• Research in Plant Disease
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• v.14 no.3
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• pp.143-152
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• 2008

Mixed-planting of two rice cultivars, HP ('Hopyeongbyeo') and NP ('Nampyeongbyeo'), having a dissimilar susceptibility to rice blast was practiced for chemical-free control of rice blast in the field. The HP/NP combination was selected for applying under mechanized agricultural conditions. Because they have similar genetic characteristics such as seed germination and heading time, culm length, rice quality and size of rice grains except susceptibility to blast. Incidence of panicle blast was reduced 50.4 % compare with supposed blast incidence by HP/NP mixed-planting when the seeds of two cultivars were combined 1 to 1 as weight. Supposed blast incidence was estimated from reduction of rice blast caused by addition of a resistant cultivar NP. Race diversity of Magnaporthe oryzae was examined for correlation with control effect of HP/NP mixed-planting on rice blast. The population of dominant race KJ-101 was diminished and replaced with various co-existing races and eleven new races were appeared in mixed-planting plot. Total number of race isolated from mixed-planting plot was not largely different from mono-culture. However, detection frequency of the new race was increased and variation of the population size of each race was decreased in mixed-planting plots. It was shown that a biased community with a dominant race (KJ-101 or KI-181) was altered to a balanced one of coexisting races. From these results, it was supposed that the balanced diversity among co-existing races within a community might be correlated to control effect by HP/NP mixed-planting on rice blast. Further more, it should be studied that genetic characteristics of the individual race including a virulence on cv. HP and NP was examined for verifying a correlation of mixed-planting effect and race diversity.

• Research in Plant Disease
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• v.15 no.2
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• pp.120-126
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• 2009

In the course of study on the roles of phytotoxins in the pathogenicity of Botrytis cinerea, we isolated two novel phytotoxins. They were identified as 3-O-acetyl botcinol and 3-O-acetyl botcinolide. In this study, we investigated correlation between the two phytotoxins and the pathogenicity of B. cinerea. In liquid cultures, the two phytotoxins were not produced by three low pathogenic isolates out of 25 B. cinerea isolates. Among strong or moderate pathogenic isolates, some produced the two phytotoxins, but the others did not. On the other hand, the ethyl acetate extracts of fermentation broths of 10 out of 25 isolates showed phytotoxic activity against various plants tested in a whole plant assay. The phytotoxins were detected in all of the 10 phytotoxic ethyl acetate extracts. In planta, the two phytotoxins were detected in all of the plant tissues infected with strong pathogenic isolates. However, there was no correlation between the ability of B. cinerea isolates to produce the two phytotoxins and their pathogenicities. The two phytotoxins began to detect in tomato plant tissues infected with B. cinerea 2-16 at 3 days after inoculation, increased gradually till 4 days after inoculation, and then decreased. The above results suggest that 3-O-acetyl botcinol and 3-O-acetyl botcinolide are one of pathogenicity factors for B. cinerea, but not a primary determinant of its pathogenicity.

• Research in Plant Disease
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• v.15 no.2
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• pp.72-76
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• 2009

It was investigated the responses of BaYMV resistant genes to Korean BaYMV(Barley yellow mosaic virus) strains. BaYMV was distributed dominantly with about 51% detection ratio among the three investigated virus such as BaYMV, BaMMV(Barley mild mosaic virus) and SBWMV(Soil-borne wheat mosaic virus) in ELISA test. Double infection with BaYMV and BaMMV was detected also higher as 38.8%, however, BaMMV sole infection ratio was lower with only 1.4%. The 11 BaYMV resistant genes were tested their responses to four Korean BaYMV strains, BaYMV-N, H, I and M. Generally, rym 3 genes showed resistant to Korean BaYMV strains and rym 4m and 5a also was better. Three genes, rym 1+5(Mokusekko-3), rym 3(Ea 52, Baitori) and rym 5a(Solan) showed resistant responses to BaYMV-N type. In -H strain test, seven genes that rym 2(Mihori Hadaka 3), rym 3(Ea 52, Haganemugi, Baitori), rym 4m(Diana, Franka), rym 5a(Solan), rym 7(Hor 3365), rym 9(Bulgarian 347), rym 12(Jochiwon Covered 2) were considered as resistant. The three genes that rym 1+5, rym 3 and rym 5a was effective to -I strain, and rym 3, rym 4m and rym 5a showed resistant to -M strain.

• Research in Plant Disease
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• v.15 no.2
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• pp.83-87
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• 2009

Direct Polymerase Chain Reaction (PCR) method that combines biological and enzymatic amplification of PCR targets was developed for the detection of Xanthomonas axonopodis pv. glycines on soybeen seeds without DNA isolation. Primers Xag F1 and Xag R1 were designed to specifically amplify a 401 bp fragment of the glycinecin A gene of X axonopodis pv. glycines. Xag F1 and Xag R1 were used to carry out the PCR analysis with genomic DNA from 45 different bacterial strains including phylogenetically related bacteria with X axonopodis pv. glycines, and other bacterial strains of different genus and species. The PCR assay using this set of primers were able to detect X axonopodis pv. glycines with DNA concentration as low as 200 fg and $1.8{\times}10^3$ cfu/ml. The Xag was detected from the seed samples incubated for 2 hrs with shaking and the intensity of the band was increase with the incubation time of seeds. The Direct PCR assay method without DNA isolation makes detection of X. axonopodis pv. glycines on soybean seeds easier and more sensitive than other conventional methods. The developed seed assay using direct PCR method will be useful for the specific detection of X. axonopodis pv. glycines in soybean seed samples.

• Research in Plant Disease
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• v.22 no.3
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• pp.145-151
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• 2016

Chemical fungicides have reduced Fusarium head blight (FHB) severity. However, by the effects of fungicide residues, they can only be used up to 30 days before time of harvest. Therefore, the development of new biofungicides that are applicable until harvest is required. In order to select plant extracts having antifungal activity against Fusarium graminearum for the control of FHB, we investigated the inhibitory effects of 225 medicinal plant extracts on spore germination of F. graminearum. Of these plant extracts, the methanol extract of Cirsium japonicum (CJ) roots showed the strongest antifungal activity. Through solvent partitioning, repeated column chromatography, and spore germination bioassay, two chemicals were purified and then their chemical structures were identified as ciryneol C (CC) and 1-heptadecene-11,13-diyne-8,9,10-triol (HD-ol) which are polyacetylene substances. Two active compounds effectively inhibited the germination of F. graminearum macroconidia; HD-ol ($IC_{50}$ of $3.17{\mu}g/ml$) showed stronger spore germination inhibitory activity than that of CC ($IC_{50}$ of $28.14{\mu}g/ml$). In addition, the wettable powder type formulation of ethyl acetate extract of CJ roots suppressed the development of FHB in dose-dependent manner, with control values of 78.92% and 31.56% at 250- and 500-fold dilutions, respectively. Combining these findings suggest that the crude extract of CJ roots containing polyacetylene compounds could be used as botanical fungicide for the control of FHB.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.07b
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• pp.37-54
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• 2003

It has been recognized that the hen. like its mammalian counterparts. provides young chicks with antibodies as protection against hostile invaders. This system facilitates the transfer of specific antibodies from serum to egg yolk. and provides a supply of antibodies called immunoglobulin Y(IgY) to the developing embryo and the hatched chick. The protection against pathogens that the relatively immuno-incompetent newly hatched chick has. is through transmission of antibodies from the mother via the egg. Egg yolk. therefore. can be loaded with a large amount of IgY against pathogens which can immobilize the existing or invading pathogens during the embryo development or in day-old chicks. Thus. the immunization of laying hens to various pathogens results in production of different antigen-specific IgY in eggs. Egg yolk contains 8~20 mg of immunoglobulins (IgY) per $m\ell$ or 136~340 mg per yolk suggesting that more than 30 g of IgY can be obtained from one immunized hen in a year. By immunizing laying hens with antigens and collecting IgY from egg yolk. low cost antibodies at less than ＄10 per g compared to more than ＄20.000 per g of mammalian IgG can be obtained. This IgY technology opens new potential market applications in medicine. public health veterinary medicine and food safety. A broader use of IgY technology could be applied as biological or diagnostic tool. nut-raceutical or functional food development. oral-supplementation for prophylaxis. and as pathogen-specific antimicrobial agents for infectious disease control. This paper has emphasized that when IgY-loaded chicken eggs are produced and consumed. the specific antibody binds. immobilizes and consequently reduces or inhibits the growth or colony forming abilities of microbial pathogens. This concept could serve as an alternative agent to replace the use of antibiotics. since today. more and more antibiotics are less effective in the treatment of infections. due to the emergence of drug-resistant bacteria.

• Journal of radiological science and technology
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• v.27 no.4
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• pp.11-16
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• 2004

Classification of esophageal motility disorders not yet finalized and is still ongoing as the new disorders are reported, and the existing classification is changed or removed. In terms of radiology, the primary peristalsis does not exist, and the lower end of the esophagus show the smooth, tapered, beak-like appearance. The esophageal motility disorder, which mostly occurs in the smooth muscle area, show the symptoms of reduction or loss (hypomotility) or abnormal increase (hypermotility) of peristalsis of the esophagus. It is important to understand the anatomy and physiology of the esophagus for the appropriate radiological method and diagnosis. Furthermore, the symptom of the patient and the manometry finding must be closely referred for the radiological diagnosis. The lower esophageal sphincter can be normally functioning and open completely as the food moves lower. Sperandio M et al. argues that the name diffuse esophageal spasm must be changed to distal esophageal spasm (DES) as most of the spasm occurs in the distal esophagus, composed of the smooth muscle. According to Ott et al., usefulness of barium method for diagnosing the esophageal motility disorder is Achalasia 95%, DES 71% and NEMD 46%, with the overall sensitivity of 56%. However, excluding the nutcracker esophagus or nonspecific disorder which cannot be diagnosed with the radiological methods, the sensitivity increases to 89%. Using videofluoroscopy and 5 time swallows, the average sensitivity was over 90%. In conclusion, the barium method is a simple primary testing method for esophageal motility test. Using not only the image but also the videofluoroscopy with good knowledge of the anatomy and physiology, it is believed that the method will yield the accurate diagnosis.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.309-315
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• 2002

Purpose : To evaluate the result of conservative management on recurrence, survival and prognostic factors of patient with operable breast cancer. Materials and Methods : Fifty three patients, treated for localized breast cancer by lumpectomy or quadrantectomy followed by radiotherapy between January 1985 and December 1996, were retrospectively studied. All patients followed up for at least five years. Their median age was 43 years $(range\;24\~72)$. The tumor stages were as follows : T1 in 30 patients, T2 in 21, Tis in 2. Thirty-eight patients had negative and 15 had positive axillary nodes. The histological types were 42 infiltrating ductal, 2 infiltrating lobular, and 2 intraductal carcinomas with 7 other histologies. The tumor locations were the outer quadrant in 38 breasts, the inner quadrant in 13 and central in 2. Radiation doses of $46\~50\;Gy$ were given to the entire breast areas with additional doses of 14-18 Gy delivered to the tumor bed areas. Results : The overall five and 10 yea actuarial and disease free survivals were $94.3\%\;and\;92.4\%,\;91.2\%\;and\;81\%$, respectively. The overall five year survivals were $100\%$ in stage I and IIa, and $66.7\%$ in stage IIb and IIIa tumors. Seven patients failed either locally or distantly. Incidence of local failure and distant metastasis for the first failure were $7.5\%\;and\;5.7\%$, respectively. Local recurrence appeared within 2 years of treatment at the primary site and after more than 8 years outside of primary lesion, whereas distant metastasis appeared between 2 and 6 years following treatment. The overall recurrences were high at a young age (< or = 35 years), with 5 out of 12 (2 local, 3 distant), and in T2 lesions with 5 out of 21 (1 local, 3 distant, and 1 in both). Distant metastasis was high in the positive axillary lymph node group with 4 out of 15 $(26.6\%)$. A high incidence in the axillary node was noted at a young age with 7 out of 12 $(58.3\%)$ and in T2 lesions with 8 out of 21 $(38.4\%)$. A young age, positive axillary node and large tumor size were all related with poor survival. Conclusion : Based on this study, lumpectomy or quadrantectomy, followed by radiation appears to be an adequate therapeutic method in operable breast cancer. A long term follow-up is necessary because a recurrence of breast can occur long time after treatment. The poor prognostic group, especially young patients with an aggressive biological behavior needs more effective treatment modalities to improve their survival.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.241-247
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• 1993

Between July 1988 and December 1992, we treated 45 patients who had deep seated inoperable or residual and/or recurrent intracranial tumors using LINAC based stereotactic radiosurgery at the Department of Therapeutic Radiology, Kangnam St. Mary's Hospital, Catholic University Medical College. Treated intracranial tumors included pituitary tumors (n=15), acoustic neurinomas (n=8), meningiomas (n=7), gliomas (n=6), craniopharyngiomas (n=4), pinealomas (n=3), hemangioblastomas (n=2), and solitary metastatic tumor from lung cancer (n=1). The dimension of treatment field varied from 0.23 to 42.88 $cm^3\;(mean;\;7.26\;cm^3)$. The maximum tumor doses ranging from 5 to 35.5 Gy (mean; 29.9 Gy) were given, and depended on patients' age, target volume, location of lesion and previous history of irradiation. There were 22 male and 23 female patients. The age was varied from 5 to 74 years of age (a median age; 43 years). The mean duration of follow-up was 35 months (2~55 months). To date, 18 $(39.1\%)$ of 46 intracranial tumors treated with SRS showed absent or decrease of the tumor by serial follow-up CT and/or MRI and 16 $(34.8\%)$ were stationary, e.g. growth arrest. From the view point of the clinical aspects, 34 $(73.9\%)$ of 46 tumors were considered improved status, that is, alive with no evidence of active tumor and 8 $(17.4\%)$ of them were stable, alive with disease but no deterioration as compared with before SRS. Although there showed slight increase of the tumor in size according to follow-up imagings of 4 cases (pituitary tumor 1, acoustic neurinomas 2, pinealoma 1), they still represented clinically stable status. Clinically, two $(4.4\%)$ Patients who were anaplastic astrocytoma (n=1) and metastatic brain tumor (n=1) were worsened following SRS treatment. So far, no serious complications were found after treatment. The minor degree headache which could be relieved by steroid or analgesics and transient focal hair loss were observed in a few cases. There should be meticulous long term follow-up inall cases.

• Radiation Oncology Journal
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• v.15 no.4
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• pp.297-303
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• 1997

Purpose : To evaluate the prognostic factors for disease-free survival and long-term results of radiotherapy for pituitary adenoma. Methods and Materials : The study involved a retrospective review of out-come in a series of 27 patients with pituitary adenoma, between 1984 and 1995 at Paik hospital. The study included 20 patients treated with surgery and postoperative radiotherapy and 7 with radiotherapy alone. The patients were followed for 12-146 months (median : 97 months). Seventeen were men and 10 were women. The numbers of functioning and nonfunctioning pituitary adenorna were 22 and 5 respectively and those of microadenoma and macroadenoma were 4 and 23 respectively. The radiation doses of 5040-5580cGy (median : 5040cGy) were deliverd over 5-7 weeks, using 4MV LINAC. The prognostic factors were analyzed by log-rank test. Results: For radiation therapy alone, the 5YSR was 100% and progression free survival rate was 85.8%, The tumor was controlled in 6/7 (85.8%). For surgery and postoperative radiotherapy. the 5YSR, progression free survival rate and local control rate were 95%, 84.8%, and 89.5% respectively. The parameters of tumor size, hormone secretion, radiation dose. radiotherapy field size were evaluated in a uni- and multivariate analysis and all the factors were not statisticaIty significant (P>0.05). Eleven of 12 (92%) with visual field defect experienced normalization or improvement, and 5 for 7 evaluabie patients with hyperprolactinoma achived normalization in 4 and decrement in S patients. Only 2 patients developed mild degree of Panhypopituitarism. Conclusion: The radiotherapy appears to be effective in controiling clinical symptoms and signs resulting from pituitary adenoma. Local control rate with radiotherapy alone or with surgery and postoperative radiotherauy was comparable. There was a trend toward high recurrence rate in Patients with nonfunctioning or prolactin secretion tumor and larger radiation field sizes.