• The Plant Pathology Journal
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• v.32 no.1
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• pp.1-7
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• 2016

Responses of Botryosphaeria dothidea to interrupted wetness periods were investigated under in vivo and in vitro conditions. Conidia of B. dothidea were allowed to germinate on apple fruits under wetting condition at $25^{\circ}C$ for 5 hr. They were air-dried for 0, 1, 2 or 4 hr, and then rewetted at $25^{\circ}C$ for 5 hr. Following an initial wetness period of 5 hr, 83% of the conidia germinated. The percent conidial germination increased to 96% when wetting was extended continuously another 5 hr. However, no further conidial germination was observed when wetting was interrupted by dry periods of 1, 2 and 4 hr, resulting in 83, 81 and 82%, respectively. The mean length of the germ tubes was $37{\mu}m$ after 5 hr of wetting and elongated to $157{\mu}m$ after 10 hr of continuous wetting. On the other hand, interruption of wetting by a dry period of 1 hr or longer after the 5 hr of initial wetting arrested the germ tube elongation at approximately $42{\mu}m$ long. Prolonged rewetting up to 40 hr did not restore germ tube elongation on slide glasses under substrate treatments. Model simulation using weather data sets revealed that ending infection periods by a dry period of at least 1 hr decreased the daily infection periods, avoiding the overestimation of infection warning. This information can be incorporated into infection models for scheduling fungicide sprays to control apple white rot with fewer fungicide applications.

• Journal of Microbiology and Biotechnology
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• v.20 no.5
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• pp.935-941
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• 2010

The emergence of antibiotic-resistant bacterial strains is one of the most critical problems of modern medicine. Bacteriophages have been suggested as an alternative therapeutic agent for such bacterial infections. In the present study, we examined the therapeutic potential of phage Kpn5 in the treatment of Klebsiella pneumoniae B5055-induced burn wound infection in a mouse model. An experimental model of contact burn wound infection was established in mice employing K. pneumoniae B5055 to assess the efficacy of phage Kpn5 in vivo. Survival and stability of phage Kpn5 were evaluated in mice and the maximum phage count in various organs was obtained at 6 h and persisted until 36 h. The Kpn5 phage was found to be effective in the treatment of Klebsiella-induced burn wound infection in mice when phage was administered immediately after bacterial challange. Even when treatment was delayed up to 18 h post infection, when all animals were moribund, approximately 26.66% of the mice could be rescued by a single injection of this phage preparation. The ability of this phage to protect bacteremic mice was demonstrated to be due to the functional capabilities of the phage and not due to a nonspecific immune effect. The levels of pro-inflammatory cytokines (IL-$1{\beta}$ and TNF-${\alpha}$) and anti-inflammatory cytokines (IL-10) were significantly lower in sera and lungs of phage-treated mice than phage untreated control mice. The results of the present study bring out the potential of bacteriophage therapy as an alternate preventive approach to treat K. pneumoniae B5055-induced burn wound infections. This approach not only helps in the clearance of bacteria from the host but also protects against the ensuing inflammatory damage due to the exaggerated response seen in any infectious process.

• Journal of Korean Academy of Nursing
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• v.46 no.3
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• pp.327-337
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• 2016

Purpose: The purpose of this study was to construct and test a structural equation model on resilience of breast cancer patients receiving chemotherapy. Methods: Participants were 204 patients with breast cancer who received chemotherapy treatment. They participated in a structured interview, which included social support, depression, symptom experience, self-efficacy, hope, resilience, and infection prevention behaviors. Data were analyzed using SPSS/WIN 20.0 and AMOS 18.0. Results: Lower depression (${\gamma}=-.33$, p=.020) and symptom experience (${\gamma}=-.31$, p=.012) and higher self-efficacy (${\gamma}=.32$, p=.005) and hope (${\gamma}=.48$, p=.016) were influenced by higher social support. Greater resilience was influenced by lower symptom experience (${\beta}=-.18$, p=.016), higher self-efficacy (${\beta}=.49$, p=.023), and higher hope (${\beta}=.46$, p=.012), and these predictors explained 66.7% of variance in resilience. Greater resilience (${\beta}=.54$, p =.009) made an impact on greater infection prevention behaviors. Resilience mediated the relations of symptom experience (${\beta}=-.10$ p=.013), self-efficacy (${\beta}=.27$, p=.006) and hope (${\beta}=.25$, p=.009) with infection prevention behaviors. These predictors explained 24.9% of variance in infection prevention behaviors. Conclusion: The findings of the study suggest that breast cancer patients with greater resilience who are receiving chemotherapy participate in increased infection prevention behaviors. Further research should be conducted to seek intervention strategies that improve breast cancer patients' resilience.

• Journal of Veterinary Science
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• v.22 no.2
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• pp.18.1-18.12
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• 2021

Background: We previously elucidated the protective mechanism of Korean red ginseng oil (RGO) against Brucella abortus infection, and our phytochemical analysis revealed that palmitic acid (PA) was an abundant component of RGO. Consequently, we investigated the contribution of PA against B. abortus. Objectives: We aimed to investigate the efficacy of PA against B. abortus infection using a murine cell line and a murine model. Methods: Cell viability, bactericidal, internalization, and intracellular replication, western blot, nitric oxide (NO), and superoxide (O₂^-) analyses and flow cytometry were performed to determine the effects of PA on the progression of B. abortus infection in macrophages. Flow cytometry for cytokine analysis of serum samples and bacterial counts from the spleens were performed to determine the effect of PA in a mouse model. Results: PA did not affect the growth of B. abortus. PA treatment in macrophages did not change B. abortus uptake but it did attenuate the intracellular survivability of B. abortus. Incubation of cells with PA resulted in a modest increase in sirtuin 1 (SIRT1) expression. Compared to control cells, reduced nitrite accumulation, augmented O₂^-, and enhanced pro-inflammatory cytokine production were observed in PA-treated B. abortus-infected cells. Mice orally treated with PA displayed a decreased serum interleukin-10 level and enhanced bacterial resistance. Conclusions: Our results suggest that PA participates in the control of B. abortus within murine macrophages, and the in vivo study results confirm its efficacy against the infection. However, further investigations are encouraged to completely characterize the mechanisms involved in the inhibition of B. abortus infection by fatty acids.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.430-436
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• 2015

This study examined the correlation of educational experience with practical behavior in infection control. Subjects were 152 dental hygienists in Gwangju from September 15 to October 5, 2015. The ratio of dental hygienists educated on infection control was higher in those worked in dental care with 2~4 dentist for 2~5 years and lower in those worked in dental cared with 1 dentist for 2~5 years (p<0.05, p<0.001). The dental hygienists with or without educational experience in infection control exhibited the highest activity rate in hand wash and the lowest in face protection. Barrier in health belief, was lower with the need for education in infection control among the factors affecting on the activity in infection control. The activity was higher with susceptibility and cue to action (p<0.05). Based on the results, education program on infection control should be developed, and applied periodically and obligatorily for dentist and all staffs of dental care to remove susceptibility and barrier, and to enhance cue to action. This will result the effective control of infection by elevating the health belief.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.227-235
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• 2021

The purpose of this study was to investigate the association factors of dental infection control by applying the health belief model in the dental hygienists. This study subject was 142 dental hygienists from 15 to July 5, 2020. Data were analyzed by chi-square test ANOVA, correlation analysis, and multiple regression analysis using SPSS version 23.0. The performance of dental infection control in accordance with the general characteristics of research subjects was high in case when they had educational experiences of infection control, and when they 'always' did medical examinations by interview about infectious diseases(p<0.01). The group of dental hygienists working for dental clinics with less than average 50 patients a day showed the highest rate of wearing a mask and latex gloves as personal protective gears(p<0.05),(p<0.01). When the wearing of protective goggles(face shield) and the frequency of exchanging masks after the outbreak of COVID-19 were more, the performance for infection control was increasing(p<0.05),(p<0.01),(p<0.001). In this study, it is difficult to generalize the results of the study because the research area and the subject are limited by selecting the subjects by convenience extraction, and focusing on the degree of awareness of infection control by dental hygienists, the actual status of infection control in dentistry is carefully illuminated. What you didn't do can be seen as a limitation. Considering the results of this study, the performance of infection control could be increased by removing obstacles and increasing the importance and perceived benefits of infection control of dental hygienists.

• Journal of the Korean Data and Information Science Society
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• v.28 no.1
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• pp.57-66
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• 2017

SIR model (Kermack and McKendrik, 1927) is one of the most popular method to explain the spread of disease, In order to construct SIR model, we need to estimate transition rate parameter and recovery rate parameter. If we don't have any information of the two rate parameters, we should estimate using observed whole trajectory of pandemic of disease. Thus, with restricted observed data, we can't estimate rate parameters. In this research, we introduced Reed-Frost model (Andersson and Britton, 2000) to calculate the probability of infection in the early stage of pandemic with the restriction of data. When we have an initial number of susceptible and infected, and a final number of infected, we can apply Reed - Frost model and we can get the probability of infection. We applied the Reed - Frost model to the Vibrio cholerae pandemic data from Republic of the Cameroon and calculated the probability of infection at the early stage. We also construct SIR model using the result of Reed - Frost model.

• Research in Plant Disease
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• v.18 no.4
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• pp.361-369
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• 2012

A population density model for bacterial wilt, which is caused by Ralstonia solanacearum, in hot pepper was developed to estimate the primary infection date after overwintering in the field. We developed the model mechansitically to predict reproduction of the pathogen and pathogensis on seedlings of the host. The model estimates the pathogen's populations both in the soil and in the host. In order to quantify environmental infection factors, various temperatures and initial population densities were determined for wilt symptoms on the seedlings of hot pepper in a chamber. Once, the pathogens living in soil multiply up to 400 cells/g of soil, they can infect successfully in the host. Primary infection in a host was supposed to be started when the population of the pathogen were over $10^9$ cells/g of root tissue. The estimated primary infection dates of bacterial wilt in 2011 in Korea were mostly mid-July or late-July which were 10-15 days earlier than those in 2010. Two kinds of meterological data, synoptic observation and field measurements from paddy field and orchard in Kyunggi, were operated the model for comparing the result dates. About 1-3 days were earlier from field data than from synoptic observation.

• IMMUNE NETWORK
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• v.15 no.2
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• pp.91-99
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• 2015

Herpes simplex virus (HSV) is a common causative agent of genital ulceration and can lead to subsequent neurological disease in some cases. Here, using a genital infection model, we tested the efficacy of vinegar-processed flos of Daphne genkwa (vp-genkwa) to modulate vaginal inflammation caused by HSV-1 infection. Our data revealed that treatment with optimal doses of vp-genkwa after, but not before, HSV-1 infection provided enhanced resistance against HSV-1 infection, as corroborated by reduced mortality and clinical signs. Consistent with these results, treatment with vp-genkwa after HSV-1 infection reduced viral replication in the vaginal tract. Furthermore, somewhat intriguingly, treatment of vp-genkwa after HSV-1 infection increased the frequency and absolute number of $CD3^-NK1.1^+NKp46^+$ natural killer (NK) cells producing interferon (IFN)-${\gamma}$ and granyzme B, which indicates that vp-genkwa treatment induces the activation of NK cells. Supportively, secreted IFN-${\gamma}$ was detected at an increased level in vaginal lavages of mice treated with vp-genkwa after HSV-1 infection. These results indicate that enhanced resistance to HSV-1 infection by treatment with vp-genkwa is associated with NK cell activation. Therefore, our data provide a valuable insight into the use of vp-genkwa to control clinical severity in HSV infection through NK cell activation.

• Journal of the Korean Mathematical Society
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• v.52 no.3
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• pp.469-487
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• 2015

We consider a model of HIV infection with various compartments, including target cells, infected cells, viral loads and immune effector cells, to describe HIV type 1 infection. We show that the proposed model has one uninfected steady state and several infected steady states and investigate their local stability by using a Jacobian matrix method. We obtain equations for adjoint variables and characterize an optimal control by applying Pontryagin's Maximum Principle in a linear control problem. In addition, we apply techniques and ideas from linear optimal control theory in conjunction with a direct search approach to derive on-off HIV therapy strategies. The results of numerical simulations indicate that hybrid on-off therapy protocols can move the model system to a "healthy" steady state in which the immune response is dominant in controlling HIV after the discontinuation of the therapy.