- PublicationCommunity engagement on the Thai-Burmese border: rationale, experience and lessons learnt(2010-06-01) Phaik Yeong Cheah; Khin Maung Lwin; Lucy Phaiphun; Ladda Maelankiri; Michael Parker; Nicholas P. Day; Nicholas J. White; François Nosten; Shoklo Malaria Research Unit; Mahidol University; Nuffield Department of Clinical Medicine; University of OxfordCommunity engagement is increasingly promoted in developing countries, especially in international health research, but there is little published experience. The Shoklo Malaria Research Unit (SMRU) conducts research with refugees, migrant workers, displaced people, and day migrants on the Thai-Burmese border, and has recently facilitated the set up of the Tak Province Border Community Ethics Advisory Board (T-CAB). Valuable lessons have been learnt from consultation with the T-CAB especially in the area of participant recruitment and the informed consent process. A lot of new research questions have emerged from consultation with the T-CAB. This paper describes our experience, lessons learnt and the unique challenges faced working with the T-CAB from its initial conception to date. We conclude that consultation with the T-CAB has made improvements in our research in particular operational and ethical aspects of our studies. © 2010 Royal Society of Tropical Medicine and Hygiene.
- PublicationA description of antimicrobial susceptibility of Streptococcus pneumoniae-Siriraj Hospital, Thailand: 2008.(2010-11-01) Somporn Srifuengfung; Kulkanya Chokephaibulkit; Chanwit Tribuddharat; Sopita Comerungsee; Mahidol UniversityStreptococcus pneumoniae was isolated from 170 patient specimens at Siriraj Hospital during January-December 2008. Patients were 66% male and ranged in age from 3 months to 94 years (mean +/- SD = 38.2 +/- 31.7). The largest proportion (29.4%) of isolates were from patients older than 60 years, followed by patients aged 2-5 years (20%) and from patients less than 2 years (12.4%). Monthly isolation was highest in December (22 isolates in December compared to the average of 13 isolates of the other months). Antimicrobial susceptibility for eight drugs was determined by the disk diffusion method. Overall, susceptibility was generally high to chloramphenicol (71.8%), linezolid (100%), ofloxacin (93.5%) and vancomycin (100%), but less susceptible to erythromycin (35.3%), penicillin (31.1%), tetracycline (28.8%) and trimethoprim/ sulfamethoxazole (24.1%). Among the 105 (62%) isolates resistant to three or more drugs, the most common resistance pattern was erythromycin-penicillin-tetracycline-trimethoprim/sulfamethoxazole, accounting for 39% of such isolates, followed by chloramphenicol-erythromycin-penicillin-tetracycline- trimethoprim/sulfamethoxazole (29.5%). The minimal inhibitory concentrations (MIC) of penicillin and cefotaxime were determined by broth microdilution. By 2008 CLSI criteria, 92% and 90% of 51 sterile site isolates were penicillin and cefotaxime susceptible, including one of two meningitis cases. In contrast, of 26 non-sterile site isolates, only 26.9% and 76.9% were susceptible to penicillin and cefotaxime, respectively. The MICs of penicillin were higher for isolates from non-sterile sites than for those from sterile sites.
- PublicationSmall Intestinal Bacterial Overgrowth(2010-08-31) Monthira Maneerattanaporn; William D. Chey; University of Michigan, Ann Arbor; Mahidol University; University of Michigan Health SystemIn summary, SIBO is the condition which may cause a wide range of clinical and nutritional manifestations. Clinical suspicion must be high in patients with disorders that disrupt the small intestine's normal defenses against SIBO. There is a growing body of evidence to suggest that the prevalence of SIBO is higher in the elderly. Though an association between SIBO and IBS has been suggested, the available evidence is not conclusive. There is no currently available test which can be considered an adequate gold standard for the diagnosis of SIBO. Small bowel culture is highly specific but lacks sensitivity, particularly for distal SIBO. Carbohydrate breath tests are noninvasive and simple to perform but lack standardization and have not been adequately validated as a reliable surrogate means of identifying SIBO. Therapy of SIBO consists of antibiotics to decontaminate the small intestine, nutritional support to address the consequences of longstanding SIBO and when possible, correction of the underlying cause of SIBO. © 2010 Blackwell Publishing Ltd.
- PublicationCost-effectiveness analysis of home rehabilitation programs for Thai stroke patients(2010-12-01) Paskorn Sritipsukh; Arthorn Riewpaiboo; Pakaratee Chaiyawa; Kongkiat Kulkantrakor; Thammasat University; Mahidol UniversityBackground: The individual home rehabilitation program for ischemic stroke patients was conducted in a Thai healthcare setting. The program demonstrated that it was statistically significantly more effective than the conventional method. However for policy makers to adopt this program, the question of cost-effectiveness must be answered. Objective: To compare the costs and effects of a home rehabilitation program versus conventional hospital care for ischemic stroke patients in Thailand. Material and Method: Cost-effectiveness analysis was conducted alongside a clinical trial. An open-label randomized control trial was conducted to explore the efficacy of a home rehabilitation program for acute stroke care for three months after hospital discharge. The Barthel Index and Modified Rankin Scale were used to evaluate the outcome measures. Success was defined as improvement by at least one level of the outcome scales. An incremental cost-effectiveness ratio, including sensitivity analysis, was presented. Results: Fifty-eight patients were included in the study. Patients were randomly assigned to the study and control groups (28 and 30, respectively). The cost and number of successful cases in the study group were higher than those of the control group. The incremental cost-effectiveness ratio (ICER) was lowest-13,644 Thai Baht (THB)-regarding the Modified Rankin Scale measurement. For patients achieving mild disability and no disability based on the Barthel Index, the ICERs were 14,212 THB and 24,364 THB, respectively. Sensitivity analyses regarding variations in number of patients and cost of home visits demonstrated more cost-effectiveness than the base case. Conclusion: Providing a home rehabilitation program with higher cost resulted in a greater number of patients avoiding disability than via conventional hospital care. The hospital had to pay approximately 24,000 THB for each additional disability-avoided patient when switching from conventional hospital care to a home rehabilitation program. This was assumed to be cost-effective when compared to per capita gross domestic product.
- PublicationOccurrences and behavior of perfluorinated compounds (PFCs) in several wastewater treatment plants (WWTPs) in Japan and Thailand(2010-06-17) Binaya Raj Shivakoti; Shuhei Tanaka; Shigeo Fujii; Chinagarn Kunacheva; Suwanna Kitpati Boontanon; Chanatip Musirat; S. T M L D Seneviratne; Hiroaki Tanaka; Kyoto University; Mahidol UniversityThis study examines occurrences of 11 perfluorinated compounds (PFCs) in several wastewater treatment plants in Japan and Thailand. Surveys are conducted in eight wastewater treatment plants (WWTPs) in Japan and central WWTPs of five industrial estates (IEs) in Thailand. Samples are collected from all major treatment processes in order to understand the behavior of PFCs in WWTPs. PFCs are detected in all WWTPs in Japan and Thailand. Concentrations of PFCs even exceed several thousands ng/L in some WWTPs. PFOS, PFOA, and PFNA are mainly detected in WWTPs in Japan, while PFBuS, PFOA, and PFHxA are mainly detected in WWTP of IEs in Thailand. Even though some of the investigated WWTPs utilize biological treatment processes coupled with chlorination, ozonation, or activated carbon adsorption, they are found ineffective to remove PFCs. During the treatment process, PFCs are found to accumulate at exceptionally high concentration levels in the activated sludge of an aeration tank and returned activated sludge. Overall, the estimated total daily mass of discharged PFCs is 124.95 g/d (PFASs: 49.81 g/d; PFCAs: 75.14 g/d) from eight WWTPs in Japan and 55.04 g/d (PFASs: 12 g/d; PFCAs: 43.04 g/d) from five WWTPs in Thailand. Although the presented data are from a single observation in each WWTP, the results indicate that certain industries using PFCs in manufacturing processes could be the principle point source, while domestic activities could be releasing PFCs at detectable levels causing environmental concern. © 2010 The Royal Society of Chemistry.
- PublicationWhat Thai students think about directions and types of frictional forces(2010-12-13) Singha Prasitpong; Ratchapak Chitaree; Mahidol UniversityThe frictional force is one of the obstacles to learning in physics. By itself, this topic consists of complicated ideas. In this study, we have investigated Thai students' ideas about directions and types of frictional forces by using open-ended questions and interviews. For example, these students believed that the direction of the frictional force always opposes to that of the motion or that of the external force exerted to such object. Moreover, most students thought that the frictional forces are resistant forces involving the object movement. They did not realize that sometimes the frictional force causes the object to move; has the same direction of the motion as well. About the kinetic friction, most students thought that if an object moves, it will always have the kinetic friction at the contact areas. From what we have found, we suggest that important steps for improving students' understanding of frictional forces is to teach students to draw free body diagrams, which can help students to visualize all forces acting on a single object. © 2010 American Institute of Physics.
- PublicationThe ubiquitin-proteasome pathway is important for dengue virus infection in primary human endothelial cells(2010-10-01) Rattiyaporn Kanlaya; Sa Nga Pattanakitsakul; Supachok Sinchaikul; Shui Tein Chen; Visith Thongboonkerd; Mahidol University; Genomics Research Center, Academia Sinica; National Taiwan UniversityDengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) are the most severe forms of dengue virus infection with hemorrhage and plasma leakage. However, pathogenic mechanisms of DHF and DSS remain poorly understood. We therefore investigated host responses as determined by changes in the cellular proteome of primary human endothelial cells upon infection with dengue virus serotype 2 (DEN-2) at a multiplicity of infection (MOI) of 10 for 24 h. Two-dimensional PAGE and quantitative intensity analysis revealed 38 significantly altered protein spots (16 upregulated and 22 downregulated) in DEN-2-infected cells compared to mock controls. These altered proteins were successfully identified by mass spectrometry, including those involved in oxidative stress response, transcription and translation, cytoskeleton assembly, protein degradation, cell growth regulation, apoptosis, cellular metabolism, and antiviral response. The proteomic data were validated by Western blot analyses [upregulated ubiquitin-activating enzyme E1 (UBE1) and downregulated annexin A2] and an immunofluorescence study (upregulated MxA). Interestingly, we found that MxA was colocalized with DEN-2 viral capsid protein, strengthening its role as an antiviral protein. Moreover, we also identified upregulation of a proteasome subunit. Our functional study revealed the significant role of ubiquitination in dengue infection and UBE1 inhibition by its specific inhibitor (UBEI-41) caused a significant reduction in the level of viral protein synthesis and its infectivity. Our findings suggest that various biological processes were triggered in response to dengue infection, particularly antiviral IFN and ubiquitin-proteasome pathways. © 2010 American Chemical Society.
- PublicationAuthentication of Coscinium fenestratum among the other Menispermaceae plants prescribed in Thai folk medicines(2010-01-01) Rith Watthanachaiyingcharoen; Katsuko Komatsu; Shu Zhu; Opa Vajragupta; Wichet Leelamanit; Srinakharinwirot University; University of Toyama; Mahidol UniversityIn Ayurveda and Thai traditional medicines, material from Coscinium fenestratum is commonly prescribed as active ingredients with diverse therapeutic purposes. However, C. fenestratum is also a seriously endangered medicinal liana. Thus, its crude material is very rare and is being substituted with substances from Arcangelisia flava or Fibraurea tinctoria (Menispermaceae), which have high morphological similarity. In this current study, nuclear 18S ribosomal RNA (rRNA) gene and nuclear ribosomal DNA internal transcribed spacer (ITS) gene sequences with the polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) technique were exploited to identify these three species. The nuclear 18S rRNA gene sequences of C. fenestratum, A. flava, and F. tinctoria consisted of 1809, 1805, and 1809 base pairs (bps), respectively, while their ITS gene regions were 694, 622, and 631 bps in length, respectively. The 18S rRNA gene of C. fenestratum digested with SmaI restriction enzyme displayed the electrophoresis profile of 729 and 790 bps; for A. flava and F. tinctoria, the digested products showed fragments of 1519 bps. Although the ITS gene regions of A. flava and F. tinctoria had unrecognized sequences with SalI, the SalI-digested ITS of C. fenestratum exhibited fragments of approximately 599 bp. Thus, the 18S rRNA gene and ITS gene sequences with PCR-RFLPs were proven to be powerful molecular markers for identifying C. fenestratum and distinguishing it from the other two Menispermaceae plants. © 2010 Pharmaceutical Society of Japan.
- PublicationProperties of natural rubber filled with ultra fine acrylate rubber powder(2010-03-01) Pongdhorn Sae-Oui; Chakrit Sirisinha; Kannika Hatthapanit; Thailand National Metal and Materials Technology Center; Mahidol UniversityProperties of natural rubber (NR) filled with various loadings of ultra-fine vulcanized acrylate rubber powder (ACMP) were investigated. ACMP loading was varied from 0 to 20 phr and, after compounding, the compound properties were determined. Results reveal that increasing ACMP loading leads to improved processability, as evidenced by the reduction of both mixing energy and Mooney viscosity. ACMP, however, has negative effect on cure, that is, both scorch time and optimum cure time are prolonged while the state of cure is reduced with increasing ACMP loading. Due to the reinforcing effect of the fine ACMP particles, both modulus and hardness are found to increase consecutively with increasing ACMP loading. The tensile strength is also found to improve with increasing ACMP loading up to 10 phr. However, due to the cure retardation effect and the high thermoplastic nature, the presence of ACMP causes deterioration of elasticity. As ACMP is highly polar and fully saturated, the addition of ACMP enhances the resistance to oil and thermal aging of the NR vulcanizate. Significant improvement of thermal aging resistance is found when 10 phr or more of ACMP is added. © The Author(s), 2010.
- PublicationSynergistic activities between carbapenems and other antimicrobial agents against Acinetobacter baumannii including multidrug-resistant and extensively drug-resistant isolates(2010-09-01) Pattarachai Kiratisin; Anucha Apisarnthanarak; Srirumpa Kaewdaeng; Mahidol University; Faculty of Medicine, Thammasat UniversityTreatment options for multidrug-resistant (MDR) and extensively drug-resistant (XDR) Acinetobacter baumannii have been seriously limited and may require combination antimicrobial therapy. In this study, we searched for synergistic activity between carbapenems (doripenem, imipenem and meropenem) and various non-traditional agents (cefoperazone/sulbactam, doxycycline, rifampicin, netilmicin and moxifloxacin) against 40 A. baumannii clinical isolates, including MDR and XDR isolates. The results showed that combination of each carbapenem with cefoperazone/sulbactam, based on the Etest method, demonstrated synergy more frequently (17.5-32.5%) than the other tested agents, which may suggest a role in combination therapy against highly resistant A. baumannii. © 2010 Elsevier B.V. and the International Society of Chemotherapy.