• Journal of Ginseng Research
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• v.45 no.4
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• pp.535-537
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• 2021

In the 1918 influenza pandemic, more than 95% of mortalities were ascribed to bacterial pneumonia. After the primary influenza infection, the innate immune system is attenuated, and the susceptibility to bacteria is increased. Subsequent bacterial pneumonia exacerbates morbidity and increases the mortality rate. Similarly, COVID-19 infection attenuates innate immunity and results in pneumonia. In addition, the current pneumococcal conjugate vaccine may have limited defense against secondary pneumococcal infection after influenza infection. Therefore, until a fully protective vaccine is available, a method of increasing immunity may be helpful. Ginseng has been shown to increase the defense against influenza in clinical trials and animal experiments, as well as the defense against pneumococcal pneumonia in animal experiments. Based on these findings, ginseng is suspected to be helpful for providing immunity against COVID-19.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.213-219
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• 2009

An understanding of anthracnose (Colletotrichum acutatum) infections, including the infection of flowers and latent infection early in the season, is necessary to achieve successful control by means of properly timed spraying with a curative fungicide. In the present study, latent anthracnose infection of chili was investigated under greenhouse and field conditions in 2007-2008. Flowers on greenhouse-grown seedlings were infected and 11% of the young fruits subsequently showed symptoms of anthracnose. Apparently healthy-looking green peppers obtained from unsprayed fields or an organic market also exhibited symptoms of anthracnose after 4 days of incubation under high moisture conditions at $25^{\circ}C$; less than 1% of the peppers were found to be latently infected. To determine the natural timing of infection in the field, 3,200 fruits were wrapped in paper bags and then selectively unwrapped and examined for signs of infection. Field experiments were conducted at Suwon (cvs. Yokkang, Manitta, Olympic) and Asan (cv. Chunhasangsa) in 2008. The 7- to 10-day wrapping periods were July 25-31, July 31-August 7, August 7-15, August 15-24, and August 24-September 3. The 1-to 2-month wrapping periods were from July 4, July 31, and August 15 until harvest (Sept. 3). The controls consisted of 1,712 field-grown non-wrapped fruits. The rates of infection on the various cultivars were Yokkang 55%, Manitta 37%, Olympic 55%, and Chunhasangsa 20%. A distinct period in which anthracnose infection suddenly increased could not be identified; however, attempts to guess the approximate timing of field infection showed that 0-39% of the plants had latent infections, while depending on the cultivar, 8-14% of the plants examined in August and 4-13.5% of the those examined during May-July showed symptoms of infection. Delaying fungicide spraying by 24 and 48 h after artificial infection decreased the rates of infection by 10% and 25-30%, respectively. Chemical control of anthracnose based on a forecasting model should be considered starting from the transplanting stage, with spraying within a day after warning and care being taken not to latently infect apparently healthy pepper fruits.

• Parasites, Hosts and Diseases
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• v.48 no.1
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• pp.23-33
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• 2010

An understanding of the nature of the immune response to asexual erythrocytic stages of malaria parasites will facilitate vaccine development by identifying which responses the vaccine should preferentially induce. The present study examined and compared the immune responses of NIH mice in either single or mixed infections with avirulent (DK) or virulent (DS) strains of Plasmodium chabaudi adami using the ELISA test for detecting and measurement of cytokines and antibody production. In both single and mixed infections, the study showed that both cell- and antibody-mediated responses were activated. In all experiments, an early relatively high level of IFN-$\gamma$ and IgG2a during the acute phase of the infection, and later elevation of IL-4 and IgG1, suggested that there was a sequential Th1/Th2 response. However, in the avirulent DK strain infection a stronger Th1 response was observed compared to the virulent DS strain-infection or in mixed infections. In the virulent DS infection, there was a stronger Th2 response compared to that in the DK and mixed infections. The faster proliferation rate of the virulent DS strain compared to the DK strain was also evident.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.88-95
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• 2015

The three endophytes, Blastophysa rhizopus, Bolbocoleon piliferum, Ulvella leptochaete, were isolated in a laboratory culture from a Grateloupia lanceolata thallus collected in Jeju. Effects of temperature and irradiance on growth and infection of the three species, were examined. Based on the unialgal cultures, their growth was examined under six temperatures (9, 13, 17, 21, 25, $29^{\circ}C$) and two irradiance levels (60, $100{\mu}mol\;m^{-2}s^{-1}$). Also, infection experiments to the five hosts (Ulva intestinalis, Scytosiphon lomentaria, Gracilaria verimiculophylla, Chondrus ocellatus, and Grateloupia elliptica) with three endophytes were carried out under four temperatures (10, 15, 20, $25^{\circ}C$) and two irradiance levels (60, $100{\mu}mol\;m^{-2}s^{-1}$). In culture of the endophytes, optimum growth was found in $100{\mu}mol\;m^{-2}s^{-1}$ in combination with $21^{\circ}C$. At the end of infection experiment, endophytes were observed at all the hosts. Among three endophytes, U. leptochaete was the most common at the five hosts. However, we did not observe any endophytes at all hosts tested under $10^{\circ}C$ condition. Based on this result, it appears that temperature acts as a limiting factor to infection of the three species.

• The Plant Pathology Journal
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• v.16 no.5
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• pp.257-263
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• 2000

Infection with rice blast fungus (Magnaporthe grisea) significantly reduced foliar net photosynthesis (A) of rice cultivars: Ilpoom, Hwasung, and Choochung in greenhouse experiments. By measuring the amount of diseased leaf area with a computer image analysis system, the relation between disease severity (DS) and net photosynthetic rate was curvilinearly correlated (r=0.679). Diseased leaves with 35% blast symptom can be predicted to have a 50% reduction of photosynthesis. The disease severity was linearly correlated (r=0.478) with total chlorophyll (chlorophyll a and chlorophyll b) per unit leaf area(TC). Light use efficiency was reduced by the fungal infection according to the light response curves. However, dark respiration (Rd) did not change after the fungal infection (p=0.526). Since the percent of reduction in photosynthesis greatly exceeded the percent of leaf area covered by blast lesions, loss of photosynthetic tissue on an area basis could not by itself account for the reduced photosynthesis. Quantitative photosynthetic reduction can be partially explained by decreasing TC, but cannot be explained by decreasing Rd. By photosynthesis (A)-internal CO$_2$ concentration (C$_i$ curve analysis, it was suggested that the fungal infection reduced ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, ribulose-1,5-bisphosphate (RuBP) regeneration, and inorganic phosphate regeneration. Thus, the reduction of photosynthesis by blast infection was associated with decreased TC and biochemical capacity, which comprises all carbon metabolism after CO$_2$ enters through the stomata.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1585-1591
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• 2010

A comprehensive study on the production of inflammatory mediators in the lungs of BALB/c mice following infection with Stenotrophomonas maltophilia was conducted. The levels of pro-inflammatory cytokines, tumor necrosis factor alpha (TNF-${\alpha}$), and interleukin-1${\beta}$ (IL-1${\beta}$) were raised in the lungs of infected mice compared with control. The production of anti-inflammatory cytokine IL-10 was slightly delayed. Its peak level was on the $2^{nd}$ day, whereas the peak of pro-inflammatory cytokines was observed on day 1 after intranasal challenge. This was accompanied by a rise in myeloperoxidase (MPO) and malondialdehyde (MDA) on day 1. The increase in MPO levels matched with histopathological observations, as neutrophils infiltration was detected on the first day. Alveolar macrophages (AMs) obtained from infected animals showed a higher rate of uptake and killing when exposed to bacteria in vitro, compared with similar experiments conducted with AMs from normal mice (control). This suggests that AMs were more efficient in cleaning the bacteria. The nitric oxide (NO) production however started early during infection but reached its maximum on the $3^{rd}$ day. No mortality was observed among the infected animals, and infection was resolved by the $5^{th}$ day post infection. No drastic changes in the lung tissue were observed on histopathological examination.

• Korean Journal of Veterinary Service
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• v.41 no.4
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• pp.263-269
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• 2018

Developing drugs targeting respiratory pathogen is essential to control respiratory diseases. Many experiments have been performed under in vivo situation. However, in vivo experiments have economical and ethical issues. The objective of this study was to determine the possibility of developing an ex vivo lung culture system with possible application for respiratory infection studies. After isolating lungs from naïve pigs, agarose-inflated lung tissues were prepared and sliced manually. These sliced lung tissues were then subsequently placed on 24-well plates. Eight different combinations of media were used to determine the optimum ex vivo lung culture condition. In addition, lung tissues were infected with porcine reproductive and respiratory syndrome (PRRS) virus at a titer of $1{\times}10^4\;TCID_{50}/mL$. Virus growth was confirmed by titration in MARC-145 cells at 2, 4, 6 days post infection (dpi). We found that ex vivo lung culture in physiological environment was not media specific based on histopathology and cytotoxicity. However, under virus-infected condition, thickened alveolar walls in the lung tissues and stable virus titers at 2, 4, 6 dpi were shown in F12K medium suggesting that it was useful for tissue maintenance and virus infection using PRRS virus infected lung tissues. The present study shows the possibility of using porcine ex vivo lung model for respiratory infection studies.

• IMMUNE NETWORK
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• v.2 no.2
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• pp.65-71
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• 2002

The immunological mechanism of the responses to ultraviolet (UV) B radiation in mouse models were investigated by the suppression of contact hypersensitivity (CHS) and delayed type hypersensitivity (DTH), and susceptibility to infection. However, there are some differences in immune suppression according to the different models as well as the irradiation protocols. Therefore, this review focused on the differences in the suppressive effects on CHS and DTH, and susceptibility to infection in relation to the different in vivo models. Recent advances in cytokine knockout mice experiments have the reexamination of the role of the critical cytokines in UVB-induced immune suppression, which was investigated previously by blocking antibodies. The characteristics of the suppressor cells responsible for UVB-induced tolerance were determined. The subcellular mechanism of UVB-induced immune suppression was also explained by the induction of apoptotic cells through the Fas and Fas-ligand interaction. The phagocytosis of the apoptotic cells is believed to induce the production of the immune suppressive cytokine like interleukin-10 by macrophages. Therefore, the therapeutic UVB response to a skin disease, such as psoriasis, by the depletion of infiltrating T cells could be considered in the extension line of apoptosis and immune suppression.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.465-467
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• 2004

This paper deals with the design and analysis of automatic virus infection machine, which can be used in blood testing at veterinary hospital. It consists of the mechanical positioning parts and electrical control parts. Two of driving motor and ball screws are used to move the liquid container into the test position and mix the blood on litmus paper. In addition, a thermal controller is installed to keep the container temperature on constant level. The user interface using with a LCD and some keys are supplied with a 8-bit single chip controller. All of the designs issue related with the mechanism and controllers are discussed in detail. Finally the proposed machine is tested in real experiment with the formal processing to judge the virus infection, and also the usefulness of designed algorithm is verified through the experiments.

• Parasites, Hosts and Diseases
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• v.21 no.1
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• pp.11-18
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• 1983

As a part of observation on the suitability as a second intermediate host of Clonorchis sinensis, various infection experiments were tried to Cyprinus carpio nodus. The results obtained were summarized as follows: 1. The cercariae which attempted to contact with Cyprinus carpio nodus in the water were observed under the stereomicroscope. After contact, cercariae began to separate its tails from the bodies at 4 minutes increasingly, and then the numbers ranged to 80% at 13 minutes after the encounter. But very few cercariae could actually invade into the epidermis of the fish. 2. When Cyprinus carpio nudes were exposed to a number of cercariae in the beaker, only a few cercariae could invade through the epidermis. Most of the invaded cercariae were killed before forming the cyst. Also rare encysted cercariae were found to be dead within 48 hours. 3. Cyprinus carpio nudes were reared with Parafossarulus manchouricus shedding numerous cercariae in the indoor aquarium. When observed after 12 days, to determine the susceptibility, no metacercaria was found infected. 4. Cyprinus carpio nudum were reared with Parafossarulus manchouricus shedding numerous cercariae in Kimhae lake for 2 months in summer of 1982, in order to check the natural infection. No metacercaria of Clonorchis sinensis was found from the fish. 5. In the cases of control fish, Pseudoraibora larva, numerous cercariae were inspected on the course of invasion through epidermis of the fish under the stereomicroscope. And many metacercariae were also found from the Ssh whenever they were kept in beaker, indoor aquarium, or the lake for natural infection. The results suggested that Cyprinus carpio kudus might not be proper intermediate host of Clonorchis sinensis.