• International Journal of Industrial Entomology and Biomaterials
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• v.23 no.1
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• pp.107-113
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• 2011

Infection effect of $Nosema$ $bombyics$ on the midgut of silkworm $Bombyx$ $mori$ and subsequent appearance of spores and the performance of larvae was studied. Autopsy of larvae showed white pustules on the surface of midgut at 5 days of post infection (pi). At later stage, important organs like midgut, silk gland and gonads reduced in size and all these organs showed white pustules. Light microscope observation of pustules revealed enormous spores. Spore multiplication was at a faster rate in young larvae. Infection of the adult larvae resulted in pebrinized pupa and moths. Larval weight, cocoon weight and cocoon shell ratio reduced as the post infection period increased. Transverse sections of midgut showed $N.$ $bombycis$ infection limited to a few columnar cells at 3-5 days of pi. At 7 days pi, cell volume increased, cells were swollen and elongated. Heavily infected cells looked like sacks filled with parasite and the apical region of certain cells were bulging into the gut lumen. Later at 8-9 days of pi, spores or its developing stages leaked into the lumen either freely or enclosed within the globules of host cytoplasm. Besides columnar cells, development of $N.$ $bombycis$ was observed in the regenerative cells and rarely in goblet cells. Development of $N.$ $bombycis$ was also observed in both longitudinal and circular muscles at the late pi period. The histopathological changes, deformities and spore production time in the host were all influenced by the spore dosage and age of the host.

• Korean Journal of Veterinary Research
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• v.34 no.1
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• pp.127-134
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• 1994

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, a delicate relationship between host and parasite, in the present studies golden hamsters were alloted to experiment 1(normal undefinitive host group) and experiment 2(immunosuppressive group treated with prednisolone acetate) and inoculated with a single dose of 1,500 embryonated Ascaris suum eggs. The recovery rates, sizes and features of the larvae and immunological responses in the hamsters were chronologically monitored according to somatic migration. In both experiments, the larvae failed to develop into the adults, but the more and larger larvae were observed for a longer period from experiment 2 in comparison with experiment 1. The numbers of the mast cells in the small intestinal mucosa and mesenteric lymph nodes, of the goblet cells in the small intestinal mucosa and of T-cells in the mesenteric lymph nodes, spleens and cardiac blood from experiment 2 were fewer than those from the experiment 1. In general, increasing of these cells followed by expulsion of the worms in the both groups. Profound leukopenia due to lymphopenia was found through trial period in experiment 2. Considering the experimental results, development or expulsion mechanism of somatic migrant larvae may be related to lymphopenia and temporary increasing tendency of the mast cells, the goblet cells and T-cells. In addition, patent infection of A suum in the hamsters was not obviously observed in spite of immunosuppression by prednisolone acetate.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.113-121
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• 2011

Foot-and-mouth disease (FMD) is a severe vesicular disease of cloven-hoofed animals including domesticated ruminants and pigs. Acute clinical signs may be mild in sheep and goats but are associated with lameness in pigs and mouth lesions with vesicles in cattle. The required condition for a successful pathogen appears to be the ability to counteract both the host innate and adaptive immune response. FMD virus (FMDV) inhibits the induction of antiviral molecules and interferes with the secretory pathway in the infected cell. The surface expression of Major Histocompatibility Complex (MHC) class I molecules is reduced in infected cells. Thus, the ability of the host to recognize and eliminate virus infected cells is decreased. Furthermore, FMDV infection results in a rapid, but transient lymphopenia, reducing the number of T and B cells, and affecting T cell function. The virus appears to premature apoptosis-mediated cell death because it has a very short replication cycle and is able to rapidly produce large amounts of virus. FMDV engages the host protective response at multiple steps to ensure its effective replication and pathogenesis. This review describes the recent pathological and immunological studies to overcome the powerful abilities of FMDV to counteract defense mechanism of host.

• Parasites, Hosts and Diseases
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• v.57 no.2
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• pp.83-92
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• 2019

Based on the reactive oxygen species (ROS) regulatory properties of diphenyleneiodonium (DPI), we investigated the effects of DPI on host-infected T. gondii proliferation and determined specific concentration that inhibit the intracellular parasite growth but without severe toxic effect on human retinal pigment epithelial (ARPE-19) cells. As a result, it is observed that host superoxide, mitochondria superoxide and $H_2O_2$ levels can be increased by DPI, significantly, followed by suppression of T. gondii infection and proliferation. The involvement of ROS in anti-parasitic effect of DPI was confirmed by finding that DPI effect on T. gondii can be reversed by ROS scavengers, N-acetyl-L-cysteine and ascorbic acid. These results suggest that, in ARPE-19 cell, DPI can enhance host ROS generation to prevent T. gondii growth. Our study showed DPI is capable of suppressing T. gondii growth in host cells while minimizing the un-favorite side-effect to host cell. These results imply that DPI as a promising candidate material for novel drug development that can ameliorate toxoplasmosis based on ROS regulation.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.220-221
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• 2003

Bacterial infection is a very complex process in which both pathogens and host cells play crucial roles, and the host cells undergo drastic changes in their physiology, releasing various proteins in response to the pathogenic infection. Human airway epithelial surface serves as a first line of defense against microorganisms and the external environment. It is well known that bronchial epithelial cells secrete various chemokines and cytokines such as IL-6 and IL-8 to cope with various respiratory pathogens. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.111.1-111.1
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• 2003

Bacterial infection is a very complex process in which both pathogens and host cells play crucial roles, and the host cells undergo drastic changes in their physiology, releasing various proteins in response to the pathogenic infection. Human airway epithelial surface serves as a first line of defense against microorganisms and the external environment. It is well known that bronchial epithelial cells secrete various chemokines and cytokines such as IL-6 and IL-8 to cope with various respiratory pathogens. (omitted)

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.350-355
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• 2004

Sulforhodamine B (SRB) assay is a rapid, sensitive, and inexpensive method for measuring cell proliferation and chemosensitivity. However, the lactate dehydrogenase (LDH) release assay is generally used to measure cytototoxicity of infectious microorganisms against host cells. In this study, we investigated the possibility of applying the SRB assay to determine cytotoxicity for infectious microorganisms, and compared the results with those obtained by the LDH release assay. We used Vibrio vulnificus as a model of infectious microorganisms. The SRB assay showed that V vulnificus strongly induced cytotoxic activity against human intestinal cells, Caco-2 and INT-407 cells. The degree of cytotoxicity closely correlated with infection time and number ratios of V. vulnificus to intestinal cells (MOI, multiplicity of infection). Furthermore, cytotoxicity values obtained by SRB assay correlated well with results obtained by the LDH release assay, and both assays gave a linear response with respect to MOI Heat-inactivation of V. vulnificus for 35 min at $60^{\circ}C$ did not induce cytotoxic activity, indicating that viability of V. vulnificus is crucial for cytotoxic activity against intestinal cells. Although both assays are suitable as cytotoxicity endpoints, the SRB assay is recommended for measuring cytotoxicity of infectious microorganisms against host cells because of its significantly lower cost and more stable endpoint than the LDH release assay.

• Parasites, Hosts and Diseases
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• v.57 no.4
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• pp.379-387
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• 2019

Clonorchis sinensis is a carcinogenic human liver fluke that promotes hepatic inflammatory environments via direct contact or through their excretory-secretory products (ESPs), subsequently leading to cholangitis, periductal fibrosis, liver cirrhosis, and even cholangiocarcinoma (CCA). This study was conducted to examine the host inflammatory responses to C. sinensis ESPs and their putative protein components selected from C. sinensis expressed sequenced tag (EST) pool databases, including $TGF-{\beta}$ receptor interacting protein 1(CsTRIP1), legumain (CsLeg), and growth factor binding protein 2 (CsGrb2). Treatment of CCA cells (HuCCT1) with the ESPs or bacterial recombinant C. sinensis proteins differentially promoted the secretion of proinflammatory cytokines ($IL-1{\beta}$, IL-6, and $TNF-{\alpha}$) as well as anti-inflammatory cytokines (IL-10, $TGF-{\beta}1$, and $TGF-{\beta}2$) in a time-dependent manner. In particular, recombinant C. sinensis protein treatment resulted in increase (at maximum) of ~7-fold in $TGF-{\beta}1$, ~30-fold in $TGF-{\beta}2$, and ~3-fold in $TNF-{\alpha}$ compared with the increase produced by ESPs, indicating that CsTrip1, CsLeg, and CsGrb2 function as strong inducers for secretion of these cytokines in host cells. These results suggest that C. sinensis ESPs contribute to the immunopathological response in host cells, leading to clonorchiasis-associated hepatobiliary abnormalities of greater severity.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.376-379
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• 2000

The methylotrophic yeast Pichia pastoris is one of the best host for the production of foreign proteins because of the presence of the strong AOX1 promoter induced by methanol. Methanol feeding induces the protein production and provides energy sources for the host cells. However, excess methanol inhibits the growth of host cells, while an insufficient methanol lead to poor growth and protein production. We have used various controled methanol feeding strategies to obtain the maximum proteins.

• BMB Reports
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• v.45 no.4
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• pp.207-212
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• 2012

Retroviruses have often been used for gene therapy because of their capacity for the long-term expression of transgenes via stable integration into the host genome. However, retroviral integration can also result in the transformation of normal cells into cancer cells, as demonstrated by the incidence of leukemia in a recent retroviral gene therapy trial in Europe. This unfortunate outcome has led to the rapid initiation of studies examining various biological and pathological aspects of retroviral integration. This review summarizes recent findings from these studies, including the global integration patterns of various types of retroviruses, viral and cellular determinants of integration, implications of integration for gene therapy and retrovirus-mediated infectious diseases, and strategies to shift integration to safe host genomic loci. A more comprehensive and mechanistic understanding of retroviral integration processes will eventually make it possible to generate safer retroviral vector platforms in the near future.