• Korean Journal of Veterinary Pathology
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• v.1 no.1
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• pp.66-71
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• 1997

Eighteen NZW rabbits used for local skin irritation study were examined grossly and microscopically for natural infection with Encephalitozoon cuniculi. For microscopic tissue evaluation histochemical techniques such as PAS Gram iron hematoxylin and HE stain were used. Although rabbits in the study had no abnormal clinical signs 7/18(38.9%) animals were microscopically infected with E. cuniculi. The affected rabbits had gray-whitish and depressed approximately 0.1∼0.6 cm diameter lesions in the kidneys. All other organs examined were grossly unremarkable. Histopathologically however in addition to segmental interstitial nephritis focal lymphocytic myocarditis and granulomatous inflammatory reaction in portal areas of the liver multifocal granulomatous foci with vasculitis were present in the brain kidney and lungs. Aggregates of minute oval organisms were observed in brain and kidney sections frequently within the granulomatous foci and sometimes without any inflammatory reaction particularly in the renal tubules. in histochemical stains the organisms were gram positive stained with iron hematoxylin and had PAS positive granule at one pole. They measured approximately 1.5×2.5μm consistent with E. cuniculi. Histochemical characterization is important to differentiate E. cuniculi from other common protozoal infection such as Toxoplasma gondii. This study demonstrate the importance of subclinical. E. cunuculi infection and the associated histological alterations may interfere with tissue evaluation in toxicologic studies.

• Journal of Veterinary Clinics
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• v.28 no.5
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• pp.530-532
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• 2011

A Eurasian jay (Garrulus glandarius) with lethargy, dyspnea, and poor physical condition was rescued and referred to the Animal Health Center, Seoul Zoo, Korea. The jay's eyelids were sealed with dark-colored hard scabs and it died the day after arrival. At necropsy, diphtheritic membranes on the tongue and oral mucosa were apparent, suggesting avian poxvirus infection based on the appearance of the oral diphtheritic lesions. PCR was conducted using a tissue sample to confirm the causative agent. The jay was diagnosed with an avian pox viral infection. This report describes the first case of a natural avian pox infection in a Eurasian jay in Korea.

• Journal of fish pathology
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• v.22 no.2
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• pp.163-166
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• 2009

The ectoparasite ciliate Trichodina has been recorded from above 100 species of freshwater and marine fishes. In April 2009, we investigated the trichodia infection in 13 species of marine fishes captured by emplacement net and gill net in order to understand trichodina infection status among the natural fish populations along the Namhae-Gun coast area, the southen coast of Korea. Trichodina infection was observed in 10 out of 10 sea basses Lateolabrax japonicus, 2 out of 5 finespotted flounder Pleuronichthys cornutus and 1 out of a stone flounder Kareius bicoloratus. The sea bass infected with the parasite showed hypertrophy and exfoliation in gill epithelium. In addition, hyperplasia and lamellar fusion of gill filament were noticed among naturally affected sea bass.

• Safety and Health at Work
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• v.10 no.1
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• pp.122-124
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• 2019

Simian malaria is a zoonotic disease caused by Plasmodium knowlesi infection. The common natural reservoir of the parasite is the macaque monkey and the vector is the Anopheles mosquito. Human cases of P. knowlesi infection has been reported in all South East Asian countries in the last decade, and it is currently the most common type of malaria seen in Malaysia and Brunei. Between 2007-2017, 73 cases of P. knowlesi infection were notified and confirmed to the Ministry of Health in Brunei. Of these, 15 cases (21%) were documented as work-related, and 28 other cases (38%) were classified as probably related to work (due to incomplete history). The occupations of those with probable and confirmed work related infections were border patrol officers, Armed Forces and security personnel, Department of Forestry officers, boatmen and researchers. The remaining cases classified as most likely not related to work were possibly acquired via peri-domestic transmission. The risk of this zoonotic infection extends to tourists and overseas visitors who have to travel to the jungle in the course of their work. It can be minimised with the recommended use of prophylaxis for those going on duty into the jungles, application of mosquito/insect repellants, and use of repellant impregnated uniforms and bed nets in jungle camp sites.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.137-143
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• 2021

Most cervical cancers are associated with high-risk human papillomavirus (HPV) infection. Currently, cervical cancer treatment entails surgical removal of the lesion, but treatment of infection and preventing tissue damage are issues that still remain to be addressed. Herbal medicine and biological studies have focused on developing antiviral drugs from natural sources. In this study, we analyzed the potential antiviral effects of Pinus densiflora Sieb. et Zucc. leaf extracts against HPV. The pine needle extracts from each organic solvent were analyzed for antiviral activity. The methylene chloride fraction (PN-MC) showed the highest activity against HPV pseudovirus (PV). The PN-MC extract was more effective before, rather than after treatment, and therefore represents a prophylactic intervention. Mice were pre-treated with PN-MC via genital application or oral administration, followed by a genital or subcutaneous challenge with HPV PV, respectively. The HPV challenge results showed that mice treated via genital application exhibited complete protection against HPV. In conclusion, PN-MC represents a potential topical virucide for HPV infection.

• Journal of Microbiology and Biotechnology
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• v.32 no.10
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• pp.1253-1261
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• 2022

Staphylococcus aureus (S. aureus) infection causes dramatic harm to human health as well as to livestock development. As an important virulence factor, alpha-hemolysin (hla) is critical in the process of S. aureus infection. In this report, we found that bavachin, a natural flavonoid, not only efficiently inhibited the hemolytic activity of hla, but was also capable of inhibiting it on transcriptional and translational levels. Moreover, further data revealed that bavachin had no neutralizing activity on hla, which did not affect the formation of hla heptamers and exhibited no effects on the hla thermal stability. In vitro assays showed that bavachin was able to reduce the S. aureus-induced damage of A549 cells. Thus, bavachin repressed the lethality of pneumonia infection, lung bacterial load and lung tissue inflammation in mice, providing potent protection to mice models in vivo. Our results indicated that bavachin has the potential for development as a candidate hla inhibitor against S. aureus.

• IMMUNE NETWORK
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• v.22 no.3
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• pp.23.1-23.12
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• 2022

Natural infection with severe acute respiratory syndrome-coronavirus-2 or vaccination induces virus-specific immunity protecting hosts from infection and severe disease. While the infection-preventing immunity gradually declines, the severity-reducing immunity is relatively well preserved. Here, based on the different longevity of these distinct immunities, we develop a mathematical model to estimate courses of endemic transition of coronavirus disease 2019 (COVID-19). Our analysis demonstrates that high viral transmission unexpectedly reduces the rates of progression to severe COVID-19 during the course of endemic transition despite increased numbers of infection cases. Our study also shows that high viral transmission amongst populations with high vaccination coverages paradoxically accelerates the endemic transition of COVID-19 with reduced numbers of severe cases. These results provide critical insights for driving public health policies in the era of 'living with COVID-19.'

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.209-213
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• 2007

In the recent, increased concern has been focused on the pharmacology and clinical utility of herbal extracts and derivatives as a drug or adjunct to chemotherapy and immunotherapy. Salicis Radicis Cortex, A decoction has been mainly used for improvement of ozena and a diuretic effect in oriental medicine, but there was no study on the molecular mechanism of Salicis Radicis Cortex as an immunomodulator. Here we investigated the role of the aqueous extract of Salicis Radicis Cortex in the expression of inflammatory mediators, surface molecule, and related receptors in vitro and in vivo. In murine macrophage RAW 264.7 cells and peritoneal macrophages of C57BL/6N mice, water extract of Salicis Radicis Cortex increased the production of secretary TNF-alpha and Nitric oxide, and the expression level of CD14, LPS co-receptor and CD86, co-stimulatory molecule compared to negative natural extract ex vivo. Moreover, i.p. injection of water extract of Salicis Radicis Cortex significantly increased the secretion level of IFN-gamma and TNF-alpha, IL-2, IL-4 and IL-5 in serum of mice in vivo. Taken together, these results suggest that Salicis Radicis Cortex may regulate the immune response by secreting Th1 and Th2 types of cytokines in vivo and the possibility of its as natural immunostimulator.

• Research in Plant Disease
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• v.24 no.4
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• pp.313-320
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• 2018

Fusarium infection rate of the paddy rice grain after harvest seemed to be influenced by the average temperature from late July (before heading) to the end of September (during ripening). In case of 2010 and 2013 in which average temperature of the same period was similar, Fusarium infection was related to cumulative precipitation, cumulative precipitation days, and precipitation durations over two days. The distribution ratio of Fusarium species complex isolated from paddy rice grains after harvest was 57% in 2010 and 45% in 2013 for Fusarium graminearum species complex (FGSC), 35% and 50% for Fusarium incarnatum-equiseti species complex, and 8% and 5% for Fusarium fujikuroi species complex (FFSC). The distribution ratios of FGSC and FFSC were higher in 2010 than 2013. Among the total 26 promoted rice varieties, the 'Mihyang' showed resistant response against the natural infection with Fusarium species belonging to FGSC and the varieties of 'Nampyeong', 'Hi-ami'and 'Younghojinmi' showed resistant response against the natural infection with overall Fusarium pathogens. Majority of the promoted rice varieties could not be classified for resistance or susceptibility. These results are valuable as basic data to determine the resistance and susceptibility of rice variety against Fusarium spp. infection in the field.

• Journal of Life Science
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• v.32 no.9
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• pp.734-741
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• 2022

Currently, around 40 million people worldwide are living with human immunodeficiency virus (HIV) infection making HIV a critical global health risk. Present therapies for HIV infection consist of drug cocktails that target different steps of the HIV life cycle to prevent infection, replication, and release of the virus. Due to its mutating nature, drug resistance coupled with side-effects of long-term drug use, novel strategies, and pharmaceuticals to treat and manage HIV infection are constant needs and continuously being studied. Plants allocate a major repertoire of chemical diversity and are therefore regarded as an important source of new bioactive agents that can be utilized against HIV. Since the early 1990s, upon recommendations of the World Health Organization, numerous studies reported phytochemicals from different structural classes such as flavonoids, coumarins, tannins and terpenes with strong inhibitory effects against HIV infection. The present review gathered and presented recent research (2021-present) on plant extracts and phytochemicals that exhibit anti-HIV properties with the aim of providing insights into future studies where ethnomedical and underutilized plant sources may yield important natural products against HIV. Considering the relation and importance of HIV treatment with current viral infection risks such as SARS-CoV-2, screening plants for anti-HIV agents is an important step towards the discovery of novel antivirals.