• The Korean Journal of Pesticide Science
• /
• v.13 no.4
• /
• pp.267-274
• /
• 2009

This study was carried out to select effective preventive pesticides against pine wilt disease caused by pinewood nematode (PWN), Bursaphelenchus xylophilus on trunk injection. 1,000 fold aquatic solution of abamectin 1.8% EC and emamectin benzoate 2.15% EC were lower mortality (7.3% and 8.3% respectively) against PWN on 1 day after treatment. However effects of abamectin 1.8% EC, emamectin benzoate 2.15% EC, fosthiazate 30% SL and fenitrothion 30% SL were inhibited the reproduction of PWN over 99.6% in Botrytis cineria media. Effect of trunk injection of abamectin 1.8% EC and emamectin benzoate 2.15% EC at the rate of $10\;m{\ell}$ per 10 cm in diameter of breast height (DBH) on mortality of Japanese black pine, Pinus thungergii by inoculated PWN was 0% and 3.3%, respectively at the applied year however when injection of fosthiazate 30% SL were treated with the rate of $5\;m{\ell}$ per 10 cm tree DBH, mortality of tree was 63.3%. Abamectin 1.8% EC and emamectin benzoate 2.15% EC was showed high preventive efficacy representing >90% against PWN at the following year. PWN preventing efficacy of trunk injection was lower in naturally occurred area (mortality of pine tree in control was 11.7% at the first year) of PWN than artificially infected site (mortality of pine tree in control was >76.7% at the first year), PWN preventing efficacy of trunk injection of abamectin 1.8% EC and emamectin benzoate 2.15% EC at the rate of $10\;m{\ell}$ per 10 cm in DBH was 91.5% and 82.9%, respectively, at the applied year and 89.5% and 82.6% respectively at the following year in PWN naturally occurred site. Control efficacy by trunk injection of abamectin 1.8% EC and emamectin benzoate 2.15% EC was more higher in 10 fold dilution with 10 fold high amount of aquatic solution than no dilution with 10 fold less amount of aquatic solution. The preventive effect of trunk injection of abamectin 1.8% EC and emamectin benzoate 2.15% EC at the rate of $5\;m{\ell}$ per 10 cm in DBH was showed 100% at the applied year in PWN inoculated tree.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.3
• /
• pp.303-309
• /
• 1999

Mass mortality of the Manila clam, Ruditapes philippinarum has been reported all along the west and south coast of Korea for the past several years. As a pathogenic agent, Perkinsus sp., an endoparasitic protozoan has been identified in this study and believed to be responsible for the mass mortalities. Prevalence and infection intensity of Perkinsus sp. was investigated from a Manila clam population inhabiting at Komsoe Bay in the west coast where mass mortality of the clam has been reported. A total of 142 Manila clam, 50 oyster, Crassostrea gigas, 10 ark shell, Scapharca broughtonii, and 5 predatory gastropada, Rapana venosa were examined for the presence and the quantity of Perkinsus sp. Ray's fluid thioglycollate medium method (FTM method) with modified Mackin's infection intensity scale and Choi's quantitative method were used in detecting and quantifying the parasite. All individuals of R. philippinarum examined in this study were infected with Perkinsus sp., indicating $100\%$ prevalence while none of the oysters and the gastropods exhibited the parasite. Six to ten individual hypnospores of Perkinsus sp. were counted from the ark shells. The number of hypnospores in the clam tissues varied from 16,667 to 4,091,667, with a mean number of 1,077,628. Average infection intensity according to Mackin's was 2.87, indicating a moderate infection. A negative correlation was observed between the number of Perkinsus sp. in the tissue and the condition index, a ratio tissue wet weight to shell cavity volume. The clam size and the infection intensity in terms of total number of parasites were positively correlated; the bigger clam, the heavier infection. Such high number of Perkinsus sp. counted in the clams could be enough to cause physiological disturbance of clams, such as retarded growth and reproduction. It is also believed that such a high infection leads mortality of the clam via continuous draining of the energy by metabolic activities and reproduction of the parasites. Correlation between the condition index and the infection intensity observed in this study supports this hypothesis.

• The Korean Journal of Mycology
• /
• v.5 no.1
• /
• pp.13-19
• /
• 1977

In order to investigate histopathologically the nature of varietal resistance and infection process of the rice bast fungus, Pyricularia oryzae. this experiment was undertaken by using the resistant cultivar Tongil and susceptible cultivars Norin No.6 and Jinheung in 1973 to 1974. 1) It was found that appressorium of the fungus forms not only at 4 hours after incubation under the favorable conditions but also peak of appressorial formation is at 48 hours treatment. Physical stimulus known to be a definite factor for appressorial formation. The optimum temperature range for appressorial infection was at $24^{\circ}C$ to $28^{\circ}C$, and pH was between 4.8 to 8.0 with 6.8 as the optimum. 2) Although percent of appressorial formation on the leaves of resistant Tongil and susceptiible Norin No.6 were only slightly different, there was a remarkable difference between resistant and susceptible cultivars with regard to percent of hyphal infection and index for hyphal extension. Index of hyphal extension was 1.6-2.7 in Tonyil. while in susceptible cultivar was 3.4-6.6. The rate of discoloration of infected cells, a indication of hypersensitivity, was greater in the resistant than in susceptible cultvar. 3) Therefore, it could be concluded that resistance of Tongil cultivar may be attributable to a higher degree of mechanical barriers as well as a higher level of antifungal substance accumulation.

• Journal of Chest Surgery
• /
• v.42 no.4
• /
• pp.447-455
• /
• 2009

Background: Prosthetic valve endocarditis usually presents with clinical symptoms that are more severe than native valve endocarditis, and prosthetic valve endocarditis shows the spread of infection into the surrounding tissue as well as into the superficial endocardial layers. The postoperative prognosis is especially poor for valve re-replacement for the cases of active endocarditis that are unable to receive a full-course of pre-antibiotic therapy due to complications and the ensuing clinical aggravation. The aim of this study was to evaluate the clinical profiles, laboratory findings and mid-term surgical results of active prosthetic valve endocarditis. Material and Method: Among the 276 surgically treated infective endocarditis patients who were treated during the period from January 1998 to July 2008, 31 patients were treated for prosthetic valve endocarditis. Among these patients, 24 received surgical treatment for an 'active' state, and they were selected for evaluation. Result: The most frequently encountered symptom was a febrile sensation. Eight cases (33.3%) were accompanied by systemic thromboembolism, among which 5 cases (20.8%) had an affected central nervous system. 'Vegetations' were most commonly found on transesophageal echocardiography, and the 'Staphylococcus species' were the most frequent pathogens. There were 4 deaths in the immediate postoperative period, and an additional 4 patients died during the follow-up period (Mean$\pm$SD, 42.1$\pm$36.9 months). The cumulative survival rate was 79% at 1 year, 73% at 3 years, 66% at 5 year, and 49.5% at 7 years. Conclusion: The cases of active prosthetic valve endocarditis that were unable to receive a full course of preoperative antibiotics therapy generally have a poor prognosis. Nevertheless, early surgery and extensive resection of all the infected tissue is pivotal in improving the survival rate of patients with surgically treated active prosthetic valve endocarditis.

• Korean Journal of Microbiology
• /
• v.17 no.3
• /
• pp.97-130
• /
• 1979

Many industrial processes those employ bacteria are subjected to phage infestations. In L-glutamic acid fermentions using acetic acid, the phage infestations of the organisms have been recently recognized. In efforts to elucidate the sources of phage contamination involved in the abnormal fermentation, a series of study was conducted to isolate the phages both from the contents of abnormally fermented tanks and the soil or sewage samples from the surroundings of a fermentation factory, to define major charateristics of the phage isolates, and finally to determine the correlation between the phage isolates and temperate phages originating from the miscellaneous bacterial species isolated from the soil or sewage samples. The results are summarized as follows; 1) All phages were isolated from the irregular fermentation tanks and soil or sewage samples, and they were designated as phage PR-1, PR-2, PR-3, PR-4, PR-5, PR-6, and PR-7, in the order of isolation. These PR-series phages were proved to be highly specific for the variant strains of Br. lactofermentum only, namely, phage PR-1 and PR-2 for Br. lactofermentum No. 468-5 and phage PR-3~PR-7 for Br. lactofemrentum No. 2256. By cross-neutralization test, the 7 phagescould be subdivided into 3 groups, i. e., phage PR-I and PR-2 the first, phage PR-3, PR-4, PR-5, PR-6 the second, and the phage PR-7 the third. 2) The 7 phages were virulent under the experimental conditions. They produced plaques with clear and relatively sharp margins without distinct halo. The mean sizes of plaques were 1.5mm in diameter for phage PR-1 and PR-2, and 1. Omm for phages PR-3~PR-7. Double layer technique modified by Hongo and described by Adams, was applied to assay of the PR-series phages. The factors influencing the plaques were as follows;young age cells of host bacteria cultured for 3-6 hours represented the largest number and size, optimum was pH 7.0, incubation temperature was $30^{\circ}C$, and agar concentration and amount of overlayer medium were 0.6% and 0.2ml, respectively. 3) PR-series phages were stable in 0.05M tris buffer and 0.1M ammonium acetate buffer solution. The addition of $5{\times}10^{-3}M$ magnesium ion effectively increased the stability. Thermostability experiments indicated that PR-series phages were stable at the teinperture between $50^{\circ}{\sim}55^{\circ}C$ in nutrient medium, $45^{\circ}{\sim}50^{\circ}C$ in buffer solution. However, the phages mere completely inactivated at 603C and 65$^{\circ}$C within 10 minutes. The phages were stable at the range of pH6~9 in nutrient medium and of pH 8-9 in buffer solution, respectively. Exposure of the phages to UV for 25, 60 and 100 seconds resulted in the complete loss of infectivily, respectively. 4) Electron microscopy showed that PR-series phage particles exhibited rather similar morphology, differing in the size All of PR-series phages had a multilateral head and had a simple long tiil about three to five times long as compared with head. By the size, phage PR-1 and PR-2, PR-3, PR-4, PR-5, and PR-6 and PR-7 were classified into same groups, respectively. The head and tail size of phage PR-1, PR-5, PR-5(T) and PR-7 were 85nm, 74nm and 235nm and 350mm, and 72nm and 210nm, respectively. 5) Nucleic acids of PR-series phages were double stranded DNA. The G+C contents of phage PR-1, PR-5 and PR-7 were 56.1, 52.9 and 53.7, respectively. The values of G+C contents derived from the $T_m$ were in agreement with the chemically determined values. 6) PR-series phages effectively adsorbed on their host bacteria at the rate of more than 90% during 5 min. K value for phage PR-1, PR-5 and PR-7 were calculated to be $6{\times}10^9 ml$ per minute, respectiveky. The pH of the medium did effect adsorption rate, but both temperature and age of host cells did not. Generally, optimum adsorption condition of phages seemed to be almost same as optimum growth conditions of host bacteria. 7) In one-step growth experiments, the latent periods at $30^{\circ}C$ for PR-1, and PR-7 were about 70, 50 and 55 min, respectively. The corresponding average burst size was 200, 70 and 90, respectively. Lpsis period according to the multiplicity of infection and a phage series. In case of m. o. i. 100, strain No. 2256 (PR-5) and No. 468-5(PR-1) failed to grow and turbidity decreased after 50 and 70min, respectively. 8) In the lysate of a plaque purified phage PR-5 infected bacteria, there observed 2 types ofphage particles, i. e., phage PR-5 and PR-5 (T) of similar morphology but differing at the length of phage tail, and phage tail like particles. The phage taillike particles could be divided into 4 types by the length. Induction experiments of Br. lactofermentum with UV irradiation, mitomycin C or bacitracin treatment produced neither phage PR-5 (T) or phage tail-like particles. 9) No lysis occured when the growth of 7 strains of miscellaneous bacteria, isolated from soil and sewage samples, were inoculated with either phage PR-5 (T) or phage tail-like particles the inoculation of phage PR-5 pellet resulted in the growth inhibition of the orgainsms in the spot test. The lysates obtained from 3 miscellaneous soil derived bacteria following mitomycin C treatment the growth of Br. lactofermentum, but did not lyze the bacterium.

• Journal of dental hygiene science
• /
• v.7 no.1
• /
• pp.1-7
• /
• 2007

This study aimed to provide basic information on dental hygienists' practicing the prevention of infections by figuring out their actual conditions in dental clinics. The subjects of the study were the dental hygienists who participated in the continuing medical education of Incheon & Gyeonggi-do association and Seoul city association in October and November 2005 and the self-administered surveys were used for the prevention of infections. The results were as below. 1. In terms of education experiences of infection prevention, those who answered "there were" were 72 persons (42.9%) and those who followed the educational route for infection prevention were "through the in-house education from the hospital" and they were 42 persons (58%), which were highest. 2. In terms of the injury experiences, those who answered "there were" were 147 persons (87.5%) and the number of annual injury out of 147 persons with injury experiences was 7.7 time. For the tools that were damaged, 125 persons (75%) damaged the "explorer," which was highest. 3. For the experiences of being infected with contagious diseases, those who answered "there were" were 6 persons (3.6%) and there were four persons for "hepatitis B", one person for "rubella" and one person for "TB." 4. The questions with high practice scores were as in the following: "2. I wash my hands after conducting medical examinations (1.86 points)," "7. I always close the lid of a shot of Novocain after doing local anesthesia (1.86 points)" and "20. I separate and collect the wastes and give them to those who treat accumulated materials (1.85 points)". Meanwhile, the questions with low practice scores were as below: "16. I change my medical gowns (doctor wears) once a day (0.24 point)" and "I wash my medical gowns every time after examining patients with contagious diseases (0.52 points)." 5. The question with high knowledge was as below: "1. The contagion during the dental treatment is determined by source of infection, infection methods, infection routes and the host that is prone to infection (0.95 point)" and the question with the lowest knowledge was "5. HBV(hepatitis B) is destroyed after adding 95oC of heat for more than 5 minutes (0.27 points)." 6. The question with the highest organization-related factors was "I am always ready to use a mask, gloves, etc. if necessary" (0.89 points)" and the question with the lowest score was "There is a guideline that I can refer when I am exposed to dangerous situations related to the contagion in my workplace (0.33 point)." 7. In terms of the equipment conditions of protectors in medical environments, 168 persons for (disposable) mask (100%), 167 persons for disposable gloves (Latex) (99.4%), which meant that most of them were equipped with them. On the contrary, 108 persons (64.3%) are equipped with the protectors for frontal faces, which is the lowest and 165 persons (98.2%) said that they had autoclave in their disinfecting and sterilizing devices.

• Journal of dental hygiene science
• /
• v.7 no.1
• /
• pp.13-20
• /
• 2007

This study is aimed at providing basic data for measures to prevent dental hygienists who are highly exposed to hepatitis-B virus due to their characteristic working conditions from being infected of it. In order to determine their perception and the extent of their exposure to the risk of infection with hepatitis-B virus, a survey was conducted with questionnaires distributed to 354 dental hygienists who are working at dental offices in Seoul. Gyeongi and Jeolla provincial areas. From the survey, following conclusions could be drawn: 1. Sixty three point seven to 100 percent of them are found to have been vaccinated against hepatitis-B virus as is generally expected from their working environment. 2. Their general characters are found to be statistically significant in terms of vaccinating point of time among those who have been vaccinated. Most respondents are either vaccinated one year or 5 years ago. The completion of 3 requested vaccinations lies in the level of 64.3%~100% depending on the general characters. By age, the best result comes from the age group of 25~29, followed by the groups older than 30 and 20-24 in order (p < 0.05). Formation of antibody belongs to the level of 45%~100% generally. But statistically significant of them is the extremely unhealthy state with 100%, followed by normal, generally healthy, very healthy and not healthy in sequence (p < 0.05). 3. In terms of family's clinical history, it is known that the older (p < 0.01), the more unhealthy (p < 0.01) and the married (p < 0.01), the more possibility of having anamnesis of hepatitis-B virus infection. 4. The level of knowledge about Hepatitis-B virus is shown to be in the extent of 4.39~5.01 out of maximum 8 points in general terms. 5. It is revealed that there are high chances for dental hygienists to get spattered with body matters of patients like blood or sputum on their faces in general characters (87.%~100%). 6. A high rate (75%~100%) of respondents has experienced being shot by needles. The older(p < 0.05) and the longer(p < 0.05) their career, the higher the rate becomes.

• Journal of Aquaculture
• /
• v.17 no.1
• /
• pp.39-45
• /
• 2004

Three experiments were conducted to determine utilization of Song-Gang(equation omitted) stone as the dietary additive for growth and immune stimulant in juvenile olive flounder. In the feeding trial, four diets were formulated to contain 0, 0.5, 1.0 and 2.0% Song-Gang(equation omitted) stone per kg diet (SGS$_{0}$ , SGS$_{0.5}$, SGS$_{1.0}$ , SGS$_{2.0}$ ). Fish averaging 5.0$\pm$0.04 g (mean$\pm$SD) were fed one of four experimental diets in triplicate groups for 8 weeks. There were no significant differences in weight gain, feed efficiency, protein efficiency ratio, hematosomatic index, condition factor and survival among fish fed all the diets. In chanlenge test, fish were infected by intraperitoneal injection of 0.1 $m\ell$ bacterial suspension with Edwardsielia tarda per fish after the feeding trial. Fish fed SGS$_{0.5}$ diet have a significantly higher cumulative survival rate than did fish fed the other diets (P<0.05). In the anti-mold test, Asprrgiilus niger, Penicillium pinophiltfm, Chaeromium globosum were inoculated with Song-Gang(equation omitted) stone using ASTM G-21 method. The amount of Α. niger, Ρ. pinuphiium. C. globosum didn't increase in Song-Gang(equation omitted) stone for 4 weeks for the test period. Therefore, these results indicate that 0.5% Song-Gang(equation omitted) stone per kg diet could increase immune resistance in juvenile olive flounder and Song-Gang(equation omitted) stone could be used as the anti-mold additive in fish feed.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.2
• /
• pp.184-194
• /
• 1999

Backgrounds : The advent of penicillin has led to the marked reduction in the mortality from pneumococcal bacteremia, however, the mortality is still relatively high in this post-antibiotic era. Actually the prevalence of infection due to penicillin-resistant penumococci is increasing worldwide, and it is especially high in Korea due to irrelevant use of antibiotics. So, the high mortality of pneumococcal sepsis might be related to the emergence of penicillin-resistant strains, however, many other antibiotics, which eradicate pneumococci effectively, are available in these days. This has led us to suspect the role of penicillin-resistance in the high mortality rate. In this study, we evaluated the effect of penicillin resistance on the mortality of patients with penumococcal bacte remia. Methods: The study population consisted of 50 adult patients with penumococcal bacteremia who were admitted between Jan, 1990 and July, 1997. Medical records were analyzed retrospectively. Results: Most of the patients (96%) had underlying diseases. The most common local disease associated with pneumococcal bacteremia was pneumonia (42%), which was followed by spontaneous bacterial peritonitis (14%), cholangitis (10%), meningitis (8%), liver abscess (4%), pharyngotonsillitis (4%), sinusitis (2%) and cellulitis (2%). While the overall case-fatality rate in this study was 24%, it was higher when peumococcal bacteremia was associated with pneumonia (42%) or meningitis (50%). The rate of penicillin resistance was 40%, which was increased rapidly from 1991. The rate of penicillin resistance was significantly higher in patients with the history of recent antibiotics use and hospitalization within 3 months respectively. The clinical manifestations, that is, age, severity of underlying diseases, nosocomial infection, associated local diseases, and the presence of shock or acute renal failure were not statistically different between the patients with penicillin-resistant and -sensitive pneumococcal bacteremia. The mortality of patients infected with penicillin-resistant pneumococci was not statistically different from those with penicillin-sensitive pneumococcal bacteremia. Conclusion: Penicillin resistance is not associated with high mortality in adult patients with pneumococcal bacteremia. As the overall mortality is high, active penumococcal vaccination is recommended in patients with high risk of infection.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.5
• /
• pp.605-611
• /
• 2012

Sea cucumber, $Stichopus$ $japonicus$, is used not only as an outstanding tonic food but also as a traditional medicine for the treatment of asthma, hypertension, rheumatism, anemia, and sinus congestion. The purpose of this study was to examine sea cucumber as an anti-gastritis and anti-gastric ulcer in HCl-ethanol-induced gastric and $H.$ $pylori$-infected animal models. Thirty 7-week-old SD rats and Mongolian gerbils were divided into normal (Nor, n=6), control (Con, 60% HCl-ethanol+water, n=6), groupI (DSCI, 60% HCl-ethanol+sea cucumber 30 mg/kg, n=6), groupII (DSCII, 60% HCl-ethanol+sea cucumber 100 mg/kg, n=6), and group III (DSCIII, 60% HCl-ethanol+sea cucumber 300 mg/kg, n=6). Sea cucumber significantly suppressed gastric lesions and ulcers in the 60% HCl-ethanol-induced gastric model. Especially, 100 mg/kg of sea cucumber showed significantly inhibitory effects. In histopathological analysis of the $H.$ $pylori$ model, we found that sea cucumber augmented the eradication rates of $H.$ $pylori$ and attenuated gastric ulcer formation. Our results suggest that sea cucumber has inhibitory effects on gastritis and gastric ulcers. In addition, sea cucumber can be applied for the treatment of $H.$ $pylori$.