Phantip Vattanaviboon

Mahidol University, Bangkok, Bangkok, Thailand

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Publications (17)38.89 Total impact

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    ABSTRACT: Erythropoiesis, a process of erythroid production, is controlled by several factors including oxygen level. In this study, the effect of oxygen tension on erythropoiesis was investigated in K562 erythroleukemic cell line and erythroid progenitor cells derived from normal and β-thalassemia/hemoglobin (Hb) E individuals. The enhanced erythroid differentiation specific markers including increased levels of α-, β- and γ-globin gene expressions, numbers of HbF positive cells and the presence of glycophorin A surface marker were observed during cell culture under hypoxic atmosphere. The result also showed that miR-210, one of the hypoxia-induced miRNAs, was up-regulated in K562 and β-thalassemia/HbE progenitor cells cultured under hypoxic condition. Inhibition of miR-210 expression leads to reduction of the globin gene expression and delayed maturation in K562 and erythroid progenitor cells. This indicated that miR-210 contributes to hypoxia-induced erythroid differentiation in both K562 cells and β-thalassemia/HbE erythroid progenitor cells.
    Blood Cells Molecules and Diseases 04/2013; · 2.26 Impact Factor
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    ABSTRACT: To become a quality clinical laboratory, personnel development is the most important factor. In order to achieve this goal, it should emphasize that clinical laboratory is not only a testing laboratory; it must be a knowledge-based service laboratory. A smart model for clinical laboratory personnel development under the Human Asset Development (HAD) program had been launched since 2003. To strengthen the competency of clinical laboratory personnel, an appropriate model was developed and apply to the clinical laboratory personnel. Medical technologist who currently worked in clinical laboratory participated in this study. The proposed model consisted of 3 phases. 1) The knowledge providing via update and refresher courses. 2) Application of learned knowledge to practice under close supervision. 3) Training on special topic and self oriented research activity. The outcome of 5 years project was evaluated. After the first phase, they were able to identify and solve their own troublesome under ours close supervision. There were 25 projects presented within 3 years. The last phase, they were very constructive. Nine projects of self created had been presented. Those projects contained clear objectives and were able to implement. The smart model for clinical laboratory personnel development leaded to many self created projects in a few years. Thus, this implies its important role in human resource development that should be continued. The keys index of success were ours strong intention, with providing motivation and periodically encouragement to the participants, and keep going on consistently.
    Journal of the Medical Association of Thailand = Chotmaihet thangphaet 11/2010; 93 Suppl 6:S203-7.
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    ABSTRACT: alpha-Thalassemia is an inherited hemoglobin disorder that results from defective synthesis of alpha-globin protein. Couples who both carry the alpha-thalassemia-1 gene are at risk of having a fetus with Hb Bart's hydrops fetalis. Rapid and accurate screening for individuals carrying the alpha-thalassemia-1 gene is the most effective strategy to prevent and control this severe form of thalassemia. In this study, a new and accurate method for alpha-thalassemia diagnosis was developed by genotyping alpha-thalassemia-1, the Southeast Asian type (--(SEA)) and Thai type (--(THAI)) deletions, using multiplex PCR followed by a melting curve analysis. Primers were designed to specifically amplify two deletion fragments, the --(SEA) and --(THAI) deletions and two normal fragments, psizeta- and alpha2-globin gene. The primers were capable of distinguishing alpha-thalassemia 1 heterozygotes from alpha-thalassemia 2 homozygotes, which are unable to be diagnosed by standard hematological data and hemoglobin typing. The melting temperatures of the --(THAI), --(SEA), psizeta-globin, and alpha2-globin gene fragments were 79.9 +/- 0.2, 89.4 +/- 0.5, 92.8 +/- 0.2, and 85.0 +/- 0.2 degrees C, respectively. Melting curve analysis was performed in 130 subjects in parallel with conventional gap-PCR analysis, and results showed 100% concordance. This method eliminates the post-PCR electrophoresis process, which is laborious, and allows high throughput screening suitable for large population screening for prevention and control of thalassemia.
    The Journal of molecular diagnostics: JMD 02/2010; 12(3):354-8. · 3.48 Impact Factor
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    ABSTRACT: beta-thalassemia occurs from the imbalanced globin chain synthesis due to the absence or inadequate beta-globin chain production. The excessive unbound alpha-globin chains precipitate in erythroid precursors and mature red blood cells leading to ineffective erythropoiesis and hemolysis. In vitro globin chain synthesis in reticulocytes from different types of thalassemic mice was performed. The effect of imbalanced globin chain synthesis was assessed from changes of red blood cell properties including increased numbers of red blood cells vesicles and apoptotic red blood cells, increased reactive oxygen species and decreased red blood cell survival. The alpha/beta-globin chain ratio in beta(IVSII-654)-thalassemic mice, 1.26+/-0.03, was significantly higher than that of wild type mice, 0.96+/-0.05. The thalassemic mice show abnormal hematologic data and defective red blood cell properties. These values were improved significantly in doubly heterozygous thalassemic mice harboring 4 copies of human beta(E)-globin transgene, with a more balanced globin chain synthesis, 0.92+/-0.05. Moreover, transgenic mice harboring 8 extra copies of the human beta(E)-globin transgene showed inversely imbalanced alpha/beta-globin synthesis ratio, 0.83+/-0.01, that resulted in a mild beta-thalassemia phenotype due to the excessive beta-globin chains. The degree of ineffective erythropoiesis also correlated with the degree of imbalanced globin chain synthesis. Bone marrow and splenic erythroid precursor cells of beta(IVSII-654)-thalassemic mice showed increased phosphatidylserine exposure in basophilic and polychromatophilic stages, which was restored to the normal level in doubly heterozygous mice. Imbalanced alpha/beta-globin chain as a consequence of either reduction or enhancement of beta-globin chain synthesis can cause abnormal red blood cell properties in mouse models.
    Haematologica 08/2009; 94(9):1211-9. · 5.94 Impact Factor
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    ABSTRACT: DNA-based diagnosis of alpha-thalassemias routinely relies on polymerase chain reaction (PCR) and gel electrophoresis. Here, we developed a new procedure for the detection and haplotype differentiation of Southeast Asian (SEA) alpha-thalassemia using a 3-primer system for PCR coupling with a DNA-based piezoelectric biosensor. PCR products amplified from genomic DNA were differentiated directly by using a quartz crystal microbalance immobilized with a single oligonucleotide probe. The frequency changes after hybridization of the PCR products amplified from a representative sample of normal alpha-globin, SEA alpha-thalassemia heterozygote, and homozygote were 206+/-11, 256+/-5, and 307+/-3 Hz, respectively. The fabricated biosensor was evaluated through an examination of 18 blind specimens. It could accurately discriminate between normal and SEA alpha-thalassemic samples, which suggests that this biosensor system is a promising alternative technique to detect SEA alpha-thalassemia because of its specificity and less hazardous exposure as compared with conventional methods.
    Translational Research 06/2008; 151(5):246-54. · 3.49 Impact Factor
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    ABSTRACT: RNA interference (RNAi), a process by which target messenger RNA (mRNA) is cleaved by small interfering complementary RNA (siRNA), is widely used for investigations of regulation of gene expression in various cells. In this study, siRNA complementary to 5' region of exon II of alpha-globin mRNA was examined for its role in erythroid colony forming cells (ECFCs) isolated from normal peripheral blood donor. On day 6 of cell culture, 1x10(6) ECFCs were transfected with lipofectamine-containing alpha-globin specific siRNA. After 48h of transfection, alpha-globin specific siRNA produced significantly reduction of alpha-globin mRNA level in a dose-dependent manner, but it did not affect the level of beta-globin mRNA. Significantly, decreased numbers of hemoglobinized erythroid cells relative to the control were observed supporting the inhibitory effect of this alpha-globin mRNA specific siRNA.
    Biochemical and Biophysical Research Communications 06/2008; 369(3):935-8. · 2.28 Impact Factor
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    ABSTRACT: Here we report the study on BRCA1 and BRCA2 mutations in 12 Thai breast and/or ovarian cancer families and 6 early-onset breast or breast/ovarian cancer cases without a family history of cancer. Five distinct rare alterations were identified in each gene: four introducing premature stop codons, one in-frame deletion, two missense changes, two intronic alterations and one silent rare variant. The BRCA1 or BRCA2 truncating mutations were detected in four of seven patients with familial or personal history of breast and ovarian cancer, in one of four isolated early onset breast cancer cases and in none of seven breast cancer site specific families. The BRCA1 and BRCA2 mutation yield in Thai patients is consistent with that reported from Europe and North America in similar groups of patients, being particularly high in individuals with personal or family history of breast and ovarian cancer. The BRCA1 and BRCA2 alterations found in this series are different from those identified in other Asian studies, and all but two have never been reported before. We report at least three novel deleterious mutations, the BRCA1 3300delA, BRCA1 744ins20 and BRCA2 6382delT. One in-frame deletion was also found, the BRCA2 5527del9, which seggregated within family members of breast-only cancer patients and was thought to be a cancer-related mutation. BRCA1 3300delA and Asp67Glu alterations were detected each in at least two families and thus could represent founder mutations in Thais.
    Human Mutation 10/2002; 20(3):230. · 5.21 Impact Factor
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    ABSTRACT: Plasmodium falciparum infecting alpha-thalassemic erythrocytes are resistant to artemisinin and its derivatives. Binding of the drug to hemoglobin H resulting in drug inactivation was previously demonstrated. We now show that an additional host factor, membrane heme, significantly accounted for decreased antimalarial activity of artemisinin. The antimalarial activity of dihydroartemisinin in the presence of normal and thalassemic erythrocyte membranes showed a correlation with the heme content of the membrane (r(2)=0.466, P<0.01). The correlation was more clearly seen when the drug effectiveness was correlated with the heme content of alpha-thalassemic membrane (r(2)=0.636, P<0.01). However, the drug effectiveness showed no correlation to ferrozine-reactive (free or non-heme) iron content (r(2)=0.0001, P>0.05). alpha-Thalassemic erythrocytes contained higher amounts of membrane heme (11.04+/-8.96 nmol/mg membrane protein) than those from normal and beta-thalassemia/HbE erythrocytes (2.68+/-1.28 and 3.98+/-3.98 nmol/mg membrane protein, respectively, P<0.01). Loss of drug effectiveness was also correlated with increment of heme content in membrane prepared from normal erythrocytes treated with phenylhydrazine. It is concluded that heme in both normal and thalassemic erythrocyte membranes is an important factor in drug inactivation.
    Biochemical Pharmacology 07/2002; 64(1):91-8. · 4.58 Impact Factor
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    ABSTRACT: Plasmodium falciparum infecting α-thalassemic erythrocytes (Hb H or Hb H/Hb Constant Spring) is resistant to artemisinin derivatives. Similar resistance, albeit at a much lower level, is shown by the parasite infecting β-thalassemia/Hb E erythrocytes. The resistance is due to host-specific factors, one of which is the higher uptake of the drugs by thalassemic erythrocytes than normal erythrocytes, due to binding with Hb H. In addition to higher drug binding, incubation of artemisinin with α-thalassemic erythrocytes resulted in preferential inactivation of the drug. Both thalassemic and normal erythrocytes have the capability to inactivate the drug. Addition of serum can protect against inactivation by normal erythrocytes, but not by thalassemic erythrocytes. Incubation with either the hemolysate or the membrane fraction from these erythrocytes also resulted in preferential inactivation of the drug. The drug was also inactivated by purified Hb H. It is concluded that the ineffectiveness of artemisinin derivatives against P. falciparum infecting thalassemic erythrocytes is due partly to competition of the host cell components for binding with the drugs, and partly to inactivation of the drugs by the cell components.
    Biochemical Pharmacology 07/2000; · 4.58 Impact Factor
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    ABSTRACT: Thalassemia and malaria are present at high frequency in tropic and subtropic regions. Impaired growth of Plasmodium falciparum has been demonstrated in vitro in both α-and β- thalasemic erythrocytes. In this study, we investigated the effects of thalassemic sera on Plasmodium falciparum developement including 5 α-thalasemia1/α-thalasemia2 (HbH) sera, 4 α-thalasemia1/hemoglobin Constant Springs (HbH/HbCS) sera and 7 β-thalassemia/ HbE sera compared to 7 normal sera. Study on malarial growth in medium containing 10% various sera for 4 days revealed that HbH and β-thalasemia/ HbE sera was significantly inhibited (p
    Journal of the Association for Laboratory Automation 09/1999; 4(4):78-79. · 1.46 Impact Factor
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    ABSTRACT: Nowadays, Thailand encounters a serious economic crisis. A clear consensus has been made that a cost-saving system must be the important tool. Both private and government organizations are engaged in this situation. We studied the cost-saving in the clinical laboratory. A questionnaire was distributed to 45 hospital laboratories located in Bangkok. Results showed that efforts to control the cost are the essential policy. There was a variety of factors contributing to the cost-saving process. The usage of public utility, non-recycle material and unnecessary utility were reconsidered. Besides, capital cost (wages and salary) personnel incentive are assessed. Forty three of the 45 respondents had attempted to reduce the cost via curtailing the unnecessary electricity. Eliminating the needless usage of telephone-call. water and unnecessary material was also an effective strategy. A reduction of 86.9%, 80 % and 80.0% of the mentioned factors respectively, was reported. An inventory system of the reagent, chemical and supplies was focused. Most of the laboratories have a policy on cost-saving by decreased the storage. Twenty eight of the 45 laboratories considered to purchase the cheaper with similar quality reagents instead. And some one would purchase a bulky pack when it is the best bargain. A specific system "contact reagent with a free rent instrument" has been used widely (33.3%). Finally, a new personnel management system has been chosen. Workload has rearranged and unnecessary extra-hour work was abandoned.
    The Southeast Asian journal of tropical medicine and public health 02/1999; 30 Suppl 3:54-6. · 0.61 Impact Factor
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    ABSTRACT: A good laboratory practice is the heart of clinical laboratory quality. One must establish a standard system in order to achieve the quality. However, standard system is not only the technical but also a state of the art. The socioeconomic and culture are the influence factors. At present, technique of reporting the blood smear examination is still a nation controversy. We surveyed the blood smear examination reporting system of the public hospital in Thailand. There were 77 hospitals participated in this study. A questionnaire comprised of 23 questions was distributed to 105 clinical laboratory staffs of the public health hospitals. Results showed that there was a diversity of blood smear examination reporting system. Generally, there were 2 ways of blood smear review. Every smeared slide and only abnormal slides were re-examined by the conventional technique. When an abnormal white blood cell blood picture was observed. The presence of either blast cell or atypical lymphocyte has clinical significance. A majority of laboratory would report in form "counting number of abnormal cell within 100% of the differential count". For other abnormalities of white blood cell; i.e. the neutrophils with toxic granules, most of laboratory reported as "presence". Interestingly, the red blood cell reporting system varied from laboratory to laboratory. There was a total of nine reporting patterns. Results indicated that pattern 4 (few or some, 1+,2+,3+,4+ are 5-10%, 11-25%, 26-50%, 51-75% and 51-100% cell/oil field, respectively) was the most popular one in reporting anisocytosis and poikilocytosis. However, the reporting pattern on red blood cell staining was difference. Pattern 4 and pattern 7 (grading by the size of central pallor) obtained a same popularity on the consideration of hypochromia. But the pattern 9 (few or some, 1+,2+,3+ are 0-1, 1-3, 4-6 and >6 cell/oil field, respectively) was the most frequently used in reporting of polychromasia. Fortunately we found that the reporting system for platelet was not complicated. A majority of laboratory chose the qualitative pattern (reporting as adequate, increased and decreased). Our study indicated that Thai clinical laboratory encounter a diversity of blood smear reporting system. Every clinical laboratory should pay a great attention to this circumstance. Since a good laboratory practice is a knot of the knot-bolt system of healthcare service, therefore, a nation standard system must be established in the near future.
    The Southeast Asian journal of tropical medicine and public health 01/1999; 30 Suppl 3:57-61. · 0.61 Impact Factor
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    P Vattanaviboon, P Wilairat, Y Yuthavong
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    ABSTRACT: Dihydroartemisinin and other artemisinin derivatives are relatively ineffective against Plasmodium falciparum infecting alpha-thalassemic erythrocytes, namely hemoglobin (Hb) H or HbH/Hb Constant Spring erythrocytes, as compared with those infecting genetically normal erythrocytes. The variant erythrocytes accumulate radiolabeled dihydroartemisinin to a much higher extent than the normal ones, and the accumulated drug was retained after extensive washing, in contrast to the drug in normal erythrocytes which was mostly removed. At initial drug concentration of 1 mM, most (82-88%) of the drug was found in the cytosol fraction of both variant and normal erythrocytes. Binding of the drug to hemoglobins accounted for 40-70% of the total uptake. Hb H accounted for 10.9 +/- 2.7% and 12.4 +/- 6.2% of total protein in HbH and HbH/Hb Constant Spring erythrocytes. HbH bound with 28.7 +/- 6.7% of the drug, whereas HbH/Hb Constant Spring erythrocytes bound with 21.8 +/- 8.3% of the drug. Binding experiments showed that Hb H had 5-7 times the drug-binding capacity of Hb A. For Hb H, the maximum binding capacity (Bmax) = 1.67 +/- 0.17 mol/mol Hb, and the dissociation constant (Kd) = 66 +/- 17 microM, and for Hb A, Bmax = 0.74 +/- 0.18 mol/mol Hb and Kd = 224 +/- 15 microM. It is concluded that preferential binding of dihydroartemisinin to Hb H over Hb A accounts partly for the higher accumulation capacity of the alpha-thalassemic erythrocytes, which leads to its antimalarial ineffectiveness.
    Molecular Pharmacology 04/1998; 53(3):492-6. · 4.41 Impact Factor
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    ABSTRACT: Nowadays, clinical laboratory service has an important role in patient care management. A quality test result must be obtained, but this can be affected by many factors. The correct process for specimen acquisition is very necessary and must be done by competent professional personnel. The objective of this study was to improve the competency of blood collection by phlebotomists through evidence-based learning. Evidence-based information gathering from nurses, medical technologists and clinical laboratory assistants was analyzed and synthesized to use as teaching material. Subjects were divided into two groups. The results showed that the trained groups of the çlectureé type and the çevidence-basedé type had different levels of improvement, with the more competent group being the evidence-based one. Five out of eight assessed parameters showed significant improvement. The overall score was increased from 49.79 to 73.08 percent In addition, the evidence-based group showed their improved competency by the ability to improve the venipuncture process from 76.59 to 92.31 percent and the time to perform venipuncture per patient was reduced by 43 seconds.
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    ABSTRACT: Quality assurance concept concerns not only non-human factors, but also human competency. In this study, we evaluated two phase competency assessments in hematological techniques from the same group of Thai laboratory staffs with 78% and 75% response rate. Laboratory staffs who participated in our program would receive informed consent forms and the assessment materials via mail. Cell and blood smear identifications and quality control process were assessed in the first phase. Case scenarios derived from improper answers of the first phase were tested in the second phase. The answers were assessed and graded as 3 levels (3 = very good, 2 = good and 1 = fair) and compared between both phases. The results showed an average grade of 2.27 ± 0.55 and 2.31 ± 0.29 for the first and second phase. The distribution of participant's grade in the first and second phase were 42.4%, 47.2%, 10.4% and 30.0%, 68.8%, 1.2% for grade 3, 2, 1, respectively. This result implies the improvement of laboratory personal competency, especially those who earned a low grade demonstrated a dramatic improved (p<0.01).
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    Patcharee Panpumthong, Phantip Vattanaviboon
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    ABSTRACT: Here, we demonstrate a modified two-step protein extraction technique to improve proteomic profile of P. falciparum in two-dimensional gel electrophoresis (2-DE). An experiment was initiated by resuspending the trophozoite in 40 mM Tris buffer followed by a freeze-thawing process. The cytosolic fraction was collected by centrifugation. The pellet was subsequently solubilized in lysis buffer containing 7 M urea, 2 M thiourea, 4% CHAPS, 2 mM tributyl phosphine (TBP), 2% IPG buffer pI 3-10 and lx protease inhibitor. These two fractions were individually applied onto the 2-DE and the protein spots were then detected by silver staining. A total of 239 protein spots were detected, while using the single-step protein extraction, only 165 visible proteins could be distinguished. More importantly, the two-step extraction provided a significant recovery of approximately l0 protein spots of surface antigens and membrane proteins as identified by their molecular weights and isoelectric points. These findings open up a potential approach for construction of a complete proteome map of P. fatciparum, which can provide for a better opportunity of drug and vaccine development.