• Toxicological Research
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• 제23권1호
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• pp.47-53
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• 2007

Amygdalin is a cyanogenic glycoside which is commonly found in almonds, bamboo shoots, and apri-cot kernels, and peach kernels. Amygdalin was first hydrolysed into prunasin, then degraded into cyanohydrin by sequential two-stage mechanism. The objective of this study was to examine the amygdalin decomposition and cyanide formation at various in vitro conditions, including acid, enzyme and anaerobic microbes (AM) in human feces (HF). In acid hydrolysis mimicking gastric environment, amygdalin was degraded to cyanide up to 0.2% in specific pH. In contrast, enzyme assay showed higher cyanide generation either by ${\beta}$-glucosidase, or by incubation with microbe. In conclusion, we are convinced of cyanide generation are occurred mainly by microbiological activities of the gut flora up to 41.53%. After ingestion with some staff, the degree and site of degradation in an organism is a key parst of regulatory decision making of that staff.

• Journal of Pharmaceutical Investigation
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• 제3권1_2호
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• pp.16-22
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• 1973

Biological determination of Pivampicillin hydrochloride was examined and an available method has been established. Unhydrolyzed Pivampicillin hydrochloride has no antibacterial activity, but it exhibits an antibacterial activity hydrolyzed with liberation of ampicillin by nonspecific enzymes present in blood and tissues from various species in vitro and in vivo. Using these properties, Pivampicillin hydrochloride can be determined as ampicillin by use of an agar-diffusion method with Bacillus subtilis as the assay organism.

• Journal of Microbiology
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• 제35권2호
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• pp.87-91
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• 1997

Monoclonal antibodies were prepared in order to an assay method for Vibrio vulnificus. Sixteen mouse ybridoma cell lines were established by immunization of whole cell antigen to BALB/c mice, fusion with SP2/O myeloma cells, and cloning. Most of them secreted IgM.lambda. antibodies. A sandwich enzyme-linked immunosorbent assay was developed with rabbit anti-V. vulnificus polyclonal antibodies as capture antibody, an IgM monoclonal antibody as detector antibody, and goat anti-mouse IgM-alkaline phosphatase conjugate as developer antibody. The range of detection was 10$\^$4/ to 10 V. vulnificus cells per microplate well. When four related Vibrio species were tested for cross-reactions, V. parahaemolyticus showed 3.5% reactively and V. carchariae, V. fluvialis, and V. furnisii showed negligibal (<1%) cross-reactivity.

• Journal of Microbiology
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• 제34권1호
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• pp.40-48
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• 1996

We have examined the chromatin structure of the HMRE/HSP82 and HMRa/HSP82 allels using three complementary approaches : DNase I chromating footprinting, micrococcal nuclease (MNase) nucleosome-protected ladder assay, and an in vivo E. coli dam methylase accessibility assay. The footprinting results indicate that the promoter and silencer sequences are assembled into nucleoprotein complexes which exhibit no detectable change in structure, despite a 70-fold range in expression levels. In addition, the promoter region of the HMRa/HSP82 allele is cleaved randomly by MNase in all cases, indicating the absence of anonical nucleosomes over this region irrespective of SIR4 or heat-shock. Finally, no discernible difference in the accessibility of the HMRE/HSP82 locus to dam methylase in SIR4 vs. sir4 cells was seenm which again suggests that the chromatin structure of HMRE/HSP82 allele is identical regardless of SIR4. Altogether, our results indicate that in contrast to other observations of the silent mating-type loci, no discernible structural alteration is detected at either HMR/HSP82 allele regardless of SIR genetic background or transcriptional state of the gene.

• 미생물학회지
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• 제26권3호
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• pp.162-166
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• 1988

Bacteriophage M13 DNAs carrying the wild type or base substituted SV40 DNA replication origins were used for replication assay. In vivo and in vitro assay with African green monkey cell line COS-1 showed that the replication of M13-SV40 recombinant DNAs was restricted like a pBR322 SV40 recombinant DNA(Lusky and Botchan, 1981). Furthermore, recombinant phage DNAs isolated from the transfected siminan cells subsequently show a reduced ability to retransform E. coli. But pATSV-W(Kim et al., 1988) was replicated in COS-1 cells normally. We think that a poison sequence may exist on bacteriophage M13 DNA like pBR322.

• 대한지역사회영양학회지
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• 제4권4호
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• pp.512-520
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• 1999

Microbiological method using a 96-well microplate reader for folate assay was established, and folate intake and blood folate concentrations of 23 female college students were assessed. To evaluate folate intake, dietary data were collected by a 3-day weight food record, and serum and RBC folate concentrations were measured by the new method. The coefficient of variation for the new method was less than 10%. Mean daily folate intake of the subjects was 126.7${\mu}g$ which is only 50.7% of the RDA. The mean concentrations of serum and RBC folate were 7.46ng/ml and 294.4ng/ml, respectively, which were within the normal range. These results indicate that folate intake seems to be underestimated due to incomplete food composition database. Therefore, folate database should be appropriately in order to asses folate intake accurately.

• 미생물학회지
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• 제27권1호
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• pp.10-15
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• 1989

Mammalian cell 연구에 쓰기 위해 개발된 SV 40 transcriptional promoter를 함유하는 pKOneo plasmid를 발암 유전인자 연구에 쓰이는 NIH3T3 쥐 세포에 stable transfection 시켜 7개의 sub clones 얻었으며, 이 subclones이 갖는 세포 형질전환에 관한 여러가지 성질을 조사하였다. 실험결과에 따르면 stable transfection 후 세포 염색체에 삽입된 pKOneo plasmid 자체만으로도 NIH3T3 세포의 형질전환을 크게 일으키는 것으로 사료되었다.

• Journal of Microbiology
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• 제35권3호
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• pp.177-180
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• 1997

The purpose of this study was to evaluate the efficiency of Line Probe Assay (LiPA) in detecting the rpoB gene mutation of clinically isolated Mycobacterium tuberculosis (MTB) and to compare the level of resistance to the various rifamycins with their mutation sites. The mutation in the rpoB gene was found in 84 (97.6%) out of 86 rifampicin (RMP) resistant strains as determined by LiPA. No mutation was observed in 2 RMP resistant strains and in any of 38 RMP susceptible strains tested. Only one of 3 strains with .DELTA.5/R5, one of 2 strains with .DELTA.3, and one of 3 strains with .DELTA.2/R2 LiPA profile showed a slightly lower level of resistance to the rifapentine than the other strains. Although we could not find correlations between mutation sites in the rpoB gene and the level of susceptibility to the various rifamycins, the LiPA is recommended as a fast screening tool for detection of RMP resistant MTB.

• Food Science and Biotechnology
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• 제16권6호
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• pp.868-872
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• 2007

The microbiological and chemical identification of antibiotic residues was attempted for livestock and seafood products including pork (n=34), beef (n=34), chicken (n=32), flatfish (n=37), armorclad rockfish (n=36), and sea bream (n=27). The meat (n=100) and seafood (n=100) samples were collected from 9 markets in 5 major Korean cities. Antibiotic substances were identified from the classes of tetracyclines, macrolides, penicillins, aminoglycosides, polyethers, peptides, sulfonamides, quinolones, chlorampenicols, and novobiocins using a microbiological assay, the Charm II test and high performance liquid chromatography (HPLC) with ultra violet (UV) and fluorescence detectors. The results showed that 2 tetracyclines (oxytetracycline and tetracycline) and 3 quinolones (ciprofloxacin, norfloxacin, and enrofloxacin) were detected in 4 samples of flatfish among all 100 seafood samples tested. No antibiotic residues were detected in the 100 livestock product samples tested. The amounts (min-max, mg/kg) of the residual antibiotics were as follows; tetracycline 0.78-0.85, oxytetracycline 0.49-0.74, ciprofloxacin 0.09-0.83, norfloxacin 0.01-0.21, enrofloxacin 0.12-2.98. These data indicate that the total detection rate of antibiotics in livestock and seafood products was approximately 2%.

• 한국식품위생안전성학회지
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• 제11권4호
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• pp.315-321
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• 1996

Various antimicrobial drug screen tests have been used in order to ensure food safety. However, the conventional screen tests, the Swab Test on Premises(STOP, USA), the Calf Antibiotic and Sulfa Test(CAST, USA) and the European Economic Community 4-plate Test(FPT, EU) are not sufficiently rapid or sensitive enough to detect low levels of sulfa drugs in meat. We developed a new screen test kit for the determination of the antimicrobial residues in meat called the Bacillus megaterium Disk Assay(BmDA). A comparison of BmDA with the older screen tests showed BmDA was as good as the older ones with several advantages. The new test kit is faster-it can be read in 4∼6 hours instead of 16∼18 hours. Moreover, BmDA can discriminate sulfa drugs from other antimicrobial drugs because p-aminobenzoic acid countacts the inhibiting action of sulfa drugs. Minimum detectable levels of sulfa drugs were significantly improved at the lever of 0.025*0.1 pp, compared with the level of 1.0 ppm in FPT. A comparison of BmDA with the older screen tests in HPLC confirmed meat samples exceeded the Korean tolerance value of 0.1 ppm showed BmDA was the most sensitive in the microbiological screen tests. As the microbiological screen tests have already known, a person familiar with simple laboratory techniques should have no difficulty in using it to detect antimicrobial residues in meat. This would be a simple, economic method of antimicrobial residues detection which might be succesfully used by many laboratories.