1.Understanding the pathogenicity of Naegleria fowleri in association with N. fowleri antigen-1 (Nfa1)
Jong-Hyun KIM ; Hae-Jin SOHN ; Ho-Joon SHIN ; Stacy E. WALZ ; Suk-Yul JUNG
Parasites, Hosts and Diseases 2024;62(4):385-398
Naegleria fowleri, a brain-eating amoeba, thrives in lakes and rivers with aquatic vegetation and causes primary amoebic meningoencephalitis (PAM) in humans. Most recently, it has become such a serious problem that N. fowleri was detected in tap water in Houston, USA. Several pathogenic factors are considered very important to destroy target cells in the brain. In particular, the food-cup where N. fowleri antigen-1 (Nfa1) is located, is strongly expressed in pseudopodia involved in the movement of N. fowleri, and is involved in phagocytosis by attaching to target cells. In this article, we reviewed the role of the Nfa1 protein and its associated pathogenicity. The nfa1 gene was cloned by cDNA library immunoscreening using infection serum and immune serum. Nfa1 protein is mainly distributed in pseudopodia important to movement and vacuoles. Moreover, heat shock protein 70, cathepsin-like proteare and Nf-actin are also associated with pseudopodia in which Nfa1 is localized. Interestingly, the amount of the nfa1 gene changed as N. fowleri trophozoites transformed into cysts. Polyclonal antiserum against Nfa1 showed a protective effect against cytotoxicity of approximately 19.7%. Nfa1-specific IgA antibodies prevent N. fowleri trophozoites from adhering to the nasal mucosa, delaying invasion. The nfa1-vaccinated mice showed significantly higher levels of Nfa1-specific antibody. The duration of anti-Nfa1 IgG in the vaccinated mice lasted 12 weeks, strongly suggesting that nfa1 is a significant pathogenic gene and that Nfa1 is a pathogenic protein. Several factors related to pseudopodia and locomotion have been linked to Nfa1. A clearer function of N. fowleri targeting nfa1 with other genes might enable target-based inhibition of N. fowleri pathogenicity.
2.Understanding the pathogenicity of Naegleria fowleri in association with N. fowleri antigen-1 (Nfa1)
Jong-Hyun KIM ; Hae-Jin SOHN ; Ho-Joon SHIN ; Stacy E. WALZ ; Suk-Yul JUNG
Parasites, Hosts and Diseases 2024;62(4):385-398
Naegleria fowleri, a brain-eating amoeba, thrives in lakes and rivers with aquatic vegetation and causes primary amoebic meningoencephalitis (PAM) in humans. Most recently, it has become such a serious problem that N. fowleri was detected in tap water in Houston, USA. Several pathogenic factors are considered very important to destroy target cells in the brain. In particular, the food-cup where N. fowleri antigen-1 (Nfa1) is located, is strongly expressed in pseudopodia involved in the movement of N. fowleri, and is involved in phagocytosis by attaching to target cells. In this article, we reviewed the role of the Nfa1 protein and its associated pathogenicity. The nfa1 gene was cloned by cDNA library immunoscreening using infection serum and immune serum. Nfa1 protein is mainly distributed in pseudopodia important to movement and vacuoles. Moreover, heat shock protein 70, cathepsin-like proteare and Nf-actin are also associated with pseudopodia in which Nfa1 is localized. Interestingly, the amount of the nfa1 gene changed as N. fowleri trophozoites transformed into cysts. Polyclonal antiserum against Nfa1 showed a protective effect against cytotoxicity of approximately 19.7%. Nfa1-specific IgA antibodies prevent N. fowleri trophozoites from adhering to the nasal mucosa, delaying invasion. The nfa1-vaccinated mice showed significantly higher levels of Nfa1-specific antibody. The duration of anti-Nfa1 IgG in the vaccinated mice lasted 12 weeks, strongly suggesting that nfa1 is a significant pathogenic gene and that Nfa1 is a pathogenic protein. Several factors related to pseudopodia and locomotion have been linked to Nfa1. A clearer function of N. fowleri targeting nfa1 with other genes might enable target-based inhibition of N. fowleri pathogenicity.
3.Understanding the pathogenicity of Naegleria fowleri in association with N. fowleri antigen-1 (Nfa1)
Jong-Hyun KIM ; Hae-Jin SOHN ; Ho-Joon SHIN ; Stacy E. WALZ ; Suk-Yul JUNG
Parasites, Hosts and Diseases 2024;62(4):385-398
Naegleria fowleri, a brain-eating amoeba, thrives in lakes and rivers with aquatic vegetation and causes primary amoebic meningoencephalitis (PAM) in humans. Most recently, it has become such a serious problem that N. fowleri was detected in tap water in Houston, USA. Several pathogenic factors are considered very important to destroy target cells in the brain. In particular, the food-cup where N. fowleri antigen-1 (Nfa1) is located, is strongly expressed in pseudopodia involved in the movement of N. fowleri, and is involved in phagocytosis by attaching to target cells. In this article, we reviewed the role of the Nfa1 protein and its associated pathogenicity. The nfa1 gene was cloned by cDNA library immunoscreening using infection serum and immune serum. Nfa1 protein is mainly distributed in pseudopodia important to movement and vacuoles. Moreover, heat shock protein 70, cathepsin-like proteare and Nf-actin are also associated with pseudopodia in which Nfa1 is localized. Interestingly, the amount of the nfa1 gene changed as N. fowleri trophozoites transformed into cysts. Polyclonal antiserum against Nfa1 showed a protective effect against cytotoxicity of approximately 19.7%. Nfa1-specific IgA antibodies prevent N. fowleri trophozoites from adhering to the nasal mucosa, delaying invasion. The nfa1-vaccinated mice showed significantly higher levels of Nfa1-specific antibody. The duration of anti-Nfa1 IgG in the vaccinated mice lasted 12 weeks, strongly suggesting that nfa1 is a significant pathogenic gene and that Nfa1 is a pathogenic protein. Several factors related to pseudopodia and locomotion have been linked to Nfa1. A clearer function of N. fowleri targeting nfa1 with other genes might enable target-based inhibition of N. fowleri pathogenicity.
4.Understanding the pathogenicity of Naegleria fowleri in association with N. fowleri antigen-1 (Nfa1)
Jong-Hyun KIM ; Hae-Jin SOHN ; Ho-Joon SHIN ; Stacy E. WALZ ; Suk-Yul JUNG
Parasites, Hosts and Diseases 2024;62(4):385-398
Naegleria fowleri, a brain-eating amoeba, thrives in lakes and rivers with aquatic vegetation and causes primary amoebic meningoencephalitis (PAM) in humans. Most recently, it has become such a serious problem that N. fowleri was detected in tap water in Houston, USA. Several pathogenic factors are considered very important to destroy target cells in the brain. In particular, the food-cup where N. fowleri antigen-1 (Nfa1) is located, is strongly expressed in pseudopodia involved in the movement of N. fowleri, and is involved in phagocytosis by attaching to target cells. In this article, we reviewed the role of the Nfa1 protein and its associated pathogenicity. The nfa1 gene was cloned by cDNA library immunoscreening using infection serum and immune serum. Nfa1 protein is mainly distributed in pseudopodia important to movement and vacuoles. Moreover, heat shock protein 70, cathepsin-like proteare and Nf-actin are also associated with pseudopodia in which Nfa1 is localized. Interestingly, the amount of the nfa1 gene changed as N. fowleri trophozoites transformed into cysts. Polyclonal antiserum against Nfa1 showed a protective effect against cytotoxicity of approximately 19.7%. Nfa1-specific IgA antibodies prevent N. fowleri trophozoites from adhering to the nasal mucosa, delaying invasion. The nfa1-vaccinated mice showed significantly higher levels of Nfa1-specific antibody. The duration of anti-Nfa1 IgG in the vaccinated mice lasted 12 weeks, strongly suggesting that nfa1 is a significant pathogenic gene and that Nfa1 is a pathogenic protein. Several factors related to pseudopodia and locomotion have been linked to Nfa1. A clearer function of N. fowleri targeting nfa1 with other genes might enable target-based inhibition of N. fowleri pathogenicity.
5.Understanding the pathogenicity of Naegleria fowleri in association with N. fowleri antigen-1 (Nfa1)
Jong-Hyun KIM ; Hae-Jin SOHN ; Ho-Joon SHIN ; Stacy E. WALZ ; Suk-Yul JUNG
Parasites, Hosts and Diseases 2024;62(4):385-398
Naegleria fowleri, a brain-eating amoeba, thrives in lakes and rivers with aquatic vegetation and causes primary amoebic meningoencephalitis (PAM) in humans. Most recently, it has become such a serious problem that N. fowleri was detected in tap water in Houston, USA. Several pathogenic factors are considered very important to destroy target cells in the brain. In particular, the food-cup where N. fowleri antigen-1 (Nfa1) is located, is strongly expressed in pseudopodia involved in the movement of N. fowleri, and is involved in phagocytosis by attaching to target cells. In this article, we reviewed the role of the Nfa1 protein and its associated pathogenicity. The nfa1 gene was cloned by cDNA library immunoscreening using infection serum and immune serum. Nfa1 protein is mainly distributed in pseudopodia important to movement and vacuoles. Moreover, heat shock protein 70, cathepsin-like proteare and Nf-actin are also associated with pseudopodia in which Nfa1 is localized. Interestingly, the amount of the nfa1 gene changed as N. fowleri trophozoites transformed into cysts. Polyclonal antiserum against Nfa1 showed a protective effect against cytotoxicity of approximately 19.7%. Nfa1-specific IgA antibodies prevent N. fowleri trophozoites from adhering to the nasal mucosa, delaying invasion. The nfa1-vaccinated mice showed significantly higher levels of Nfa1-specific antibody. The duration of anti-Nfa1 IgG in the vaccinated mice lasted 12 weeks, strongly suggesting that nfa1 is a significant pathogenic gene and that Nfa1 is a pathogenic protein. Several factors related to pseudopodia and locomotion have been linked to Nfa1. A clearer function of N. fowleri targeting nfa1 with other genes might enable target-based inhibition of N. fowleri pathogenicity.
6.Species identification and pyrethroid resistance genotyping of recently resurgent Cimex lectularius and Cimex hemipterus in Korea
Susie CHO ; Heung Chul KIM ; Hoonsik EOM ; Jae Rok LEE ; Chung Hyun KO ; E-hyun SHIN ; Won Kyu LEE ; Si Hyeock LEE ; Ju Hyeon KIM
Parasites, Hosts and Diseases 2024;62(2):251-256
The global resurgence of bed bug infestations, exacerbated by increasing international travel, trade, and insecticide resistance, has significantly impacted Korea. This study identified the bed bug species and performed pyrethroid resistance genotyping of recently resurgent bed bugs in Korea. Thirty-one regional bed bug samples were collected from 5 administrative regions: Gyeonggi-do (n=14), Seoul (n=13), Busan (n=2), Jeonllanam-do (n=1), and Chungcheongbuk-do (n=1). The samples underwent morphological and molecular identification. Twenty-four regional samples (77.4%) were identified as the tropical bed bug, Cimex hemipterus, and the remaining 7 regional samples (22.6%) were identified as the common bed bug, Cimex lectularius. The C. hemipterus regional samples carried at least three mutations associated with knockdown resistance (kdr), including 2 super-kdr mutations. The 7 C. lectularius regional samples possessed at least one of the 3 kdr-related mutations associated with pyrethroid resistance. This study confirms that the prevalent bed bug species recently in Korea is C. hemipterus, replacing the previously endemic C. lectularius. Additionally, the rise in bed bug populations with pyrethroid resistance underscores the necessity of introducing alternative insecticides.
7.The Effects of the Nursing Practice Environment and Self-leadership on Person-centered Care Provided by Oncology Nurses
Korean Journal of Hospice and Palliative Care 2021;24(3):174-183
Purpose:
This study aimed to investigate the effects of the nursing practice environment and self-leadership on person-centered care provided by oncology nurses.
Methods:
This cross-sectional study included 145 nurses who worked in oncology wards at eight university hospitals in Seoul, Daejeon, and Chungcheong Province with at least six months of experience. Data were collected using a self-administered survey and analyzed using descriptive statistics, Pearson correlation coefficients, the t-test, analysis of variance, and hierarchical multiple regression analysis in SPSS version 26.0.
Results:
Person-centered care was significantly correlated with the nursing practice environment (r=0.27, P<0.001) and self-leadership (r=0.40, P<0.001), and the nursing practice environment was correlated with self-leadership (r=0.380, P<0.001). Hierarchical multiple regression analysis showed that the nursing practice environment was a significant predictor of person-centered care (β=0.31, P<0.001), after adjusting for covariates including monthly salary, total clinical career, and the position of oncology nurses. Self-leadership was a significant predictor of person-centered care (β=0.34, P<0.001) after controlling for the nursing practice envi-ronment, along with covariates. The final model explained 18.7% of the variance in personcentered care.
Conclusion
Our findings emphasize the importance of the nursing practice environment and nurses’ self-leadership for providing person-centered care in oncology care units. Educational programs to reinforce nurses’ self-leadership and administrative support for nursing practice are necessary to improve oncology nurses’ capability to provide person-centered care.
8.The Effects of the Nursing Practice Environment and Self-leadership on Person-centered Care Provided by Oncology Nurses
Korean Journal of Hospice and Palliative Care 2021;24(3):174-183
Purpose:
This study aimed to investigate the effects of the nursing practice environment and self-leadership on person-centered care provided by oncology nurses.
Methods:
This cross-sectional study included 145 nurses who worked in oncology wards at eight university hospitals in Seoul, Daejeon, and Chungcheong Province with at least six months of experience. Data were collected using a self-administered survey and analyzed using descriptive statistics, Pearson correlation coefficients, the t-test, analysis of variance, and hierarchical multiple regression analysis in SPSS version 26.0.
Results:
Person-centered care was significantly correlated with the nursing practice environment (r=0.27, P<0.001) and self-leadership (r=0.40, P<0.001), and the nursing practice environment was correlated with self-leadership (r=0.380, P<0.001). Hierarchical multiple regression analysis showed that the nursing practice environment was a significant predictor of person-centered care (β=0.31, P<0.001), after adjusting for covariates including monthly salary, total clinical career, and the position of oncology nurses. Self-leadership was a significant predictor of person-centered care (β=0.34, P<0.001) after controlling for the nursing practice envi-ronment, along with covariates. The final model explained 18.7% of the variance in personcentered care.
Conclusion
Our findings emphasize the importance of the nursing practice environment and nurses’ self-leadership for providing person-centered care in oncology care units. Educational programs to reinforce nurses’ self-leadership and administrative support for nursing practice are necessary to improve oncology nurses’ capability to provide person-centered care.
9.Annual Fluctuation in Chigger Mite Populations and Orientia Tsutsugamushi Infections in Scrub Typhus Endemic Regions of South Korea
Seong Yoon KIM ; Byoungchul GILL ; Bong Gu SONG ; Hyuk CHU ; Won Il PARK ; Hee Il LEE ; E hyun SHIN ; Shin Hyeong CHO ; Jong Yul ROH
Osong Public Health and Research Perspectives 2019;10(6):351-358
OBJECTIVES: Chigger mites are vectors for scrub typhus. This study evaluated the annual fluctuations in chigger mite populations and Orientia tsutsugamushi infections in South Korea.METHODS: During 2006 and 2007, chigger mites were collected monthly from wild rodents in 4 scrub typhus endemic regions of South Korea. The chigger mites were classified based on morphological characteristics, and analyzed using nested PCR for the detection of Orientia tsutsugamushi.RESULTS: During the surveillance period, the overall trapping rate for wild rodents was 10.8%. In total, 17,457 chigger mites (representing 5 genera and 15 species) were collected, and the average chigger index (representing the number of chigger mites per rodent), was 31.7. The monthly chigger index was consistently high (> 30) in Spring (March to April) and Autumn (October to November). The mite species included Leptotrombidium pallidum (43.5%), L. orientale (18.9%), L. scutellare (18.1%), L. palpale (10.6%), and L. zetum (3.6%). L. scutellare and L. palpale populations, were relatively higher in Autumn. Monthly O. tsutsugamushi infection rates in wild rodents (average: 4.8%) and chigger mites (average: 0.7%) peaked in Spring and Autumn.CONCLUSION: The findings demonstrated a bimodal pattern of the incidence of O. tsutsugamushi infections. Higher infection rates were observed in both wild rodents and chigger mites, in Spring and Autumn. However, this did not reflect the unimodal incidence of scrub typhus in Autumn. Further studies are needed to identify factors, such as human behavior and harvesting in Autumn that may explain this discordance.
Globus Pallidus
;
Humans
;
Incidence
;
Korea
;
Mites
;
Orientia tsutsugamushi
;
Polymerase Chain Reaction
;
Rodentia
;
Scrub Typhus
;
Trombiculidae
10.Retrospective study of combination chemotherapy with etoposide and ifosfamide in patients with heavily pretreated recurrent or persistent epithelial ovarian cancer.
Wonkyo SHIN ; Hye joo LEE ; Seong J YANG ; E sun PAIK ; Hyun jin CHOI ; Tae Joong KIM ; Chel Hun CHOI ; Jeong Won LEE ; Duk Soo BAE ; Byoung Gie KIM
Obstetrics & Gynecology Science 2018;61(3):352-358
OBJECTIVE: This retrospective study is to evaluate the efficacy and toxicity of combination chemotherapy with etoposide and ifosfamide (ETI) in the management of pretreated recurrent or persistent epithelial ovarian cancer (EOC). METHODS: Patients with recurrent or persistent EOC who had measurable disease and at least one chemotherapy regimen were to receive etoposide at a dose of 100 mg/m²/day intravenous (IV) on days 1 to 3 in combination with ifosfamide 1 g/m²/day IV on days 1 to 5, every 21 days. RESULTS: From August 2008 to August 2016, 66 patients were treated with ETI regimen. Most patients were heavily pretreated prior to ETI: 53 (80.3%) patients had received 3 or more chemotherapy regimens. The response rate (RR) of ETI chemotherapy was 18.2% and median duration of response was 6.8 months (range, 0–30). Median survival of all patients was 5 months at a median follow up of 7.2 months. Platinum-free interval (PFI) more than 6 months prior to ETI has statistically significant correlation with overall survival (OS; 9.2 vs. 5.6 months; P=0.029) and RR (34.5% vs. 5.4%; P < 0.010). However, treatment free interval before ETI, number of prior chemotherapy regimen, and optimality of primary surgery did not show significant difference for RR or OS. Grade 3 or 4 hematologic toxicities were observed in 7 cases (3%) of the 232 cycles of ETI. CONCLUSION: The ETI combination regimen shows comparatively low toxicity and modest activity in heavily pretreated recurrent or persistent EOC patients with more than 6 months of PFI after last platinum treatment.
Drug Therapy
;
Drug Therapy, Combination*
;
Etoposide*
;
Follow-Up Studies
;
Humans
;
Ifosfamide*
;
Ovarian Neoplasms*
;
Platinum
;
Recurrence
;
Retrospective Studies*

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