• Title/Summary/Keyword: infection process

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Ultrastructure of Compatible and Incompatible Interactions of Pumpkin Stems Infected with Phytophthora capsici

  • Lee, Byung-Kook;Hong, Jeum-Kyu;Hwang, Byung-Kook
    • The Plant Pathology Journal
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    • v.17 no.1
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    • pp.29-35
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    • 2001
  • Early infection process of Phytophthora capsici in pumpkin stems was similar in the compatible and incompatible interactions 24 h after inoculation. Intercellularly growing hyphae penetrated host parenchyma cells by growing hyphae penetrated host parenchyma cells by forming haustoria. An extrahaustorial matrix was found around the haustoria in both compatible and incompatible interactions. No wall appositions were observed at the infection sites in the parenchyma cells. In the compatible interaction, infecting hyphae grew well in the intercellular spaces between xylem vessels in stem tissues. Degraded host cell wall, plasmolysis of plasma membrane, and degenerated chloroplasts were pathological features of pumpkin stem tissues in both compatible and incompatible interactions. A characteristic host response in the resistant pumkin cultivar Danmatmaetdol was rapid cytoplasmic movement of host cells toward the oomycete haustoria.

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NMMP1, a Matrix Metalloprotease in Nicotiana benthamiana Has a Role in Protection against Bacterial Infection

  • Kang, So-Ra;Oh, Sang-Keun;Kim, Jong-Joo;Choi, Do-Il;Baek, Kwang-Hyun
    • The Plant Pathology Journal
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    • v.26 no.4
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    • pp.402-408
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    • 2010
  • Plant matrix metalloproteases (MMPs) are a family of apoplastic metalloproteases closely related to human matrilysins. Up-regulation of Nicotiana benthamiana matrix metalloprotease 1 (NMMP1) expression by treatment with pathogens, ethephon and aging indicates that the gene is related to plant defense and the aging process through ethylene signaling. NMMP1 expression was higher than in normal growth leaves following infection with an incompatible pathogen Pseudomonas syringae pv. tomato T1 or a compatible pathogen P. syringae pv. tabaci and in aged leaves. Transient overexpression of NMMP1 in N. benthamiana leaves lowered the growth of P. syringae pv. tabaci. However, NMMP1-silenced leaves showed increased growth of P. syringae pv. tabaci. These data strongly suggest that NMMP1 in N. benthamiana is a defense related gene, which is positively regulated by ethylene.

Pathophysiology of Oral Mucositis induced by Anticancer Therapy (항암치료 후 발생하는 구강 점막염의 병태생리)

  • Yoon, Jung-Hoon;Choj, Jong-Hoon
    • Journal of Oral Medicine and Pain
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    • v.25 no.4
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    • pp.365-369
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    • 2000
  • Oral mucositis or stomatitis produced by stomatotoxic chemotherapy and/or radiation therapy are painful, restrict oral intake and, importantly, act as sites of secondary infection and potals of entry for the endogenous oral microflora often leading to bacteremias or sepsis. A number of clinical observations and studies of animal model suggests a pathophysiological complexity in the development of mucositis. The condition appears to represent a sequential interaction of the oral mucosal cells and tissues, pro-inflammatory cytokines, and local environmental factors in the mouth. This article discussed and reviewed biological process of the mucositis and, the role of cytokines as initiators and amplifiers of the process. The recognition that the pathophysiology of mucositis is a multifactorial process has presented opportunities for intervention based upon biological attenuation.

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Characterization of Bacillus anthracis proteases through protein-protein interaction: an in silico study of anthrax pathogenicity

  • Banerjee, Amrita;Pal, Shilpee;Paul, Tanmay;Mondal, Keshab Chandra;Pati, Bikash Ranjan;Sen, Arnab;Mohapatra, Pradeep Kumar Das
    • CELLMED
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    • v.4 no.1
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    • pp.6.1-6.12
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    • 2014
  • Anthrax is the deadly disease for human being caused by Bacillus anthracis. Instantaneous research work on the mode of infection of the organism revealed that different proteases are involved in different steps of pathogenesis. Present study reports the in silico characterization and the detection of pathogenic proteases involved in anthrax infection through protein-protein interaction. A total of 13 acid, 9 neutral, and 1 alkaline protease of Bacillus anthracis were selected for analysing the physicochemical parameter, the protein superfamily and family search, multiple sequence alignment, phylogenetic tree construction, protein-protein interactions and motif finding. Among the 13 acid proteases, 10 were found as extracellular enzymes that interact with immune inhibitor A (InhA) and help the organism to cross the blood brain barrier during the process of infection. Multiple sequence alignment of above acid proteases revealed the position 368, 489, and 498-contained 100% conserved amino acids which could be used to deactivate the protease. Among the groups analyzed, only acid protease were found to interact with InhA, which indicated that metalloproteases of acid protease group have the capability to develop pathogenesis during B. anthracis infection. Deactivation of conserved amino acid position of germination protease can stop the sporulation and germination of B anthracis cell. The detailed interaction study of neutral and alkaline proteases could also be helpful to design the interaction network for the better understanding of anthrax disease.

Recurrent Herpes-Stomatitis Mimicking Acute Necrotizing Ulcerative Gingivitis (급성괴사성궤양성 치은염을 닮은 재발성 허피스 구내염)

  • Kim, Han-Seok;Lee, Suk-Keun;Park, Young-Wook
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.33 no.1
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    • pp.89-92
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    • 2011
  • Herpes simplex is caused by viruses of the herpesvirus hominus family. HSV have four categories: type 1, 2, 6, and 8. Generally HSV-1 affects the mouth. Once infected by HSV, the person's infection is permanent. Retrograde transport through adjacent neural tissue to sensory ganglia leads to a lifelong latent infection. Recently, we treated a patient with recurrent herpes-stomatitis mimicking acute necrotizing ulcerative gingivitis (ANUG). The results were satisfactorty so we report this case. 31 years old male patient showed sore throat, gingival ulceration, palpable both submandibular lymph node, and sulcular pus formation around posterior decayed teeth. This is the third time he has suffered from this symptom. Tentative diagnosis was acute necrotizing ulcerative gingivitis. Antibiotic therapy was started. But, intraoral symptom got worse in process of time. Especially ulcer of marginal gingiva got worse. Viral disease was suspected. We carried out viral cultivation. At the same time topical application of antiviral ointment (herpecid$^{(R)}$) was performed on oral ulcer unilaterally for the purpose of diagnosis and reducing pain experimentally. The next day pain was decreased dramatically on application area. Basing on the viral cultivation and clinical effect of antiviral ointment (herpecid$^{(R)}$), we have diagnosed it as a recurrent herpes-stomatitis and concluded that viral infection was major cause of disease and bacterial infection was secondary.

Proliferation of Toxoplasma gondii Suppresses Host Cell Autophagy

  • Lee, Youn-Jin;Song, Hyun-Ouk;Lee, Young-Ha;Ryu, Jae-Sook;Ahn, Myoung-Hee
    • Parasites, Hosts and Diseases
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    • v.51 no.3
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    • pp.279-287
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    • 2013
  • Autophagy is a process of cytoplasmic degradation of endogenous proteins and organelles. Although its primary role is protective, it can also contribute to cell death. Recently, autophagy was found to play a role in the activation of host defense against intracellular pathogens. The aims of our study was to investigate whether host cell autophagy influences Toxoplasma gondii proliferation and whether autophagy inhibitors modulate cell survival. HeLa cells were infected with T. gondii with and without rapamycin treatment to induce autophagy. Lactate dehydrogenase assays showed that cell death was extensive at 36-48 hr after infection in cells treated with T. gondii with or without rapamycin. The autophagic markers, LC3 II and Beclin 1, were strongly expressed at 18-24 hr after exposure as shown by Western blotting and RT-PCR. However, the subsequent T. gondii proliferation suppressed autophagy at 36 hr post-infection. Pre-treatment with the autophagy inhibitor, 3-methyladenine (3-MA), down-regulated LC3 II and Beclin 1. The latter was also down-regulated by calpeptin, a calpain inhibitor. Monodansyl cadaverine (MDC) staining detected numerous autophagic vacuoles (AVs) at 18 hr post-infection. Ultrastructural observations showed T. gondii proliferation in parasitophorous vacuoles (PVs) coinciding with a decline in the numbers of AVs by 18 hr. FACS analysis failed to confirm the presence of cell apoptosis after exposure to T. gondii and rapamycin. We concluded that T. gondii proliferation may inhibit host cell autophagy and has an impact on cell survival.

Involvement of the CXC Chemokines Mig and IP-10 in Response to M. bovis BCG in Mice

  • Hong, Seong-Tshool;Cho, Jung-Gil;Lee, Hwang-Ho
    • The Journal of the Korean Society for Microbiology
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    • v.35 no.2
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    • pp.117-127
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    • 2000
  • The non-ELR-containing CXC chemokines Mig and IP-10 have been shown to function as chemotactic cytokines for activated T lymphocytes. In this study, we examined the potential involvement of Mig and IP-10 in antimycobacterial response of mice immunized or infected with M. bovis BCG. The accumulation of Mig and IP-10 mRNA in resident peritoneal monocytes ($RPM{\Phi}$) was slightly reduced by stimulation with vBCG, and the degree was greater for 24 hr culture even though IFN-${\gamma}$ was added. Expression of Mig, IP-10, and IFN-${\gamma}$ in 24 hr delayed-type hypersensitivity (DTH) response was stronger in vBCG-immune mice than in the non-immune. The increase of DTH measured by foot-pad thickness appears to be clearly related to the levels of chemokines Mig and IP10 messages and those of IFN-${\gamma}$ and IL-12. Stimulation with vBCG for 2 days decreased or completely dropped the levels of Mig message in non-immune or immune splenocytes, respectively, whereas IP-10 message was slightly decreased in 2 days culture. Moreover, messages for IL-12 (p40) showed similar kinetics for Mig. The levels of Mig and IP-10 mRNA during the course of infection with BCG were not readily changed in lungs, livers, and spleens from BCG-infected mice. Although there was no obvious changes of Mig and IP-10 messages in the target organs during infection process, we found that the infection progressed over the first 3 wk before being contained by the emerging immune response suggested from detectable amount of IFN-${\gamma}$ mRNA around this time. In view of selectivity of chemokines Mig and IP-10 for activated T cells, these data suggest that chemokine Mig and IP-10, especially in collaboration with IL-12 and IFN-${\gamma}$, may playa role as T cell recruiters in immune response against mycobacterial infection.

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Studies on the Comparative Migration Patterns of Ascaris suum Larvae between Primary and Re-infected Mice (돼지회충(Ascaris suum) 유충 감염력이 재감염에 미치는 영향)

  • 송종술;김재진
    • Parasites, Hosts and Diseases
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    • v.23 no.2
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    • pp.247-252
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    • 1985
  • In the present study, the effect of primary infection to reinfection with Ascaris suum larvae was experimented in mouse model. Mice were challenged with 1,000 infective stage eggs of Ascaris suum. The embryonated eggs were directly introduced into stomach of mice. Reinfection was performed at 50 days after the primary infection with same method as primary infection. Mice were sacrificed 3, 5, 7, 10, 15 and 20 days after infection in both groups respectively. Larvae collected from livers and lungs with Baermann's apparatus were enumerated and measured after sacrifice. Sera of mice were also collected at same time. The results of the experiment were as follows: With antigen prepared from coelomic fluid of adult Ascaris suum and sera collected from mice before reinfection, the production of antibody in experimental mice was confirmed by the gel-diffusion technique. In the livers of reinfected mice, the larvae were recovered up to 10 days after challenge, otherwhile in the primary infected mice, the larvae were observed up to 7 days. The maximum number of larvae were observed in the lungs of primary infected mice on 10 days after inoculation. In the lungs of reinfected mice, maximum number of larvae were recovered on 7 days after, only few larvae were recovered on 10 days after reinfection. As regards the growth of the larvae, the third stage larvae, over $500{\mu\textrm{m}}$ in length, appeared in livers at 5 days after reinfection, but it couldn't be found on 7 days and 10 days after challenge. The third stage larvae continuously developed were observed in lungs of mice from 5 days after reinfection. In conclusion, it was found that development of larvae in livers of immune mice were probably repressed by the immune mechanisms being rises in livers and defence mechanism is also acting by interfering with the process of larval penetration into the lung from the liver.

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Repeat Auditing of Primary Health-care Facilities Against Standards for Occupational Health and Infection Control: A Study of Compliance and Reliability

  • Cloete, Brynt;Yassi, Annalee;Ehrlich, Rodney
    • Safety and Health at Work
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    • v.11 no.1
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    • pp.10-18
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    • 2020
  • Background: The elevated risk of occupational infection such as tuberculosis among health workers in many countries raises the question of whether the quality of occupational health and safety (OHS) and infection prevention and control (IPC) can be improved by auditing. The objectives of this study were to measure (1) audited compliance of primary health-care facilities in South Africa with national standards for OHS and IPC, (2) change in compliance at reaudit three years after baseline, and (3) the inter-rater reliability of the audit. Methods: The study analyzed audits of 60 primary health-care facilities in the Western Cape Province of South Africa. Baseline external audits in the time period 2011-2012 were compared with follow-up internal audits in 2014-2015. Audits at 25 facilities that had both internal and external audits conducted in 2014/2015 were used to measure reliability. Results: At baseline, 25% of 60 facilities were "noncompliant" (audit score<50%), 48% "conditionally compliant" (score >50 < 80%), and only 27% "compliant" (score >80%). Overall, there was no significant improvement in compliance three years after baseline. Percentage agreement on specific items between internal and external audits ranged from 28% to 92% and kappa from -0.8 to 0.41 (poor to moderate). Conclusion: Low baseline compliance with OHS-IPC measures and lack of improvement over three years reflect the difficulties of quality improvement in these domains. Low inter-rater reliability of the audit instrument undermines the audit process. Evidence-based investment of effort is required if repeat auditing is to contribute to occupational risk reduction for health workers.

NECROTIZING GINGIVOSTOMATITIS : CASE REPORT (괴사성 치은구내염환아의 증례보고)

  • Jung, Hee-Kyung;Yang, Kyu-Ho;Kim, Seon-Mi;Choi, Nam-Ki
    • Journal of the korean academy of Pediatric Dentistry
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    • v.33 no.1
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    • pp.85-90
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    • 2006
  • Necrotizing ulcerative gingivitis(NUG), necrotizing ulcerative periodontitis(NUP), necrotizing stomatitis (NS), and Noma (cnacrum oris) are rapidly destructive debilitating and potentially serious oral infection which considered to be different clinical stages of the same process. These have been collectively referred to as: Vincent's infection, infectious oral necrosis, or necrotizing gingivostomatitis(NG). Prevalence of necrotizing gingivostomatitis is $0.19{\sim}0.5%$ and peak incidence is 2-6 years of age. The etiology and pathogenesis of necrotizing gingivostomatitis have been associated with virulent bacteria and impaired host defense and the primary diagnostic signs are pain, interdental ulceration or necrosis, and gingival bleeding. Secondary diagnostic sign is pseudomembrane. This case report was about oral conditions and treatment of the patient who referred from the Dept. of PED and diagnosed a necorotizing gingivostomatitis.

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