Publications (93) View all
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Article: A novel test tube method of screening for hemoglobin E.
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ABSTRACT: Hemoglobin (Hb) E is a β-structural variant common worldwide. This Hb disorder can form a compound heterozygous state with the β-thalassemia gene, leading to life-threatening hereditary hemolytic anemia, HbE/β-thalassemia. Screening of HbE has proven to be a challenging practice in prevention and control of the HbE/β-thalassemia. A novel test tube method for HbE screening using diethyl aminoethyl (DEAE)-cellulose resin was described. With the developed system, HbE/A(2) did not bind to the resin and remained dissolved in the supernatant, whereas other Hbs completely bound to the resin. The red color of the supernatant observed in the test tube indicated the presence of HbE. Colorless or markedly pale color of the supernatant indicates the absence of HbE. Accuracy and efficiency of the established method in detecting HbE was comparable with the standard cellulose acetate electrophoresis method. The developed method is cheap and simple with no requirement of sophisticated equipment. The reagent could be stored at 4 °C for up to 5 months. Hemolysate samples aged up to 5 months were still suitable for this test. The described novel test tube method could be an alternative method of mass population screening for HbE, particularly in small health care facilities.International journal of laboratory hematology 08/2011; 34(1):59-64. · 1.30 Impact Factor -
Article: Anti-P-glycoprotein conjugated nanoparticles for targeting drug delivery in cancer treatment.
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ABSTRACT: Targeting therapeutics to specific sites can enhance the efficacy of drugs, reduce required doses as well as unwanted side effects. In this work, using the advantages of the specific affinity of an immobilized antibody to membrane P-gp in two different nanoparticle formulations were thus developed for targeted drug delivery to multi-drug resistant cervical carcinoma (KB-V1) cells. Further, this was compared to the human drug sensitive cervical carcinoma cell line (KB-3-1) cells. The two nanoparticle preparations were: NP1, anti-P-gp conjugated with poly (DL-lactic-coglycolic acid) (PLGA) nanoparticle and polyethylene glycol (PEG); NP2, anti-P-gp conjugated to a modified poloxamer on PLGA nanoparticles. The cellular uptake capacity of nanoparticles was confirmed by fluorescent microscopy. Comparing with each counterpart core particles, there was a higher fluorescence intensity of the targeted nanoparticles in KBV1 cells compared to KB-3-1 cells suggesting that the targeted nanoparticles were internalized into KB-V1 cells to a greater extent than KB-3-1 cell. The results had confirmed the specificity and the potential of the developed targeted delivery system for overcoming multi-drug resistance induced by overexpression of P-gp on the cell membrane.Archives of Pharmacal Research 10/2011; 34(10):1679-89. · 1.59 Impact Factor -
Article: Association of CD99 short and long forms with MHC class I, MHC class II and tetraspanin CD81 and recruitment into immunological synapses.
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ABSTRACT: CD99, a leukocyte surface glycoprotein, is broadly expressed in many cell types. On the cell surface, CD99 is expressed as two distinct isoforms, a long form and a short form. CD99 has been demonstrated to play a key role in several biological processes, including the regulation of T cell activation. However, the molecular mechanisms by which CD99 participates in such processes are unclear. As CD99 contains a short cytoplasmic tail, it is unlikely that CD99 itself takes part in its multi-functions. Association of CD99 with other membrane proteins has been suggested to be necessary for exerting its functions. In this study, we analyzed the association of CD99 with other cell surface molecules involved in T cell activation. We demonstrate the association of MHC class I, MHC class II and tetraspanin CD81 with CD99 molecules on the cell surface. Association of CD99 with its partners was observed for both isoforms. In addition, we determined that CD99 is a lipid raft-associated membrane protein and is recruited into the immunologic synapse during T cell activation. The implication of CD99 on T cell activation was investigated. Inhibition of anti-CD3 induced T cell proliferation by an anti-CD99 monoclonal antibody was observed. We provide evidence that CD99 directly interact and form the complex with the MHC class I and II, and tetraspanin CD81, and is functionally linked to the formation of the immunologic synapse. Upon T cell activation, CD99 engagement can inhibit T cell proliferation. We speculate that the CD99-MHC-CD81 complex is a tetraspanin web that plays an important role in T cell activation.BMC Research Notes 08/2011; 4:293. -
Article: Accuracy of immunochromatographic strip test in diagnosis of alpha-thalassemia-1 carrier.
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ABSTRACT: To determine the accuracy of alpha-thal immunochromatographic (IC) strip in diagnosis of alpha-thalassemia 1 carrier among pregnant women, using PCR for alpha-thalassemia 1 (SEA type) as a gold standard. Asymptomatic pregnant women attending the antenatal care clinic were recruited Their blood samples were taken for IC Strip Test (alpha Thal IC strip, i+Med Laboratories Company Limited) in predicting alpha-thalassemia 1 carrier and separately sent for PCR for diagnosis of alpha-thalassemia 1 carrier as a gold standard Four hundred ninety nine pregnant women were recruited into the present study at various gestational weeks. The accuracy of alpha-Thal IC strip test was relatively high as shown in Table 1. Of them, 62 cases were proven to be alpha-thalassemia 1 trait and all ofthem had the results of positive IC strip, giving a sensitivity of 100%. However 45 pregnant women of non-alpha-thalassemia 1 trait had positive test, giving a specificity of 89%. The present study was solid evidence for clinical application of alpha-thal IC strip in screening program of thalassemia to reduce the need for PCR in diagnosis of a-thalassemia 1 carrier because of its very high sensitivity. The negative test reassures the non alpha-thalassemia 1 carrier status. Moreover, due to its simplicity, convenience to use, low cost, less-time consuming, clear interpretation and no need for either equipment or expensive laboratories, it may probably be very helpful in a massive screening program.Journal of the Medical Association of Thailand = Chotmaihet thangphaet 07/2011; 94(7):761-5. -
Article: Role of CD137 signaling in dengue virus-mediated apoptosis.
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ABSTRACT: Hepatic dysfunction is a well recognized feature of dengue virus (DENV) infection. However, molecular mechanisms of hepatic injury are still poorly understood. A complex interaction between DENV and the host immune response contributes to DENV-mediated tissue injury. DENV capsid protein (DENV C) physically interacts with the human death domain-associated protein Daxx. A double substitution mutation in DENV C (R85A/K86A) abrogates Daxx interaction, nuclear localization and apoptosis. Therefore we compared the expression of cell death genes between HepG2 cells expressing DENV C and DENV C (R85A/K86A) using a real-time PCR array. Expression of CD137, which is a member of the tumor necrosis factor receptor family, increased significantly in HepG2 cells expressing DENV C compared to HepG2 cells expressing DENV C (R85A/K86A). In addition, CD137-mediated apoptotic activity in HepG2 cells expressing DENV C was significantly increased by anti-CD137 antibody compared to that of HepG2 cells expressing DENV C (R85A/K86A). In DENV-infected HepG2 cells, CD137 mRNA and CD137 positive cells significantly increased and CD137-mediated apoptotic activity was increased by anti-CD137 antibody. This work is the first to demonstrate the contribution of CD137 signaling to DENV-mediated apoptosis.Biochemical and Biophysical Research Communications 06/2011; 410(3):428-33. · 2.48 Impact Factor
