• Journal of Animal Science and Technology
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• 제62권5호
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• pp.682-691
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• 2020

Careful cleaning and disinfection of pigpens is essential to prevent disease spread and avoid the resultant economic losses. Hygiene in pigpens is generally evaluated by visual monitoring supplemented with bacteriological monitoring, which includes counting the total aerobic bacteria (TAB) and/or fecal indicator bacteria (FIB). However, these methods present drawbacks such as time and labor requirements. As adenosine triphosphate (ATP) is ubiquitous in all living organisms including microorganisms, this study aimed to directly compare the results of microbial assessment and ATP quantification, and to suggest possible detailed application methods of the ATP test for hygiene evaluation in pigpens of a farrowing unit. Before and after standard cleaning procedures, samples were collected from the floor corner, floor center, and feeding trough of four pigpens at different time points. No FIB were detected and both the TAB and ATP levels were significantly decreased in the floor center area after cleaning. FIB were continuously detected after cleaning and disinfection of the floor corners, and there was no significant ATP level reduction. The feeding trough did not show any significant difference in these values before and after cleaning, indicating insufficient cleaning of this area. The levels of TAB and ATP after cleaning were significantly correlated and the average ATP value was significantly lower in the absence of FIB than in their presence. In the absence of standard references, a more thorough hygiene management could be achieved evenly by supplementing cleaning or disinfection based on the lowest ATP results obtained at the cleanest test site, which in the present study was the floor center. Overall, these results indicate that the on-farm ATP test can be used to determine the cleanliness status, in addition to visual inspection, as an alternative to laboratory culture-based testing for the presence of microorganisms.

• Journal of Animal Science and Technology
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• 제56권8호
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• pp.32.1-32.4
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• 2014

Though many alternative methods to tuberculin skin testing (TST) have been established and evaluated in recent years, sensitivities and specificities of most methods could not meet the requirements of golden standards. In this study, we sought to identify whether repeated TSTs could affect the immune responses in experimental monkeys. Nine natural tuberculosis (TB) monkeys receiving repeated TSTs biweekly were used to demonstrate the effect on TST responsiveness. Two healthy monkeys were administrated with repeated TSTs to analyze the immune response profiling. Intrapalpebral reactions in TB infections gradually weakened or presented intermittent positive reactions. The leukocyte counts, cytokine responses, and antibody responses to all antigens except Old tuberculin (OT) and MPT64L showed no specific changes for TB in healthy monkeys. Positive antibody responses to OT and MPT64L emerged during the first half experimental period, which may cause by their cross-reactivity with mycobacterial species. Results showed that repeated TSTs had no significant effects on immune responses in healthy monkeys but a progressive reduction in TST responsiveness in TB infections.

• Toxicological Research
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• 제25권1호
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• pp.9-15
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• 2009

Historically, research in toxicology has utilized non-human mammalian species, particularly rats and mice, to study in vivo the effects of toxic exposure on physiology and behavior. However, ethical considerations and the overwhelming increase in the number of chemicals to be screened has led to a shift away from in vivo work. The decline in in vivo experimentation has been accompanied by an increase in alternative methods for detecting and predicting detrimental effects: in vitro experimentation and in silico modeling. Yet, these new methodologies can not replace the need for in vivo work on animal physiology and behavior. The development of new, non-mammalian model systems shows great promise in restoring our ability to use behavioral endpoints in toxicological testing. Of these systems, the zebrafish, Danio rerio, is the model organism for which we are accumulating enough knowledge in vivo, in vitro, and in silico to enable us to develop a comprehensive, high-throughput toxicology screening system.

• 대한화장품학회지
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• 제22권1호
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• pp.84-101
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• 1996

동물시험을 최소화 하고, 동물시험에 사용되는 노력과 비용을 줄이기 위해 동일한 동물에서 광독성과 광알러지성을 함께 보는 새로운 방법을 제안하고, in vitro alternatives로서 photostability와 spectrophotometric carbonyl assay의 유용성을 검토하였다. Modified photosensitization model에서는 Ichikawa 방법과는 달리 동물수, 휴식 기간, 첩포 횟수를 단순히하고 폐쇄 첩포를 추가하였다. 방법의 유용성을 보기 위해 Benzocaine, 6-methyl coumarine을 Ichikawa 방법 및 본 시험 방법으로 결과를 비교한 결과 macroscopic, histologic examination에서 비슷한 결과를 얻었다. Photostability 시험에서는 pbotoreactive agent 들이 모두 20%이상의 흡광도 감소를 보여 pbotosensitization potential을 측정하기 위한 전 단계 실험으로서의 가능성을 보여주었고, spectrophotometric carbonyl assay에서는 salmonella를 이용한 광독성 실험에서는 나타나지 않았던 저농도의 Amthracene, Hematoporphyrin에서 조차도 phtotoxic prtential을 보여주어 in vitro alternatives로서의 가능성을 보여주었다.

• BMB Reports
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• 제55권5호
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• pp.213-219
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• 2022

The blood-brain barrier (BBB) is an interface between cerebral blood and the brain parenchyma. As a gate keeper, BBB regulates passage of nutrients and exogeneous compounds. Owing to this highly selective barrier, many drugs targeting brain diseases are not likely to pass through the BBB. Thus, a large amount of time and cost have been paid for the development of BBB targeted therapeutics. However, many drugs validated in in vitro models and animal models have failed in clinical trials primarily due to the lack of an appropriate BBB model. Human BBB has a unique cellular architecture. Different physiologies between human and animal BBB hinder the prediction of drug responses. Therefore, a more physiologically relevant alternative BBB model needs to be developed. In this review, we summarize major features of human BBB and current BBB models and describe organ-on-chip models for BBB modeling and their applications in neurological complications.

• 한국가스학회지
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• 제16권6호
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• pp.7-16
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• 2012

화재시 당면할 수 있는 위험성의 여러 인자 가운데 연소 독성 영향은 피난 및 최종 생존에 중요한 영향을 미치고 있다. 화재 독성에 지금까지 대한 대부분의 연구는 치사 측면에 국한되어 왔다. 이에 본 연구에서는 대표적인 질식성 가스인 HCN을 대상으로 가스유해성시험방법(KS F 2271)을 통하여 실험동물(흰쥐)에 직접 독성가스를 흡입시킨 후 평균행동정지시간을 측정하고, 이들 실험동물군의 내부 장기 변화, 혈액학 분석 및 단세포전기영동분석을 통해 연소 독성가스가 생체에 미치는 영향을 정량적으로 분석하고자 하였으며, 기존 가스유해성시험에서 확인할 수 없었던 접근(병리검사, 혈액검사, 혈액생화학검사, 단세포전기영동분석)을 통해 연소 독성학 분야의 생물학적 위험도를 측정하고자 하였다.

• 대한수의학회지
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• 제50권1호
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• pp.43-48
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• 2010

Animal disease surveillance system, defined as the continuous investigation of a given population to detect the occurrence of disease or infection for control purposes, has been key roles to assess the health status of an animal population and, more recently, in international trade of animal and animal products with regard to risk assessment. Especially, for a system aiming to determine whether or not a disease is present in a population sensitivity of the system should be maintained high enough not to miss an infected animal. Therefore, when planning the implementation of surveillance system a number of factors that affecting surveillance sensitivity should be taken into account. Of these parameters sample size is of important, and different approaches are used to calculate sample size, usually depending on the objective of surveillance systems. The purpose of this study was to evaluate the sensitivity of the current national serological surveillance programs for four selected bovine diseases assuming a specified sampling plan, to examine factors affecting the probability of detection, and to provide sample sizes required for achieving surveillance goal of detecting at least an infection in a given population. Our results showed that, for example, detecting low level of prevalence (0.2% for bovine tuberculosis) requires selection of all animals per typical Korean cattle farm (n = 17), and thus risk-based target surveillance for high risk groups can be an alternative strategy to increase sensitivity while not increasing overall sampling efforts. The minimum sample size required for detecting at least one positive animal was sharply increased as the disease prevalence is low. More importantly, high reliability of prevalence estimation was expected with increased sampling fraction even when zero-infected animal was identified. The effect of sample size is also discussed in terms of the maximum prevalence when zero-infected animals were identified and on the probability of failure to detect an infection. We suggest that for many serological surveillance systems, diagnostic performance of the testing method, sample size, prevalence, population size, and statistical confidence need to be considered to correctly interpret results of the system.

• 대한화장품학회지
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• 제38권4호
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• pp.305-310
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• 2012

우리는 평생 동안 하루도 빠짐없이 치약과 같은 구강관리 제품들을 사용한다. 이와 같이 매일 입에 사용되는 제품의 안전성이 담보되어야 함은 매우 중요한 일이다. 이전까지 이루어진 동물시험이나 임상시험에서 치약 내 계면활성제 등에 의한 구강 자극이 유발될 수 있음이 알려져 있다. 하지만, 동물복지를 위하여 유럽 화장품 법안은 화장품과 그에 사용하는 원료에 대한 동물 시험을 금지했다. 그로 인해 여러 분야에서 동물을 대체하거나 동물의 사용을 줄일 수 있는 동물대체 시험법의 개발이 활발하게 이루어지고 있다. 하지만, 현재까지 구강 점막 독성을 측정할 수 있는 방법으로 임상시험과 동물시험이 있었으며, 최근에는 구강 점막 조직 모델이나 구강 세포들을 활용한 방법들이 연구되고 있다. 이번 연구의 목적은 구강관리 제품의 안전성을 확보할 수 있는 동물대체 시험법을 개발하는 것이다. 구강 세포주(YD-38 cell)를 활용해 불용성 물질을 포함한 치약에 대한 시험이 가능하도록 구강 점막 자극 시험법을 개발하였고, 이 시험법으로 이전에 이루어진 동물시험에서 자극유발원으로 알려진 물질에 의한 자극을 구별해낼 수 있었다. 또한, 유아와 어린이 치약의 자극 수준이 일반 성인 치약에 비해 낮음을 증명하였다. 이 결과를 바탕으로 동물을 사용하지 않고 인체에 대한 위해성을 줄일 수 있도록, 구강관리 제품의 구강 점막 자극 수준을 평가할 수 있는 이 시험법이 하나의 새로운 구강 자극 시험 방법으로 사용될 수 있으리라 사료된다.

• Animal Bioscience
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• 제36권8호
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• pp.1209-1220
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• 2023

Objective: The use of probiotics as an alternative to antibiotics in animal feed has received considerable attention in recent decades. Lactic acid bacteria (LAB) have remarkable functional properties promoting host health and are major microorganisms for probiotic purposes. The aim of this study was to characterize LAB strains of the chicken digestive tract and to determine their functional properties for further use as potential probiotics in poultry. Methods: A total of 2,000 colonies were isolated from the ileum and cecal contents of the chickens based on their phenotypic profiles and followed by a preliminary detection for acid and bile tolerance. The selected 200 LAB isolates with exhibited well-tolerance in acid and bile conditions were then identified by sequencing the 16S rDNA gene, followed by acid and bile tolerance, antimicrobial activity, adhesion to epithelial cells and additional characteristics on the removal of cholesterol. Then, the two probiotic strains (L. ingluviei and L. salivarious) which showed the greatest advantage in vitro testing were selected to assess their efficacy in broiler chickens. Results: It was found that 200 LAB isolates that complied with all measurement criteria belonged to five strains, including L. acidophilus (63 colonies), L. ingluviei (2 colonies), L. reuteri (58 colonies), L. salivarius (72 colonies), and L. saerimneri (5 colonies). We found that the L. ingluviei and L. salivarius can increase the population of LAB and Bifidobacterium spp. while reducing Enterobacteria spp. and Escherichia coli in the cecal content of chickens. Additionally, increased concentrations of valeric acid and short chain fatty acids were also observed. Conclusion: This study indicates that all five Lactobacillus strains isolated from gut contents of chickens are safe and possess probiotic properties, especially L. ingluviei and L. salivarius. Future studies should evaluate the potential for growth improvement in broilers.

• Toxicological Research
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• 제33권2호
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• pp.107-118
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• 2017

Although alternative test methods based on the 3Rs (Replacement, Reduction, Refinement) are being developed to replace animal testing in reproductive and developmental toxicology, they are still in an early stage. Consequently, we aimed to develop alternative test methods in male animals using mouse spermatogonial stem cells (mSSCs). Here, we modified the OECD TG 489 and optimized the in vitro comet assay in our previous study. This study aimed to verify the validity of in vitro tests involving mSSCs by comparing their results with those of in vivo tests using C57BL/6 mice by gavage. We selected hydroxyurea (HU), which is known to chemically induce male reproductive toxicity. The 50% inhibitory concentration ($IC_{50}$) value of HU was 0.9 mM, as determined by the MTT assay. In the in vitro comet assay, % tail DNA and Olive tail moment (OTM) after HU administration increased significantly, compared to the control. Annexin V, PI staining and TUNEL assays showed that HU caused apoptosis in mSSCs. In order to compare in vitro tests with in vivo tests, the same substances were administered to male C57BL/6 mice. Reproductive toxicity was observed at 25, 50, 100, and 200 mg/kg/day as measured by clinical measures of reduction in sperm motility and testicular weight. The comet assay, DCFH-DA assay, H&E staining, and TUNEL assay were also performed. The results of the test with C57BL/6 mice were similar to those with mSSCs for HU treatment. Finally, linear regression analysis showed a strong positive correlation between results of in vitro tests and those of in vivo. In conclusion, the present study is the first to demonstrate the effect of HU-induced DNA damage, ROS formation, and apoptosis in mSSCs. Further, the results of the current study suggest that mSSCs could be a useful model to predict male reproductive toxicity.