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Publication Open Access Evaluation of CDC light traps for mosquito surveillance in a malaria endemic area on the Thai-Myanmar border(2015) Patchara Sriwichai; Stephan Karl; Yudthana Samung; Suchada Sumruayphol; Kirakorn Kiattibutr; Anon Payakkapol; Ivo Mueller; Guiyun Yan; Liwang Cui; Jetsumon Sattabongkot; Mahidol University. Faculty of Tropical Medicine. Mahidol Vivax Research Unitstudy was aimed at evaluating the performance of baited and unbaited CDC-LT for indoor and outdoor trapping of endemic mosquito species in northwestern Thailand. Methods: CDC-LT (n = 112) with and without dry ice baits were set both indoorsPublication Open Access Vegetables from the mangrove areas(2002-06) Nuntavan Bunyapraphatsara; Vimol Srisukh; Aranya Jutiviboonsuk; Prapinsara Sornlek; Wilaiwan Thongbainoi; Wongsatit Chuakul; Fong, Harry H.S.; Pezzuto, John M.; Kosmeder, Jerry; Mahidol University. Faculty of Pharmacy. Department of Pharmaceutical BotanySurvey of the mangrove areas in Nakorn Srithammarat and Trang provinces found 33 species of edible plants. We attempted to evaluate the nutritional and medical values of these plants. Due to the seasonal availability and unpleasant taste of the plants, only 20 samples of 19 plants were analyzed for their nutritional values: the water content, crude protein, crude fat, dietary fiber, ash, carbohydrate contents, along with the calcium content. Among these edible plants, Rhizophora mucronata Poir contained the highest dietary fiber and calcium contents; several other plants were rich in dietary fiber and calcium as well. The medical values of the plants were based on the antioxidant, lipid peroxidation and cancer chemoprevention. The pods of Bruguiera gymnorrhiza (L.) Savigny showed strong quinone reductase inhibition. Further studies on isolation of active components are being carried out.Publication Open Access Proteomic analysis of Chikungunya virus infected microgial cells(2012-04) Bizunesh Abere; Nitwara Wikan; Sukathida Ubol; Prasert Auewarakul; Atchara Paemanee; Suthathip Kittisenachai; Sittiruk Roytrakul; Duncan R. Smith; Mahidol University. Institute of Molecular Biosciences. Molecular Pathology Laboratory; Mahidol University. Faculty of Science. Department of Microbiology; Mahidol University. Center for Emerging and Neglected Infectious Disease.Chikungunya virus (CHIKV) is a recently re-emerged public health problem in many countries bordering the Indian Ocean and elsewhere. Chikungunya fever is a relatively self limiting febrile disease, but the consequences of chikungunya fever can include a long lasting, debilitating arthralgia, and occasional neurological involvement has been reported. Macrophages have been implicated as an important cell target of CHIKV with regards to both their role as an immune mediator, as well evidence pointing to long term viral persistence in these cells. Microglial cells are the resident brain macrophages, and so this study sought to define the proteomic changes in a human microglial cell line (CHME-5) in response to CHIKV infection. GeLC-MS/MS analysis of CHIKV infected and mock infected cells identified some 1455 individual proteins, of which 90 proteins, belonging to diverse cellular pathways, were significantly down regulated at a significance level of p<0.01. Analysis of the protein profile in response to infection did not support a global inhibition of either normal or IRES-mediated translation, but was consistent with the targeting of specific cellular pathways including those regulating innate antiviral mechanisms.Publication Open Access Detection of non-amplified mycobacterium tuberculosis genomic DNA using piezoelectric DNA-based biosensors(2010) Thongchai Kaewphinit; Somchai Santiwatanakul; Chamras Promptmas; Kosum ChansiriPiezoelectric DNA-based biosensor technology was developed as a new method for detection of M. tuberculosis. This method consists of immobilizing a thiol-modified oligonucleotide probe on the gold electrode surface of a quartz crystal, using a selfassembled monolayer method. The advantage of this study is that a non-amplified genomic bacterial DNA target was used. Instead, the genomic DNA was digested by restriction enzyme to obtain DNA fragments containing the target sequence. The fabricated biosensor was evaluated through an examination of 200 samples. No cross hybridization were observed against M. avium complex and other microorganisms. This target DNA preparation, without PCR amplification, will reduce time, costs, and the tedious step of amplification.Publication Open Access Proteome analyses of cellular proteins in methicillin-resistant staphylococcus aureus treated with rhodomyrtone, a novel antibiotic Candidate(2011) Wipawadee Sianglum; Potjanee Srimanote; Wijit Wonglumsom; Kanokwan Kittiniyom; Supayang P.VoravuthikunchaiThe ethanolic extract from Rhodomyrtus tomentosa leaf exhibited good antibacterial activities against both methicillinresistant Staphylococcus aureus (MRSA) and S. aureus ATCC 29213. Its minimal inhibitory concentration (MIC) values ranged from 31.25–62.5 mg/ml, and the minimal bactericidal concentration (MBC) was 250 mg/ml. Rhodomyrtone, an acylphloroglucinol derivative, was 62.5–125 times more potent at inhibiting the bacteria than the ethanolic extract, the MIC and MBC values were 0.5 mg/ml and 2 mg/ml, respectively. To provide insights into antibacterial mechanisms involved, the effects of rhodomyrtone on cellular protein expression of MRSA have been investigated using proteomic approaches. Proteome analyses revealed that rhodomyrtone at subinhibitory concentration (0.174 mg/ml) affected the expression of several major functional classes of whole cell proteins in MRSA. The identified proteins involve in cell wall biosynthesis and cell division, protein degradation, stress response and oxidative stress, cell surface antigen and virulence factor, and various metabolic pathways such as amino acid, carbohydrate, energy, lipid, and nucleotide metabolism. Transmission electron micrographs confirmed the effects of rhodomyrtone on morphological and ultrastructural alterations in the treated bacterial cells. Biological processes in cell wall biosynthesis and cell division were interrupted. Prominent changes including alterations in cell wall, abnormal septum formation, cellular disintegration, and cell lysis were observed. Unusual size and shape of staphylococcal cells were obviously noted in the treated MRSA. These pioneer findings on proteomic profiling and phenotypic features of rhodomyrtone-treated MRSA may resolve its antimicrobial mechanisms which could lead to the development of a new effective regimen for the treatment of MRSA infections.Publication Open Access Dietary fluoride intake of children aged 3-7 years in remote areas of Thailand(2000-09) Somsak Chuckpaiwong; สมศักดิ์ จักรไพวงศ์; Siriruk Nakornchai; ศิริรักษ์ นครชัย; Rudee Surari; ฤดี สุราฤทธิ์; Surin Soo-ampon; สุรินทร์ สูอำพัน; Mahidol University. Faculty of Dentistry. Department of Hospital Dentistry; Mahidol University. Faculty of Dentistry. Department of Pediatric Dentistry; Mahidol University. Faculty of Dentistry. Department of Physiology and BiochemistryThe objectives of this study were to measure dietary fluoride intake in children aged 3-7 years, to correlate dietary fluoride and fluoride content in water for use in schools and to estimate fluoride gained from the daily diet. Fifty food samples were collected in 45 schools under the jurisdiction of the Border Patrol Police Department. The schools were sampled by multiple stratified cluster random sampling. The food samples were weighed, then measured for fluoride content by a microdiffusion method. Statistical analysis was conducted using the Kruskal-Wallis test. Dietary fluoride in each age group was compared by Student's t test. Analysis for the relationship between dietary fluoride and fluoride content in water was done using Kendall's tau-b. Our results showed that the mean of dietary fluoride in lunch was 0.08 +/- 0.1 ppm. There were no differences when comparing dietary fluoride between different regions of Thailand (p = 0.07). No correlation was found between dietary fluoride and fluoride content in water used in different schools (r(tau) = 0.017, p = 0.85). The daily dietary fluoride intake in children aged 3-6 years was 0.002-0.004 mgF/kg bw/day, in children aged 7 years was 0.003-0.004 mgF/kg bw/day in boys and 0.002-0.004 mgF/kg bw/day in girls.Publication Open Access Asymptomatic Plasmodium infections in 18 villages of southern Savannakhet Province, Lao PDR (Laos)(2016) Koukeo Phommasone; Bipin Adhikari; Henriques, Gisela; Tiengkham Pongvongsa; Panom Phongmany; Seidlein, Lorenz von; White, Nicholas J.; Day, Nicholas P. J.; Dondorp, Arjen M.; Newton, Paul N.; Mallika Imwong; Mayfong Mayxay; Mahidol University. Faculty of Tropical Medicine. Mahidol Oxford Tropical Medicine Research Unit (MORU)Background: A large fraction of Plasmodium infections do not cause clinical signs and symptoms of disease and persist at densities in blood that are not detectable by microscopy or rapid diagnostic tests. These infections may be critical as a transmission reservoir in areas of low malaria endemicity. Understanding the epidemiology of these infections would be helpful for malaria elimination. Methods: A cross-sectional survey was conducted in Thapangthong and Nong Districts of Savannakhet Province, Lao PDR, to determine the prevalence of parasitaemia. A total of 888 blood samples were collected from afebrile volunteers aged ≥15 years in 18 villages during March and July 2015. Plasmodium infections were diagnosed by rapid diagnostic tests (RDT) and high volume, ultra-sensitive quantitative polymerase chain reaction (uPCR). Results: uPCR detected Plasmodium infections in 175 of 888 samples (20 %). The species distribution was Plasmodium falciparum 3.6 % (32/888), Plasmodium vivax 11.1 % (99/888), mixed infections with P. falciparum and P. vivax 1.6 % (14/888) and Plasmodium of undetermined species 3.4 % (30/888). RDT identified only 2 % (18/888) positive cases. Using uPCR as reference, the sensitivity and specificity of RDTs were 28 and 100 %, respectively, in detecting P. falciparum infections, and 3 and 99 % in detecting asymptomatic P. vivax infections. The K13 kelch propeller domain C580Y mutation, associated with reduced susceptibility to artemisinin derivatives, was found in 75 % (12/18) of P. falciparum isolates from Thapangthong and in 7 % (2/28) from Nong (p < 0.001). In a multivariate analysis, males were more likely to have P. vivax infections [adjusted odds ratio (aOR) 4.76 (95 % CI 2.84–8.00)] while older villagers were at lower risk for parasitaemia [aOR for increasing age 0.98 (95 % CI 0.96–0.99)]. Conclusion: There is a high prevalence of asymptomatic Plasmodium infections in southern Savannakhet. Artemisinin- resistant P. falciparum strains form an increasing proportion of the parasite population in Thapangthong District and are already present in the more remote Nong District. This worrying trend has wider implications for Laos and could reverse the gains achieved by the successful control of malaria in Laos and the Greater Mekong Sub-region (GMS). Rapid elimination of P. falciparum has to be a top priority in Laos as well as in the wider GMS.Publication Open Access Ecotopia 2121: Car-freeCities of the 22nd Century(2015) Marshall, Alan; Mahidol University. Faculty of Social Sciences and HumanitiesThe long-term futures of five cities from around the planet are outlined with the use of one visual image for each city. These cities are : Abu Dhabi(UAE), Denver(USA), Sao Paulo(Brazil), San Diego(USA), and Perth(Australia). These city’s futures are presented in ‘eco-utopian’ terms in which each city studied is proffered to operate within some sort of planned (or naturally-achieved) peaceful, happy and communally-desirable setting that exists in socio-ecological harmony (that is, harmony between society, people, and the environment). The central common feature investigated for all these cities of the future are their ‘car-free’ or ‘car-less’ character. In the spirit of previous idealistic imaginings by writers and artists that have worked on formulating utopias in decades and centuries past, some explanation about how each city can get to this eco-utopian status(by the year 2121AD) is declared, along with an explanation about the social, technical, and economic background that may be present then and there.Publication Open Access Amphetamine and pseudoephedrine cross-tolerance measured by c-Fos protein expression in brains of chronically treated rats(2008) Nootchanart Ruksee; Walaiporn Tongjaroenbuangam; Stefano O Casalotti; Piyarat GovitrapongBackground: Pseudoephedrine is a drug commonly prescribed as a nasal decongestant and bronchodilator and is also freely available in cold remedies and medications. The structural and pharmacological similarity of pseudoephedrine to amphetamine has led to evaluation of its psychomotor stimulant properties within the central nervous system. Previous investigations have shown that the acute responses to pseudoephedrine were similar to those of amphetamine and other psychostimulants. Results: This study examined the effect of chronic administration of pseudoephedrine in rat nucleus accumbens and striatum and identified three further similarities to amphetamine. (i) Chronic exposure to pseudoephedrine reduced the c-Fos response to acute pseudoephedrine treatment suggesting that pseudoephedrine induced tolerance in the animals. (ii) In animals chronically treated with amphetamine or pseudoephedrine the acute c-Fos response to pseudoephedrine and amphetamine was reduced respectively as compared to naïve animals indicating cross-tolerance for the two drugs. (iii)The known involvement of the dopamine system in the response to amphetamine and pseudoephedrine was further confirmed in this study by demonstrating that pseudoephedrine similarly to amphetamine, but with lower potency, inhibited [3H]dopamine uptake in synaptosomal preparations. Conclusion: This work has demonstrated further similarities of the effect of pseudoephedrine to those of amphetamine in brain areas known to be associated with drug addiction. The most significant result presented here is the cross tolerance effect of amphetamine and psudoephedrine. This suggests that both drugs induce similar mechanisms of action in the brain. Further studies are required to establish whether despite its considerable lower potency, pseudoephedrine could pose health and addiction risks in humans similar to that of known psychostimulants.Publication Open Access Persistent Plasmodium falciparum and Plasmodium vivax infections in a western Cambodian population: implications for prevention, treatment and elimination strategies(2016) Rupam Tripura; Peto, Thomas J.; Jeremy Chalk; Lee, Sue J.; Pasathorn Sirithiranont; Chea Nguon; Mehul Dhorda; Seidlein, Lorenz von; Maude, Richard J.; Day, Nicholas P. J.; Mallika Imwong; White, Nicholas J.; Dondorp, Arjen M.; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research UnitBackground: Subclinical Plasmodium parasitaemia is an important reservoir for the transmission and persistence of malaria, particularly in low transmission areas. Methods: Using ultrasensitive quantitative PCR (uPCR) for the detection of parasitaemia, the entire population of three Cambodian villages in Pailin province were followed for 1 year at three-monthly intervals. A cohort of adult participants found initially to have asymptomatic malaria parasitaemia was followed monthly over the same period. Results: The initial cross sectional survey in June 2013 (M0) of 1447 asymptomatic residents found that 32 (2.2 %) had Plasmodium falciparum, 48 (3.3 %) had P. vivax, 4 (0.3 %) had mixed infections and in 142/1447 (9.8 %) malaria was detected but there was insufficient DNA to identify the species (Plasmodium. species). Polymorphisms in the ‘K13-propeller’ associated with reduced susceptibility to artemisinin derivatives (C580Y) were found in 17/32 (51 %) P. falciparum strains. Monthly follow-up without treatment of 24 adult participants with asymptomatic mono or mixed P. falciparum infections found that 3/24 (13 %) remained parasitaemic for 2–4 months, whereas the remaining 21/24 (87 %) participants had cleared their parasitaemia after 1 month. In contrast, 12/34 (35 %) adult participants with P. vivax mono-infection at M0 had malaria parasites (P. vivax or P. sp.) during four or more of the following 11 monthly surveys. Conclusions: This longitudinal survey in a low transmission setting shows limited duration of P. falciparum carriage, but prolonged carriage of P. vivax infections. Radical treatment of P. vivax infections by 8-aminoquinoline regimens may be required to eliminate all malaria from Cambodia. Trial registration ClinicalTrials.gov NCT01872702