• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.3
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• pp.483-490
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• 2022

Malaria is a disease caused by a parasite and it is prevalent in all over the world. The usual method used to recognize malaria cells is a thick and thin blood smears examination methods, but this method requires a lot of manual calculation, so the efficiency and accuracy are very low as well as the lack of pathologists in impoverished country has led to high malaria mortality rates. In this paper, a malaria cell image recognition model using transfer learning is proposed, which consists in the feature extractor, the residual structure and the fully connected layers. When the pre-training parameters of the VGG-19 model are imported to the proposed model, the parameters of some convolutional layers model are frozen and the fine-tuning method is used to fit the data for the model. Also we implement another malaria cell recognition model without residual structure to compare with the proposed model. The simulation results shows that the model using the residual structure gets better performance than the other model without residual structure and the proposed model has the best accuracy of 97.33% compared to other recent papers.

• Parasites, Hosts and Diseases
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• v.59 no.2
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• pp.113-119
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• 2021

The computer vision diagnostic approach currently generates several malaria diagnostic tools. It enhances the accessible and straightforward diagnostics that necessary for clinics and health centers in malaria-endemic areas. A new computer malaria diagnostics tool called the malaria scanner was used to investigate living malaria parasites with easy sample preparation, fast and user-friendly. The cultured Plasmodium parasites were used to confirm the sensitivity of this technique then compared to fluorescence-activated cell sorting (FACS) analysis and light microscopic examination. The measured percentage of parasitemia by the malaria scanner revealed higher precision than microscopy and was similar to FACS. The coefficients of variation of this technique were 1.2-6.7% for Plasmodium knowlesi and 0.3-4.8% for P. falciparum. It allowed determining parasitemia levels of 0.1% or higher, with coefficient of variation smaller than 10%. In terms of the precision range of parasitemia, both high and low ranges showed similar precision results. Pearson's correlation test was used to evaluate the correlation data coming from all methods. A strong correlation of measured parasitemia (r²=0.99, P<0.05) was observed between each method. The parasitemia analysis using this new diagnostic tool needs technical improvement, particularly in the differentiation of malaria species.

• Parasites, Hosts and Diseases
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• v.57 no.2
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• pp.101-115
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• 2019

The pathogenesis of cerebral malaria is biologically complex and involves multi-factorial mechanisms such as microvascular congestion, immunopathology by the pro-inflammatory cytokine and endothelial dysfunction. Recent data have suggested that a pleiotropic T-cell immunomodulatory protein (TIP) could effectively mediate inflammatory cytokines of mammalian immune response against acute graft-versus-host disease in animal models. In this study, we identified a conserved homologue of TIP in Plasmodium berghei (PbTIP) as a membrane protein in Plasmodium asexual stage. Compared with PBS control group, the pathology of experimental cerebral malaria (ECM) in rPbTIP intravenous injection (i.v.) group was alleviated by the downregulation of pro-inflammatory responses, and rPbTIP i.v. group elicited an expansion of regulatory T-cell response. Therefore, rPbTIP i.v. group displayed less severe brain pathology and feverish mice in rPbTIP i.v. group died from ECM. This study suggested that PbTIP may be a novel promising target to alleviate the severity of ECM.

• Parasites, Hosts and Diseases
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• v.48 no.1
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• pp.15-21
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• 2010

Astrocytes are the most abundant cells in the central nervous system that play roles in maintaining the blood-brain-barrier and in neural injury, including cerebral malaria, a severe complication of Plasmodium falciparum infection. Prostaglandin (PG) $D_2$ is abundantly produced in the brain and regulates the sleep response. Moreover, $PGD_2$ is a potential factor derived from P. falciparum within erythrocytes. Heme oxygenase-1 (HO-1) is catalyzing enzyme in heme breakdown process to release iron, carbon monoxide, and biliverdin/bilirubin, and may influence iron supply to the P. falciparum parasites. Here, we showed that treatment of a human astrocyte cell line, CCF-STTG1, with $PGD_2$ significantly increased the expression levels of HO-1 mRNA by RT-PCR. Western blot analysis showed that $PGD_2$ treatment increased the level of HO-1 protein, in a dose- and time-dependent manner. Thus, $PGD_2$ may be involved in the pathogenesis of cerebral malaria by inducing HO-1 expression in malaria patients.

• Korean Journal of Veterinary Service
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• v.23 no.1
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• pp.9-17
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• 2000

Epidemic malaria is prevalent in the demilitarized zone and the northern area of Kyonggi province in Korea. Malaria has broken out in Gangwha-Gun since 1997 due to geographical condition. The results obtained from an epidemiological surveillance for the malaria that happened in 1999 were as follows ; Anopheles sinensis collected in UV-light traps in the barn in Wolgogri and Dangsanri of Songhaemyon showed the distribution of 27,156 of 49,280 figures, corresponding to 55.1%, between July and August. The numbers of patients with malaria were 48(32.4%) in July, 36(24.3%) in August, and 38(25.7%) in September with a prevalence with the ages of the twenties to the seventies. Of a total 154 patients, the male were 86(58.1%) and the female were 68(41.8%). The annual parasite index(API) were 6.44, 5.89 and 4.45 in Songhaemyon, Yangsamyon and Kyodongmyon, respectively. A high infection rate was found Particularly in the areas within 2km from the Han river. By the immunofluorescence assays(IFA), 26 cases were positive with an antibody titers of $\geq$ 1 : 32, of 220 residents in Songhaemyon and 336 ones with a potential case and contacted with the patients. By the blood test, there was no significance in alkaline phosphatase, alanine aminotransferase, total cholesterol, glucose, hemoglobin, hematocrit, white blood cell, red blood cell, and platelet between residents with an antibody titers of $\geq$ 1 : 32 and < 1 : 32 in Songhaemyon.

• Parasites, Hosts and Diseases
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• v.39 no.4
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• pp.293-299
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• 2001

The characteristics of vivax malaria epidemics along the demilitarized Bone (DMZ) in the Republic of Korea has been established by the early surveillance data. To further characterize the epidemic, data of civilian patients microscopically diagnosed with malaria from 1995 through 2000 were analyzed in Yonchon-gun (county) . Malaria incidence was greater in male civilians > 30 years of age (p < 0.05). The annual parasite index was significantly higher in those living in the administrative areas (Myeon) traversed by DMZ than those living in Myons not traversed by DMZ (p < 0.05). Analysis according to the distance (4 to 14 km) from DMZ showed that people living in villages close to DMZ had higher annual parasite indices than those living in villages remote from DMZ (p for trend < 0.05). Civilians living in Myeons with plains and located in northwestern part of the county had higher annual parasite indices than those living in hilly Myeons located in southeastern part of the county (p for trend f 0.05). These findings suggest that the contraction of vivax malaria is related with night-time outdoor activities, and that the distance from DMZ is a risk factor. In this area, the flying distance of infected vector mosquitos can explain the annually repeating occurrence of civilian cases.

• Parasites, Hosts and Diseases
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• v.39 no.2
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• pp.171-176
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• 2001

Western blot analysis was performed to diagnose vivax malaria using stage-specific recombinant antigens. Genomic DNA from the whole blood of a malaria patient was used as templates to amplify the coding regions for the antigenic domains of circumsporozoite protein (CSP-1), meroxoite surface protein (MSP-1), apical merozoite antigen (AMA- 1), serine repeat antigen (SERA), and exported antigen (EXP- 1) of Plasmodium vivax. Each amplified DNA fragment was inserted into a pGEX-4T plasmid to induce the expression of GST fusion protein in Escherichia coli by IPTG. The bacterial cell extracts were separated on 10% SDS-PAGE followed by western blot analysis with patient sera which was confirmed by blood smear examination. When applied with patient sera, 147 (91.9%) out of 160 vivax malaria, 12 (92.3%) out of 13 falciparum malaria, and all 9 vivax/falciparum mixed malaria reacted with at least one antigen, while no reactions occurred with 20 normal uninfected sera. In the case of vivax malaria, CSP-1 reacted with 128 (80.0%) sera, MSP-1 with 102 (63.8%), AMA-1 with 128 (80.0%), SERA with 115 (71.9%), and EXP-1 with 89 (55.6%), respectively. We obtained higher detection rates when using S antigens (91.9%) rather than using each antigen solely (55.6 - 80%), a combination of 2 (76.3 - 87.5%), 3 (85.6 - 90.6%), or 4 antigens (89.4 - 91.3%). This method can be applied to serological diagnosis, mass screening in endemic regions, or safety test in transfusion of prevalent vivax malaria.

• Journal of Korean Neurosurgical Society
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• v.38 no.1
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• pp.47-53
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• 2005

Objective : Anti-malaria drugs may modulate tumor resistance to chemotherapeutic agents, but it has not been proven effective in the treatment of malignant gliomas. The aim of this study was to determine whether adequate pre-clinical data on co-administration of chemotherapeutic agents with anti-malaria drugs on malignant cell lines could be obtained that would warrant its further potential consideration for use in a clinical trial for malignant gliomas. Methods : Two malignant glioma cell lines [U87MG, T98G] were treated with chemotherapeutic agents alone or with anti-malaria drugs. Cells were incubated with drugs for 4 days. Following the 4-day incubation, drug sensitivity assays were performed using 3-[4,5-dimethyl-2-thiazol-2-yl] 2,5-diphenyltetrazolium bromide [MTT] assay following optimization of experimental conditions for each cell lines and cell viability was calculated. Results : In all of four chemotherapeutic agents[doxorubicin. vincrisitne, nimustine, and cisplatin], the cell viability was found to be markedly decreased when hydroxychloroquine was co-administered on both U87MG and T98G cell lines. The two way analysis of variance[ANOVA] yielded a statistically significant two-sided p-value of 0.0033[doxorubicin], 0.0005[vincrisitne], 0.0007[nimustine], and 0.0003[cisplatin] on U87MG cell lines and 0.0006[doxorubicin], 0.0421[vincrisitne], 0.0317[nimustine], and 0.0001[cisplatin] on T98G cell lines, respectively. However, treatment with chloroquine and primaquine did not induce a decrease in cell viability on both U87MG and T98G cell lines. Conclusion : Our data support further consideration of the use of hydroxychloroquine prior to systemic chemotherapy to maximize its tumoricidal effect for patients with malignant gliomas.

• Parasites, Hosts and Diseases
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• v.44 no.4 s.140
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• pp.285-294
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• 2006

Changing patterns of the reemerging Plasmodium vivax malaria in the Republic of Korea (South Korea) during the period 1993 to 2005 are briefly analyzed with emphasis on the control measures used and the effects of meteorological and entomological factors. Data were obtained from the Communicable Diseases Monthly Reports published by the Korea Center for Disease Control and Prevention, and webpages of World Health Organization and United Nations. Meteorological data of Kangwon-do (Province) were obtained from local weather stations. After its first reemergence in 1993, the prevalence of malaria increased exponentially, peaking in 2000, and then decreased. In total, 21,419 cases were reported between 1993 and 2005 in South Korea. In North Korea, a total of 916,225 cases were reported between 1999 and 2004. The occurrence of malaria in high risk areas of South Korea was significantly (P < 0.05) correlated with the mosquito population but not with temperature and rainfall, Control programs, including early case detection and treatment, mass chemoprophylaxis of soldiers, and international financial aids to North Korea for malaria control have been instituted. The situation of the reemerging vivax malaria in the Republic of Korea is remarkably improving during the recent years, at least in part, due to the control activities undertaken in South and North Korea.

• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.289-295
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• 2013

Different functions have been attributed to $CD4^+CD25^+Foxp3^+$ regulatory T-cells (Tregs) during malaria infection. Herein, we describe the disparity in Treg response and pro- and anti-inflammatory cytokines during infection with Plasmodium berghei ANKA between young (3-week-old) and middle-aged (8-month-old) C57BL/6 mice. Young mice were susceptible to cerebral malaria (CM), while the middle-aged mice were resistant to CM and succumbed to hyperparasitemia and severe anemia. The levels of pro-inflammatory cytokines, such as TNF-${\alpha}$, in young CM-susceptible mice were markedly higher than in middle-aged CM-resistant mice. An increased absolute number of Tregs 3-5 days post-inoculation, co-occurring with elevated IL-10 levels, was observed in middle-aged CM-resistant mice but not in young CM-susceptible mice. Our findings suggest that Treg proliferation might be associated with the suppression of excessive pro-inflammatory Th1 response during early malaria infection, leading to resistance to CM in the middle-aged mice, possibly in an IL-10-dependent manner.