Filters

2005 - 200922010 - 201721
Reset filters

Settings

Author: White, Nicholas J.

Search Results

Now showing 1 - 10 of 23
  • Thumbnail Image
    PublicationOpen Access
    Genetic diversity of Plasmodium vivax in Kolkata, India.
    (2006-08-14) Kim, Jung-Ryong; Mallika Imwong; มัลลิกา อิ่มวงศ์; Nandy, Amitabha; Kesinee Chotivanich; เกศินี โชติวานิช; Apichart Nontprasert; อภิชาต นนท์ประเสริฐ; Naowarat Tonomsing; Maji, Ardhendu; Addy, Manjulika; Day, Nick P.J.; White, Nicholas J.; Sasithon Pukrittayakamee; ศศิธร ผู้กฤตยาคามี; Mallika Imwong; Mahidol University. Faculty of Tropical Medicine. Department of Clinical Tropical Medicine
    copy genes were selected for a study of genetic diversity in Kolkata strains. METHODS: Blood from 151 patients with P. vivax infection diagnosed in Kolkata between April 2003 and September 2004 was genotyped at three polymorphic loci: the P. vivax...BACKGROUND: Plasmodium vivax malaria accounts for approximately 60% of malaria cases in Kolkata, India. There has been limited information on the genotypic polymorphism of P. vivax in this malaria endemic area. Three highly polymorphic and single
  • Thumbnail Image
    PublicationOpen Access
    Protein-based signatures of functional evolution in Plasmodium falciparum
    (2011-09-14) Gardner, Kate B.; Sinha, Ipsita; Bustamante, Leyla Y.; Day, Nicholas P.J.; White, Nicholas J.; Woodrow, Charles J.; Woodrow, Charles J.; Mahidol University. Faculty of Tropical Medicine. Wellcome Trust Mahidol University-Oxford Tropical Medicine Research Unit (MORU).
    fundamental challenge to attempts to identify the molecular basis of adaptive change in malaria parasites. RESULTS: Evolutionary comparisons were undertaken using a set of forty P. falciparum metabolic enzyme genes, both within the hominid malaria clade (P.... reichenowi) and across the genus (P. chabaudi). All genes contained coding elements highly conserved across the genus, but there were also a large number of regions of weakly or non-aligning coding sequence. These displayed remarkable levels of non-synonymous
  • Thumbnail Image
    PublicationOpen Access
    Geographic distribution of amino acid mutations in DHFR and DHPS in Plasmodium vivax isolates from Lao PDR, India and Colombia
    (2016) Naowarat Saralamba; Supatchara Nakeesathit; Mayfong Mayxay; Newton, Paul N.; Lyda Osorio; Kim, Jung‑Ryong; White, Nicholas J.; Day, Nicholas P. J.; Dondorp, Arjen M.; Mallika Imwong; Mahidol University. Faculty of Tropical Medicine. Department of Molecular Tropical Medicine and Genetics
    Background: Non-synonymous mutations in dhfr and dhps genes in Plasmodium vivax are associated with sulfadoxine– pyrimethamine (SP) resistance. The present study aimed to assess the prevalence of point mutations in P. vivax dhfr (pvdhfr) and P.... vivax dhps (pvdhps) genes in three countries: Lao PDR, India and Colombia. Methods: Samples from 203 microscopically diagnosed vivax malaria were collected from the three countries. Five codons at positions 13, 57, 58, 61, and 117 of pvdhfr and two
  • Thumbnail Image
    PublicationOpen Access
    Genetic variability of Plasmodium malariae dihydropteroate synthase (dhps) in four Asian countries.
    (2014-04-03) Naowarat Tanomsing; เนาวรัตน์ ถนอมสิงห์; Mayxay, Mayfong; Newton, Paul N.; Nosten, Francois; Dolecek, Christiane; Hien, Tran Tinh; White, Nicholas J.; Day, Nicholas P. J.; Dondorp, Arjen M.; Mallika Imwong; มัลลิกา อิ่มวงศ์; Mallika Imwong; Mahidol University. Faculty of Tropical Medicine. Department of Molecular Tropical Medicine and Genetics; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit; Mahidol University. Faculty of Tropical Medicine. Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Uni.
    The dihydropteroate synthase (dhps) genes of 44 P. malariae strains from four Asian countries were isolated. Only a limited number of polymorphisms were observed. Comparison with homologous mutations in other Plasmodium species showed... that these polymorphisms are unlikely to be associated with sulfadoxine resistance.
  • Thumbnail Image
    PublicationOpen Access
    Plasmodium falciparum Kelch 13 mutations and treatment response in patients in Hpa-Pun District, Northern Kayin State, Myanmar.
    (2017) Bonnington, Craig A.; Aung Pyae Phyo; Ashley, Elizabeth A.; Mallika Imwong; Kanlaya Sriprawat; Parker, Daniel M.; Proux, Stephane; White, Nicholas J.; Nosten, Francois; Mahidol University. Faculty of Tropical Medicine. Shoklo Malaria Research Unit; Mahidol University. Faculty of Tropical Medicine. Mahidol Oxford Research Unit; Mahidol University. Faculty of Tropical Medicine. Department of Molecular Tropical Medicine and Genetics
    Background: Artemisinin resistance, linked to polymorphisms in the Kelch gene on chromosome 13 of Plasmodium falciparum (k13), has outpaced containment eforts in South East Asia. For national malaria control programmes in the region..., it is important to establish a surveillance system which includes monitoring for k13 polymorphisms associated with the clinical phenotype. Methods: Between February and December 2013, parasite clearance was assessed in 35 patients with uncomplicated P
  • Thumbnail Image
    PublicationOpen Access
    Genetic marker suitable for identification and genotyping of Plasmodium ovale curtisi and Plasmodium ovale wallikeri.
    (2013-12) Naowarat Tanomsing; เนาวรัตน์ ถนอมสิงห์; Mallika Imwong; มัลลิกา อิ่มวงศ์; Sutherland, Colin J.; Dolecek,Christiane; Hien,Tran Tinh; Nosten, Francois; Day, Nicholas P. J.; White, Nicholas J.; Snounouh, Georges; Mallika Imwong; Mahidol University. Faculty of Tropical Medicine. Department of Molecular Tropical Medicine and Genetics.; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit.; Mahidol University. Faculty of Tropical Medicine. Shoklo Malaria Research Unit.
    We present a seminested PCR method that specifically discriminates between Plasmodium ovale curtisi and P. ovale wallikeri with high sensitivity. The test is based on species-specific amplification of a size-polymorphic fragment... of the tryptophan-rich antigen gene, potra, which also permits discrimination of intraspecific sequence variants at this locus.
  • Thumbnail Image
    PublicationOpen Access
    Sequence variation does not confound the measurement of plasma PfHRP2 concentration in African children presenting with severe malaria
    (2012-08-16) Thiranut Ramutton; Hendriksen, Ilse CE; Mwanga-Amumpaire, Juliet; Mtove, George; Olaosebikan, Rasaq; Tshefu, Antoinette K.; Onyamboko, Marie A.; Karema, Corine; Maitland, Kathryn; Gomes, Ermelinda; Gesase, Samwel; Reyburn, Hugh; Kamolrat Silamut; Kesinee Chotivanich; เกศินี โชติวานิช; Kamoltip Promnares; Fanello, Caterina I.; Seidlein, Lorenz von; Day, Nicholas P.J.; White, Nicholas J.; Dondorp, Arjen M.; Mallika Imwong; มัลลิกา อิ่มวงศ์; Woodrow, Charles J.; Woodrow, Charles J.; Mahidol University. Faculty of Tropical Medicine. Department of Clinical Tropical Medicine.; Mahidol University. Faculty of Tropical Medicine. Department of Molecular Tropical Medicine and Genetics.; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit.
    BACKGROUND: Plasmodium falciparum histidine-rich protein PFHRP2 measurement is used widely for diagnosis, and more recently for severity assessment in falciparum malaria. The Pfhrp2 gene is highly polymorphic, with deletion of the entire gene... countries contributing to the largest hospital-based severe malaria trial (AQUAMAT). The quantitative relationship between sequence polymorphism and PFHRP2 plasma concentration was examined in samples from selected sites in Mozambique and Tanzania
  • Thumbnail Image
    PublicationOpen Access
    Practical PCR genotyping protocols for Plasmodium vivax using Pvcs and Pvmsp1.
    (2005-04-27) Mallika Imwong; มัลลิกา อิ่มวงศ์; Sasithon Pukrittayakamee; Grüner, Anne Charlotte; Rénia, Laurent; Letourneur, Frank; Sornchai Looareesuwan; ศรชัย หลูอารีย์สุวรรณ; White, Nicholas J.; Snounou, Georges; Mallika Imwong; Mahidol University. Faculty of Tropical Medicine. Department of Clinical Tropical Medicine.
    BACKGROUND: The use of antimalarial drug combinations with artemisinin derivatives is recommended to overcome drug resistance in Plasmodium falciparum. The fixed combination of oral artemether-lumefantrine, an artemisinin combination therapy (ACT) is highly effective and well tolerated. It is the only registered fixed combination containing an artemisinin. The trial presented here was conducted to monitor the efficacy of the six-dose regimen of artemether-lumefantrine (ALN) in an area of multi-drug resistance, along the Thai-Myanmar border. METHODS: The trial was an open-label, two-arm, randomized study comparing artemether-lumefantrine and mefloquine-artesunate for the treatment of uncomplicated falciparum malaria with 42 days of follow up. Parasite genotyping by polymerase chain reaction (PCR) was used to distinguish recrudescent from newly acquired P. falciparum infections. The PCR adjusted cure rates were evaluated by survival analysis. RESULTS: In 2001-2002 a total of 490 patients with slide confirmed uncomplicated P. falciparum malaria were randomly assigned to receive artemether-lumefantrine (n = 245) or artesunate and mefloquine (n = 245) and were followed for 42 days. All patients had rapid initial clinical and parasitological responses. In both groups, the PCR adjusted cure rates by day 42 were high: 98.8% (95% CI 96.4, 99.6%) for artemether-lumefantrine and 96.3% (95% CI 93.1, 98.0%) for artesunate-mefloquine. Both regimens were very well tolerated with no serious adverse events observed attributable to either combination. CONCLUSION: Overall, this study confirms that these two artemisinin-based combinations remain highly effective and result in equivalent therapeutic responses in the treatment of highly drug-resistant falciparum malaria.
  • Thumbnail Image
    PublicationOpen Access
    Comparative genome‑wide analysis and evolutionary history of haemoglobin‑processing and haem detoxification enzymes in malarial parasites
    (2016) Patrath Ponsuwanna; Theerarat Kochakarn; Duangkamon Bunditvorapoom; Krittikorn Kümpornsin; Otto, Thomas D.; Chase Ridenour; Kesinee Chotivanich; Prapon Wilairat; White, Nicholas J.; Olivo Miotto; Thanat Chookajorn; Mahidol University. Faculty of Tropical Medicine. Genomic and Evolutionary Medicine Unit, Centre of Excellence in Malaria
    -synonymous mutations mapped onto protein structures revealed clusters of amino acid residues in close proximity or near the active sites of proteases. Conclusion: A high degree of polymorphism at the haemoglobin processing genes implicates an imposition... within Plasmodium species, and with the representatives of Apicomplexan species with various host tropisms, were created. Genetic variants were mapped onto existing three-dimensional structures. Genome-wide single nucleotide polymorphism data were used
  • Thumbnail Image
    PublicationOpen Access
    A population survey of the glucose-6-phosphate dehydrogenase (G6PD) 563C>T (Mediterranean) mutation in Afghanistan
    (2014-02-21) Natsuda Jamornthanyawat; นาถสุดา จามรธัญญวาท; Awab, Ghulam R.; Naowarat Tanomsing; เนาวรัตน์ ถนอมสิงห์; Sasithon Pukrittayakamee; ศศิธร ผู้กฤตยาคามี; Yamin, Fazel; Dondorp, Arjen M.; Day, Nicholas P. J.; White, Nicholas J.; Woodrow, Charles J.; Mallika Imwong; มัลลิกา อิ่มวงศ์; Mallika Imwong; Mahidol University. Faculty of Tropical Medicine. Department of Clinical Tropical Medicine; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit (MORU); Mahidol University. Faculty of Tropical Medicine. Department of Molecular Tropical Medicine and Genetics
    odds ratio = 1.73, 0.73-4.13). Testing of known polymorphic markers (1311C>T in exon 11, and C93T in intron XI) in a subset of 82 individuals wild-type at C563 revealed a mixture of 3 haplotypes in the background population and was consistent with data