• Korean Journal of Veterinary Research
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• v.25 no.1
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• pp.7-17
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• 1985

Many investigators have been pursuing various attempts so far to produce hepatitis B surface antigen(HBsAg) vaccines using the techniques such as isolation from plasma of chronic HBsAg carrier, recombinant DNA technique or preparation of synthetic peptides specific for immunogenic determinants. Hepatitis B virus can not grow on any cell lines by the tissue culture technique at the present time. The plasma of chronic HBsAg carrier is expensive and its source is limited. The HBsAg from the recombinant DNA technique gave still very low yield. Another approach, therefore, has been initiated to develop a synthetic hepatitis B virus vaccine. The possible use of several distinct synthetic vaccines in prophylaxis can be facilitated by availability of full synthetic immunogens. Peptides synthesized for potential application as antiviral vaccines have been mostly tested in the form of conjugates with carrier proteins, although the free synthetic peptide can be immunogenic. To understand basic knowledges on the antigenicity and immunogenicity of a synthetic peptide specific for major immunogenic determinant of HBsAg, a nonapeptide, $H_2N^{139}Cys-Thr-Lys-Pro-Thr-Asp-Gly-^{146}Asn-Aba$ COOH, which corresponds to HBsAg amino acid residues 139 to 147, was synthesized by the Merrifield's solid-phase method with a slight modification. The antigenicity and immunogenicity of this specific synthetic peptide were examined comparing with purified plasma-derived natural HBsAg. The results obtained are as follows; 1. The peptide synthesized showed the identical amino acid composition to the theoretical value. The degree of purification and molecular weight were acertained by methods of high performance liquid chromatography and mass spectrometry. 2. Using m-maleimidobenzoyl-N-hydroxysuccinimide ester as a conjugating agent, the synthetic peptide was conjugated to rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin. Their conjugation yields were 8.3, 9.5, 15.8, 13.5, and 11.2%, respectively. 3. The natural HBsAg was purified from plasma of chronic HBsAg carrier. By the electron microscopic observation of the purified natural HBsAg preparation, no Dane particles were observed and the preparation showed negative DNA polymerase activity. 4. Antigenicity of the synthetic peptide and the plasma-derived natural HBsAg was determined by competition radioimmunoassay using $^{125}I$-natural HBsAg. Their 50% inhibitions appeared as $90{\mu}g/ml$ and $0.12{\mu}g/ml$ for the synthetic peptide and the natural HBsAg, respectively. This indicates that the former was about 750-fold less antigenic than the latter. 5. Immunogenicity of the synthetic peptide was determined by administering the peptide-carrier conjugates into rabbits with and without Freund's complete adjuvant. Regardless the carrier proteins and adjuvant, positive immune responses to the synthetic peptide were observed. The higher antibody titers, however, were shown in the groups administered with Freund's complete adjuvant. 6. Immunizing dose 50% in mice of the various peptide-carrier conjugates was 5.47, 6.00, 65.16, 31.25 and $13.03{\mu}g/dose$ for rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin, respectively, while the natural HBsAg showed $0.65{\mu}g/dose$. 7. It was postulated that homologous proteins prefer to heterologous ones as the carriers.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.1-6
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• 2008

Purpose: Plastic optical monomer materials having ultra high refractive index have an income of the whole quantity from advanced nations to domestic companies which are related to plastic optical lens. It is necessary to develop novel plastic optical lens materials in order to overcome a FTA provision and revitalize a stagnating optical lens industry in the interior optical lens industries. The new plastic optical lens materials against the substitution effect of income should be gradually demanded. This work will be synthesized novel super high refractive monomer resin materials of urethane lens series and studied the properties of optical lens using it. Methods: ETS-4 (2-(2-mercaptoethylthio)-3-{2-[3-mercapto-2-(2-mercaptoethylthio)propyl thio]ethylthio}propane -1-thiol), which is optical lens monomer resin having super high refractive index, was synthesized and identified its structure and property by elemental analysis, EI-MS, TGA, FT-IR spectroscopy, $^1H$ and $^{13}C$ NMR spectroscopies. After mixing evenly from mixed monomer resin and diisocyanate series, it was casting in glass mold. After thermal curing, the obtained optical lenses were measured and compared with the refractive index and Abbe number for studies of their optical properties. Results: We have synthesized the novel ultra high refractive index monomer resin, ETS-4, and have identified its structure and property by elemental analysis, EI-MS, TGA, FT-IR spectroscopy, $^1H$ and $^{13}C$ NMR spectroscopies. The existence of three isomers for EST-4 was identified by $^{13}C$ NMR spectroscopy. The refractive index ($N_d$ at $25^{\circ}C$) of monomer resin in liquid state obtained from the Abbe refractometer was 1.647. The refractive indexes of raw plastic optical lenses prepared from the mixed ETS-4 monomer and diisocyanate series were in the range of 1.656~1.680. Conclusions: Novel super high refractive index plastic optical lens monomer was synthesized and analysed, the optical lenses prepared using it were colorless transparency and excellent properties. It is of utility for the industrialization.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.1
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• pp.31-38
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• 2006

Purpose: Infantile constipation is one of the most common problems in pediatric gastrointestinal outpatient clinic. We planed to show the clinical feature of infantile constipation and explore the possible relationship between diets and symptoms of constipation. Methods: We analyzed the medical records and telephone questionnaire about infants under 2 years of age with constipation, who visited outpatient clinic of Department of Pediatrics, Ilsan Paik Hospital during the time from March 2002 to February 2005. Data including the symptoms and signs of constipation, diet history, and past-medical history were analyzed. Results: Total 96 infants, 40 male and 56 female, were enrolled in this study. The mean age was 9 months. Twenty-three infants were exclusively breast milk fed (BMF), 20 infants were cow's milk fed (CMF) and 53 infants had a history of mixed feeding with cow's milk and breast milk (MMF). Patients showed painful defecation (95.8%), abdominal distension (53.1%), palpable rectal stool (35.1%), hard stool (30.2%), blood-tinged stool (29.2%) and anal fissure (16.7%). Patients with exclusive cow milk feeding had prominent clinical features, such as anal fissure (p=0.03), hematochezia (p=0.04) and palpable rectal stool (p=0.025). Patients who had a history of larger intake of liquid food had a tendency to get anal skin tag (p<0.05). Conclusion: Exclusive breast milk feeding seemed important to avoid constipation with clinical significance. To educate caregivers in appropriate way of the weaning food may help the infants with constipation.

• The Korean Journal of Nuclear Medicine
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• v.39 no.1
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• pp.21-25
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• 2005

Purpose: $^{14}C$-urea breath test (UBT) is a non-invasive and reliable method for the diagnosis of Helicobacter pylori (HP) infection. In this study, we evaluated the diagnostic performance of a new and rapid $^{14}C$-UBT (Heliprobe method), which was equipped with $Geiger-M\ddot{u}ller$ counter and compared the results with those obtained by using the conventional method. Materials and Methods: Forty-nine patients with dyspepsia underwent gastroduodenoscopy and $^{14}C$-UBT. A 37 KBq $^{14}C$-urea capsule was administered to patients and breath samples were collected. In Heliprobe method, patients exhaled into a Hellprobe BreathCard for 10 min. And then the activities of the BreathCard were countered using Heliprobe analyzer. In the conventional method, results were countered using liquid scintillation counter. During gastroduodenoscopy, 18 of 49 patients were underwent biopsies. According to these histologic results, we evaluated the diagnostic performance of two different methods and compared them. Also we evaluated the concordant and disconcordant rates between them. Results: In all 49 patients, concordant rate of both conventional and Heliprobe methods was 98% (48/49) and the discordant rate was 2% (1/49). Thirteen of 18 patients to whom biopsies were applied, were found to be HP positive on histologic results. And both Heliprobe method and conventional method classified 13 of 13 HP-positive patients and 5 of 5 HP-negative patients correctly (sensitivity 100%, specificity 100%, accuracy 100%). Conclusion: The Heliprobe method demonstrated the same diagnostic performance compared with the conventional method and was a simpler and more rapid technique.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.743-760
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• 2014

This study aimed to isolate and identify freshwater algae from the organic agricultural ecosystems and investigate its biological characteristics to study the possibility of utilizing a biomass freshwater algae in organic farming. In the survey area, average water temperature was $12.4{\sim}28.2^{\circ}C$ and the pH ranges were from 6.1 to 8.5. The solid culture method is more suitable than liquid culture method for isolation of freshwater algae with lower contamination level and higher isolation frequency. A total of 115 strains were isolated from six freshwater algae habitats in nine regions in Korea. BGMM (BG11 Modified Medium) amended with NaNO3 and $KNO_3$ as a nitrogen, and $Na_2CO_3$ as carbon source was designed to isolate and culture freshwater algae. Absorbance of freshwater algae culture has increased dramatically to four days and decreased after eight days after inoculation. CHK008 of the seven isolates showed the highest absorbance in seven days after culturing in BGMM. The optimal pH of BGMM for culturing freshwater algae was pH 6-7. As light intensity increased, growth of freshwater algae increased. Among the five kinds of carbon sources, glucose and galactose promoted good growth of freshwater algae in BGMM. The colony color of purified 16 green algae isolates showed a separation of green, dark and light green, and of them, eleven algae strains showed a strong fluorescent light under fluorescence microscopy. Cell size of the green algae showed a wide range of variation depending on the species. General morphology of the green algae strains was spherical. Chlamydomonas sp. was elliptical, and Chlorella sorokiniana was ellipsoidal and cylindrical. All strains of the green algae except for Chlamydomonas sp. did not have flagella. One isolate of Chlamydomonas sp. and five isolates of C. sorokiniana secreted mucus. Sixteen isolates of 16 green algae were identified as two family and six species, Chlorella vulgalis, C. sorokiniana, C. pyrenoidosa, C. kessleri, C. emersonii, and Chlamydomonas sp. based on their morphological characteristics.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.111-119
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• 2013

Eleven mycotoxins, including aflatoxins, ochratoxin A, fumonisins, zearalenone, T-2 toxin, deoxynivalenol, and HT-2 toxin, were analyzed simultaneously in rice, barley, and maize produced in 2011 by liquid chromatography coupled with triple quadrupole mass spectrometry (LC/MS/MS). Limits of detection (LOD) are 0.2 ${\mu}g/kg$ for aflatoxin $B_1$, and $G_1$, 0.3 ${\mu}g/kg$ for aflatoxins $B_2$, and $G_2$, 0.1 ${\mu}g/kg$ for ochratoxin, fumonisins, zearalenone, and T-2 toxin and 3.0 ${\mu}g/kg$ for deoxynivalenol and HT-2 toxin. Limits of quantification (LOQ) were 0.6 ${\mu}g/kg$ for aflatoxins $B_1$, and $G_1$, 0.9 ${\mu}g/kg$ for aflatoxins $B_2$, and $G_2$, 0.3 ${\mu}g/kg$ for ochratoxin, fumonisins, zearalenone, and T-2 toxin and 10.0 ${\mu}g/kg$ for deoxynivalenol and HT-2 toxin. Recoveries for 11 mycotoxins ranged from 70.45 to 111.11%. Fumonisins, deoxynivalenol, and zaeralenone were detected from 0.9 to 334.0 ${\mu}g/kg$ in the polished rice, barley and raw corn cultivated in Korea. Other mycotoxins were not detected. Deoxynivalenol contamination was mainly found in barley (24 out of 43 samples) and the average value in positive samples was 113.30 ${\mu}g/kg$.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.152-159
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• 2008

The purpose of this study was to determine the accurate quantification of vitamin A in infant formula by comparing two different standard stock solutions as well as various sample weights using high performance liquid chromatography. The sources of uncertainty in measurement, such as sample weight, final smaple vloume, and the instrumental results, were identified and used as parameters to determine the combined standard uncertainty based on GUM(guide to the expression of uncertainty in measurement) and the Draft EURACHEM/CITAC Guide. The uncertainty components in measuring were identified as standard weight, purity, molecular weight, dilution of the standard solution, calibration curve, recovery, reproducibility, sample weight, and final sample volume. Each uncertainty component was evaluated for type A and type B and included to calculate the combined uncertainty. The analytical results and combined standard uncertainties of vitamin A according to the two different methods of stock solution preparation were 627 ${\pm}$ 33 ${\mu}$g R.E./100 g for 1,000 mg/L of stock solution, and 627 ${\pm}$ 49 ${\mu}$g R.E./100 g for 100 mg/L of stock solution. The analytical results and combined standard uncertainties of vitamin A according to the various sample weighs were 622 ${\pm}$ 48 ${\mu}$g R.E./100 g, 627 ${\pm}$ 33 ${\mu}$g R.E./100 g, and 491 ${\pm}$ 23 ${\mu}$g R.E./100 g for 1 g, 2 g, and 5 g of sampling, respectively. These data indicate that the preparation method of standard stock solution and the smaple amount were main sources of uncertainty in the analysis results for vitamin A. Preparing 1,000 mg/L of stock solution for standard material sampling rather than 100 mg, and sampling not more than 2 g of infant formula, would be effective for reducing differences in the results as well as uncertainty.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.508-514
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• 2016

Effects of the ethyl acetate fraction from gomchwi (Ligularia fischeri) extract against high $glucose/H_2O_2-induced$ oxidative stress and in vitro neurodegeneration were investigated to confirm the physiological property of the extract. The ethyl acetate fraction of gomchwi extract showed the highest total phenolic contents than the other solvent fractions. An anti-hyperglycemic activity of the ethyl acetate fraction was evaluated using the ${\alpha}-glucosidase$ inhibitory assay, and the half maximal inhibitory concentration ($IC_{50}$) value for ${\alpha}-glucosidase$ was found to be $727.64{\mu}g/mL$. In addition, the ethyl acetate fraction showed excellent 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt radical scavenging activity, and inhibition of malondialdehyde production. The ethyl acetate fraction also decreased intracellular reactive oxygen species, whereas neuronal cell viability against high glucose/$H_2O_2$-induced cytotoxicity was found to be increased. Finally, 3,5-dicaffeoylquinic acid as a main phenolic compound in the ethyl acetate fraction was analyzed by high-performance liquid chromatography. These results suggest that gomchwi might be a good natural source of functional materials to prevent diabetic neurodegeneration.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.430-437
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• 2017

The protective effect of Pteridium aquilinum on high glucose-induced cytotoxicity was examined in vitro to investigate the relationship between diabetic condition and neuronal dysfunction. The ethyl acetate fraction of P. aquilinum (EFPA), with total phenolic content of 265.08 mg gallic acid equivalent/g, showed higher 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)/2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and lipid peroxidation inhibitory effect than any other fraction. In addition, EFPA showed a significant reduction in the inhibitory effect on ${\alpha}$-glucosidase activity ($IC_{50}$ value=$205.26{\mu}g/mL$) compared to the acarbose positive control. The anti-oxidative effect in PC12 cells, protective effects on high glucose-induced oxidative stress in neuronal cells, and neurotoxicity were measured using 2',7'-dichlorofluorescin diacetate, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide, and lactate dehydrogenase assays, respectively. EFPA showed conspicuous inhibitory effect on cellular reactive oxygen species production and neuronal cell apoptosis. Finally, kaempferol-3-glucoside was identified as the main phenolic compound of EFPA using high performance liquid chromatography.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.172-182
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• 2016

This study was aimed to determine the changes in vitamin $B_5$ and $B_6$ contents compared to fresh materials after parboiling treatment of the main vegetables consumed in Korea. The specificity of accuracy and precision for vitamin $B_5$ and $B_6$ analysis method were validated using high-performance liquid chromatography (HPLC). The recovery rate of standard reference material (SRM) was excellent, and all analysis was under the control line based on the quality control chart for vitamin $B_5$ and $B_6$. The Z-score for vitamin $B_6$ in food analysis performance assessment scheme (FAPAS) proficiency test was -1.0, confirming reliability of analytical performance. The vitamin $B_5$ and $B_6$ contents in a total of 39 fresh materials and parboiled samples were analyzed. The contents of vitamin $B_5$ and $B_6$ ranged from 0.000 to 2.462 and from 0.000 to $0.127mg{\cdot}100g^{-1}$, respectively. The highest contents of vitamin $B_5$ and $B_6$ were $2.462mg{\cdot}100g^{-1}$ in fresh fatsia shoots (stem vegetables), and $0.127mg{\cdot}100g^{-1}$ in fresh spinach beet (leafy vegetables), respectively. Moreover, the vitamin $B_5$ and $B_6$ contents for parboiling treatment in most vegetables were reduced or not detected. In particular, the contents of vitamin $B_5$ in parboiled fatsia shoots and vitamin $B_6$ in parboiled yellow potato and spinach beet were decreased 20- and 4-fold compared with fresh material, respectively. These results can be used as important basic data for utilization and processing of various vegetable crops, information for dietary life, management of school meals, and national health for Koreans.