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Publication Open 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.Publication Open Access Molecular detection and speciation of pathogenic Leptospira spp. in blood from patients with culture-negative leptospirosis(2011-12-13) Siriphan Boonsilp; Janjira Thaipadungpanit; จันทร์จิรา ไทยผดุงพานิช; Premjit Amornchai; เปรมจิตต์ อมรชัย; Vanaporn Wuthiekanun; Wirongrong Chierakul; Direk Limmathurotsakul; ดิเรก ลิ้มมธุรสกุล; Day, Nicholas P.; Peacock, Sharon J.; Janjira Thaipadungpanit; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research UnitBACKGROUND: Pathogenic Leptospira spp. present in the blood of patients with leptospirosis during the first week of symptoms can be detected using culture or PCR. A proportion of patients who are positive by PCR are negative by culture... prospective study of 418 consecutive patients presenting to a hospital in northeast Thailand with an acute febrile illness. Admission blood samples were taken for Leptospira culture and PCR. A single tube nested PCR that amplified a region of the rrs genePublication Open Access Epidemiological and Molecular Characterization of Dengue Virus Circulating in Bhutan, 2013-2014(2015-08-21) Sangay Zangmo; Chonticha Klungthong; Piyawan Chinnawirotpisan; Srisurang Tantimavanich; Nathamon Kosoltanapiwat; Butsaya Thaisomboonsuk; Kelzang Phuntsho; Sonam Wangchuk; In-Kyu Yoon; Stefan Fernandez; Mahidol University. Faculty of Medical Technology. Department of Clinical Microbiology and Applied TechnologyDengue is one of the most significant public health problems in tropical and subtropical countries, and is increasingly being detected in traditionally non-endemic areas. In Bhutan, dengue virus (DENV) has only recently been detected and limited information is available. In this study, we analyzed the epidemiological and molecular characteristics of DENV in two southern districts in Bhutan from 2013–2014. During this period, 379 patients were clinically diagnosed with suspected dengue, of whom 119 (31.4%) were positive for DENV infection by NS1 ELISA and/or nested RT-PCR. DENV serotypes 1, 2 and 3 were detected with DENV-1 being predominant. Phylogenetic analysis of DENV-1 using envelope gene demonstrated genotype V, closely related to strains from northern India.Publication Open Access Improvement of culture conditions for long‑term in vitro culture of Plasmodium vivax(2015) Wanlapa Roobsoong; Tharinjaroen, Chayada S; Nattawan Rachaphaew; Porpimon Chobson; Louis Schofield; Liwang Cui; Adams, John H; Jetsumon Sattabongkot; Mahidol University. Faculty of Tropical Medicine. Mahidol Vivax Research Unit: Clinical samples were collected from patients diagnosed with P. vivax in western Thailand. Leukocytedepleted P. vivax infected blood samples were cultured in a modified McCoy’s 5A medium at 5% haematocrit under hypoxic condition (5% O2, 5% CO2, and 90% N2...). Reticulocytes purified from adult peripheral blood were added daily to maintain 4% reticulocytes. Parasites were detected by microscopic examination of Giemsa-stained smears and molecular methods. Results: The effects of culture variables were first analysedPublication Open Access A flow cytometric analysis of the inhibition of platelet reactivity due to nitrite reduction by deoxygenated erythrocytes(2014) Krittapoom Akrawinthawong; Park, Ji Won; Barbora Piknova; Nathawut Sibmooh; Suthat Fucharoen; Schechter, Alan N.; Mahidol University. Faculty of Science. Department of Pharmacology; Mahidol University. Faculty of Medicine Siriraj Hospital. Department of Biochemistry; Mahidol University. Institute of Science and Technology for Research and Development. Thalassemia Research CenterNitric oxide (NO), a small gas molecule, has long been known to be a potent inhibitor of platelet function but the physiological and pathological implications of platelet inhibition by NO have not been well clarified. We recently showed that the addition of nitrite to platelet-rich plasma in the presence of erythrocytes could inhibit platelet aggregation and this inhibitory effect of nitrite + erythrocytes was enhanced by deoxygenation of erythrocytes as measured by P-selectin expression and cGMP production. In order to study the nitrite effect on platelets at different oxygen levels, we used the flow cytometric assays to detect platelet membrane surface markers upon activation. The P-selectin and activated gpIIb/IIIa expression on platelet membranes in response to ADP, collagen and thrombin stimulation was measured at various hematocrit and oxygen levels. Nitrite (0.1 to 1.0 mM) significantly decreased the percentage of these surface markers on the platelet membrane at the hematocrit values above 23% and oxygen levels lower than 49 mmHg. The inhibitory effect of nitrite was augmented by increasing hematocrit values and decreasing oxygen saturation. C-PTIO (an NO scavenger) prevented the platelet inhibition by nitrite + erythrocytes whereas the inhibitors of NO synthase and xanthine oxidoreductase had no effect. These results support the proposal that circulating nitrite decreases platelet reactivity in the presence of partially deoxygenated erythrocytes through its reduction to NO, which may also explain certain differences between arterial and venous thrombosis and support directly the role of deoxyhemoglobin in this process. We believe that our flow cytometric assays offer a possibility to identify the individual molecular process involved in these effects.Publication Open Access False rumours of disease outbreaks caused by infectious myonecrosis virus (IMNV) in the whiteleg shrimp in Asia(2011) Saengchan Senapin; Kornsunee Phiwsaiya; Warachin Gangnonngiw; Flegel, Timothy W.; Mahidol University. Faculty of Science. Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp)Background: Infectious myonecrosis virus (IMNV) disease outbreaks in cultivated whiteleg shrimp Penaeus (Litopenaeus) vannamei are characterized by gross signs of whitened abdominal muscles and by slow mortality reaching up to 70%. In 2006 the first disease outbreaks caused by IMNV in Asia occurred in Indonesia. Since then rumours have periodically circulated about IMNV disease outbreaks in other Asian countries. Our findings indicate that these are false rumours. Findings: Our continual testing by nested RT-PCR of shrimp samples suspected of IMNV infection from various Asian countries since 2006 has yielded negative results, except for samples from Indonesia. Our results are supported by the lack of official reports of IMNV outbreaks since January 2007 in the Quarterly Report on Aquatic Animal Diseases (QAAD) from the Network of Aquaculture Centers in Asia Pacific (NACA). In most cases, our shrimp samples for which tissue sections were possible showed signs of muscle cramp syndrome that also commonly causes muscle whitening in stressed whiteleg shrimp. Thus, we suspect that most of the false rumours in Asia about IMNV outside of Indonesia have resulted because of muscle cramp syndrome. Conclusions: Results from continual testing of suspected IMNV outbreaks in Asian countries other than Indonesia since 2006 and the lack of official country reports of IMNV outbreaks since January 2007, indicate that rumours of IMNV outbreaks in Asian countries outside of Indonesia are false. We suspect that confusion has arisen because muscle cramp syndrome causes similar signs of whitened tail muscles in whiteleg shrimp.Publication Open Access Mitochondrial genome sequences reveal deep divergences among Anopheles punctulatus sibling species in Papua New Guinea.(2013-02-14) Logue, Kyle; Chan, Ernest R.; Phipps, Tenisha; Small,Scott T.; Reimer, Lisa; Henry-Halldin, Cara; Jetsumon Sattabongkot; เจตสุมน สัตตบงกช; Siba, Peter M.; Zimmerman, Peter A.; Serre, David; Zimmerman, Peter A.; Serre, David; Mahidol University. Faculty of Tropical Medicine.species are able to transmit malaria requires a better comprehension of their evolutionary history. In particular, understanding relationships and divergence times among Anopheles species may enable assessing how malaria-related traits (e.g. blood feedingPublication Open Access Increased alpha-defensin expression is associated with risk of coronary heart disease: a feasible predictive inflammatory biomarker of coronary heart disease in hyperlipidemia patients(2016) Yaowapa Maneerat; Kriengchai Prasongsukarn; Surachet Benjathummarak; Wilanee Dechkhajorn; Urai Chaisri; Mahidol University. Faculty of Tropical Medicine. Department of Tropical Pathologyand the development of CHD, and whether it was a useful predictive indicator for CHD risk. Methods: First, DNA microarray analysis was performed on peripheral blood mononuclear cells (PBMCs) from Thai control, hyperlipidemia and CHD male patients (n = 7). GenePublication Open Access Post-partum, post-sterilization tubo-ovarian abscess caused by Fusobacterium necrophorum: a case report(2012) Chenchit Chayachinda; Amornrut Leelaporn; Pornpimol Ruangvutilert; Manopchai Thamkhantho; Mahidol University. Faculty of Medicine Siriraj Hospital. Unit of Gynecologic Infectious Diseases and Female Sexually Transmitted DiseasesIntroduction: Post-partum, post-sterilization tubo-ovarian abscess is a rare event. Fusobacterium necrophorum subspecies funduliforme, a normal flora found mainly in the oral cavity, appears to be the etiologic organism. Case presentation: In this case report, a 25-year-old Thai woman had a post-partum, post-sterilization tubo-ovarian abscess caused by the strictly anaerobic bacterium, Fusobacterium necrophorum subspecies funduliforme. Progressively severe symptoms started 3 weeks after her third vaginal delivery with a tubal sterilization on the following day. On admission, she presented with peritonitis and impending shock. An exploratory laparotomy showed a ruptured left tubo-ovarian abscess. A segment of her ileum had to be resected because of severe inflammation. Conclusions: Fusobacterium necrophorum subspecies funduliforme can be an etiologic organism of a ruptured tubo-ovarian abscess following tubal sterilization in a healthy host.Publication Open Access Glutathione Redox system in Beta-Thalassemia/Hb E patients(2013) Kalpravidh, Ruchaneekorn W.; Thongchai Tangjaidee; Suneerat Hatairaktham; Ratiya Charoensakdi; Narumol Panichkul; Noppadol Siritanaratkul; Suthat Fucharoen; Mahidol University. Institute of Molecular Biosciences. Thalassemia Research Center; Mahidol University. Faculty of Medicine Siriraj Hospital. Department of Medicine; Mahidol University. Faculty of Medicine Siriraj Hospital. Department of Biochemistryand splenectomy on redox status expressed by whole blood glutathione (GSH)/glutathione disulfide (GSSG) and also to evaluate glutathione-related responses to oxidation in β-thalassemia/Hb E patients. Twenty-seven normal subjects and 25 β-thalassemia/Hb E patients... were recruited and blood was collected. The GSH/GSSG ratio, activities of glutathione-related enzymes, hematological parameters, and serum ferritin levels were determined in individuals. Patients had high iron-induced oxidative stress, shown