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Ang R, Lim P, Hunter RJ, Dhinoja MB, Chow AC, Schilling RJ, Earley MJ, Segal OR. 82Long term outcome following left atrial appendage occlusion: real world experience from a single centre prospective registry. Europace 2017. [DOI: 10.1093/europace/eux283.077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Lohy Das J, Dondorp AM, Nosten F, Phyo AP, Hanpithakpong W, Ringwald P, Lim P, White NJ, Karlsson MO, Bergstrand M, Tarning J. Population Pharmacokinetic and Pharmacodynamic Modeling of Artemisinin Resistance in Southeast Asia. AAPS JOURNAL 2017; 19:1842-1854. [PMID: 28895080 DOI: 10.1208/s12248-017-0141-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 08/23/2017] [Indexed: 11/30/2022]
Abstract
Orally administered artemisinin-based combination therapy is the first-line treatment against uncomplicated P. falciparum malaria worldwide. However, the increasing prevalence of artemisinin resistance is threatening efforts to treat and eliminate malaria in Southeast Asia. This study aimed to characterize the exposure-response relationship of artesunate in patients with artemisinin sensitive and resistant malaria infections. Patients were recruited in Pailin, Cambodia (n = 39), and Wang Pha, Thailand (n = 40), and received either 2 mg/kg/day of artesunate mono-therapy for 7 consecutive days or 4 mg/kg/day of artesunate monotherapy for 3 consecutive days followed by mefloquine 15 and 10 mg/kg for 2 consecutive days. Plasma concentrations of artesunate and its active metabolite, dihydroartemisinin, and microscopy-based parasite densities were measured and evaluated using nonlinear mixed-effects modeling. All treatments were well tolerated with minor and transient adverse reactions. Patients in Cambodia had substantially slower parasite clearance compared to patients in Thailand. The pharmacokinetic properties of artesunate and dihydroartemisinin were well described by transit-compartment absorption followed by one-compartment disposition models. Parasite density was a significant covariate, and higher parasite densities were associated with increased absorption. Dihydroartemisinin-dependent parasite killing was described by a delayed sigmoidal Emax model, and a mixture function was implemented to differentiate between sensitive and resistant infections. This predicted that 84% and 16% of infections in Cambodia and Thailand, respectively, were artemisinin resistant. The final model was used to develop a simple diagnostic nomogram to identify patients with artemisinin-resistant infections. The nomogram showed > 80% specificity and sensitivity, and outperformed the current practice of day 3 positivity testing.
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D’Humières T, Faivre L, Lim P, Ternacle J. New Three-Dimensional Echocardiography Method to Quantify Aortic Valve Calcification. ARCHIVES OF CARDIOVASCULAR DISEASES SUPPLEMENTS 2017. [DOI: 10.1016/s1878-6480(17)30002-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Mukherjee A, Bopp S, Magistrado P, Wong W, Daniels R, Demas A, Schaffner S, Amaratunga C, Lim P, Dhorda M, Miotto O, Woodrow C, Ashley EA, Dondorp AM, White NJ, Wirth D, Fairhurst R, Volkman SK. Artemisinin resistance without pfkelch13 mutations in Plasmodium falciparum isolates from Cambodia. Malar J 2017; 16:195. [PMID: 28494763 PMCID: PMC5427620 DOI: 10.1186/s12936-017-1845-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 04/29/2017] [Indexed: 12/31/2022] Open
Abstract
Background Artemisinin resistance is associated with delayed parasite clearance half-life in vivo and correlates with ring-stage survival under dihydroartemisinin in vitro. Both phenotypes are associated with mutations in the PF3D7_1343700 pfkelch13 gene. Recent spread of artemisinin resistance and emerging piperaquine resistance in Southeast Asia show that artemisinin combination therapy, such as dihydroartemisinin–piperaquine, are losing clinical effectiveness, prompting investigation of drug resistance mechanisms and development of strategies to surmount emerging anti-malarial resistance. Methods Sixty-eight parasites isolates with in vivo clearance data were obtained from two Tracking Resistance to Artemisinin Collaboration study sites in Cambodia, culture-adapted, and genotyped for pfkelch13 and other mutations including pfmdr1 copy number; and the RSA0–3h survival rates and response to antimalarial drugs in vitro were measured for 36 of these isolates. Results Among these 36 parasites one isolate demonstrated increased ring-stage survival for a PfKelch13 mutation (D584V, RSA0–3h = 8%), previously associated with slow clearance but not yet tested in vitro. Several parasites exhibited increased ring-stage survival, yet lack pfkelch13 mutations, and one isolate showed evidence for piperaquine resistance. Conclusions This study of 68 culture-adapted Plasmodium falciparum clinical isolates from Cambodia with known clearance values, associated the D584V PfKelch13 mutation with increased ring-stage survival and identified parasites that lack pfkelch13 mutations yet exhibit increased ring-stage survival. These data suggest mutations other than those found in pfkelch13 may be involved in conferring artemisinin resistance in P. falciparum. Piperaquine resistance was also detected among the same Cambodian samples, consistent with reports of emerging piperaquine resistance in the field. These culture-adapted parasites permit further investigation of mechanisms of both artemisinin and piperaquine resistance and development of strategies to prevent or overcome anti-malarial resistance. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1845-5) contains supplementary material, which is available to authorized users.
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Amato R, Lim P, Miotto O, Amaratunga C, Dek D, Pearson RD, Almagro-Garcia J, Neal AT, Sreng S, Suon S, Drury E, Jyothi D, Stalker J, Kwiatkowski DP, Fairhurst RM. Genetic markers associated with dihydroartemisinin-piperaquine failure in Plasmodium falciparum malaria in Cambodia: a genotype-phenotype association study. THE LANCET. INFECTIOUS DISEASES 2017; 17:164-173. [PMID: 27818095 PMCID: PMC5564489 DOI: 10.1016/s1473-3099(16)30409-1] [Citation(s) in RCA: 242] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 08/11/2016] [Accepted: 08/12/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND As the prevalence of artemisinin-resistant Plasmodium falciparum malaria increases in the Greater Mekong subregion, emerging resistance to partner drugs in artemisinin combination therapies seriously threatens global efforts to treat and eliminate this disease. Molecular markers that predict failure of artemisinin combination therapy are urgently needed to monitor the spread of partner drug resistance, and to recommend alternative treatments in southeast Asia and beyond. METHODS We did a genome-wide association study of 297 P falciparum isolates from Cambodia to investigate the relationship of 11 630 exonic single-nucleotide polymorphisms (SNPs) and 43 copy number variations (CNVs) with in-vitro piperaquine 50% inhibitory concentrations (IC50s), and tested whether these genetic variants are markers of treatment failure with dihydroartemisinin-piperaquine. We then did a survival analysis of 133 patients to determine whether candidate molecular markers predicted parasite recrudescence following dihydroartemisinin-piperaquine treatment. FINDINGS Piperaquine IC50s increased significantly from 2011 to 2013 in three Cambodian provinces (2011 vs 2013 median IC50s: 20·0 nmol/L [IQR 13·7-29·0] vs 39·2 nmol/L [32·8-48·1] for Ratanakiri, 19·3 nmol/L [15·1-26·2] vs 66·2 nmol/L [49·9-83·0] for Preah Vihear, and 19·6 nmol/L [11·9-33·9] vs 81·1 nmol/L [61·3-113·1] for Pursat; all p≤10-3; Kruskal-Wallis test). Genome-wide analysis of SNPs identified a chromosome 13 region that associates with raised piperaquine IC50s. A non-synonymous SNP (encoding a Glu415Gly substitution) in this region, within a gene encoding an exonuclease, associates with parasite recrudescence following dihydroartemisinin-piperaquine treatment. Genome-wide analysis of CNVs revealed that a single copy of the mdr1 gene on chromosome 5 and a novel amplification of the plasmepsin 2 and plasmepsin 3 genes on chromosome 14 also associate with raised piperaquine IC50s. After adjusting for covariates, both exo-E415G and plasmepsin 2-3 markers significantly associate (p=3·0 × 10-8 and p=1·7 × 10-7, respectively) with decreased treatment efficacy (survival rates 0·38 [95% CI 0·25-0·51] and 0·41 [0·28-0·53], respectively). INTERPRETATION The exo-E415G SNP and plasmepsin 2-3 amplification are markers of piperaquine resistance and dihydroartemisinin-piperaquine failures in Cambodia, and can help monitor the spread of these phenotypes into other countries of the Greater Mekong subregion, and elucidate the mechanism of piperaquine resistance. Since plasmepsins are involved in the parasite's haemoglobin-to-haemozoin conversion pathway, targeted by related antimalarials, plasmepsin 2-3 amplification probably mediates piperaquine resistance. FUNDING Intramural Research Program of the US National Institute of Allergy and Infectious Diseases, National Institutes of Health, Wellcome Trust, Bill & Melinda Gates Foundation, Medical Research Council, and UK Department for International Development.
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Faivre L, D’humières T, Chammous E, Dubois-Randé J, Monin J, Lim P, Ternacle J. New three-dimensional echocardiography method to quantify aortic valve calcification. ARCHIVES OF CARDIOVASCULAR DISEASES SUPPLEMENTS 2017. [DOI: 10.1016/s1878-6480(17)30159-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Lee G, McMahon C, McCabe M, Jiang H, Lee S, Lim P, Jiang B. 205 Attitudes and Barriers to Premature Ejaculation (Pe) and its Treatment Among Men and Their Partners in the Asia-Pacific Region – Results From A Web-Based Survey. J Sex Med 2017. [DOI: 10.1016/j.jsxm.2016.11.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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D’humières T, Damy T, Dubois-Randé J, Lim P, Ternacle J. Outcome of cardiac amyloidosis admitted in intensive care unit. ARCHIVES OF CARDIOVASCULAR DISEASES SUPPLEMENTS 2017. [DOI: 10.1016/s1878-6480(17)30112-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Morgentaler A, Zitzmann M, Traish AM, Fox AW, Jones TH, Maggi M, Arver S, Aversa A, Chan J, Dobs AS, Hackett GI, Hellstrom WJ, Lim P, Lunenfeld B, Mskhalaya G, Schulman CC, Torres LO. The consensus recommendations of a group of international experts on the fundamental concepts related to the issues of testosterone deficiency and its treatment. ACTA ACUST UNITED AC 2016. [DOI: 10.14341/omet2016315-31] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Conference on the development of the international expert consensus to address frequently asked questions related to a medical condition of testosterone deficiency (TD, male hypogonadism) and testosterone therapy was held in Prague (Czech Republic) on October 1, 2015. The included experts were representatives from a variety of medical specialties, including urology, endocrinology, diabetology, internal medicine, as well as representatives of basic medical sciences. An international team of experts came to the following conclusions: TD - an important medical condition that affects the health and well-being of men; TD symptoms is a consequence of low testosterone levels, regardless of whether background etiology installed; TD consequences are global; care must be taken in an attempt to use any uniform threshold levels of testosterone for a decision on the appointment of testosterone therapy; a person does not have any reason to refrain from appointing testosterone therapy only on the basis of age; the existing evidence does not suggest increasing the prostate cancer or cardiovascular disease risk during testosterone therapy; there is evidence conserning the feasibility of a major research initiative to explore possible cardioprotective beneficial effects of testosterone therapy in men with metabolic disorders, including diabetes.
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Srimuang K, Miotto O, Lim P, Fairhurst RM, Kwiatkowski DP, Woodrow CJ, Imwong M. Analysis of anti-malarial resistance markers in pfmdr1 and pfcrt across Southeast Asia in the Tracking Resistance to Artemisinin Collaboration. Malar J 2016; 15:541. [PMID: 27825353 PMCID: PMC5101715 DOI: 10.1186/s12936-016-1598-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 10/31/2016] [Indexed: 01/07/2023] Open
Abstract
Background Declining anti-malarial efficacy of artemisinin-based combination therapy, and reduced Plasmodium falciparum susceptibility to individual anti-malarials are being documented across an expanding area of Southeast Asia (SEA). Genotypic markers complement phenotypic studies in assessing the efficacy of individual anti-malarials. Methods The markers pfmdr1 and pfcrt were genotyped in parasite samples obtained in 2011–2014 at 14 TRAC (Tracking Resistance to Artemisinin Collaboration) sites in mainland Southeast Asia using a combination of PCR and next-generation sequencing methods. Results Pfmdr1 amplification, a marker of mefloquine and lumefantrine resistance, was highly prevalent at Mae Sot on the Thailand–Myanmar border (59.8% of isolates) and common (more than 10%) at sites in central Myanmar, eastern Thailand and western Cambodia; however, its prevalence was lower than previously documented in Pailin, western Cambodia. The pfmdr1 Y184F mutation was common, particularly in and around Cambodia, and the F1226Y mutation was found in about half of samples in Mae Sot. The functional significance of these two mutations remains unclear. Other previously documented pfmdr1 mutations were absent or very rare in the region. The pfcrt mutation K76T associated with chloroquine resistance was found in 98.2% of isolates. The CVIET haplotype made up 95% or more of isolates in western SEA while the CVIDT haplotype was common (30–40% of isolates) in north and northeastern Cambodia, southern Laos, and southern Vietnam. Conclusions These findings generate cause for concern regarding the mid-term efficacy of artemether–lumefantrine in Myanmar, while the absence of resistance-conferring pfmdr1 mutations and SVMNT pfcrt haplotypes suggests that amodiaquine could be an efficacious component of anti-malarial regimens in SEA. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1598-6) contains supplementary material, which is available to authorized users.
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Chen JT, Mustafa EM, Vello V, Lim P, Sulaiman NMN, Majid NA, Phang S, Tahir PM, Liew K. Preliminary assessment of Malaysian micro-algae strains for the production of bio jet fuel. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/1757-899x/152/1/012042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Akodad M, Lim P, Roubille F. Does ivabradine balance dobutamine effects in cardiogenic shock? A promising new strategy. Acta Physiol (Oxf) 2016; 218:73-7. [PMID: 27291979 DOI: 10.1111/apha.12733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abdulla S, Ashley EA, Bassat Q, Bethell D, Björkman A, Borrmann S, D'Alessandro U, Dahal P, Day NP, Diakite M, Djimde AA, Dondorp AM, Duong S, Edstein MD, Fairhurst RM, Faiz MA, Falade C, Flegg JA, Fogg C, Gonzalez R, Greenwood B, Guérin PJ, Guthmann JP, Hamed K, Hien TT, Htut Y, Juma E, Lim P, Mårtensson A, Mayxay M, Mokuolu OA, Moreira C, Newton P, Noedl H, Nosten F, Ogutu BR, Onyamboko MA, Owusu-Agyei S, Phyo AP, Premji Z, Price RN, Pukrittayakamee S, Ramharter M, Sagara I, Se Y, Suon S, Stepniewska K, Ward SA, White NJ, Winstanley PA. Baseline data of parasite clearance in patients with falciparum malaria treated with an artemisinin derivative: an individual patient data meta-analysis. Malar J 2015; 14:359. [PMID: 26390866 PMCID: PMC4578675 DOI: 10.1186/s12936-015-0874-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/26/2015] [Indexed: 11/15/2022] Open
Abstract
Background Artemisinin resistance in Plasmodium falciparum manifests as slow parasite clearance but this measure is also influenced by host immunity, initial parasite biomass and partner drug efficacy. This study collated data from clinical trials of artemisinin derivatives in falciparum malaria with frequent
parasite counts to provide reference parasite clearance estimates stratified by location, treatment and time, to examine host factors affecting parasite clearance, and to assess the relationships between parasite clearance and risk of recrudescence during follow-up. Methods Data from 24 studies, conducted from 1996 to 2013, with frequent parasite counts were pooled. Parasite clearance half-life (PC1/2) was estimated using the WWARN Parasite Clearance Estimator. Random effects regression models accounting for study and site heterogeneity were used to explore factors affecting PC1/2 and risk of recrudescence within areas with reported delayed parasite clearance (western Cambodia, western Thailand after 2000, southern Vietnam, southern Myanmar) and in all other areas where parasite populations are artemisinin sensitive. Results PC1/2 was estimated in 6975 patients, 3288 of whom also had treatment outcomes evaluate d during 28–63 days follow-up, with 93 (2.8 %) PCR-confirmed recrudescences. In areas with artemisinin-sensitive parasites, the median PC1/2 following three-day artesunate treatment (4 mg/kg/day) ranged from 1.8 to 3.0 h and the proportion of patients with PC1/2 >5 h from 0 to 10 %. Artesunate doses of 4 mg/kg/day decreased PC1/2 by 8.1 % (95 % CI 3.2–12.6) compared to 2 mg/kg/day, except in populations with delayed parasite clearance. PC1/2 was longer in children and in patients with fever or anaemia at enrolment. Long PC1/2 (HR = 2.91, 95 % CI 1.95–4.34 for twofold increase, p < 0.001) and high initial parasitaemia (HR = 2.23, 95 % CI 1.44–3.45 for tenfold increase, p < 0.001) were associated independently with an increased risk of recrudescence. In western Cambodia, the region with the highest prevalence of artemisinin resistance, there was no evidence for increasing PC1/2 since 2007. Conclusions Several factors affect PC1/2. As substantial heterogeneity in parasite clearance exists between locations, early detection of artemisinin resistance requires reference PC1/2 data. Studies with frequent parasite count measurements to characterize PC1/2 should be encouraged. In western Cambodia, where PC1/2 values are longest, there is no evidence for recent emergence of higher levels of artemisinin resistance. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0874-1) contains supplementary material, which is available to authorized users.
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Lim P, Alonzi R, Hoskin P. Indications, complications and efficacy of transperineal template biopsy (TPTB) in the management of prostate cancer (PC) at Mount Vernon Cancer Centre (MVCC). Clin Oncol (R Coll Radiol) 2015. [DOI: 10.1016/j.clon.2015.04.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Miotto O, Amato R, Ashley EA, MacInnis B, Almagro-Garcia J, Amaratunga C, Lim P, Mead D, Oyola SO, Dhorda M, Imwong M, Woodrow C, Manske M, Stalker J, Drury E, Campino S, Amenga-Etego L, Thanh TNN, Tran HT, Ringwald P, Bethell D, Nosten F, Phyo AP, Pukrittayakamee S, Chotivanich K, Chuor CM, Nguon C, Suon S, Sreng S, Newton PN, Mayxay M, Khanthavong M, Hongvanthong B, Htut Y, Han KT, Kyaw MP, Faiz MA, Fanello CI, Onyamboko M, Mokuolu OA, Jacob CG, Takala-Harrison S, Plowe CV, Day NP, Dondorp AM, Spencer CCA, McVean G, Fairhurst RM, White NJ, Kwiatkowski DP. Genetic architecture of artemisinin-resistant Plasmodium falciparum. Nat Genet 2015; 47:226-34. [PMID: 25599401 PMCID: PMC4545236 DOI: 10.1038/ng.3189] [Citation(s) in RCA: 396] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 12/15/2014] [Indexed: 01/31/2023]
Abstract
We report a large multicenter genome-wide association study of Plasmodium falciparum resistance to artemisinin, the frontline antimalarial drug. Across 15 locations in Southeast Asia, we identified at least 20 mutations in kelch13 (PF3D7_1343700) affecting the encoded propeller and BTB/POZ domains, which were associated with a slow parasite clearance rate after treatment with artemisinin derivatives. Nonsynonymous polymorphisms in fd (ferredoxin), arps10 (apicoplast ribosomal protein S10), mdr2 (multidrug resistance protein 2) and crt (chloroquine resistance transporter) also showed strong associations with artemisinin resistance. Analysis of the fine structure of the parasite population showed that the fd, arps10, mdr2 and crt polymorphisms are markers of a genetic background on which kelch13 mutations are particularly likely to arise and that they correlate with the contemporary geographical boundaries and population frequencies of artemisinin resistance. These findings indicate that the risk of new resistance-causing mutations emerging is determined by specific predisposing genetic factors in the underlying parasite population.
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Mok S, Ashley EA, Ferreira PE, Zhu L, Lin Z, Yeo T, Chotivanich K, Imwong M, Pukrittayakamee S, Dhorda M, Nguon C, Lim P, Amaratunga C, Suon S, Hien TT, Htut Y, Faiz MA, Onyamboko MA, Mayxay M, Newton PN, Tripura R, Woodrow CJ, Miotto O, Kwiatkowski DP, Nosten F, Day NPJ, Preiser PR, White NJ, Dondorp AM, Fairhurst RM, Bozdech Z. Drug resistance. Population transcriptomics of human malaria parasites reveals the mechanism of artemisinin resistance. Science 2015; 347:431-5. [PMID: 25502316 PMCID: PMC5642863 DOI: 10.1126/science.1260403] [Citation(s) in RCA: 277] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Artemisinin resistance in Plasmodium falciparum threatens global efforts to control and eliminate malaria. Polymorphisms in the kelch domain-carrying protein K13 are associated with artemisinin resistance, but the underlying molecular mechanisms are unknown. We analyzed the in vivo transcriptomes of 1043 P. falciparum isolates from patients with acute malaria and found that artemisinin resistance is associated with increased expression of unfolded protein response (UPR) pathways involving the major PROSC and TRiC chaperone complexes. Artemisinin-resistant parasites also exhibit decelerated progression through the first part of the asexual intraerythrocytic development cycle. These findings suggest that artemisinin-resistant parasites remain in a state of decelerated development at the young ring stage, whereas their up-regulated UPR pathways mitigate protein damage caused by artemisinin. The expression profiles of UPR-related genes also associate with the geographical origin of parasite isolates, further suggesting their role in emerging artemisinin resistance in the Greater Mekong Subregion.
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Ariey F, Witkowski B, Amaratunga C, Beghain J, Langlois AC, Khim N, Kim S, Duru V, Bouchier C, Ma L, Lim P, Leang R, Duong S, Sreng S, Suon S, Chuor CM, Bout DM, Ménard S, Rogers WO, Genton B, Fandeur T, Miotto O, Ringwald P, Le Bras J, Berry A, Barale JC, Fairhurst RM, Benoit-Vical F, Mercereau-Puijalon O, Ménard D. A molecular marker of artemisinin-resistant Plasmodium falciparum malaria. Nature 2014; 505:50-5. [PMID: 24352242 PMCID: PMC5007947 DOI: 10.1038/nature12876] [Citation(s) in RCA: 1385] [Impact Index Per Article: 138.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 11/12/2013] [Indexed: 12/24/2022]
Abstract
Plasmodium falciparum resistance to artemisinin derivatives in southeast Asia threatens malaria control and elimination activities worldwide. To monitor the spread of artemisinin resistance, a molecular marker is urgently needed. Here, using whole-genome sequencing of an artemisinin-resistant parasite line from Africa and clinical parasite isolates from Cambodia, we associate mutations in the PF3D7_1343700 kelch propeller domain ('K13-propeller') with artemisinin resistance in vitro and in vivo. Mutant K13-propeller alleles cluster in Cambodian provinces where resistance is prevalent, and the increasing frequency of a dominant mutant K13-propeller allele correlates with the recent spread of resistance in western Cambodia. Strong correlations between the presence of a mutant allele, in vitro parasite survival rates and in vivo parasite clearance rates indicate that K13-propeller mutations are important determinants of artemisinin resistance. K13-propeller polymorphism constitutes a useful molecular marker for large-scale surveillance efforts to contain artemisinin resistance in the Greater Mekong Subregion and prevent its global spread.
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Kalcik M, Gursoy M, Astarcioglu M, Gokdeniz T, Karakoyun S, Cakal B, Yesin M, Kahveci G, Yildiz M, Ozkan M, Cresti A, Cesareo F, Guerrini F, Capati E, Miracapillo G, Severi S, Ternacle J, Lellouche N, Gallet R, Deux JF, Dubois-Rande JL, Teiger E, Lim P, Polizzi V, Pino P, Luzi G, Fiorilli R, Buffa V, Visconti C, Bellavia D, Violini R, Musumeci F, Saura Espin D, Oliva Sandoval M, Gonzalez Carrillo J, Caballero Jimenez L, Espinosa Garcia M, Garcia Navarro M, Lopez Ruiz M, Valdes Chavarri M, De La Morena Valenzuela G. Oral Abstract session * Imaging in structural interventions: 13/12/2013, 08:30-10:00 * Location: Bursa. Eur Heart J Cardiovasc Imaging 2013. [DOI: 10.1093/ehjci/jet222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Muraru D, Mihaila S, Piasentini E, Casablanca S, Naso P, Puma L, Ermacora D, Zoppellaro G, Iliceto S, Badano L, Farsalinos K, Daraban A, Unlu S, Pellikka P, Lancellotti P, Thomas J, Badano L, Voigt JU, Antoine C, Dadfarin-Bejou A, Gallet R, Bremont C, Dubois-Rande J, Lim P, Acosta Martinez J, Lopez-Haldon J, Rodriguez-Rodriguez J, Lopez-Pardo F, Martinez-Martinez A, Nylander E, Hard L, Andersson J, Lindqvist P, Remmets J, Winter R, Andersson B, Roijer A, Gao S, Maret E, Esposito R, Santoro C, Raia R, Schiano-Lomoriello V, Lauria R, Arpino G, De Simone G, Galderisi M, El Ghannudi S, Samet H, Germain P, Jeung MY, Gangi A, Roy C, Marta L, Placido R, Ramalho A, Cortez-Dias N, Nobre Menezes M, Santos L, Infante Oliveira E, Martins S, Almeida A, Nunes Diogo A, Bech-Hanssen O, Pergola V, Fadel B, Di Salvo G, Buccheri S, Mangiafico S, Lavanco V, Bottari V, Arcidiacono A, Tamburino C, Monte IP. Moderated Posters session * The emerging role of 2-dimensional strain in clinical practice: 13/12/2013, 14:00-18:00 * Location: Moderated Poster area. Eur Heart J Cardiovasc Imaging 2013. [DOI: 10.1093/ehjci/jet211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Leang R, Ros S, Duong S, Navaratnam V, Lim P, Ariey F, Kiechel JR, Ménard D, Taylor WRJ. Therapeutic efficacy of fixed dose artesunate-mefloquine for the treatment of acute, uncomplicated Plasmodium falciparum malaria in Kampong Speu, Cambodia. Malar J 2013; 12:343. [PMID: 24060207 PMCID: PMC3852322 DOI: 10.1186/1475-2875-12-343] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Accepted: 09/10/2013] [Indexed: 11/10/2022] Open
Abstract
Background Cambodia stopped using co-blistered, non-fixed, artesunate-mefloquine (ASMQ) in 2008 when treatment failure rates approximated 20%. Fixed dose combination (FDC) ASMQ is efficacious against acute uncomplicated, drug resistant Plasmodium falciparum malaria in Southeast Asia but has not been tested in Cambodia. Methods A 42-day WHO therapeutic efficacy study (TES) was conducted in 2010 in Oral, Kampong Speu province, south-west Cambodia, in patients with acute uncomplicated P. falciparum. Daily administered FDC ASMQ for three days was dosed by age. Genotyping of isolates at day 0 and day of recrudescence by polymerase chain reaction (PCR) classified post-treatment recurrent falciparum parasitaemia. Ex vivo drug sensitivity testing ([3H] hypoxanthine method) was performed on baseline parasites and reported as the drug concentration inhibiting 50% parasite growth vs no drug (IC50). Results Recruited patients numbered 45; five aged <15 years. On day 3, five of 45 [11.1 (3.7-24.05)] % patients were still parasite-positive; one of whom later failed treatment on day 21. There were 5/45 (11.1%) late treatment failures on day 21, 28 and 35; all were PCR diagnosed recrudescent infections. The day 0 MQ IC50s ranged from 11.5-238.9 (median 58.6) nM. Conclusions This TES demonstrated reasonable efficacy in an area of possible reduced artemisinin sensitivity and high MQ IC50s. Efficacy testing of FDC ASMQ should continue in Cambodia and be considered for reintroduction if efficacy returns.
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Witkowski B, Amaratunga C, Khim N, Sreng S, Chim P, Kim S, Lim P, Mao S, Sopha C, Sam B, Anderson JM, Duong S, Chuor CM, Taylor WRJ, Suon S, Mercereau-Puijalon O, Fairhurst RM, Menard D. Novel phenotypic assays for the detection of artemisinin-resistant Plasmodium falciparum malaria in Cambodia: in-vitro and ex-vivo drug-response studies. THE LANCET. INFECTIOUS DISEASES 2013; 13:1043-9. [PMID: 24035558 DOI: 10.1016/s1473-3099(13)70252-4] [Citation(s) in RCA: 419] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Artemisinin resistance in Plasmodium falciparum lengthens parasite clearance half-life during artemisinin monotherapy or artemisinin-based combination therapy. Absence of in-vitro and ex-vivo correlates of artemisinin resistance hinders study of this phenotype. We aimed to assess whether an in-vitro ring-stage survival assay (RSA) can identify culture-adapted P falciparum isolates from patients with slow-clearing or fast-clearing infections, to investigate the stage-dependent susceptibility of parasites to dihydroartemisinin in the in-vitro RSA, and to assess whether an ex-vivo RSA can identify artemisinin-resistant P falciparum infections. METHODS We culture-adapted parasites from patients with long and short parasite clearance half-lives from a study done in Pursat, Cambodia, in 2010 (registered with ClinicalTrials.gov, number NCT00341003) and used novel in-vitro survival assays to explore the stage-dependent susceptibility of slow-clearing and fast-clearing parasites to dihydroartemisinin. In 2012, we implemented the RSA in prospective parasite clearance studies in Pursat, Preah Vihear, and Ratanakiri, Cambodia (NCT01736319), to measure the ex-vivo responses of parasites from patients with malaria. Continuous variables were compared with the Mann-Whitney U test. Correlations were analysed with the Spearman correlation test. FINDINGS In-vitro survival rates of culture-adapted parasites from 13 slow-clearing and 13 fast-clearing infections differed significantly when assays were done on 0-3 h ring-stage parasites (10·88% vs 0·23%; p=0·007). Ex-vivo survival rates significantly correlated with in-vivo parasite clearance half-lives (n=30, r=0·74, 95% CI 0·50-0·87; p<0·0001). INTERPRETATION The in-vitro RSA of 0-3 h ring-stage parasites provides a platform for the molecular characterisation of artemisinin resistance. The ex-vivo RSA can be easily implemented where surveillance for artemisinin resistance is needed. FUNDING Institut Pasteur du Cambodge and the Intramural Research Program, NIAID, NIH.
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Mouillet G, Deballon R, Lellouche N, Yamamoto M, Oguri A, Lim P, Hayat D, Monin JL, Dubois-Rande JL, Teiger E. QRS duration after TAVI with self expanding bioprosthesis: a useful tool to predict permanent pacemaker implantation requirement. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht311.5934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ternacle J, Lellouche N, Gallet R, Gueret P, Dubois-Randes JL, Teiger E, Lim P. LAA closure monitoring by trans-esophageal echocardiography using ICE probe. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht309.p2946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Ternacle J, Gallet R, Jurzak P, Champagne S, Gellen B, Pongas D, Gueret P, Dubois-Rande JL, Teiger E, Lim P. Accuracy of 2D and 3D speckle tracking to identify early subclinical ischemia induced during PCI. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.p2052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Miotto O, Almagro-Garcia J, Manske M, MacInnis B, Campino S, Rockett KA, Amaratunga C, Lim P, Suon S, Sreng S, Anderson JM, Duong S, Nguon C, Chuor CM, Saunders D, Se Y, Lon C, Fukuda MM, Amenga-Etego L, Hodgson AVO, Asoala V, Imwong M, Takala-Harrison S, Nosten F, Su XZ, Ringwald P, Ariey F, Dolecek C, Hien TT, Boni MF, Thai CQ, Amambua-Ngwa A, Conway DJ, Djimdé AA, Doumbo OK, Zongo I, Ouedraogo JB, Alcock D, Drury E, Auburn S, Koch O, Sanders M, Hubbart C, Maslen G, Ruano-Rubio V, Jyothi D, Miles A, O’Brien J, Gamble C, Oyola SO, Rayner JC, Newbold CI, Berriman M, Spencer CCA, McVean G, Day NP, White NJ, Bethell D, Dondorp AM, Plowe CV, Fairhurst RM, Kwiatkowski DP. Multiple populations of artemisinin-resistant Plasmodium falciparum in Cambodia. Nat Genet 2013; 45:648-55. [PMID: 23624527 PMCID: PMC3807790 DOI: 10.1038/ng.2624] [Citation(s) in RCA: 340] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 04/04/2013] [Indexed: 11/09/2022]
Abstract
We describe an analysis of genome variation in 825 P. falciparum samples from Asia and Africa that identifies an unusual pattern of parasite population structure at the epicenter of artemisinin resistance in western Cambodia. Within this relatively small geographic area, we have discovered several distinct but apparently sympatric parasite subpopulations with extremely high levels of genetic differentiation. Of particular interest are three subpopulations, all associated with clinical resistance to artemisinin, which have skewed allele frequency spectra and high levels of haplotype homozygosity, indicative of founder effects and recent population expansion. We provide a catalog of SNPs that show high levels of differentiation in the artemisinin-resistant subpopulations, including codon variants in transporter proteins and DNA mismatch repair proteins. These data provide a population-level genetic framework for investigating the biological origins of artemisinin resistance and for defining molecular markers to assist in its elimination.
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