• Development and Reproduction
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• v.5 no.2
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• pp.123-129
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• 2001

When mammalian oocytes undergo maturation, cumulus cells surrounding the oocyte exhibit remodeling of their structure known as cumulus expansion. Many molecules including hyaluronic acid participate in this remodeling. The present study aimed to investigate a possible existence of matrix metalloproteinases(MMPs) in the extracellular matrix(ECM) of human oocyte-cumulus complex. ECM was extracted from the human oocyte-cumulus complex. Gelatin gel zymogram of ECM exhibited 7 gelatinases having molecular weight of 300kDa, 240kDa, 200kDa, 180kDa, 116kDa, 97kDa, and 84kDa. This gelatinase profile was very different from that of ovarian mural granulosa cell extract or white blood cell extract, indicating that the oocyte-cumulus complex donating ECM was free from other than cumulus cells. When ethylenediaminetetraacetic acid or 1', 10'-phenanthroline was added to the reaction buffer during zymographic development, almost gelatinase activities were abolished, suggesting that they were MMPs. Following incubation of ECM in the presence of aminophenylmercuric acetate, an activator of proMMPs, 4 gelatinases of 240kDa, 180kDa, 97kDa, and 84kDa disappeared with the concomitant appearance of 80kDa, 65kDa, and 60kDa gelatinases. Based upon these observation, it is suggested that ECM of the human oocyte-cumulus complex consists of gelatinases, presumed to be MMP-2 and MMP-9 isoforms.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.1-16
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• 1986

Fifty-one strains of Pseudomonas aeruginosa were isolated from various clinical specimens. Among them, 26 (51%) strains were gentamicin-resistant (Gm') and 25 (49%) were susceptible to gentamicin (Gm'). The frequencies of resistant strains to piperacillin (Pi), cefotaxime, moxalactam, cefoperazone (Cz), and amikacin (Ak) ranged from 21.6 to 31.4%, and $MIC_{50}$ of these drugs were lower than the critical concentrations of susceptibility and resistance. Thirty (58.8%) strains were multiply resistant to 12 or more drugs. All Gm' strains were multiply resistant to 12 or more drugs and one was resistant to all 18 drugs tested, while only four Gm' strains were multiply resistant to 12 drugs and the multiplicity of resistance of the other Gm' strains were less than 10 drugs. Resistance to Gm appeared to have a significant correlation with the resistance to tobramycin (Tb), Ak, Pi, and Cz. All Gm' strains were resistant to Tb and about 38.4 to 46.1% of them were resistant to Ak, Pi, and Cz. The incorporation of $Ca^{++}$ and $Mg^{++}$ ions in Mueller-Hinton agar (MHA) did not influence the MICs of Gm, Tb, carbenicillin (Cb), Pi, and Cz as compared with the results obtained in MHA without these ions. Gm strains were studied on the combined effect of beta-lactam antibiotics and aminoglycosides by the methods of checkerboard and modified paper strip diffusion. Most Gm' strains showed significant synergistic effects by the FIC index between Ak and three beta-lactam antibiotics; Cb, Pi, and Cz, but these results did not in agreement the results obtained through the method of modified paper strip diffusion test. In order to know the nature of the drug resistance of P. aernginosa, the plasmid profile analysis was studied. Agarose gel electrophoresis of lysates processed by the method of Kado and Liu showed one or more plasmids in 22 (43.1%) strains. A group of 19 strains showed at least one band of plasmid and three strains two bands. The range of the molecular weight of plasmids was 3.8 to 243 Mdal. All strains carrying large plasmids larger than 200 Mdal were isolated from wound specimens. Three Gm' strains also harboured the plasm ids of 13 to 203 Mdal.

• Food Science of Animal Resources
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• v.25 no.3
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• pp.285-294
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• 2005

The objective of this study was to evaluate the physico-chemical properties and flavor compounds of sausages with various levels and molecular weight (MWs) of chitosans, during storage at $4^{\circ}C$. Various MWs (Low: 1.5 kDa; Medium: $30{\sim}50$ kDa; High: 200 kDa) and two levels (0.3 and $0.6\%$) of chiosans were dissolved and measured the viscosity at $4^{\circ}C$, pH values were not affected (p>0.05) by either MWs or levels of chitosans. The addition or high MWs or chitosan into the pork salt soluble protein (SSP) increased the viscosity, whereas no differences were observed in low and medium MWs of chitosan. Textural profile analysis (TPA) was affected by the addition of medium or high MWs of chitosan. As a result, the addition of medium of chitosan increased the hardness, gumminess, chewiness, cohesiveness and springiness values, whereas increased level of chitosan didn't affect TPA values, except few cases. Approximately twenty-nine flavor compounds were identified in the low-fat and regular-fat sausages, however the addition of chitosans didn't impair the flavor composition of the sausages, These results indicated that the addition of chitosans didn't affect the flavor profiles, but affected the textural properties in the sausages, especially MWs higher than 30 kDa.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.274-279
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• 2012

The objective of this study was to develop oral matrix tablets for the sustained release of vitamin C. In this study hydroxypropyl methylcellulose (HPMC) has been utilized as an excipient, as it is one of the most widely used polymers, for use during long periods of time in formations. The vitamin C tablet formulation depends on the molecular weight and concentration of sustained-delivery in HPMC. Anti-oxidants have been added as a dissolution medium in order to prevent vitamin C degradation in water. The dissolution test was carried out in a distilled water medium, and the release model equation was applied to analyze the vitamin C release pattern. The results demonstrated that the release and lasting power of vitamin C tablets, containing HPMC, lasted for more than 12 h.

• Food Science of Animal Resources
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• v.23 no.2
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• pp.128-136
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• 2003

This study was peformed to evaluate physico-chemical and textural properties, and shelf-life effect of low-fat functional sausages(LFFS) manufactured with sodium lactate(SL), lac color and various molecular weights of chitosans(low=1.5 kDa, medium=30∼40 kDa and high=200 kDa) during storage at 4$^{\circ}C$ for 8 weeks. LFFS had a pH range of 6.39∼6.50, 76∼78% moisture, <2% fat, 14∼15% protein. The combination of SL and low molecular weight(MW) of chitosan improved water holding capacity(WHC), however those of SL and medium MW of chitosan reduced WHC. Vacuum purge(VP) reduced with increased MW of chitosans during refrigerated storage. The addition of chitosans reduced the lightness and yellowness, but increased the redness values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm. LFFS containing SL and medium MW of chitosan increased most texture profile analysis(TPA) values, as compared to controls with 75 and 150 ppm. The addition of SL in LFFS retarded the microbial growth for Listeria monocytogenes, however no synergistic effect with the addition of chitosans were observed. E coli O157:H7 and Salmonella typhimurium reduced during refrigerated storage, regardless of SL and chitosan treatments. Increased storage time increased values for VP, yellowness and textural properties. These results indicated that the combination of SL and various MW of chitosans affected the functional and textural properties, and inhibited the microbial growth for LM effectively. In addition, 0.5% lac color as a replacer for sodium nitrite improved the color development, resulting in similar hunter color values, which was comparable to the sodium nitrite concentration between 75 and 150 ppm.

• Journal of environmental and Sanitary engineering
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• v.3 no.2 s.5
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• pp.23-41
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• 1988

Two hundred and eighty-six strains of Salmonella species were isolated from the twelve provincial institutes of health and 19 general hospitals of urban and rural areas in Korea from January to December in 1986. The antimicrobial susceptibility test of these cultures was done by the method of agar diluton. The resistance frequency of Salmonella cultures was $29.7\%$. Among these resistant cultures, the most provalent resistance pattern of Salmonella was ampicillin, carbenicillin, chloramphenicol, tetracycline, streptomycin, and its resistance frequency was $15\%$. In plasmid profile of resistance strains, average number of plasmid harboring in Salmonella was 1-4 and molecular weight of plasmid ranged 1.6 to 70 megadalton (Md.). Plasmid pattern of strains isolated from Seoul and Kang-won showed the same or similar profiles. Plasmid pattern was identical in the same resistance pattern.