Mahidol University

About: Mahidol University is a education organization based out in Bangkok, Nakhon Pathom, Thailand. It is known for research contribution in the topics: Population & Malaria. The organization has 23758 authors who have published 39761 publications receiving 878781 citations.

T Cell Responses in Dengue Hemorrhagic Fever: Are Cross-Reactive T Cells Suboptimal?

Abstract: Dengue virus infection poses a growing public health and economic burden in a number of tropical and subtropical countries. Dengue circulates as a number of quasispecies, which can be divided by serology into four groups or serotypes. An interesting feature of Dengue, recognized over five decades ago, is that most severe cases that show hemorrhagic fever are not suffering from a primary infection. Instead, they are reinfected with a virus of different serotype. This observation poses considerable problems in vaccine design, and it is therefore imperative to gain a full understanding of the mechanisms underlying this immunological enhancement of disease. In this study, we examined a T cell epitope restricted by HLA-A*24, a major MHC class I allele, in Southeast Asia in a cohort of children admitted to a hospital with acute Dengue infection. The cytokine profiles and the degranulation capacity of T cells generated to this epitope are defined and compared across different viral serotypes. Cross-reactive Dengue-specific T cells seem to show suboptimal degranulation but high cytokine production, which may contribute to the development of the vascular leak characteristic of Dengue hemorrhagic fever.

Efficacy of risperidone for prevention of postoperative delirium in cardiac surgery.

Abstract: This randomised, double-blinded, placebo-controlled study was primarily aimed to evaluate the potential of risperidone to prevent postoperative delirium following cardiac surgery with cardiopulmonary bypass and the secondary objective was to explore clinical factors associated with postoperative delirium. One-hundred-and-twenty-six adult patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomly assigned to receive either 1 mg of risperidone or placebo sublingually when they regained consciousness. Delirium and other outcomes were assessed. The confusion assessment method for intensive care unit was used to assess postoperative delirium. The incidence of postoperative delirium in the risperidone group was lower than the placebo group (11.1% vs. 31.7% respectively, P=0.009, relative risk = 0.35, 95% confidence interval [CI] = 0.16-0.77). Other postoperative outcomes were not statistically different between the groups. In exploring the factors associated with delirium, univariate analysis showed many factors were associated with postoperative delirium. However multiple logistic regression analysis showed a lapse of 70 minutes from the time of opening eyes to following commands and postoperative respiratory failure were independent risk factors (P=0.003, odds ratio [OR] = 4.57, 95% CI = 1.66-12.59 and P=0.038, OR = 13.78, 95% CI = 1.15-165.18 respectively). A single dose of risperidone administered soon after cardiac surgery with cardiopulmonary bypass reduces the incidence of postoperative delirium. Multiple factors tended to be associated with postoperative delirium, but only the time from opening eyes to following commands and postoperative respiratory failure were independent risk factors in this study.

Improved Green Fluorescent Protein Reporter Gene-Based Microplate Screening for Antituberculosis Compounds by Utilizing an Acetamidase Promoter

Abstract: Tuberculosis continues to be a major global public health problem. In addition, the increasing prevalence of multidrug-resistant Mycobacterium tuberculosis is of concern (20) and has fostered a sense of urgency with regard to the need to acquire new drugs. Several rapid methods such as the microplate Alamar Blue assay (MABA) (3, 5), the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-based assay (9), and the luciferase assay (1, 2, 7, 21) have been established for the screening of the antimycobacterial activities of compounds. However, each has one or more drawbacks for high-throughput screening, including the need to add a dye or a substrate to test the viability of the bacteria, a step which both increases labor and decreases safety. Fluorometric assays based on the Aequorea victoria gfp gene encoding a green fluorescent protein (GFP) or its mutants have been used widely in prokaryotes (8, 10, 11, 24) due to several properties of gfp that are advantageous for use as a reporter for bacterial viability and growth, including the low level of toxicity, continuous production during replication, and easy imaging and quantification (11, 25). Previous studies with mycobacteria exclusively used the hsp60 promoter, which has been fused to gfp in a variety of investigations (8, 11, 26). Collins et al. (6) demonstrated that a recombinant M. tuberculosis strain carrying pFPV2, an hsp60::gfp construct, could be used to assess the MICs of known antimycobacterial compounds. However, the low level of the fluorescence signal and the relatively high background autofluorescence of the medium precluded the establishment of a robust assay that could be used with confidence for high-throughput screening. Previous investigators (6, 13, 17, 18, 23) have identified a highly inducible promoter sequence which regulates the expression of the acetamidase gene in M. smegmatis NCTC 8159 and which demonstrated a high level of gene expression in the presence of amide inducers such as acetamide. In this study we demonstrate that an acetamidase promoter from M. smegmatis strain mc2155 permits constitutive, high-level gfp expression in M. tuberculosis strains H37Ra, H37Rv, and Erdman, resulting in a fluorescence signal significantly higher than that which is achievable with the hsp60 promoter and facilitating the determination of MICs of antimicrobial agents without the addition of reagents postincubation.

The first fermi lat supernova remnant catalog

Abstract: To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.