolates was estimated to be the strongest antagonist against the sclerotium disease. Using strain AB02, the antifungal spectrum was tested against 5 different plant pathogens. According to the results of the test, strain AB02 . showed the high antagonistic effect against Botrytis cinerea and Sclerotinia sclerotiorum. For the experiment of biological control against the sclerotium disease, it was estimated the suppression effect and the control effect by the strain in the pot experiment using the green perilla. According to the result of the pot experiments, the suppression effect was 40% and the control effect was 62%, respectively. For the stimulation effect of the tested plant growth by strain AB02 compared to the control, it was improved as 120% for the total length, 141% for the liveweight, 121% for the total number of leaves, 185% for the leaf area, and 327% for the liveweight of the root, respectively. Strain AB02 showing the antagonistic effect against the sclerotium disease and the stimulation effect for the plant growth was identified as Bacillus sp.

• Animal cells and systems
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• v.15 no.4
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• pp.259-267
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• 2011

This study was undertaken to produce a $F_{ab}$ fragment of a human monoclonal antibody reactive to oxidized and carbamylated low-density lipoprotein (oxLDL and cLDL) using phage display technology. An analysis of DNA sequences of this $F_{ab}$, termed plaque 15,16-46 $F_{ab}$, revealed that the rearranged $V_H$ was highly mutated. Complementarity-determining regions of the $V_H$ showed a very high R/S ratio and contained many positively charged amino acids. In direct binding and competitive ELISA, the $F_{ab}$ reacted strongly with both MDA-LDL and Cu-oxLDL forms of oxLDL, and also showed high affinity for cLDL. Immunofluorescence and immunohistochemical analyses showed that this $F_{ab}$ positively stained atherosclerotic aortic plaques in $ApoE^{-/-}$ mice as well as those in patients with atherosclerosis. The $F_{ab}$ also showed positive staining in placental decidua from patients with preeclampsia. It is suggested that the plaque 15,16-46 $F_{ab}$ against oxLDL and cLDL might possibly be applicable for developing a diagnostic reagent for both human and rodent animal research to detect and characterize atherosclerotic disease progression in atherosclerotic lesions as well as exploring the pathogenesis of atherogenic diseases such as preeclampsia.