Association between CYP2D6 phenotype and recurrence of Plasmodium vivax infection in south Korean patients.

BACKGROUND: Primaquine is activated by CYP2D6 in the hepatocytes. In Korea, primaquine is the only hypnozoitocidal agent used for patients with vivax malaria. Thus, patients with poor CYP2D6 activity could have an increased risk of primaquine failure and subsequent relapse. The study sought to identify the association between CYP2D6 phenotype and recurrence of malaria in Korean patients. METHODS: A total of 102 patients with vivax malaria were prospectively enrolled from eight institutions in Korea. An additional 38 blood samples from patients with recurred vivax malaria were provided by the Korea Disease Control and Prevention Agency. Malaria recurrence was defined as more than one episode of vivax malaria in the same or consecutive years. CYP2D6 star alleles, phenotypes, and activity scores were examined. RESULTS: Genotyping for CYP2D6 was successful in 101 of the prospectively enrolled patients and 38 samples from the Korea Disease Control and Prevention Agency, of which 91 were included in the no-recurrence group and 48 were included in the recurrence group. Reduced CYP2D6 activity (intermediate metabolizer) phenotype was more common in the recurrence group than in the no-recurrence group (OR, 2.33 (95% CI, 1.14-4.77); p = 0.02). Patients with lower CYP2D6 activity had a higher probability of recurrence (p = 0.029). CONCLUSION: This study suggests that CYP2D6 polymorphism may affect primaquine efficacy and thus Plasmodium vivax recurrence in Korea.

Knowledge, Attitudes and Perceptions Regarding Endemic Vivax Malaria in Inhabitants and Patients in Two Cities of Northern Gyeonggi-do, Korea, 2020.

An understanding of the knowledges, attitudes and perceptions of different populations is key for public health policy makers. Here, a survey was performed on knowledge, attitudes, and perceptions about malaria diagnosis, prevention, control, and treatment. The 407 survey participants included both uninfected inhabitants and patients from 2 cities (Gimpo- and Paju-si) of Northern Gyeonggi-do, known as high-risk areas for vivax malaria. We used community-based study design and non-probability sampling method using the primary data. Association between variables were tested using χ2-tests. In general, the information on malaria reported by the participants in this study was unsystematic and included inaccurate details. The knowledge of malaria symptoms, identified as headache, chills and fever, was high, but the surveyed community lacks knowledge of the specific medications used for malaria treatment, with a large number of respondents having no knowledge of any form of medication. Survey questions with high correct answer rates included questions about easy treatment of malaria in Korea, the high daytime activity of malaria-borne mosquitoes, and the infection risk posed by outdoor activities. However, a large portion of the respondents was unable to provide simple medical and biological information about the disease. This study aimed to comprehensively evaluate the knowledge, attitude, and practical behavior of the surveyed community with respect to malaria and the implications reported here could be applicable to other malaria endemic areas in Korea.

A Profile of Glucose-6-Phosphate Dehydrogenase Variants and Deficiency of Multicultural Families in Korea.

Vivax malaria incidence in Korea is now decreased and showing a low plateau. Nowadays, vivax malaria in Korea is expected to be successfully eliminated with anti-malaria chemotherapy, primaquine, and vector control. The glucose-6-phosphate dehydrogenase (G6PD) deficiency is associated with potential hemolytic anemia after primaquine administration. This inborn disorder has a pivotal polymorphism with genetic variants and is the most prevalent X-chromosome-linked disorder. The prevalence of G6PD deficiency was previously reported negligible in Korea. As the population of multicultural families pertaining marriage immigrants and their adolescents increases, it is necessary to check G6PD deficiency for them prior to primaquine treatment for vivax malaria. The prevalence of G6PD variants and G6PD deficiency in multicultural families was performed in 7 counties and 2 cities of Jeollanam-do (Province), Gyeonggi-do, and Gangwon-do. A total of 733 blood samples of multicultural family participants were subjected to test the phenotypic and genetic G6PD deficiency status using G6PD enzyme activity quantitation kit and PCR-based G6PD genotyping kit. The G6PD phenotypic deficiency was observed in 7.8% of male adolescent participants and 3.2% of materfamilias population. Based on the PCR-based genotyping, we observed total 35 participants carrying the mutated alleles. It is proposed that primaquine prescription should seriously be considered prior to malaria treatment.

An Epidemiological Analysis of 28 Vivax Malaria Cases in Gimpo-si, Korea, 2020.

Since 1993, vivax malaria has been recognized as a public health burden in Korea. Despite of pan-governmental malaria-control efforts and the dramatic reduction in the burden of this disease over the last 10 years, vivax malaria has not been well controlled and has remained continuously endemic. We focused interviewed and examined the charts of 28 confirmed vivax malaria patients given malarial therapy for whom daily records were kept from Gimpo-si, Gyeonggido of Korea. Various epidemiological characteristics of vivax malaria, including the incubation period, medication used, and recurrence, and an evaluation of the parasitic characteristics from the focused interviews of patients from this region are described here. Most of the participants indicated the 3 most common symptoms of malaria (headache, chills and fever). Of the 28 cases, 2 experienced a second attack and there were 17 and 11 cases with short- and long-term incubation periods, respectively, yielding a short-term to long-term ratio of 1.5. Based on the parasitemia stages, most of the participants were tested at 5 to 7 days (11 cases) and 7 to 15 days (11 cases) after initial wave of asexual parasites. In conclusion, public health authorities should consider developing management measures to decrease the time lag for diagnosis and drafting unified and robust guidelines for drug use for malaria and drawing up unified and robust guidelines on the use of medication for malaria. It also suggests that routine monitoring, surveillance, and precise medical surveys in high-risk vivax malaria endemic areas are pivotal to controlling this persistent public disease and finally eliminating it from Korea.

Detecting mpox infection in the early epidemic: an epidemiologic investigation of the third and fourth cases in Korea.

OBJECTIVES: As few mpox cases have been reported in Korea, we aimed to identify the characteristics of mpox infection by describing our epidemiologic investigation of a woman patient (index patient, the third case in Korea) and a physician who was infected by a needlestick injury (the fourth case). METHODS: We conducted contact tracing and exposure risk evaluation through interviews with these 2 patients and their physicians and contacts, as well as field investigations at each facility visited by the patients during their symptomatic periods. We then classified contacts into 3 levels according to their exposure risk and managed them to minimize further transmission by recommending quarantine and vaccination for post-exposure prophylaxis and monitoring their symptoms. RESULTS: The index patient had sexual contact with a man foreigner during a trip to Dubai, which was considered the probable route of transmission. In total, 27 healthcare-associated contacts across 7 healthcare facilities and 9 community contacts were identified. These contacts were classified into high (7 contacts), medium (9 contacts), and low (20 contacts) exposure risk groups. One high-risk contact was identified as a secondary patient: a physician who was injured while collecting specimens from the index patient. CONCLUSIONS: The index patient visited several medical facilities due to progressive symptoms prior to isolation. Although the 2022 mpox epidemic mainly affected young men, especially men who have sex with men, physicians should also consider mpox transmission in the general population for the timely detection of mpox-infected patients.

The Seroprevalence of Severe Fever with Thrombocytopenia Syndrome: An Epidemiological Study of Korean Veterinary Hospital Workers.

Severe fever with thrombocytopenia syndrome (SFTS) is a zoonotic tick-borne infectious disease caused by the SFTS virus (SFTSV). Few studies have assessed SFTS seroprevalence among veterinary hospital staff and their awareness of SFTS. From January to May 2021, serum samples from 103 veterinary hospital staff were tested for SFTS using an enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay, and a 50% plaque reduction neutralization antibody test, which yielded positive results in four (3.9%), three (2.9%), and two (1.9%) participants, respectively. A questionnaire was used for an epidemiological investigation. ELISA positivity was higher among those who lacked awareness of possible animal-to-human SFTS transmission (p = 0.029). SFTS awareness was significantly lower among veterinary hospital staff than among the veterinarians (p < 0.001). Providing staff with training concerning standard precautions and the use of appropriate personal protective equipment is important.

Nosocomial outbreak of severe fever with thrombocytopenia syndrome among healthcare workers in a single hospital in Daegu, Korea.

BACKGROUND: In August 2020, 17 healthcare workers (HCWs) were simultaneously diagnosed with severe fever with thrombocytopenia syndrome (SFTS) at a university hospital in Daegu, Republic of Korea. METHODS: An epidemiologic investigation using questionnaires was conducted for all suspected HCWs who had viral infection symptoms or who had the possibility of exposure to the index patient. RESULTS: A total of 17 HCWs infected with the SFTS virus (SFTSV) (28.8%) were identified among the 59 HCWs who had contact with the patient. Operating a bag valve mask during cardiopulmonary resuscitation (CPR) (OR 7.50, 95% CI 1.75-41.07), cardiac massage during CPR (OR 12.00, 95% CI 1.76-241.94), exposure to the patient's body fluids (OR 7.43, 95% CI 1.91-34.69), and shorter individual hospital work experience periods (OR 6.79, 95% CI 1.70-32.10) were significantly associated with SFTS infection in the univariate analysis. However, exposure to body fluids was found to be the only statistically significant risk factor when multivariate analysis was conducted (OR 6.27. 95% CI 1.23-42.81, p = 0.036). CONCLUSIONS: This finding illustrates the importance of wearing appropriate personal protective equipment in treatment areas and when conducting any medical procedures, including CPR for patients with SFTS, and any procedure that involves potential exposure to body fluids.

α-TEA induces apoptosis of human breast cancer cells via activation of TRAIL/DR5 death receptor pathway.

Vitamin E derivative RRR-α-tocopherol ether-linked acetic acid analog (α-TEA) induces apoptosis in MCF-7 and HCC-1954 human breast cancer cells in a dose- and time-dependent manner. α-TEA induces increased levels of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and death receptor-5 (DR5) and decreased levels of antiapoptotic factor, cellular FLICE-like inhibitory protein (c-FLIP L). DR5/TRAIL induced apoptosis involves downregulation of c-FLIP (L), caspase-8 activation, activated proapoptotic mediators tBid and Bax, mitochondrial permeability transition, and activation of caspase-9. siRNA knockdown of either DR5 or TRAIL blocks the ability of α-TEA to enhance DR5 protein levels, downregulate c-FLIP(L) protein levels and induce apoptosis. Combination of α-TEA + TRAIL acts cooperatively to induce apoptosis, and increase DR5 and decrease c-FLIP (L) protein levels. siRNA knockdown of c-FLIP produces a low level of spontaneous apoptosis and enhances α-TEA- and TRAIL-induced apoptosis. Taken together, these studies show that α-TEA induces TRAIL/DR5 mitochondria-dependent apoptosis in human breast cancer cells, and that TRAIL/DR5-dependent increases in DR5 and decreases in c-FLIP expression are triggered by TRAIL or α-TEA treatments.

α-TEA-induced death receptor dependent apoptosis involves activation of acid sphingomyelinase and elevated ceramide-enriched cell surface membranes.

BACKGROUND: Alpha-tocopherol ether-linked acetic acid (α-TEA), an analog of vitamin E (RRR-alpha-tocopherol), is a potent and selective apoptosis-inducing agent for human cancer cells in vivo and in vitro. α-TEA induces apoptosis via activation of extrinsic death receptors Fas (CD95) and DR5, JNK/p73/Noxa pathways, and suppression of anti-apoptotic mediators Akt, ERK, c-FLIP and survivin in breast, ovarian and prostate cancer cells. RESULTS: In this study, we demonstrate that α-TEA induces the accumulation of cell surface membrane ceramide, leading to co-localization with Fas, DR5, and FADD, followed by activation of caspases-8 and -9 and apoptosis in human MDA-MB-231 breast cancer cells. α-TEA treatment leads to increased acid sphingomyelinase (ASMase) activity by 30 min, peaking at 4 hrs, which is correlated with ASMase translocation from cytosol to the cell surface membrane. Functional knockdown of ASMase with either the chemical inhibitor, desipramine, or siRNA markedly reduces α-TEA-induced cell surface membrane accumulation of ceramide and its co-localization with Fas, DR5, and FADD, cleavage of caspases-8 and -9 and apoptosis, suggesting an early and critical role for ASMase in α-TEA-induced apoptosis. Consistent with cell culture data, immunohistochemical analyses of tumor tissues taken from α-TEA treated nude mice bearing MDA-MB-231 xenografts show increased levels of cell surface membrane ceramide in comparison to tumor tissues from control animals. CONCLUSION: Taken together, these studies demonstrate that ASMase activation and membrane ceramide accumulation are early events contributing to α-TEA-induced apoptosis in vitro and perhaps in vivo.

RRR-gamma-tocopherol induces human breast cancer cells to undergo apoptosis via death receptor 5 (DR5)-mediated apoptotic signaling.

Goal of this study was to investigate the pro-apoptotic properties of RRR-gamma-tocopherol (gammaT) in human breast cancer cells. gammaT was shown to induce cancer cells but not normal cells to undergo apoptosis, sensitize cancer cells to Tumor necrosis factor-Related Apoptosis-Inducing Ligand (TRAIL)-induced apoptosis, and increase death receptor 5 (DR5) mRNA, protein and cell surface expression. Knockdown of DR5 attenuated gammaT-induced apoptosis. Investigations of post-receptor signaling showed: caspase-8, Bid and Bax activation, increases in mitochondria permeability, cytochrome c release and caspase-9 activation. Thus, gammaT is a potent pro-apoptotic agent for human breast cancer cells inducing apoptosis via activation of DR5-mediated apoptotic pathway.

Role of endoplasmic reticulum stress in alpha-TEA mediated TRAIL/DR5 death receptor dependent apoptosis.

BACKGROUND: Alpha-TEA (RRR-alpha-tocopherol ether-linked acetic acid analog), a derivative of RRR-alpha-tocopherol (vitamin E) exhibits anticancer actions in vitro and in vivo in variety of cancer types. The objective of this study was to obtain additional insights into the mechanisms involved in alpha-TEA induced apoptosis in human breast cancer cells. METHODOLOGY/PRINCIPAL FINDINGS: alpha-TEA induces endoplasmic reticulum (ER) stress as indicated by increased expression of CCAAT/enhancer binding protein homologous protein (CHOP) as well as by enhanced expression or activation of specific markers of ER stress such as glucose regulated protein (GRP78), phosphorylated alpha subunit of eukaryotic initiation factor 2 (peIF-2alpha), and spliced XBP-1 mRNA. Knockdown studies using siRNAs to TRAIL, DR5, JNK and CHOP as well as chemical inhibitors of ER stress and caspase-8 showed that: i) alpha-TEA activation of DR5/caspase-8 induces an ER stress mediated JNK/CHOP/DR5 positive amplification loop; ii) alpha-TEA downregulation of c-FLIP (L) protein levels is mediated by JNK/CHOP/DR5 loop via a JNK dependent Itch E3 ligase ubiquitination that further serves to enhance the JNK/CHOP/DR5 amplification loop by preventing c-FLIP's inhibition of caspase-8; and (iii) alpha-TEA downregulation of Bcl-2 is mediated by the ER stress dependent JNK/CHOP/DR5 signaling. CONCLUSION: Taken together, ER stress plays an important role in alpha-TEA induced apoptosis by enhancing DR5/caspase-8 pro-apoptotic signaling and suppressing anti-apoptotic factors c-FLIP and Bcl-2 via ER stress mediated JNK/CHOP/DR5/caspase-8 signaling.

Downregulation of Epidermal Growth Factor Receptor Expression Contributes to alpha-TEA's Proapoptotic Effects in Human Ovarian Cancer Cell Lines.

RRR-alpha-tocopherol derivative alpha-TEA (RRR-alpha-tocopherol ether-linked acetic acid analog) has been shown to be a potent antitumor agent both in vivo and in vitro. In this study, we investigated the effects of alpha-TEA on the expression of epidermal growth factor receptor (EGFR) family members, ErbB1, 2 and 3, and the role of ErbB 2 and 3 in alpha-TEA-induced apoptosis and suppression of Akt, FLIP and survivin in the cisplatin-sensitive (A2780S) and -resistant (A2780/CP70R) human ovarian cancer cell lines. Data show that alpha-TEA's ability to induced apoptosis was associated with reduced expression of ErbB1 (cisplatin-resistant cells), 2 and 3 (both cell types) and reduced levels of the phosphorylated (active) form of Akt; as well as, reduced levels of FLIP and survivin proteins in both cell types. Ectopic overexpression and siRNA knockdown studies showed that ErbB2, ErbB3, Akt, FLIP and survivin are involved in alpha-TEA-induce apoptosis and that alpha-TEA downregulates FLIP and survivin via suppression of pAkt, which is mediated by ErbB2 and ErB3. Thus, alpha-TEA is a potent pro-apoptotic agent for both cisplatin-sensitive and -resistant ovarian cancer cell lines in cell culture and it produces cell death, at least in part, by downregulation of members of the EGFR family.

Anticancer actions of natural and synthetic vitamin E forms: RRR-alpha-tocopherol blocks the anticancer actions of gamma-tocopherol.

Two naturally occurring dietary sources of vitamin E (i.e. RRR-alpha-tocopherol (alphaT) and RRR-gamma-tocopherol (gammaT)), the manufactured synthetic form of vitamin E, all-racemic-alpha-tocopherol (all-rac-alphaT), as well as a potent antitumor analog of vitamin E, RRR-alpha-tocopherol ether-linked acetic acid analog (alpha-TEA), were assessed for anticancer actions. Data showed that gammaT, all-rac-alphaT, and alpha-TEA but not alphaT or alphaT+gammaT significantly inhibited tumor burden of human MDA-MB-231 cells in nude mice. Immunohistochemical analyses of tumor tissue showed that all-rac-alphaT and alpha-TEA increased apoptosis and decreased proliferation in tumor cells while gammaT was associated with increased tumor cell apoptosis only. In vitro data showed alpha-TEA and gammaT but not all-rac-alphaT or alphaT to inhibit colony formation and induce apoptosis. Anticancer actions of alpha-TEA and gammaT involved death receptor 5 protein upregulation, Survivin protein downregulation and poly (ADP-ribose) polymerase cleavage, all of which were blocked by co-treatment with alphaT. In summary, both gammaT and alpha-TEA exhibited promising anticancer properties in vivo and in vitro, whereas all-rac-alphaT exhibited promising anticancer properties in vivo only. Importantly, alphaT not only failed to exhibit anticancer properties but it also reduced anticancer actions of gammaT in vivo and gammaT and alpha-TEA in vitro.

In vitro and in vivo evaluation of anticancer actions of natural and synthetic vitamin E forms.

The goal of these studies was to investigate the potential anticancer properties of two naturally occurring plant sources and two manufactured synthetic forms of vitamin E, i. e., RRR-alpha-tocopherol (alphaT), RRR-gamma-tocopherol (gammaT), all-rac-alpha-tocopherol (all-rac-alphaT), and all-rac-alpha-tocopheryl acetate (all-rac-alphaTAc) in breast cancer models. Vitamin E compounds were evaluated in vitro for inhibition of colony formation and induction of apoptosis in human MDA-MB-435 and MCF-7 breast cancer cells and murine 66cl-4 mammary cancer cells and in vivo for ability to reduce tumor growth and lung and lymph node metastases using the transplantable syngeneic BALB/c mouse 66cl-4-GFP mammary cancer model. gammaT inhibited colony formation and induced apoptosis in all three cancer cell lines. alphaT and all-rac-alphaT were less effective and all-rac-alphaTAc was ineffective. gammaT-induced apoptosis was correlated with activation of caspases-8 and -9 and down-regulation of protein expression of c-FLIP and survivin. In vivo study 1 analyses showed that all-rac-alphaT and all-rac-alphaTAc significantly inhibited tumor growth and inhibited both visible and microscopic size lung metastases. In vivo study 2 analyses showed that alphaT and gammaT reduced tumor growth, but only gammaT reduced tumor growth significantly in comparison to control. In conclusion, synthetic, but not natural, vitamin E exhibits promising anti-cancer properties in vivo.