• Title/Summary/Keyword: Disease models

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Effects of Opuntia ficus-indica extract on the activation of immune cells with special reference to autoimmune disease models (손바닥선인장 추출물이 면역계세포의 활성화에 미치는 영향)

  • Shin, Tae-Kyun;Lee, Sun-Joo;Kim, Sae-Je
    • Korean Journal of Veterinary Pathology
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    • v.2 no.1
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    • pp.31-36
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    • 1998
  • The Opuntia ficus-indica extract(OFE) has been claimed to have several therapeutic properties including anti-inflammation and anti-rheumatoid arthritis in oriental medicine but little is known about their effect on macrophages. This study demonstrated that OFE could stimulate TNF-alpha production in cultured macrophages. which is one of important mediators in autoimmune diseases including experimental autoimmune encephalomyelitis(EAE). In vivo study showed that oral administration of OFE exacerbate the onset of clinical paralysis. This finding suggests that OFE stimulates cytokine production and exacerbates autoimmune inflammatory diseases including EAE.

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Simulation model-based evaluation of a survey program with reference to risk analysis

  • Chang, Ki-Yoon;Pak, Son-Il
    • Korean Journal of Veterinary Research
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    • v.46 no.2
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    • pp.159-164
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    • 2006
  • A stochastic simulation model incorporated with Reed-Frost approach was derived for evaluating diagnostic performance of a test used for a screening program of an infectious disease. The Reed-Frost model was used to characterize the within-herd spread of the disease using a hypothetical example. Specifically, simulation model was aimed to estimate the number infected animals in an infected herd, in which imperfect serologic tests are performed on samples taken from herds and to illustrate better interpreting survey results at herd-level when uncertainty inevitably exists. From a risk analysis point of view, model output could be appropriate in developing economic impact assessment models requiring probabilistic estimates of herd-level performance in susceptible populations. The authors emphasize the importance of knowing the herd-level diagnostic performance, especially in performing emergency surveys in which immediate control measures should be taken following the survey. In this context this model could be used in evaluating efficacy of a survey program and monitoring infection status in the area concerned.

ESCRT, autophagy, and frontotemporal dementia

  • Lee, Jin-A;Gao, Fen-Biao
    • BMB Reports
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    • v.41 no.12
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    • pp.827-832
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    • 2008
  • Many age-dependent neurodegenerative diseases are associated with the accumulation of abnormally folded proteins within neurons. One of the major proteolytic pathways in the cell is the autophagy pathway, which targets cytoplasmic contents and organelles to the lysosomes for bulk degradation under various physiological and stressful conditions. Although the importance of autophagy in cellular physiology is well appreciated, its precise roles in neurodegeneration remain largely unclear. Recent studies indicate that components of the endosomal sorting complex required for transport (ESCRT) are important in the autophagy pathway. Reduced activity of some ESCRT subunits leads to the accumulation of autophagosomes and failure to clear intracellular protein aggregates. Interestingly, rare mutations in CHMP2B, an ESCRT-III subunit, are associated with frontotemporal dementia linked to chromosome 3 (FTD3). Mutant CHMP2B proteins seem to disrupt the fusion of autophagosomes and lysosomes in cell culture models. These findings suggest a potential mechanism for the pathogenesis of FTD3 and possibly other neurodegenerative diseases as well.

A Study on the Hepatoprotective effect of PS-1 from Artemisia iwayomogi (한인전 추출물의 간장보호 작용에 관한 연구)

  • 이순복;조태순;윤기욱;이종찬;이선미;심성보
    • Biomolecules & Therapeutics
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    • v.6 no.2
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    • pp.119-129
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    • 1998
  • The dose-response effect of polysaccharide extracts(PS-1) from Artemisia iwayomogi was inves-tigated under various hepatic disease models. Silymarin, DDB and UDCA were used as reference compounds. We found that the maximal effective dose of PS-1 was 100 mg/kg b.wt. in $CCl_4$-induced hepatotoxicity, D-galactosamine-induced hepatitis, in ANIT-induced cholestasis and 300 mg/kg b.wt. in $CCl_4$-induced chronic liver disease, 30 mg/tg b.wt. in chronic bile duct ligation and chronic ethanol fatty liver. These findings suggest that PS-1 fraction protects the hepatocyte against various hepatic injuries, and this fracton might be of therapeutic value.

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Crosstalk Signaling between IFN-γ and TGF-β in Microglia Restores the Defective β-amyloid Clearance Pathway in Aging Mice with Alzheimer's Disease

  • Choi, Go-Eun
    • Biomedical Science Letters
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    • v.24 no.4
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    • pp.305-310
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    • 2018
  • Microglia are emerging as critical regulators of innate immune responses in AD and other neurodegenerative disorders, highlighting the importance of understanding their molecular and cellular mechanisms. We attempted to determine the role of crosstalk signaling between $IFN-{\gamma}$ and $TGF-{\beta}$ in $A{\beta}$ clearance by microglia cells. We used in vitro and in vivo mouse models that recapitulated acute and chronic aspects of microglial responses to $A{\beta}$ peptides. We showed that crosstalk signaling between $TGF-{\beta}$ and Smad2 was an important mediator of neuro-inflammation. These findings suggest that microglial $TGF-{\beta}$ activity enhances the pathological progression to AD. As $TGF-{\beta}$ displays broad regulatory effects on beneficial microglial functions, the activation of inflammatory crosstalk signaling between $TGF-{\beta}$ and Smad2 may be a promising strategy to restore microglial functions, halt the progression of $A{\beta}$-driven pathology, and prevent AD development.

A Novel Feature Selection Approach to Classify Breast Cancer Drug using Optimized Grey Wolf Algorithm

  • Shobana, G.;Priya, N.
    • International Journal of Computer Science & Network Security
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    • v.22 no.9
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    • pp.258-270
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    • 2022
  • Cancer has become a common disease for the past two decades throughout the globe and there is significant increase of cancer among women. Breast cancer and ovarian cancers are more prevalent among women. Majority of the patients approach the physicians only during their final stage of the disease. Early diagnosis of cancer remains a great challenge for the researchers. Although several drugs are being synthesized very often, their multi-benefits are less investigated. With millions of drugs synthesized and their data are accessible through open repositories. Drug repurposing can be done using machine learning techniques. We propose a feature selection technique in this paper, which is novel that generates multiple populations for the grey wolf algorithm and classifies breast cancer drugs efficiently. Leukemia drug dataset is also investigated and Multilayer perceptron achieved 96% prediction accuracy. Three supervised machine learning algorithms namely Random Forest classifier, Multilayer Perceptron and Support Vector Machine models were applied and Multilayer perceptron had higher accuracy rate of 97.7% for breast cancer drug classification.

DYNAMICS OF AN IMPROVED SIS EPIDEMIC MODEL

  • Reza Memarbashi;Milad Tahavor
    • The Pure and Applied Mathematics
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    • v.30 no.2
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    • pp.203-220
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    • 2023
  • A new modification of the SIS epidemic model incorporating the adaptive host behavior is proposed. Unlike the common situation in most epidemic models, this system has two disease-free equilibrium points, and we were able to prove that as the basic reproduction number approaches the threshold of 1, these two points merge and a Bogdanov-Takens bifurcation of codimension three occurs. The occurrence of this bifurcation is a sign of the complexity of the dynamics of the system near the value 1 of basic reproduction number. Both local and global stability of disease-free and endemic equilibrium point are studied.

Mechanistic modelling for African swine fever transmission in the Republic of Korea

  • Eutteum Kim;Jun-Sik Lim;Son-Il Pak
    • Journal of Veterinary Science
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    • v.24 no.2
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    • pp.21.1-21.5
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    • 2023
  • Under the current African swine fever (ASF) epidemic situation, a science-based ASF-control strategy is required. An ASF transmission mechanistic model can be used to understand the disease transmission dynamics among susceptible epidemiological units and evaluate the effectiveness of an ASF-control strategy by simulating disease spread results with different control options. The force of infection, which is the probability that a susceptible epidemiological unit becomes infected, could be estimated by applying an ASF transmission mechanistic model. The government needs to plan an ASF-control strategy based on an ASF transmission mechanistic model.

Understanding the Host Innate Immune Responses against SARS-CoV-2 Infection and COVID-19 Pathogenesis

  • Yeon-Woo Kang;Subin Park;Kun-Joo Lee;Dain Moon;Young-Min Kim;Seung-Woo Lee
    • IMMUNE NETWORK
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    • v.21 no.1
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    • pp.1.1-1.16
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    • 2021
  • The emergence of a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has become a significant health concern worldwide. Undoubtedly, a better understanding of the innate and adaptive immune responses against SARS-CoV-2 and its relationship with the coronavirus disease 2019 (COVID-19) pathogenesis will be the sole basis for developing and applying therapeutics. This review will summarize the published results that relate to innate immune responses against infections with human coronaviruses including SARS-CoV-1 and SARS-CoV-2 in both humans and animal models. The topics encompass the innate immune sensing of the virus to the dysregulation of various innate immune cells during infection and disease progression.

The role of insulin/IGF-1 signaling in the longevity of model invertebrates, C. elegans and D. melanogaster

  • Altintas, Ozlem;Park, Sangsoon;Lee, Seung-Jae V.
    • BMB Reports
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    • v.49 no.2
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    • pp.81-92
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    • 2016
  • Insulin/insulin-like growth factor (IGF)-1 signaling (IIS) pathway regulates aging in many organisms, ranging from simple invertebrates to mammals, including humans. Many seminal discoveries regarding the roles of IIS in aging and longevity have been made by using the roundworm Caenorhabditis elegans and the fruit fly Drosophila melanogaster. In this review, we describe the mechanisms by which various IIS components regulate aging in C. elegans and D. melanogaster. We also cover systemic and tissue-specific effects of the IIS components on the regulation of lifespan. We further discuss IIS-mediated physiological processes other than aging and their effects on human disease models focusing on C. elegans studies. As both C. elegans and D. melanogaster have been essential for key findings regarding the effects of IIS on organismal aging in general, these invertebrate models will continue to serve as workhorses to help our understanding of mammalian aging.