• Title/Summary/Keyword: Pathogenic mechanisms

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Antimicrobial and Immunomodulatory Effects of Bifidobacterium Strains: A Review

  • Lim, Hyun Jung;Shin, Hea Soon
    • Journal of Microbiology and Biotechnology
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    • v.30 no.12
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    • pp.1793-1800
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    • 2020
  • Bifidobacterium strains can provide several health benefits, such as antimicrobial and immunomodulatory effects. Some strains inhibit growth or cell adhesion of pathogenic bacteria, including multidrug-resistant bacteria, and their antibacterial activity can be intensified when combined with certain antibiotics. In addition, some strains of bifidobacteria reduce viral infectivity, leading to less epithelial damage of intestinal tissue, lowering the virus shedding titer, and controlling the release of antiviral substances. Furthermore, bifidobacteria can modulate the immune system by increasing immunoglobulins, and inducing or reducing pro- or anti-inflammatory cytokines, respectively. In particular, these anti-inflammatory effects are helpful in the treatment of patients who are already suffering from infection or inflammatory diseases. This review summarizes the antimicrobial effects and mechanisms, and immunomodulatory effects of Bifidobacterium strains, suggesting the potential of bifidobacteria as an alternative or complementary treatment option.

Metatranscriptomic Analysis of Plant Viruses in Imported Pear and Kiwifruit Pollen

  • Lee, Hyo-Jeong;Jeong, Rae-Dong
    • The Plant Pathology Journal
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    • v.38 no.3
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    • pp.220-228
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    • 2022
  • Pollen is a vector for viral transmission. Pollenmediated viruses cause serious economic losses in the fruit industry. Despite the commercial importance of pollen-associated viruses, the diversity of such viruses is yet to be fully explored. In this study, we performed metatranscriptomic analyses using RNA sequencing to investigate the viral diversity in imported apple and kiwifruit pollen. We identified 665 virus-associated contigs, which corresponded to four different virus species. We identified one virus, the apple stem grooving virus, from pear pollen and three viruses, including citrus leaf blotch virus, cucumber mosaic virus, and lychnis mottle virus in kiwifruit pollen. The assembled viral genome sequences were analyzed to determine phylogenetic relationships. These findings will expand our knowledge of the virosphere in fruit pollen and lead to appropriate management of international pollen trade. However, the pathogenic mechanisms of pollen-associated viruses in fruit trees should be further investigated.

A Literature Study of Senile Constipation (노인(老人) 변비(便秘)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Jeong, Chang-Hwan;Shin, Hyeon-Chul;Jeong, Ji-Cheon
    • The Journal of Internal Korean Medicine
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    • v.16 no.1
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    • pp.40-61
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    • 1995
  • This study was performed to investigate concept, systoms, causes of disease, pathogenic mechanisms, therapies and precriptions about senile constipation through the successive medical literature, recent chinese medical literature and chinese medical joumals. Senile constipation seems to be applicable to dryness syndrom and constipation of insufficiency type, have something to do with kidney(the most), lung, spleen and large intestine. The most principal cause of disease is yin-fluid, the rest deficiency of qi, insufficiency of yang, stagnation of qi and retention of fever etc. There are enriching the blood and moistening dryness in principal therapy, the rest are invigorating qi and loosing the bowel, warming and invigorating the spleen and kidney, regulating the flow of qi and promoting the stagnancy of qi and expelling the pathogenic heat etc. In prescriptions there are Yunjangtang, Jengaektang, Hwanggitang, Jechunjeon, Yukmatang and Majainhwan as the causes of disease, meanwhile are Yungjang-tang, Jechunjeon and Majainhwan in the vulgaris prescriptions. And in medical herbs there are nourishing yin medicines as Rhizoma rehmanniac, Radix ophiopogonis and Radix scrophulariae etc., invigorating qi medicines as Radix astragali, Radix codonopsitis and Radix polygoni multiflori etc, invigorating yang medicines as Caulis cistanchis and Semen psoraleae etc., promoting qi circulating medicines as Radix saussurea, Lignum aquilariae and Radix linderae etc., and reducing fever and therapeutic method to keep the adverse qi flowing downward medicines as Semen cannabis, Rhizoma rhei, Fructus immaturus ponciri, and Cortex magnoliae etc.. Meantime Rhizoma rehmanniae, Radix ophiopogonis, Caulis cistanchis, Radix angelicae gigantis, Semen cannabis, Semen biotae, Semen pruni japonicae and Semen persicae in principal herb-medicines. In clinical reports the process of disease was between 10 to 20 years, the evacuation cycle between 4 to 7 days, generally possessed chronic diseases as hypertension, diabetes, arteriosclerosis and cerebro- vascular disorders etc. and the efficiency rate was more than 90%. The senile constipation is occured in succession or promoted by chronic diseases as obesity, hypertension, diabetes, arteriosclerosis. hrperlipemia, cerebro- vascular disorders etc., so diet-regulating, adequate exercise, proper evacuation-habit and psychologic rest etc. are important more than medicine-treatments.

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Colibacillosis in domestic animals, a review (가축에서 대장균 감염증)

  • 송희종;채효석
    • Korean Journal of Veterinary Service
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    • v.21 no.4
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    • pp.413-429
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    • 1998
  • Escherichia coli is recovered from a wide variety of infections in many animals species. It may be a primary or secondary agent. Nursing and young animals are particularly susceptible, and urinary tract infections are frequent. The various serotypes of E coli are intestinal inhabitants of animals including humans and probably infect most mammals and birds : therefore, they have a cosmopolitan distribution. Colibacillosis refers to any totalized or systemic infection caused entirely or partly by E coli. Collibacillosis in mammals is most often a primary enteric disease, whereas collibacillosis in poultry is typically a secondary located or systemic disease occurring when host defenses have been impaired or overwhelmed. Other opportunistic bacteria, which can be identified by culture, may play a similar role to that of I coli in secondary infections. Collectively, infections caused by E coli are responsible for significant economic losses to the animal performance. From the standpoint of pathogenic mechanisms and diseases, four major categories of E coli are recognized : enterotoxigenic(ETEC), enteropathogenic (EPEC), enteroinvasive(EIEC), and enterohemorrhagic(EHEC). In addition, two less-well-defined E coli categories are recognized in animals and humans : enteroaggregative and cytotoxin necrotizing factor-positive. The aforementioned categories are represented by different serotypes. Certain serotypes show a host preference and are encountered more frequently in some disease syndromes. Of the four major categories, ETEC is the most common cause of diarrhea in calves, lambs, and pigs. Strains in the other categories cause the less-common diarrhea and other disease syndromes. Enterotoxins and pilus antigens are the two most prominent virulence factors thus far identified for ETEC. Two enterotoxins, one heat-stable(ST) and one heat-labile(LT), are produced by enterotoxigenic strains of E coli : not all culture produce both of these plasmid-based enterotoxins.

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Inactivation of Foodborne Pathogens by Lactic Acid Bacteria

  • Daliri, Frank;Aboagye, Agnes Achiaa;Daliri, Eric Banan-Mwine
    • Journal of Food Hygiene and Safety
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    • v.35 no.5
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    • pp.419-429
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    • 2020
  • The problems caused by foodborne pathogens are not only a concern to the food industry but also with regard to global public health. Over the years, fermentation technology has proved to be one of the cheapest and safest methods for inactivating and controlling pathogenic microorganisms in food. Scientific evidence shows that lactic acid bacteria fermentation exerts significant antimicrobial effect against pathogenic bacteria and viruses. Lactic acid bacteria metabolites such as organic acids, bacteriocins and hydrogen peroxides have adverse effects on foodborne pathogens which lead to their inhibition. These compounds do not only cause physical injuries, but also have significant effects on the pathogens' gene expression. Furthermore, the presence of lactic acid bacteria in food provides nutritional competition among foodborne pathogens, and all these factors together suppress their growth. This study reviews our current knowledge of the antimicrobial abilities of lactic acid bacteria, their molecular mechanisms, and their application for inactivating foodborne pathogens.

C9orf72-Associated Arginine-Rich Dipeptide Repeat Proteins Reduce the Number of Golgi Outposts and Dendritic Branches in Drosophila Neurons

  • Park, Jeong Hyang;Chung, Chang Geon;Seo, Jinsoo;Lee, Byung-Hoon;Lee, Young-Sam;Kweon, Jung Hyun;Lee, Sung Bae
    • Molecules and Cells
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    • v.43 no.9
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    • pp.821-830
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    • 2020
  • Altered dendritic morphology is frequently observed in various neurological disorders including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), but the cellular and molecular basis underlying these pathogenic dendritic abnormalities remains largely unclear. In this study, we investigated dendritic morphological defects caused by dipeptide repeat protein (DPR) toxicity associated with G4C2 expansion mutation of C9orf72 (the leading genetic cause of ALS and FTD) in Drosophila neurons and characterized the underlying pathogenic mechanisms. Among the five DPRs produced by repeat-associated non-ATG translation of G4C2 repeats, we found that arginine-rich DPRs (PR and GR) led to the most significant reduction in dendritic branches and plasma membrane (PM) supply in Class IV dendritic arborization (C4 da) neurons. Furthermore, expression of PR and GR reduced the number of Golgi outposts (GOPs) in dendrites. In Drosophila brains, expression of PR, but not GR, led to a significant reduction in the mRNA level of CrebA, a transcription factor regulating the formation of GOPs. Overexpressing CrebA in PR-expressing C4 da neurons mitigated PM supply defects and restored the number of GOPs, but the number of dendritic branches remained unchanged, suggesting that other molecules besides CrebA may be involved in dendritic branching. Taken together, our results provide valuable insight into the understanding of dendritic pathology associated with C9-ALS/FTD.

Mitochondrial Damage and Metabolic Compensatory Mechanisms Induced by Hyperoxia in the U-937 Cell Line

  • Scatena, Roberto;Messana, Irene;Martorana, Giuseppe Ettore;Gozzo, Maria Luisa;Lippa, Silvio;Maccaglia, Alessandro;Bottoni, Patrizia;Vincenzoni, Federica;Nocca, Giuseppina;Castagnola, Massimo;Giardina, Bruno
    • BMB Reports
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    • v.37 no.4
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    • pp.454-459
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    • 2004
  • Experimental hyperoxia represents a suitable in vitro model to study some pathogenic mechanisms related to oxidative stress. Moreover, it allows the investigation of the molecular pathophysiology underlying oxygen therapy and toxicity. In this study, a modified experimental set up was adopted to accomplish a model of moderate hyperoxia (50% $O_2$, 96 h culture) to induce oxidative stress in the human leukemia cell line, U-937. Spectrophotometric measurements of mitochondrial respiratory enzyme activities, NMR spectroscopy of culture media, determination of antioxidant enzyme activities, and cell proliferation and differentiation assays were performed. The data showed that moderate hyperoxia in this myeloid cell line causes: i) intriguing alterations in the mitochondrial activities at the levels of succinate dehydrogenase and succinate-cytochrome c reductase; ii) induction of metabolic compensatory adaptations, with significant shift to glycolysis; iii) induction of different antioxidant enzyme activities; iv) significant cell growth inhibition and v) no significant apoptosis. This work will permit better characterization the mitochondrial damage induced by hyperoxia. In particular, the data showed a large increase in the succinate cytochrome c reductase activity, which could be a fundamental pathogenic mechanism at the basis of oxygen toxicity.

Diabetic Nephropathy in Childhood and Adolescence (II) ; Pathology and Pathophysiology (소아청소년기 당뇨병성 신병증 (II) ; 병리 소견 및 병태생리를 중심으로)

  • Ha, Tae-Sun
    • Childhood Kidney Diseases
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    • v.13 no.2
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    • pp.99-117
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    • 2009
  • Diabetic nephropathy is a major cause of chronic renal failure in developing countries, and the prevalence rate has markedly increased during the past decade. Diabetic nephropathy shows various specific histological changes not only in the glomeruli but also in the tubulointerstitial region. In the early stage, the effacement of podocyte foot processes and thickened glomerular basement membrane (GBM) is noticed even at the stage of microalbuminuria. Nodular, diffuse, and exudative lesions, so-called diabetic glomerulosclerosis, are well known as glomerular lesions. Interstitial lesions also exhibit fibrosis, edema, and thickened tubular basement membrane. Diabetic nephropathy is considered to be multifactorial in origin with increasing evidence that one of the major pathways involved in the development and progression of diabetic nephropathy as a result of hyperglycemia. Hyperglycemia induces renal damage directly or through hemodynamic alterations, such as, glomerular hyperfiltration, shear stress, and microalbuminuria. Chronic hyperglycemia also induces nonhemodynamic dysregulations, such as, increased production of advanced glycosylation endproducts, oxidative stress, activation of signal pathway, and subsequent various cytokines. Those pathogenic mechanisms resulted in extracellular matrix deposition including mesangial expansion and GBM thickening, glomerular hypertrophy, inflammation, and proteinuria. In this review, recent opinions on the histopathologic changes and pathophysiologic mechanisms leading to initiation and progression of diabetic nephropathy will be introduced.

Therapeutic Effects of Cheonggisan Extract on Th2 cell differentiation and $NF-kB$ p65 activation (청기산(淸肌散)이 Th2 세포 분화와 염증에 미치는 영향)

  • Ku, Young-Hui;Hong, Seung-Ug
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.20 no.3
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    • pp.63-70
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    • 2007
  • Objectives : Atopic dermatitis is a recurrent or chronic eczematous skin disease with severe pruritus. Although the pathogenic mechanisms of atopic dermatitis are yet unknown, recently hyperresponsive Th2 cells in the acute phase are reported as the important mechanisms. Cheonggisan(CGS) is used in oriental clinics for curing acute skin lesions of eczema, atopic dermatitis or urticaria. There have been no studies on the therapeutic mechanism of CGS for curing atopic dermatitis. We aimed to find out the therapeutic mechanism of CGS on atopic dermatitis, so we observed Th2 cell differentiation in EL 4 cells and $NF-kB$ p65 activation in RAW 264.7 cells. Materials and Methods : EL 4 cells were induced the increase of IL-4 mRNA expression by phorbol-12-myristate-13-acetate(PMA) and 4-tert-Octylphenol(OP) and treated with CGS extract. RAW 264.7 cells were induced the increase of cyclooxygenase(COX)-2 mRNA expression by lipopolysaccharide(LPS) and treated with CGS extract. Results : The PMA and OP induced IL-4 mRNA expression was dose-dependantly decreased in CGS treated EL 4 cells. The LPS-induced COX-2 mRNA expression was dose-dependantly decreased in CGS treated RAW 264.7 cells. Conclusion : The results may suggest that the CGS inhibits Th2 cell differentiation in EL 4 cells and inhibits $NF-kB$ p65 activation in RAW 264.7 cells.

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Defense Genes Induced by Pathogens and Abiotic Stresses in Panax ginseng C.A. Meyer

  • Lee, Ok-Ran;Sathiyaraj, Gayathri;Kim, Yu-Jin;In, Jun-Gyo;Kwon, Woo-Seang;Kim, Ju-Han;Yang, Deok-Chun
    • Journal of Ginseng Research
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    • v.35 no.1
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    • pp.1-11
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    • 2011
  • Korean ginseng is a medicinally important perennial herb from the family Araliaceae. It has been cultivated for its highly valued medicinal properties for over 1,000 years in east Asian countries such as China, Korea, and Japan. Due to its longtime cultivation in shady areas, ginseng is frequently exposed to pathogenic infections. Plants protect themselves from microbial pathogens using an array of defense mechanisms, some of which are constitutively active, while others are activated upon pathogen invasion. These induced defense responses, controlled by defense-related genes, require tradeoffs in terms of plant fitness. We hypothesize that ginseng, as with other plants, possesses regulatory mechanisms that coordinate the activation of attacker-specific defenses in order to minimize fitness costs while attaining optimal resistance. Several classes of defense-related genes are induced by infection, wounds, irradiation, and other abiotic stresses. Both salicylates and jasmonates have been shown to cause such responses, although their specific roles and interactions in signaling and development are not fully understood in ginseng. This review summarizes possible defense-related genes in ginseng based on their expression patterns against biotic and abiotic stresses and describes their functional roles.