Single nucleotide polymorphism analysis of pvmdr-1 in Plasmodium vivax isolated from military personnel of Republic of Korea in 2016 and 2017.

BACKGROUND: Malaria chemoprophylaxis using chloroquine (CQ) and primaquine (PQ) has been administered to resident soldiers in the 3rd Army of Republic of Korea (ROK) to prevent malaria infection since the year 1997. Due to mass chemoprophylaxis against malaria, concern exists about the occurrence of chloroquine resistance (CQR). This study aimed to investigate the single nucleotide polymorphisms (SNPs) of the Plasmodium vivax multi-drug resistance protein-1 (pvmdr-1) gene to monitor the risk of CQR. METHODS: SNPs of the pvmdr-1 gene were analysed in 73 soldiers of the 3rd Army of ROK diagnosed with infection by P. vivax. RESULTS: Quintuple mutations (G698S, L845F, M908L, T958M, and F1076L) were detected in 73 soldiers. A newly identified non-synonymous mutation in the Y541C position had been introduced into P. vivax malaria-endemic areas in ROK, at a frequency of 1.3% (1/73). In addition, synonymous mutations were detected at positions K44 (38.4%, 28/73), L493 (26%, 19/73), T529 (61.6%, 45/73), and E1233 (52.1%, 38/73). Based on these SNPs, pvmdr-1 sequences of ROK were classified into 6 haplotypes. The phylogenetic analysis closed to the type of North Korean showed that P. vivax malaria of ROK could be a reason of influx from North Korea. CONCLUSIONS: This study showed that synonymous and non-synonymous mutations of pvmdr-1 were observed in the malaria chemoprophylaxis-executed regions of ROK from 2016 to 2017. Based on the rapid transition of pvmdr-1 SNPs, continuous surveillance for SNPs of pvmdr-1 related to CQR in the malaria-endemic regions of ROK is essential.

Investigation of glucose-6-phosphate dehydrogenase (G6PD) deficiency prevalence in a Plasmodium vivax-endemic area in the Republic of Korea (ROK).

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most prevalent inborn disorder. This X-chromosome-linked recessive disease affects more than 400 million people globally, and is associated with haemolytic anaemia after medication with the anti-latent malaria drug, primaquine. To prevent malaria, the Republic of Korea (ROK) Army administers malaria chemoprophylaxis. Due to the previously low G6PD deficiency prevalence in the ROK, prior to primaquine administration, testing for G6PD deficiency was not mandatory. In this study, to evaluate the risk from malaria chemoprophylaxis in the ROK, G6PD deficiency prevalence was investigated. METHODS: Blood specimens from 1632 soldiers entering training camp for the 3rd Infantry of the ROK Army were collected. CareStart™ Biosensor for G6PD and haemoglobin (Hb) was used to detect G6PD levels. G6PD variants using the DiaPlexC G6PD Genotyping kit (Asian type) and full-length sequencing were examined. RESULTS: Of 1632 blood specimens tested, none was observed to be G6PD deficient. The median value of all tested samples was 7.582 U/g Hb. An investigation of 170 G6PD DNA variants was analysed and categorized as partially low normal [n = 131, 30-80% (2.27-6.05 U/g Hb) of the median value], high [n = 3, > 150% (> 11.373 U/g Hb) of the median value], or normal [n = 36, 80-150% (6.05-11.373 U/g Hb) of the median value], and none was amplified by the DiaPlexC kit. Five silent mutations (C→T) in 131 partially low normal specimens were found at the 1311th nucleotide position by sequence analysis. Another 8 silent mutations (T93C) were also detected in 131 partially low normal specimens. Thus, it is inferred that these silent mutations could be related to G6PD activity. CONCLUSIONS: This G6PD deficiency prevalence study, conducted among participants from the 3rd Infantry of the ROK Army, provided crucial evidence for the safety of malaria chemoprophylaxis. This study showed that the prevalence of G6PD deficiency among 1632 young soldiers was wholly absent. Although G6PD phenotypic mutations were not detected, many silent mutations (C1311T and T93C) were observed. Thus, it is inferred that malaria chemoprophylaxis is relatively safe against G6PD deficiency-mediated haemolytic anaemia. However, given the number of individuals whose G6PD were at the partially low normal range and the frequent detection of G6PD deficiency-related mutations, consistent monitoring of G6PD deficiency is needed.

Antitumor effect and safety profile of systemically delivered oncolytic adenovirus complexed with EGFR-targeted PAMAM-based dendrimer in orthotopic lung tumor model.

Adenovirus (Ad)-mediated cancer gene therapy has been proposed as a promising alternative to conventional therapy for cancer. However, success of systemically administered naked Ad has been limited due to the immunogenicity of Ad and the induction of hepatotoxicity caused by Ad's native tropism. In this study, we synthesized an epidermal growth factor receptor (EGFR)-specific therapeutic antibody (ErbB)-conjugated and PEGylated poly(amidoamine) (PAMAM) dendrimer (PPE) for complexation with Ad. Transduction of Ad was inhibited by complexation with PEGylated PAMAM (PP) dendrimer due to steric hindrance. However, PPE-complexed Ad selectively internalized into EGFR-positive cells with greater efficacy than either naked Ad or Ad complexed with PP. Systemically administered PPE-complexed oncolytic Ad elicited significantly reduced immunogenicity, nonspecific liver sequestration, and hepatotoxicity than naked Ad. Furthermore, PPE-complexed oncolytic Ad demonstrated prolonged blood retention time, enhanced intratumoral accumulation of Ad, and potent therapeutic efficacy in EGFR-positive orthotopic lung tumors in comparison with naked Ad. We conclude that ErbB-conjugated and PEGylated PAMAM dendrimer can efficiently mask Ad's capsid and retarget oncolytic Ad to be efficiently internalized into EGFR-positive tumor while attenuating toxicity induced by systemic administration of naked oncolytic Ad.

Immunocytochemical Localization of Calbindin D28K, Calretinin, and Parvalbumin in Bat Superior Colliculus.

The purpose of this study was to investigate the localization of cells containing the calcium-binding proteins (CBPs) calbindin D28K (CB), calretinin (CR), and parvalbumin (PV) in the superior colliculus (SC) of the bat using immunocytochemistry. CB-immunoreactive (IR) cells formed a laminar tier within the upper superficial gray layer (SGL), while CR-IR cells were widely distributed within the optic layer (OL). Scattered CR-IR cells were also found within the intermediate gray, white, and deep gray layers. By contrast, PV-IR cells formed a laminar tier within the lower SGL and upper OL. Scattered PV-IR cells were also found throughout the intermediate layers, but without a specific laminar pattern. The CBP-IR cells varied in size and morphology: While most of the CB-IR cells in the superficial layers were small round or oval cells, most CR-IR cells in the intermediate and deep layers were large stellate cells. By contrast, PV-IR cells were small to large in size and included round or oval, stellate, vertical fusiform, and horizontal cells. The average diameters of the CB-, CR-, and PV-IR cells were 11.59, 17.17, and 12.60 µm, respectively. Double-immunofluorescence revealed that the percentage of co-localization with GABA-IR cells was 0.0, 0.0, and 10.27% of CB-, CR-, and PV-IR cells, respectively. These results indicate that CBP distribution patterns in the bat SC are unique compared with other mammalian SCs, which suggest functional diversity of these proteins in visually guided behaviors.