• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.166-177
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• 2005

Purpose : The purpose of this study was to examine the molecular epidemiology and genetic variability of adenovirus(Ad) serotypes Ad1, Ad2, and Ad5 over 14 years in Korea. Methods : A total of 382 adenoviral strains isolated from the nasopharyngeal aspirates of children with lower respiratory tract infections in Seoul, Korea from November 1990 to February 2003 were serotyped by neutralization assay with type-specific antisera. Viral DNAs were extracted from infected cell lysates by the modified Hirt procedure. Genome type(GT) was determined by DNA restriction analysis with 12 restriction enzymess(BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmaI, XbaI, and XhoI). To evaluate the genetic relatedness, pairwise comigrating restriction fragments(PCRF) analysis was performed. Results : Of 382 strains, 33 strains(9%) were Ad1, 45 strains(12%) were Ad2, and 24 strains(6%) were Ad5. Eighteen GTs(Ad1p1-Ad1p7, Ad1a, Ad1b, Ad1b1-Ad1b3, Ad1c, Ad1d, Ad1e, Ad1e1, Ad1e2, Ad1f) among Ad1, 24(Ad2p1-Ad2p11, Ad2a, Ad2a1-Ad2a6, Ad2b, Ad2c, Ad2d, Ad2e, Ad2e1-Ad2e3) among Ad2, and 10(Ad5p1, Ad5p2, Ad5a, Ad5a1-Ad5a7) among Ad5 strains were identified. One or two strains of the vast majority of GTs were isolated during the study period while a few GTs were identified sporadically with more than 2 strains. It is notable that some GTs such as Ad1p5 and Ad5a1 appeared in cluster during a short period. In analysis of genetic relatedness, the degree of PCRFs(pairwise comigrating restriction fragments) for Ad1 varied from 79 to 99%, for Ad2, 82 to 99%, and for Ad5, 85 to 99%. Conclusion : This study established the comprehensive nomenclature systems of Ad1, Ad2, and Ad5. Diverse GTs identified in this study have crucial implications in the genomic diversity and epidemiological characteristics of Ad1, Ad2, and Ad5.

• The Korean Journal of Pesticide Science
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• v.5 no.3
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• pp.1-11
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• 2001

New technologies will have a large impact on the discovery of new herbicide site of action. Genomics, combinatorial chemistry, and bioinformatics help take advantage of serendipity through tile sequencing of huge numbers of genes or the synthesis of large numbers of chemical compounds. There are approximately $10^{30}\;to\;10^{50}$ possible molecules in molecular space of which only a fraction have been synthesized. Combining this potential with having access to 50,000 plant genes in the future elevates tile probability of discovering flew herbicidal site of actions. If 0.1, 1.0 or 10% of total genes in a typical plant are valid for herbicide target, a plant with 50,000 genes would provide about 50, 500, and 5,000 targets, respectively. However, only 11 herbicide targets have been identified and commercialized. The successful design of novel herbicides depends on careful consideration of a number of factors including target enzyme selections and validations, inhibitor designs, and the metabolic fates. Biochemical information can be used to identify enzymes which produce lethal phenotypes. The identification of a lethal target site is an important step to this approach. An examination of the characteristics of known targets provides of crucial insight as to the definition of a lethal target. Recently, antisense RNA suppression of an enzyme translation has been used to determine the genes required for toxicity and offers a strategy for identifying lethal target sites. After the identification of a lethal target, detailed knowledge such as the enzyme kinetics and the protein structure may be used to design potent inhibitors. Various types of inhibitors may be designed for a given enzyme. Strategies for the selection of new enzyme targets giving the desired physiological response upon partial inhibition include identification of chemical leads, lethal mutants and the use of antisense technology. Enzyme inhibitors having agrochemical utility can be categorized into six major groups: ground-state analogues, group specific reagents, affinity labels, suicide substrates, reaction intermediate analogues, and extraneous site inhibitors. In this review, examples of each category, and their advantages and disadvantages, will be discussed. The target identification and construction of a potent inhibitor, in itself, may not lead to develop an effective herbicide. The desired in vivo activity, uptake and translocation, and metabolism of the inhibitor should be studied in detail to assess the full potential of the target. Strategies for delivery of the compound to the target enzyme and avoidance of premature detoxification may include a proherbicidal approach, especially when inhibitors are highly charged or when selective detoxification or activation can be exploited. Utilization of differences in detoxification or activation between weeds and crops may lead to enhance selectivity. Without a full appreciation of each of these facets of herbicide design, the chances for success with the target or enzyme-driven approach are reduced.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.17-28
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• 2008

Purpose: It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. Methods and Materials: Two hundred nineteen patients (M: 70, F: 149, mean age: $62.9{\pm}6.9$ y/o) who were diagnosed as PD without dementia clinically and 55 patients (M:15, F:40, mean age: $61.4{\pm}9.2$ y/o) as normal controls who had no past illness history were performed $^{99m}Tc$-HMP AO brain perfusion SPECT and neuropsychological test. Results: At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood perfusion in 32 (14.7%) of 219 patients with PD, decreased perfusion on the frontal lobe in 45 patients (20.6%), the temporal lobe in 39 patients (17.4%), the parietal lobe in 39 patients (17.9%), the occipital lobe in 40 patients (18.3%), diffuse area in 14 patients (6.4%) and unclassified in 10 patients (4.6%). Fifthly, we compared the results of the neuropsychological test and cerebral perfusion pattern. There was no correlation between two tests except visuospatial function. Conclusion: Various perfusion state were found in patients with PD according to the age and sex. Also we were able to classify perfusion state into several groups and compare the neuropsychological test with cerebral perfusion.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.39-43
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• 2008

Purpose: We evaluated whether it was necessary to perform whole body acquisition of $^{18}F$-FDG PET/CT including whole skull and lower extremity (LE) distal to mid-thigh (MT) in patients with multiple myeloma (MM). Materials and Methods: Thirty patients underwent 45 whole body $^{18}F$-FDG PET/CT scans including skull and LE distal to MT. PET scans were divided by 2 subgroups according to the presence of abnormal focal $^{18}F$-FDG uptake in skull or LE distal to MT. Clinical characteristics including age, sex, and stages were compared between the 2 subgroups. Results: Of total 45 whole body PET/CT scans, focally increased abnormal FDG uptake in the skull or LE distal to MT suggesting myeloma involvement was found in 22 scans (48.9%) of 14 patients (46.7%). Skull lesions were more frequently observed than LE lesions distal to MT on PET (86.4% vs. 40.9%, p<0.005). There were no significant differences in age, sex, initial Durie/Salmon stage, and tumor burden at the time of PET scan suggested by serum hemoglobin level, serum calcium level, serum and urine paraprotein level, and serum creatinine level between the two subgroups. The presence of the skull or LE distal MT lesions on PET did not affect on the Durie/Salmon plus stage except only 1 case (1/22, 4.5%, p>0.05). Conclusion: Abnormal lesions in the skull or LE distal to MT on $^{18}F$-FDG PET/CT did not affect significantly on the tumor burden and Durie/Salmon plus stage of MM. Therefore, torso PET acquisition including head may be sufficient for evaluating patients with MM.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.409-419
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• 2015

This study was conducted to establish an efficient screening method for watermelon plants resistant to Fusarium wilt (FW), which is caused by Fusarium oxysporum f. sp. niveum (Fon). An HA isolate was prepared from a wilted watermelon plant in Haman-gun and identified as F. oxysporum f. sp. niveum based on morphological characteristics, molecular analyses of ITS (internal transcribed spacer) and TEF (translation elongation factor $1{\alpha}$) sequences, and host specificity on cucurbits including watermelon, melon, oriental melon, and cucumber. The assay for disease response of watermelon differentials indicated that the HA isolate was race 0. Among seven liquid media tested, the highest amount of Fon spores was produced from V8-juice broth, which was selected as a medium for mass production of Fon. The disease assay for 21 watermelon and 11 watermelon-rootstock cultivars demonstrated that 20 watermelon cultivars except for 'Soknoranggul' were susceptible; 'Soknoranggul' was moderately resistant. All the tested rootstock cultivars were highly resistant to the HA isolate. The evaluation of disease development depending on various conditions suggested that an efficient screening method for FW resistance in watermelon plants is to dip the roots of 10-day-old seedlings in spore suspension of $1.0{\times}10^5-1.0{\times}10^6conidia{\cdot}mL^{-1}$ for 30 min., to transplant the seedlings to plastic pots with a fertilized soil, and then to cultivate the plants at $25^{\circ}C$ for 3 weeks.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.307-313
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• 2013

This study was carried out to investigate the residual characteristics of fungicide azoxystrobin and difenoconazole in Prunus mume fruits, and establish pre-harvest residue limits (PHRL) based on dissipation and biological half-lives of fungicide residues. The fungicides were sprayed onto the crop at recommended dosage once and 3 times in 7 days interval, respectively. The samples were harvested at 0, 1, 2, 4, 6, 8, 10, 12 and 14 days after treatment. These residual pesticides were extracted with QuEChERS method, clean-up with $NH_2$ SPE cartridge, and residues were analyzed by HPLC/DAD and GLC/ECD, respectively. Method quantitative limits (MQL) of azoxystrobin were 0.03 mg $kg^{-1}$ and of difenoconazole were 0.006 mg $kg^{-1}$. Average recovery were $93.2{\pm}2.49%$, $85.5{\pm}1.97%$ for azoxystrobin at fortification levels at 0.3 and 1.5 mg $kg^{-1}$, and $100.8{\pm}6.74%$, $87.6{\pm}9.92%$ for difenoconazole at fortification levels at 0.06 and 0.3 mg $kg^{-1}$, respectively. The biological half-lives of azoxystrobin were 5.9 and 5.2 days at recommended dosage once and 3 times in 7 days interval, respectively. The biological half-lives of difenoconazole were 9.3 and 8.0 days at recommended dosage once and 3 times in 7 days interval, respectively. The PHRL of azoxystrobin and difenoconazole were recommended as 5.32 and 1.64 mg $kg^{-1}$ for 10 days before harvest, respectively.

• Journal of Life Science
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• v.26 no.4
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• pp.460-467
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• 2016

A filamentous cyanobacterium, Limnothrix sp. KNUA012, was axenically isolated from a freshwater bloom sample in Lake Hapcheon, Hapcheon-gun, Gyeongsangnam-do, Korea. Its morphological and molecular characteristics led to identification of the isolate as a member of the genus Limnothrix. Maximal growth was attained when the culture was incubated at 25℃. Analysis of its lipid composition revealed that strain KNUA012 could autotrophically synthesize alkanes, such as pentadecane (C₁₅H₃₂) and heptadecane (C₁₇H₃₆), which can be directly used as fuel without requiring a transesterification step. Two genes involved in alkane biosynthesis－an acyl-acyl carrier protein reductase and an aldehyde decarbonylase－were present in this cyanobacterium. Some common algal biodiesel constituents－myristoleic acid (C_14:1), palmitic acid (C_16:0), and palmitoleic acid (C_16:1)－were produced by strain KNUA012 as its major fatty acids. A proximate analysis showed that the volatile matter content was 86.0% and an ultimate analysis indicated that the higher heating value was 19.8 MJ kg⁻¹. The isolate also autotrophically produced 21.4 mg g⁻¹ phycocyanin－a high-value antioxidant compound. Therefore, Limnothrix sp. KNUA012 appears to show promise for application in cost-effective production of microalga-based biofuels and biomass feedstock over crop plants.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.877-882
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• 2015

This study was carried out treatment of polyethylene glycol (PEG) in order to increase of survival rate of acclimated plants of strawberry's in vitro plantlets through bioreactor culture. We used PEG with molecular weight 6000 (PEG 6000) in this study. Concentration of PEG is non-treatment, 5, 10, 15, and $20g{\cdot}L^{-1}$ each bioreactor. $5g{\cdot}L^{-1}$ of PEG was treated at $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$, and $5^{th}$ week during culture. We investigated growth characteristics of in vitro plantlets after 6 weeks cultivation. Growth amount of all PEG treatment decreased as compared to non-treatment. The more concentration increased, the more plant growth decreased. In $5g{\cdot}L^{-1}$ of PEG, shoot length was shorter than non-treatment that shoot length was 7.9 cm and especially fresh weight that is 1.6 g was more decrease than non-treatment. Shoot length was ranged 3.0-3.9 cm at $1^{st}$ week treatment to $4^{th}$ week treatment of $5g{\cdot}L^{-1}$ PEG. The shoot length was not significant by 5.3 cm at $5^{th}$ week treatment. The survival rate was improved 5.4% at the treatment of $4^{th}$ week and was improved 8.7% at the $5^{th}$ week as compared to non-treatment. In order to improve of survival rate of strawberry' in vitro plantlets through bioreactor culture, the method is suitable that adding $5g{\cdot}L^{-1}$ of PEG in the medium and $5^{th}$ week's treatment is suitable.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.130-139
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• 2016

A bacterial strain, producing an excellent lipolytic enzyme, was isolated from the intestinal tracts of an earthworm (Eisenia fetida). The strain was identified as Aeromonas hydrophila by phenotypic, chemotaxonomic characteristics and 16S ribosomal DNA analysis, and was designated as Aeromona hydrophila PL43. The lipolytic enzyme from A. hydrophila PL43 was purified via 35−45% ammonium sulfate precipitation, DEAE-sepharose fast flow ion-exchange, and sephacryl S-300HR gel filtration chromatography. The yield of the purified enzyme was 3.7% and 2.5% of the total activity of crude extracts with p-nitrophenyl butyrate (pNPB) and p-nitrophenyl palmitate (pNPP) as substrates, respectively. The molecular weight of the purified enzyme was approximately 74 kDa using gel filtration, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and zymography. The optimal activity of purified enzyme was observed at 50℃ and pH 8.0 using pNPB, and 60℃ and pH 8.0 using pNPP. The purified enzyme was stable in the ranges 20− 60℃ and pH 7.0−10.0. The activity of purified enzyme was inhibited by PMSF, pepstatin A, Co²⁺, Cu²⁺, and Fe²⁺, but was recovered by metal chelating of EDTA. The K_m and V_max values of the purified enzyme were 1.07 mM and 7.27 mM/min using pNPB and 1.43 mM and 2.72 mM/min using pNPP, respectively.

• Microbiology and Biotechnology Letters
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• v.36 no.3
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• pp.215-220
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• 2008

Rahnella aquatilis AY2000 has an unique characteristic which produces an anti-yeast substance (AYS). The AYS of the strain AY2000 was always secreted on agar plate, however, its activity in liquid culture was labile upon storage of the medium. In this paper, cultural conditions of the strain AY2000 for the AYS production were investigated in liquid culture, and minimal inhibitory concentration (MIC) against Saccharomyces cerevisiae was determined for the AYS activity. MIC of the AYS cultured in PYG broth at $^25{\circ}C$ for 24 hr was $23.5{\mu}g/mL$, however, that in MYCS (pH 5.5) broth at the same condition was $15.5{\mu}g/mL$. The activity of the AYS had increased rather in MYCS broth excluded $NH_4$-citrate than in the same broth contained $NH_4$-citrate, and MIC of the AYS produced in MYCS broth without $NH_4$-citrate was $15.5{\mu}g/mL$. When the strain AY2000 was maintained in MYCS broth without $NH_4$-citrate but added $100{\mu}M$ $FeCl_3$, the activity of the AYS had increased and its MIC was $7.8{\mu}g/mL$. MIC of the AYS was $7.8{\mu}g/mL$ after the strain AY2000 was cultured in MYCS broth containing $100{\mu}M$ $FeCl_3$ without $NH_4$-citrate, however, its MIC was $31.3{\mu}g/mL$ after 48-60 hr culture in the same broth.