• 제목/요약/키워드: Microbial Pathogenesis

검색결과 52건 처리시간 0.022초

임프란트 주위염의 이해와 치료 (Treatment considerations in peri-implantitis)

  • 김보배;고영경;박준범
    • 대한치과의사협회지
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    • 제53권5호
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    • pp.318-325
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    • 2015
  • Peri-implantitis is defined as an inflammatory process affecting the tissues around an osseointegrated implant, resulting in the loss of the supporting bone. Microbial adherence and colonization appear to play a major role in the pathogenesis of periimplantitis. The decision regarding treatment strategies is based on the diagnosis. The severity of the peri-implant lesion and the treatment strategies must include mechanical cleaning (infection control) procedures. Mechanical instrumentation is widely used for the debridement of dental implants, but this may alter the titanium's surface properties. Therefore, selection of the type of instrumentation should be made depending on the type of surface to be debrided. Also, patients with dental implants must always be enrolled in a supportive therapy program.

Antimicrobial Property of $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-Glucopyranoside$ Isolated From the Root Bark of Lycium chinense Miller Against Human Pathogenic Microorganisms

  • Lee Dong Gun;Jung Hyun Jun;Woo Eun-Rhan
    • Archives of Pharmacal Research
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    • 제28권9호
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    • pp.1031-1036
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    • 2005
  • [ $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ ] (1) was isolated from an ethyl acetate extract of the root bark from Lycium chinense Miller, and its structure was determined using 1D and 2D NMR spectroscopy including DEPT, HMQC, and HMBC. $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ exhibited potent antimicrobial activity against antibiotic-resistant bacterial strains, methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients, and human pathogenic fungi without having any hemolytic effect on human erythrocytes. In particular, compound 1 induced the accumulation of intracellular trehalose on C. albicans as stress response to the drug, and disrupted the dimorphic transition that forms pseudo-hyphae caused by the pathogenesis. This indicates that $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ has excellent potential as a lead compound for the development of antibiotic agents.

Regulatory roles of NKT cells in Anaplasma phagocytophilum infection

  • Choi, Kyoung-Seong;Chae, Joon-Seok
    • 대한수의학회지
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    • 제49권2호
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    • pp.167-172
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    • 2009
  • Human granulocytic anaplasmosis (HGA) is caused by the obligate intracellular bacterium Anaplasma (A.) phagocytophilum. Natural killer T (NKT) cells are key players in host defense against various microbial infections. We investigated the role of NKT cells in immune response to A. phagocytophilum infection using NKT-knockout ($J\alpha$18-/-) mice. $J\alpha$18-/- and wild-type (WT) mice were infected with low-passage A. phagocytophilum and assayed for hepatic histopathology and cytokine production during 7 days post-infection. Compared to WT controls, the infected $J\alpha$18 -/- mice had much less histopathologic lesions and less apoptosis through day 7, and lower concentrations of ${IFN\gamma}$ and IL- 12, but not of IL-10. This result suggests that NKT cells are major components in the pathogenesis of HGA.

치매와 구강 건강의 관계 (Association between dementia and oral health)

  • 강경리
    • 대한치과의사협회지
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    • 제56권4호
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    • pp.218-230
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    • 2018
  • According to the burst of aged people, researchers have focused on aging-related diseases. Cognitive impairment including Alzheimer's disease (AD), one of the representative diseases related to aging, has no treatment option until now. Recently, it has been revealed that systemic inflammation plays a fundamental role in the pathogenesis of AD. Previous studies have suggested the association between poor oral health and cognitive impairment. Poor oral health can cause dental caries, chronic periodontitis, multiple tooth loss, and poor chewing ability, etc. Especially, periodontitis is a well-known chronic inflammatory disease and affects cognitive impairment directly and indirectly by inflammatory products mediators. Therefore, reduction of pathogenic microbial burden and inflammatory products by treating periodontitis can be a therapeutic modality to prevent cognitive impairment or to slow down the progression of it. Future studies are necessary to elucidate the causal relations and plausible mechanisms between poor oral health and cognitive impairment.

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Molecular and Cellular Mechanisms of Syndecans in Tissue Injury and Inflammation

  • Bartlett, Allison H.;Hayashida, Kazutaka;Park, Pyong Woo
    • Molecules and Cells
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    • 제24권2호
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    • pp.153-166
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    • 2007
  • The syndecan family of heparan sulfate proteoglycans is expressed on the surface of all adherent cells. Syndecans interact with a wide variety of molecules, including growth factors, cytokines, proteinases, adhesion receptors and extracellular matrix components, through their heparan sulfate chains. Recent studies indicate that these interactions not only regulate key events in development and homeostasis, but also key mechanisms of the host inflammatory response. This review will focus on the molecular and cellular aspects of how syndecans modulate tissue injury and inflammation, and how syndecans affect the outcome of inflammatory diseases in vivo.

The Modulation of Inflammatory Gene Expression by Lipids: Mediation through Toll-like Receptors

  • Lee, Joo Y.;Hwang, Daniel H.
    • Molecules and Cells
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    • 제21권2호
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    • pp.174-185
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    • 2006
  • Toll-like receptors (TLRs) were evolved to detect invading pathogens and to induce innate immune responses in order to mount host defense mechanisms. It becomes apparent that the activation of certain TLRs is also modulated by endogenous molecules including lipid components, fatty acids. Results from epidemiological and animal studies demonstrated that saturated and polyunsaturated dietary fatty acids can differentially modify the risk of development of many chronic diseases. Inflammation is now recognized as an important underlying etiologic condition for the pathogenesis of many chronic diseases. Therefore, if the activation of TLRs and consequent inflammatory and immune responses are differentially modulated by types of lipids in vivo, this would suggest that the risk of the development of chronic inflammatory diseases and the host defense against microbial infection may be modified by the types of dietary fat consumed.

Optogenetic neuromodulation with gamma oscillation as a new strategy for Alzheimer disease: a narrative review

  • Ko, Haneol;Yoon, Sang-Pil
    • Journal of Yeungnam Medical Science
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    • 제39권4호
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    • pp.269-277
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    • 2022
  • The amyloid hypothesis has been considered a major explanation of the pathogenesis of Alzheimer disease. However, failure of phase III clinical trials with anti-amyloid-beta monoclonal antibodies reveals the need for other therapeutic approaches to treat Alzheimer disease. Compared to its relatively short history, optogenetics has developed considerably. The expression of microbial opsins in cells using genetic engineering allows specific control of cell signals or molecules. The application of optogenetics to Alzheimer disease research or clinical approaches is increasing. When applied with gamma entrainment, optogenetic neuromodulation can improve Alzheimer disease symptoms. Although safety problems exist with optogenetics such as the use of viral vectors, this technique has great potential for use in Alzheimer disease. In this paper, we review the historical applications of optogenetic neuromodulation with gamma entrainment to investigate the mechanisms involved in Alzheimer disease and potential therapeutic strategies.

N,N,N-Trimethylphytosphingosine (TMP)의 염증성 피부질환 치료제 가능성에 관한 연구 (Study for Possibility of N,N,N-Trimethylphytosphingosine (TMP) for Management of Chronic Skin Diseases)

  • 서원상;오한나;박우정;엄상용;강상모
    • KSBB Journal
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    • 제29권1호
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    • pp.36-41
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    • 2014
  • Skin disease is one of the most common diseases and its incidence is increasing dramatically in modern society. Specially, many attempts have been made to treat chronic skin inflammation diseases, such as psoriasis and atopic dermatitis, but effective therapies for the immune cell-mediated skin diseases, including psoriasis and atopic dermatitis have not been developed. Until recently, several drug candidates which were claimed to be effective for skin diseases have been reported, but most of them are not used to treat chronic skin disease. Especially, Psoriasis is characterized by excessive growth and aberrant differentiation of keratinocytes, but is fully reversible with appropriate therapy. The trigger of the keratinocyte response is thought to be activation of the cellular immune system, with T cells and various immune-related cytokines. Formation of new blood vessels starts with early psoriatic changes and disappears with disease clearance. Several angiogenic mediators are up-regulated in psoriasis development. Contact- and mediator-dependent factors derived from keratinocytes, mast cells and immune cells may contribute to the strong blood vessel formation of psoriasis. New technologies and experimental models provide new insights into the role of angiogenesis in psoriasis pathogenesis. TMP and its derivatives themselves effectively inhibited in vitro cell migration, tube formation, and the expression of angiogenic factors. However, TMP and its derivatives induced side effects including hemolysis and local side effects. Therefore, in an attempt to reduce the toxicity and the undesirable side effects of TMP and derivatives, a liposomal formulation was prepared and tested for its effectiveness. TMP and derivatives liposomes retained the effectiveness of TMP in vitro while side effects were reduced. These results support the conclusion that TMP effectively inhibits in vitro angiogenesis, with the possibility that use as a psoriasis relief agent.

Gut Microbiome Alterations and Functional Prediction in Chronic Spontaneous Urticaria Patients

  • Zhang, Xinyue;Zhang, Jun;Chu, Zhaowei;Shi, Linjing;Geng, Songmei;Guo, Kun
    • Journal of Microbiology and Biotechnology
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    • 제31권5호
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    • pp.747-755
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    • 2021
  • The effects of the gut microbiome on both allergy and autoimmunity in dermatological diseases have been indicated in several recent studies. Chronic spontaneous urticaria (CSU) is a disease involving allergy and autoimmunity, and there is no report detailing the role of microbiota alterations in its development. This study was performed to identify the fecal microbial composition of CSU patients and investigate the different compositions and potential genetic functions on the fecal microbiota between CSU patients and normal controls. The gut microbiota of CSU patients and healthy individuals were obtained by 16s rRNA massive sequencing. Gut microbiota diversity and composition were compared, and bioinformatics analysis of the differences was performed. The gut microbiota composition results showed that Firmicutes, Bacteroidetes, Proteobacteria, and Verrucomicrobia were dominant microbiota in CSU patients. The differential analysis showed that relative abundance of the Proteobacteria (p = 0.03), Bacilli (p = 0.04), Enterobacterales (p = 0.03), Enterobacteriaceae (p = 0.03) was significantly increased in CSU patients. In contrast, the relative abundance of Megamonas, Megasphaera, and Dialister (all p < 0.05) in these patients significantly decreased compared with healthy controls. The different microbiological compositions impacted normal gastrointestinal functions based on function prediction, resulting in abnormal pathways, including transport and metabolism. We found CSU patients exhibited gut microbiota dysbiosis compared with healthy controls. Our results indicated CSU is associated with gut microbiota dysbiosis and pointed out that the bacterial taxa increased in CSU patients, which might be involved in the pathogenesis of CSU. These results provided clues for future microbial-based therapies on CSU.

Dendritic Cell-Mediated Mechanisms Triggered by LT-IIa-B5, a Mucosal Adjuvant Derived from a Type II Heat-Labile Enterotoxin of Escherichia coli

  • Lee, Chang Hoon;Hajishengallis, George;Connell, Terry D.
    • Journal of Microbiology and Biotechnology
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    • 제27권4호
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    • pp.709-717
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    • 2017
  • Mucosal tissues are the initial site through which most pathogens invade. As such, vaccines and adjuvants that modulate mucosal immune functions have emerged as important agents for disease prevention. Herein, we investigated the immunomodulatory mechanisms of the B subunit of Escherichia coli heat-labile enterotoxin type IIa ($LT-IIa-B_5$), a potent non-toxic mucosal adjuvant. Alternations in gene expression in response to $LT-IIa-B_5$ were identified using a genome-wide transcriptional microarray that focused on dendritic cells (DC), a type of cell that broadly orchestrates adaptive and innate immune responses. We found that $LT-IIa-B_5$ enhanced the homing capacity of DC into the lymph nodes and selectively regulated transcription of pro-inflammatory cytokines, chemokines, and cytokine receptors. These data are consistent with a model in which directional activation and differentiation of immune cells by $LT-IIa-B_5$ serve as a critical mechanism whereby this potent adjuvant amplifies mucosal immunity to co-administered antigens.