• Title/Summary/Keyword: Challenge test

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Safety and efficacy of modified-live infectious laryngotracheitis vaccines (닭 전염성 후두기관염 생독백신의 안전성과 효능)

  • Han, Myung-Guk;Lee, O-Soo;Kim, Jea-Hong
    • Korean Journal of Veterinary Research
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    • v.42 no.2
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    • pp.241-251
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    • 2002
  • Modified-live (ML) infectious laryngotracheitis (ILT) vaccines have been widely used as a preventive measure in Korea since the first outbreak of ITL. Recently, it has been observed that chickens vaccinated with the commercially available ML ILT vaccine have sometimes exhibited adverse clinical signs. In this study, we evaluated the quality of the vaccines by comparing titer of each vaccine batch and testing the stability of ILT virus (ILTV) in vaccine diluents and compared the safety and efficacy of vaccines in specific pathogen free (SPF) chickens. The ratio of maximum titer to minimum titer of vaccine produced by most manufacturers was 2 to 15. However, 2 out of 11 manufacturers produced vaccines of which the ratio was 74 to 478. Most vaccines examined were maintained vaccine titers suitable for national regulations within expiry date. However, some vaccines did not keep the titer required for the national regulations. In the test for stability of ILTV in various diluents, ILTV was highly stable in lactose-phosphate-glutamine-gelatin solution, sucrose-phophate-glutamine-albumin solution and some vaccine diluents produced by manufacturers. The safety of ML ILT vaccines was assessed in 10-day-old SPF chicks. Mortality in SPF chicks inoculated intratracheally with one dose of vaccine varied depending on vaccines and some vaccines produced 50-85% mortality. Seven-week-old SPF chickens were vaccinated intraocularly with ML ILT vaccines and then challenged intratracheally with ILT challenge virus 14 days after vaccination. The protection rate was assessed by clinical signs and reisolation of the ILT challenge virus from tracheas taken at day 4 after challenge. There were slight respiratory reactions in some vaccinated chickens after vaccination but these reactions disappeared within 5 days after vaccination. No further clinical signs and death were observed. Protection rate determined by clinical signs and mortality was 100% in all vaccinated groups. However, the challenge virus was isolated from all tracheas of chickens vaccinated with vaccine B or control groups. The challenge virus was also isolated in the trachea of one in five chickens vaccinated with either vaccine F or K, but not in tracheas of chickens vaccinated with other vaccines. In the present study, the stability of vaccine diluents, pathogenicity and protection rate based on reisolation test of the challenge virus were different depending on vaccines produced by eleven manufacturers.

A Study on the Cosmetic Preservative Effects of Cornus officinalis seed Extracts (산수유 종자 추출물의 화장품 방부효능에 관한 연구)

  • Yang, Jae-Chan
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.2
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    • pp.333-341
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    • 2016
  • To evaluate the possibility as a natural preservative of Cornus officinalis seed extracts, we investigated the anti-microbial activity and preservation effect of cosmetics. Cornus officinalis seed extracted with 1,3-Butylene Glycol(1,3-BG) and Ethanol(EtOH). As a result, Cornus officinalis seed extracts showed anti-microbial activity at Staphylococcus aureus, Staphylococcus epidermidis, Propionibacterium acnes and Cornus officinalis seed 1,3-BG extracts(COS-A) showed $26.7{\pm}4.0mm$ clear zone at the $1000.0{\mu}l/ml$. Minimum inhibitory concentration of S. epidermidis was observed at Cornus officinalis seed EtOH extracts(COS-B) $25.0{\mu}l/ml$. The result of challenge test for preservation effect on cosmetics, S. aureus and S. epidermidis was 100% eliminated from emulsion containing COS-A and COS-B after 7 days. These results suggest that Cornus officinalis seed extracts may have possibility as the natural preservative instead of synthetic perservative on cosmetics.

The Reliability and Validity of the Health-Related Hardiness Scale in a Sample of Korean Nursing Students (간호학생을 대상으로한 건강관련 강인성 도구(HRHS)의 신뢰도와 타당도 검증 및 수정)

  • Lee, Mi-Ra
    • Research in Community and Public Health Nursing
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    • v.11 no.1
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    • pp.199-208
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    • 2000
  • The purpose of this study is to test the psychometric properties of the Korean version of the Health-Related Hardiness Scale(HRHS) in a sample of Korean nursing students. The korean version of HRHS was administered to 234 nursing students including 135 college students and 99 university students. The Korean version of HRHS was measured on a 6 Likert scale, assessing three factors of HRHS : control, commitment, and challenge. Internal consistency was used to test the instrument's reliability. The internal consistency of the scale was measured using a coefficient alpha. The coefficient alpha was .69(control), .49(commitment). and .69(challenge), Item analysis and confirmatory factor analysis (CFA) were used to test the instrument's construct validity. The item analysis identified that there were 13 items. which were lower than the .25 item-total correlation. CFA revealed that the scale's fadoral validity was not proper by showing unfit indices(RMSEA .07. stand, RMR .09. GFI .71). According to the findings of this study, the reliability and construct validity of the Korean version of HRHS is not satisfactory in the sample of nursing students. As a result. the researcher modified the scale through item analysis and repetitive CFA process, and proposed the revised 25-item Korean version of HRHS for nursing students. The revised scale's reliability(control .74, commitment .73. challenge .77) and factorial validity were within acceptable levels. The item analysis identified that there was no item, which is lower than the .25 item-total correlation. CFA revealed that the scale's factoral validity was proper by showing fit indices(RMSEA .08 stand. RMR .08. GFI .80).

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Effects of Dietary Antioxidant Supplementation on the Growth, Serum Chemistry, Body Composition and Challenge Test Results of Juvenile Rockfish Sebastes schlegelii (항산화 기능 사료첨가제가 조피볼락(Sebastes schlegelii)의 성장, 체조성, 혈액성상 및 세균 공격성에 미치는 영향)

  • Yun, Ahyeong;Kim, Hee Sung;Seo, Youngwan;Cho, Sung Hwoan;Bae, Jun Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.3
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    • pp.323-329
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    • 2016
  • The effects of dietary antioxidant [saltwort (SW), leek (LK), and dandelion (DD)] supplementation on the growth, body composition, serum chemistry, and challenge test results of juvenile rockfish, Sebastes schlegelii, were determined. In an experiment, 320 fish were randomly distributed into eight, 50-L flow-through tanks (40 fish per tank). Four experimental diets were prepared: the control diet (Con) with synthetic antioxidant: and diets with SW, LK, or DD from natural sources. Each diet was randomly assigned to duplicate tanks of fish, which were hand-fed to satiation twice daily for 8 weeks. After the 8-week feeding trial, 20 fish from each tank were artificially infected with Streptococcus iniae and monitored for 6 days. The dietary additives did not affect survival, weight gain, specific growth rate, feed efficiency (FE), protein efficiency ratio (PER), or plasma chemistry. However, the cumulative mortality of fish fed the SW, LK and DD diets was lower than that of fish fed the control diet beginning 4 days after infection. In conclusion, dietary supplementation with SW, LK, and DD did not affect the growth, FE, PER, or plasma chemistry of rockfish. However, dietary inclusion of SW, LK, and DD lowered the mortality of rockfish following infection with S. iniae.

A Study on the Evaluation of Antimicrobial Effect of Orostachys Japonicus A. Berger Ethyl Acetate Fraction (와송 에틸아세테이트 분획물의 항균효능 평가에 관한 연구)

  • Im, Eun Kyung;Yang, Jae Chan
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.2
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    • pp.488-496
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    • 2021
  • In this study, a study was conducted to utilize Orostachys japonica A. Berger EtOAc fraction extract as an antibacterial activity and cosmetic ingredient. As a result of measuring the antimicrobial activity of Orostachys japonica A. Berger EtOAc, the growth of S. aureus, S. epidermidis, and P. aeruginosa was inhibited. Among them, S. aureus was an extract of 18.35 ± 1.5 mm Orostachys japonica A. Berger EtOAc fraction at a concentration of 0.5 g / mL, showing superior antibacterial activity than methyl paraben (16.83 ± 1.0 mm), and was shown as a positive control. As a result of evaluating the MIC of the Orostachys japonica A. Berger EtOAc fraction extract through MIC measurement, the remaining strains excluding Candida. A showed a MIC of 17.5 mg/mL. As a result of evaluating the cosmetic preservation effect through the challenge test applied to the cosmetic emulsion formulation, the growth inhibitory effect of S. aureus in the emulsion containing 0.3% Orostachys japonica A. Berger EtOAc fraction extract 7 days after microbial inoculation was 100%.

Challenge of Personalized Medicine in the Genomic Era (유전의료시대의 "맞춤의학")

  • Kim, Hyon-J.
    • Journal of Genetic Medicine
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    • v.5 no.2
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    • pp.89-93
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    • 2008
  • "Personalized medicine," the goal of which is to provide better clinical care by applying patient's own genomic information to their health care is a global challenge for the $21^{st}$ century "genomic era." This is especially true in Korea, where provisions for clinical genetic services are inadequate for the existing demand, let alone future demands. Genomics-based knowledge and tools make it possible to approach each patient as a unique biological individual, which has led to a paradigm-shift in medical practice, giving it more of a predictive focus as compared with current treatment oriented approach. With recent advancements in genomics, many genetic tests, such as susceptibility genetic tests, have been developed for both rare single gene diseases and more common multifactorial diseases. Indeed, genetic tests for presymtomatic individuals and genetic tests for drug response have become widely available, and personalized medicine will face the challenge of assisting patients who use such tests to make appropriate and wise use of genetic risk assessment. A major challenge of genomic medicine lies in understanding and communicating disease risk in order to facilitate and support patients and their families in making informed decisions. Establishment of a health care system with provisions for genetic counseling as an integral part of health care service, in addition to genomic literacy of health care providers, is vital to meet this growing challenge. Realization of the promise of personalized medicine in the era of genomics for improvement of health care is dependent on further development of next generation sequencing technology and affordable sequencing test costs. Also necessary will be policy development concerning the ethical, legal and social issues of genomic medicine and an educated and ready medical community with clinical practice guidelines for genetic counseling and genetic testing.

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Differential Excretion of Urinary Eosinophil Protein X after Methacholine Challenge Test in Children with Asthma (천식 환아에서 요중 Eosinophil Protein X의 메타콜린 기관지 유발 시험 전·후의 변화)

  • Shin, Su-A;Oh, Jae-Won;Lee, Ha-Baik
    • Clinical and Experimental Pediatrics
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    • v.46 no.5
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    • pp.495-499
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    • 2003
  • Purpose : Eosinophil is one of the important inflammatory cell involved in the airway inflammation in childhood asthma. It has been demonstrated that markers of eosinophil activation, including eosinophil cationic protein or eosinophil protein X(EPX), are increased in childhood asthma. Furthermore, they are related to disease activity and are assumed to be helpful in monitoring the treatment effect as urinary EPX(U-EPX) can be obtained easily and in a noninvasive way in children of all ages. Methods : Twenty-five children(22 male and three female) aged $11.87{\pm}3.82$ years with stable asthma were challenged with methacholine and urine was collected from each child during the following periods; before methacholine challenge test(MCT); 0-3 hr after the end of MCT; 4-7 hr after the end of MCT; and 8-24 hr after the end of MCT. Bronchial reactivity was determined by using Dosimeter( Jeager, Germany) with serially diluted methacholine from 0.05 to 25.0 mg. The $FEV_1$ less than 80% of baseline value were classified into positive MCT. U-EPX was measured with a sensitive and specific radioimmunoassay(Pharmacia & Upjohn AB, Uppsala, Sweden). Results were expressed as ${\mu}gEPX/mmol$ creatinine. Results : An early airway response after MCT was associated with an increase of U-EPX excretion for 0-3 hr after methacholine inhalation in comparison with beseline values. Most subjects showed a small increase in U-EPX excretion during late asthmatic response for 4-7 hr, which then decreased to normal level in 8-24 hr. Also, a tendency for a higher increase of U-EPX was associated with a lower threshold of methacholine challenge and a longer duration of asthma. Conclusion : Measurement of EPX in urine is a noninvasive and easy method to assess the severity of airway inflammation in asthmatic children. It may be a helpful index of the events underlying the airway inflammatory responses during nonspecific bronchial challenge, and in monitoring asthma management.

Experimental Infection for the Neutralization of White Spot Syndrome Virus (WSSV) in Wild Captured Sand Shrimp, Crangon affinis (자연산 자주새우(Crangon affinis)에서 흰반점바이러스(WSSV)의 neutralization을 위한 인위감염(experimental infection))

  • Gong, Soo-Jung;Kim, Yeong-Jin;Choi, Mi-Ran;Kim, Sung-Koo
    • Journal of Life Science
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    • v.20 no.9
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    • pp.1294-1298
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    • 2010
  • White spot syndrome virus (WSSV) is one of the most virulent viral agents threatening the penaeid shrimp culture industry. This study was carried out to evaluate the susceptibility of the sand shrimp, Crangon affinis, to WSSV as an alternative experimental model. WSSV caused 100% mortality in C. affinis within 7 days after experimental infection by immersion. Based on challenge studies, it was confirmed that C. affinis could be a potential host in WSSV transmission. Also, the neutralization of WSSV was carried out using an antiserum raised against recombinant envelop protein rVP466 to evaluate the WSSV infection mechanism. A constant amount of WSSV (at $1{\times}10^4$ diluted stocks) was incubated with various amounts of antiserum and then mixed to 20 l reservoir for the immersion challenge of C. affinis for neutralization. At 5 days post challenge, the shrimp in the positive control immersed in the immersion reservoir containing WSSV stock showed 100% mortality. The shrimps challenged with the 3 different mixtures of WSSV and rVP466 antiserum (1:0.1, 1:0.5 and 1:1) showed 100%, 68.8% and 68.8% mortality at 14 days post challenge, respectively. These results indicated that the antiserum raised against rVP466 could block WSSV infection in C. affinis. Therefore, this study confirmed that C. affinis can be naturally infected by WSSV as another potential host and that C. affinis can be used as an alternative experimental animal instead of penaeid shrimps.

Production of the Antiserum against Recombinant Envelop Protein, rVP466 for the Neutralization of White Spot Syndrome Virus (WSSV) (흰반점바이러스(WSSV)의 중화를 위한 재조합단백질 rVP466의 항혈청 생산)

  • Gong, Soo-Jung;Kim, Yeong-Jin;Choi, Mi-Ran;Kim, Sung-Koo
    • Journal of Life Science
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    • v.20 no.10
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    • pp.1427-1432
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    • 2010
  • This study was carried out to evaluate neutralization effects against WSSV using antiserum produced from recombinant envelop protein, rVP466 of WSSV. The VP466 gene of WSSV was cloned into pCold I expression vector and rVP466 was expressed in E. coli RIPL. The antiserum against rVP466 was produced in white rabbits (New Zealand white rabbit). The specific immunoreactivity to the antigen, rVP466, was confirmed by Western blot. The constant amounts of WSSV at $1{\times}10^4$ diluted stocks were mixed with various antiserum concentrations and then injected to the muscle of shrimp, Penaeus chinensis, for the neutralization challenge. The shrimps challenged with WSSV as a positive control and those with the mixture of WSSV and preimmune serum as a preimmune control showed 100% cumulative mortality at 17 days post challenge and 83% at 25 days post challenge, respectively. The shrimps challenged with 3 different mixtures of WSSV and rVP466 antiserum at ratios of 1:0.01, 1:0.1 and 1:1 showed 73%, 53% and 46% cumulative mortalities at 25 days post challenge, respectively. These results indicated that WSSV could be neutralized by the rVP466 antiserum. These results suggest that envelop protein VP466 is involved in the initial step of WSSV infection in shrimp.

Family variation in survival of olive flounder Paralichthys olivaceus after Edwardsiella tarda infection in challenge tests (Edwardsiella tarda 인위감염에 의한 넙치, Paralichthys olivaceus의 가계별 내성변이)

  • Kim, Hyun-Chul;Sohn, Sae-Bom;Jeong, Jong-Geun;Lee, Jeong-Ho;Choi, Hye-Sung;Noh, Jae-Koo;Park, Choul-Ji;Min, Byung-Hwa;Kim, Jong-Hyun;Kim, Kyung-Kil;Myeong, Jeong-In
    • Journal of fish pathology
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    • v.22 no.3
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    • pp.275-282
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    • 2009
  • In this study, effect of mating group, mating dam and mating sire was analyzed using olive flounder Paralichthys olivaceus challenged with Edwardsiella tarda. A challenge test was conducted using 1,708 olive flounder fingerlings obtained through $4{\times}4$ factorial cross from parents selected based on resistant degree. Regarding the means of resistant index, survival rate and days of survival by each mating group, the group(RR) produced by mating among resistant parents were 17.98, 13.77%, and 18.36 days, respectively; the group(SS) produced by mating among susceptible parents were 12.46, 2.71%, and 12.40 days, respectively. This study gives an indication that challenge test results may be successfully used as selection criteria for disease resistance to E. tarda in olive flounder, P. olivaceus.