• Parasites, Hosts and Diseases
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• 제55권6호
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• pp.623-630
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• 2017

Plasmodium lactate dehydrogenase (pLDH) is a strong target antigen for the determination of infection with Plasmodium species specifically. However, a more effective antibody is needed because of the low sensitivity of the current antibody in many immunological diagnostic assays. In this study, recombinant Plasmodium vivax LDH (PvLDH) was experimentally constructed and expressed as a native antigen to develop an effective P. vivax-specific monoclonal antibody (mAb). Two mAbs (2CF5 and 1G10) were tested using ELISA and immunofluorescence assays (IFA), as both demonstrated reactivity against pLDH antigen. Of the 2 antibodies, 2CF5 was not able to detect P. falciparum, suggesting that it might possess P. vivax-specificity. The detection limit for a pair of 2 mAbs-linked sandwich ELISA was 31.3 ng/ml of the recombinant antigen. The P. vivax-specific performance of mAbs-linked ELISA was confirmed by in vitro-cultured P. falciparum and P. vivax-infected patient blood samples. In conclusion, the 2 new antibodies possessed the potential to detect P. vivax and will be useful in immunoassay.

• 동의생리병리학회지
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• 제17권5호
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• pp.1321-1324
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• 2003

To produce anti-malarial drugs, natural products were extracted from 18 species of marine algae by various mechanical methods. Twelve species of marine algae were found to have antiplasmodial activity by inhibiting the growth of the chloroquine-resistant Plasmodium falciparum strain FCR-3 with EC/sub 50/ values less than 100 ㎍/㎖. The methanol extract of Neoholmeria japonica had the strongest antiplasmodial activity with EC/sub 50/ value of 62 ㎍/㎖.

• Parasites, Hosts and Diseases
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• 제34권3호
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• pp.211-213
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• 1996

Malaysian, Ajricn and Thai PZQsmodiumJnkipamm isolates were cultured in uiko by the Tracer and Jensen method (1976, 1977) and were later cloned by the limiting dilution method (Rosario, 1981), Forty-eight clones were obtained and were characterized by electrophoretic variations of GDH (NADP-dependent glutamate dehydrogenase)(EC. 1.4.1.4). It was found that they were pure clones because they possessed either GDH-1 or GDH-2 unlike their parent isolates which exhibited both GDH-1 and GDH-2.

• Parasites, Hosts and Diseases
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• 제43권3호
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• pp.123-126
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• 2005

Each diastereomer of 10-thiophenyl- and 10-benzenesulfonyl-dihydroartemisinin was synthesized from artemisinin in three steps, and screened against chloroquine-resistance and chloroquine-sensitive Plasmodium falciparum. Three of the four tested compounds were found to be effective. Especially, 10$\beta$-benzenesulfonyl-dihy-droartemisinin showed stronger antimalarial activity than artemisinin.

• Parasites, Hosts and Diseases
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• 제47권2호
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• pp.83-91
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• 2009

The completion of many malaria parasite genomes provides great opportunities for genomewide characterization of gene expression and high-throughput genotyping. Substantial progress in malaria genomics and genotyping has been made recently, particularly the development of various microarray platforms for large-scale characterization of the Plasmodium falciparum genome. Microarray has been used for gene expression analysis, detection of single nucleotide polymorphism (SNP) and copy number variation (CNV), characterization of chromatin modifications, and other applications. Here we discuss some recent advances in genetic mapping and genomic studies of malaria parasites, focusing on the use of high-throughput arrays for the detection of SNP and CNV in the P. falciparum genome. Strategies for genetic mapping of malaria traits are also discussed.

• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.407-414
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• 2016

Malaria remains a serious public health problem in Shandong Province, China; therefore, it is important to explore the characteristics of the current malaria prevalence situation in the province. In this study, data of malaria cases reported in Shandong during 2012-2014 were analyzed, and Plasmodium species were confirmed by smear microscopy and nested-PCR. A total of 374 malaria cases were reported, 80.8% of which were reported from 6 prefectures. Of all cases, P. falciparum was dominant (81.3%), followed by P. vivax (11.8%); P. ovale and P. malariae together accounted for 6.4% of cases. Notably, for the first time since 2012, no indigenous case had been reported in Shandong Province, a situation that continued through 2014. Total 95.2% of cases were imported from Africa. The ratio of male/female was 92.5:1, and 96.8% of cases occurred in people 20-54 years of age. Farmers or laborers represented 77.5% of cases. No significant trends of monthly pattern were found in the reported cases. All patients were in good condition after treatment, except for 3 who died. These results indicate that imported malaria has increased significantly since 2012 in Shandong Province, especially for P. falciparum, and there is an emergence of species diversity.

• Parasites, Hosts and Diseases
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• 제49권4호
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• pp.431-436
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• 2011

The onset, severity, and ultimate outcome of malaria infection are influenced by parasite-expressed virulence factors as well as by individual host responses to these determinants. In both humans and mice, liver injury follows parasite entry, persisting to the erythrocytic stage in the case of infection with the fatal strain of Plasmodium falciparum. Hepatic nuclear factor (HNF)-$1{\alpha}$ is a master regulator of not only the liver damage and adaptive responses but also diverse metabolic functions. In this study, we analyzed the expression of host HNF-$1{\alpha}$ in relation to malaria infection and evaluated its interaction with the 5'-untranslated region of subtilisin-like protease 2 (subtilase, Sub2). Recombinant human HNF-$1{\alpha}$ expressed by a lentiviral vector (LV HNF-$1{\alpha}$) was introduced into mice. Interestingly, differences in the activity of the 5'-untranslated region of the Pf-Sub2 promoter were detected in 293T cells, and LV HNF-$1{\alpha}$ was observed to influence promoter activity, suggesting that host HNF-$1{\alpha}$ interacts with the Sub2 gene.

• Parasites, Hosts and Diseases
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• 제45권2호
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• pp.111-114
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• 2007

Chloroquine remains the drug of choice for the treatment of vivax malaria in Thailand. Mixed infections of falciparum and vivax malaria are also common in South-East Asia. Laboratory confirmation of malaria species is not generally available. This study aimed to find alternative regimens for treating both malaria species by using falciparum antimalarial drugs. From June 2004 to May 2005, 98 patients with Plasmodium vivax were randomly treated with either artemether-lumefantrine (n = 47) or chloroquine (n = 51). Both treatments were followed by 15 mg of primaquine over 14 days. Adverse events and clinical and parasitological outcomes were recorded and revealed similar in both groups. The cure rate was 97.4% for the artemether-lumefantrine treated group and 100% for the chloroquine treated group. We concluded that the combination of artemether-lumefantrine and primaquine was well tolerated, as effective as chloroquine and primaquine, and can be an alternative regimen for treatment of vivax malaria especially in the event that a mixed infection of falciparum and vivax malaria could not be ruled out.

• Parasites, Hosts and Diseases
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• 제56권5호
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• pp.447-452
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• 2018

Prompt diagnosis of malaria cases with rapid diagnostic tests (RDTs) has been widely adopted as an effective malaria diagnostic tool in many malaria endemic countries, primarily due to their easy operation, fast result output, and straightforward interpretation. However, there has been controversy about the diagnostic accuracy of RDTs. This study was conducted to evaluate the diagnostic performances of the 2 commercially available malaria RDT kits, RapiGEN Malaria Ag Pf/Pv (pLDH/pLDH) and Asan $EasyTest^{TM}$ Malaria Ag Pf/Pv (HRP-2/pLDH) for their abilities to detect Plasmodium species in blood samples collected from Ugandan patients with malaria. To evaluate the diagnostic performances of these 2 RDT kits, 229 blood samples were tested for malaria infection by microscopic examination and a species-specific nested polymerase chain reaction. The detection sensitivities for P. falciparum of Malaria Ag Pf/Pv (pLDH/pLDH) and Asan $EasyTest^{TM}$ Malaria Ag Pf/Pv (HRP-2/pLDH) were 87.83% and 89.57%, respectively. The specificities of the 2 RDTs were 100% for P. falciparum and mixed P. falciparum/P. vivax infections. These results suggest that the 2 RDT kits showed reasonable levels of diagnostic performances for detection of the malaria parasites from Ugandan patients. However, neither kit could effectively detect P. falciparum infections with low parasitaemia (<$500parasites/{\mu}l$).

• Parasites, Hosts and Diseases
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• 제47권3호
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• pp.227-233
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• 2009

Local malaria transmission in the United Arab Emirates (UAE) came to an end in 1997. Nevertheless, UAE has been subjected to substantial importation of malaria cases from abroad, concerning both UAE nationals and immigrants from malarious countries with a total number of 2,119 cases in 2007. To evaluate a new DNA extraction technique using nested PCR, blood samples were collected from 132 individuals who presented to Infectious Diseases Department in Rashid Hospital, Dubai, and Central Department of Malaria Control with fever and persistent headache. Giemsa-stained blood films and ELISA test for malaria antibodies were carried out for detection of Plasmodium infection. Plasmodium infections were identified with the genus-specific primer set and species differentiation using nested PCR. A rapid procedure for diagnosis of malaria infections directly from dried blood spots using for the first time DNA extract from FTA Elute cards was evaluated in contrast to extraction techniques using FTA classic cards and rapid boiling technique. Our new simple technique for DNA extraction using FTA Elute cards was very sensitive giving a sensitivity of 100% compared to 94% using FTA classic cards and 62% in the rapid boiling technique. No complex preparation of blood samples was required prior to the amplification. The production cost of DNA isolation in our PCR assay was much less incomparable to that of other DNA extraction protocols. The nested PCR detected plasmodial infection and could differentiate P. falciparum from P. vivax, and also detected the mixed infection.