• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.147-153
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• 2023

Lampung is a malaria-endemic region in Indonesia with an annual parasite incidence of 0.06 per 1,000 population. The socio-demographic factors, clinical conditions, and artemisinin combination therapy (ACT) types might affect parasite clearance and parasite density. This study aims to investigate factors that influence parasite clearance and parasite density in malaria patients. A retrospective analytic observational and a cross-sectional approach was used to conduct this study. A total of 66 malaria patients were examined to investigate parasite density and clearance, socio-demographic profiles, clinical conditions, and ACT types. To analyze data, univariate, bivariate, and multivariate tests were used. Age (P=0.045; r=0.238) and ACT type (P=0.021; r=0.273) were the only variables that had a significant correlation with parasite clearance. Age (P=0.003; r=0.345) had a significant correlation with parasite density. The most influential factors related to parasite clearance were the ACT type (dihydroartemisinin piperaquine) (P=0.017; odds ratio (OR) 0.109; 95.0% confidence interval (CI), 0.018-0.675) and age (P=0.030; OR 0.132; 95.0% CI, 0.021-0.823). Age (P=0.046; OR 0.320; 0.105-0.978, 95.0% CI) was the most significant variable associated with parasite density.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.127-137
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• 2023

Bovine trypanosomiasis is a significant health concern for livestock intensification in Côte d'Ivoire. This study aimed to determine the prevalence and distribution of pathogenic trypanosomes and identify the most infected cattle breed in northern Côte d'Ivoire. We examined 700 cattle and found that polymerase chain reaction (PCR) was more sensitive (12.3%) than microscopic observation (5.6%). Among the trypanosome species detected in naturally infected cattle, Trypanosoma vivax was 7.3%, Trypanosoma simiae tsavo was 6.7%, and Trypanosoma congolense was 0.4%. The overall prevalence of trypanosome infection in all cattle breeds was 12.3%, while the prevalence in individual breeds was 14.8%, 7.3%, 10.6%, and 12.3% for N'Dama, Baoule, Zebu, and Mere breed, respectively. The infected animals had low packed cell volume, influencing the prevalence. Our findings indicate that bovine trypanosomes are prevalent in Côte d'Ivoire, and their prevalence varies by region and breed. These pathogens include T. vivax, T. simiae tsavo, and T. congolense.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.194-197
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• 2023

Ascaris lumbricoides causes one of the most common soil-transmitted helminthiases globally. The worms mostly infect the human small intestine and elicit negligible or nonspecific symptoms, but there are reports of extraintestinal ectopic ascariasis. We describe a rare case of biliary ascariasis mistaken for biliary stent in a 72-year-old female patient with a history of liver resection. She visited our outpatient clinic complaining of right upper quadrant pain and fever for the past week. She had previously undergone left lateral sectionectomy for recurrent biliary and intrahepatic duct stones 2 years ago. Besides mildly elevated gamma-glutamyl transferase levels, her liver function tests were normal. Magnetic resonance cholangiopancreatography revealed a linear filling defect closely resembling an internal stent from the common bile duct to the right intrahepatic bile duct. A live female A. lumbricoides adult worm was removed by endoscopic retrograde cholangiopancreatography (ERCP). Despite a significant decrease of the ascariasis prevalence in Korea, cases of biliary ascariasis are still occasionally reported. In this study, a additional case of biliary ascariasis, which was radiologically misdiagnosed as the biliary stent, was described in a hepatic resection patient by the worm recovery with ERCP in Korea.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.198-201
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• 2023

In the past decade, experts have conducted parasitological research on archaeological specimens in Korea to collect historical parasite infection data. In these studies, parasitologists successfully described the infection pattern of each parasite species in history. However, in the first half of the 20th century, archaeoparasitological reports have been scant. In 2021, we conducted a parasitological examination of a toilet-like structure that emerged in the early 20th century. This structure was built by stacking 2 wooden barrels; and in the study samples, we found ancient Trichuris trichiura, Ascaris lumbricoides (unfertilized), and Taenia spp. eggs and therefore proposed a higher possibility that the barrels could have been used as a toilet at the time. To understand how the antihelminthic campaign since the 1960s helped reduce parasite infection rates in Korea, more research should focus on early-20th-century toilet ruins.

• BMB Reports
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• v.56 no.11
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• pp.584-593
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• 2023

Hypoxia, a widespread occurrence observed in various malignant tumors, results from rapid tumor growth that outpaces the oxygen supply. Tumor hypoxia precipitates several effects on tumor biology; these include activating angiogenesis, intensifying invasiveness, enhancing the survival of tumor cells, suppressing anti-tumor immunity, and fostering resistance to therapy. Aligned with the findings that correlate CMGC kinases with the regulation of Hypoxia-Inducible Factor (HIF), a pivotal modulator, reports also indicate that hypoxia governs the activity of CMGC kinases, including DYRK1 kinases. Prolyl hydroxylation of DYRK1 kinases by PHD1 constitutes a novel mechanism of kinase maturation and activation. This modification "primes" DYRK1 kinases for subsequent tyrosine autophosphorylation, a vital step in their activation cascade. This mechanism adds a layer of intricacy to comprehending the regulation of CMGC kinases, and underscores the complex interplay between distinct post-translational modifications in harmonizing precise kinase activity. Overall, hypoxia assumes a substantial role in cancer progression, influencing diverse aspects of tumor biology that include angiogenesis, invasiveness, cell survival, and resistance to treatment. CMGC kinases are deeply entwined in its regulation. To fathom the molecular mechanisms underpinning hypoxia's impact on cancer cells, comprehending how hypoxia and prolyl hydroxylation govern the activity of CMGC kinases, including DYRK1 kinases, becomes imperative. This insight may pave the way for pioneering therapeutic approaches that target the hypoxic tumor microenvironment and its associated challenges.

• Parasites, Hosts and Diseases
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• v.61 no.4
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• pp.428-438
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• 2023

Clonorchis sinensis is commonly found in East Asian countries. Clonorchiasis is prevalent in these countries and can lead to various clinical symptoms. In this study, we used overlap extension polymerase chain reaction (PCR) and the Xenopus laevis oocyte expression system to isolate a cDNA encoding the choline transporter of C. sinensis (CsChT). We subsequently characterized recombinant CsChT. Expression of CsChT in X. laevis oocytes enabled efficient transport of radiolabeled choline, with no detectable uptake of arginine, α-ketoglutarate, p-aminohippurate, taurocholate, and estrone sulfate. Influx and efflux experiments showed that CsChT-mediated choline uptake was time- and sodium-dependent, with no exchange properties. Concentration-dependent analyses of revealed saturable kinetics consistent with the Michaelis-Menten equation, while nonlinear regression analyses revealed a Km value of 8.3 µM and a Vmax of 61.0 pmol/oocyte/h. These findings contribute to widen our understanding of CsChT transport properties and the cascade of choline metabolisms within C. sinensis.

• Parasites, Hosts and Diseases
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• v.61 no.4
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• pp.471-475
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• 2023

Archaeoentomological investigations were conducted on soil contents from a grave belonging to the Joseon Dynasty as part of the Urban Environment Maintenance Project (UEMP) in Cheongjin 12-16 dong (districts), Jongno-gu, Seoul, Korea, from December 01, 2008 to February 19, 2011. A total of 28 insect puparia with hard shells of the common green bottle fly Lucilia sericata were identified in the soil. Evidence suggested that the corpse was placed outside for some days instead of being buried immediately after death. This is the first report of fly puparia in soil samples from a tomb of the Joseon Dynasty during 16-17 AD in Korea. Our findings may help determine the timeframe of burial and offer archaeological insights into the funerary customs of the period.

• Parasites, Hosts and Diseases
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• v.61 no.4
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• pp.388-396
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• 2023

Entamoeba histolytica is an enteric tissue-invasive protozoan parasite causing amoebic colitis and liver abscesses in humans. Amoebic contact with host cells activates intracellular signaling pathways that lead to host cell death via generation of caspase-3, calpain, Ca²⁺ elevation, and reactive oxygen species (ROS). We previously reported that various NADPH oxidases (NOXs) are responsible for ROS-dependent death of various host cells induced by amoeba. In the present study, we investigated the specific NOX isoform involved in ROS-dependent death of hepatocytes induced by amoebas. Co-incubation of hepatoma HepG2 cells with live amoebic trophozoites resulted in remarkably increased DNA fragmentation compared to cells incubated with medium alone. HepG2 cells that adhered to amoebic trophozoites showed strong dichlorodihydrofluorescein diacetate (DCF-DA) fluorescence, suggesting intracellular ROS accumulation within host cells stimulated by amoebic trophozoites. Pretreatment of HepG2 cells with the general NOX inhibitor DPI or NOX2-specific inhibitor GSK 2795039 reduced Entamoeba-induced ROS generation. Similarly, Entamoeba-induced LDH release from HepG2 cells was effectively inhibited by pretreatment with DPI or GSK 2795039. In NOX2-silenced HepG2 cells, Entamoeba-induced LDH release was also significantly inhibited compared with controls. Taken together, the results support an important role of NOX2-derived ROS in hepatocyte death induced by E. histolytica.

• Parasites, Hosts and Diseases
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• v.61 no.4
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• pp.397-404
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• 2023

Acanthamoeba species are free-living amoebae those are widely distributed in the environment. They feed on various microorganisms, including bacteria, fungi, and algae. Although majority of the microbes phagocytosed by Acanthamoeba spp. are digested, some pathogenic bacteria thrive within them. Here, we identified the roles of 3 phagocytosis-associated genes (ACA1_077100, ACA1_175060, and AFD36229.1) in A. castellanii. These 3 genes were upregulated after the ingestion of Escherichia coli. However, after the ingestion of Legionella pneumophila, the expression of these 3 genes was not altered after the consumption of L. pneumophila. Furthermore, A. castellanii transfected with small interfering RNS (siRNA) targeting the 3 phagocytosis-associated genes failed to digest phagocytized E. coli. Silencing of ACA1_077100 disabled phagosome formation in the E. coli-ingesting A. castellanii. Alternatively, silencing of ACA1_175060 enabled phagosome formation; however, phagolysosome formation was inhibited. Moreover, suppression of AFD36229.1 expression prevented E. coli digestion and consequently led to the rupturing of A. castellanii. Our results demonstrated that the ACA1_077100, ACA1_175060, and AFD36229.1 genes of Acanthamoeba played crucial roles not only in the formation of phagosome and phagolysosome but also in the digestion of E. coli.

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.139-144
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• 2024

Acanthamoeba infection is associated with keratitis in humans; however, its association with keratitis in dogs remains unclear. To investigate this possibility, we collected 171 conjunctival swab samples from dogs with eye-related diseases (65 with keratitis and 106 without keratitis) at Chungbuk National University Veterinary Teaching Hospital, Korea, from August 2021 to September 2022. Polymerase chain reaction identified 9 samples (5.3%) as Acanthamoeba positive; of these, 3 were from dogs with keratitis (4.6%) and 6 were from dogs without keratitis (5.7%). Our results indicated no significant association between Acanthamoeba infection and keratitis, season, sex, or age. All Acanthamoeba organisms found in this study had the genotype T4, according to 18S ribosomal RNA analysis. Acanthamoeba infection in dogs might have only a limited association with keratitis.