Huai Krachao, Thailand
Huai Krachao, Thailand

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Kreetachat T.,University of Phayao | Kruenate J.,National Metal and Materials Technology Center | Suwannahong K.,Western University of Thailand
Applied Mechanics and Materials | Year: 2013

Biodegradable of polylactic acid (PLA), polybutylene adipate-co-terephthalate (PBAT) and polybutylene succinate (PBS), which were biodegradable aliphatic polyesters, composite films were contained with titanium dioxide (TiO2) as a photocatalyst to evaluate the photocatalytic activity of bidegradable composite films for toluene removal. The synthesized TiO2 was prepared by sol-gel method between titanium isopropoxide with acetic acid. To form the anatase structure, it was calcined at 500oC. TiO2 were added to PLA/PBAT/PBS as a biopolymer blend at 0, 5 and 10 wt%.The TiO2/Bio-composite films were fabricated via blown film technique to produce 40 μm films. Photocatalytic activity efficiency of TiO2/Bio-composite films was performed in an annular closed system under UV light. Since the amount of TiO2 affected the efficiency of the photocatalytic activity, this work was mainly concentrated on the effort to embed the high amount of TiO2 in the biopolymer matrix. The developed photocatalyst was characterized by XRD, UV-Vis spectrophotometer and SEM. The SEM images revealed the high homogeneity of the deposition of TiO2 on the biopolymer matrix. The X-ray diffraction (XRD) ensures the deposition of TiO2 as crystalline anatase phase. In addition, the photocatalytic results shown that the toluene removal efficiencies increased with an increasing TiO2 dosages at 0 wt%, 5 wt%, and 10 wt%, respectively. As aspects, the photocatalytic degradation results showed the highest tolune photocatalytic degradation efficiency of 52.0% at 10 wt% TiO2. © (2013) Trans Tech Publications, Switzerland.


PubMed | Murdoch University, Western University of Thailand, University of Western Australia and Queen Elizabeth Medical Center
Type: Journal Article | Journal: Pathology | Year: 2016

The objective of this study was to establish a population based reference range for a commercial immunoblot assay detecting myositis specific autoantibodies (MSAs) and myositis associated autoantibodies (MAAs), and to assess the diagnostic performance of this reference range against the manufacturers recommended ranges in a myositis patient cohort. A total of 124 patients from a myositis cohort and 197 healthy controls were serologically assessed using a commercial immunoblot containing eleven autoantigens (Jo-1, EJ, OJ, PL7, PL12, Mi-2, SRP, Ku, PMScl75, PMScl100 and Ro52) according to the manufacturers instructions. Use of the manufacturers reference ranges resulted in detection of MSAs in 19.4% of myositis patients and 9.1% of controls; MAAs were detected in 41.1% of myositis patients and 14.2% of controls. Reference values derived from the healthy control population resulted in significant differences in cut-off values for some autoantibodies, particularly Ro52 and PMScl75. Use of local reference ranges reduced detection of MSAs to 16.9% of myositis patients and 3% of healthy controls, with MAAs 23.4% of patients and 2% of healthy controls. Application of population based reference ranges resulted in significant differences in detection of MSAs and MAAs compared to the manufacturers recommended ranges. Cut-off levels should be assessed to ensure suitability for the population tested.


Suksangpleng T.,Mahidol University | Leartsakulpanich U.,National Science and Technology Development Agency | Moonsom S.,Mahidol University | Siribal S.,Western University of Thailand | And 3 more authors.
Malaria Journal | Year: 2014

Background: Based on resistance of currently used anti-malarials, a new anti-malarial drug target against Plasmodium falciparum is urgently needed. Damaged DNA cannot be transcribed without prior DNA repair; therefore, uracil-DNA glycosylase, playing an important role in base excision repair, may act as a candidate for a new anti-malarial drug target. Methods. Initially, the native PfUDG from parasite crude extract was partially purified using two columns, and the glycosylase activity was monitored. The existence of malarial UDG activity prompted the recombinant expression of PfUDG for further characterization. The PfUDG from chloroquine and pyrimethamine resistant P. falciparum strain K1 was amplified, cloned into the expression vector, and expressed in Escherichia coli. The recombinant PfUDG was analysed by SDS-PAGE and identified by LC-MS/MS. The three dimensional structure was modelled. Biochemical properties were characterized. Inhibitory effects of 12 uracil-derivatives on PfUDG activity were investigated. Inhibition of parasite growth was determined in vitro using SYBR Green I and compared with results from human cytotoxicity tests. Results: The native PfUDG was partially purified with a specific activity of 1,811.7 units/mg (113.2 fold purification). After cloning of 966-bp PCR product, the 40-kDa hexa-histidine tagged PfUDG was expressed and identified. The amino acid sequence of PfUDG showed only 24.8% similarity compared with the human enzyme. The biochemical characteristics of PfUDGs were quite similar. They were inhibited by uracil glycosylase inhibitor protein as found in other organisms. Interestingly, recombinant PfUDG was inhibited by two uracil-derived compounds; 1-methoxyethyl-6-(p-n-octylanilino) uracil (IC50 of 16.75 μM) and 6-(phenylhydrazino)uracil (IC 50 of 77.5 μM). Both compounds also inhibited parasite growth with IC50s of 15.6 and 12.8 μM, respectively. Moreover, 1-methoxyethyl-6-(p-n-octylanilino)uracil was not toxic to HepG2 cells, with IC50 of > 160 μM while 6-(phenylhydrazino)uracil exhibited cytoxicity, with IC50 of 27.5 μM. Conclusions: The recombinant PfUDG was expressed, characterized and compared to partially purified native PfUDG. Their characteristics were not significantly different. PfUDG differs from human enzyme in its size and predicted amino acid sequence. Two uracil derivatives inhibited PfUDG and parasite growth; however, only one non-cytotoxic compound was found. Therefore, this selective compound can act as a lead compound for anti-malarial development in the future. © 2014 Suksangpleng et al.; licensee BioMed Central Ltd.


Pongpom M.,Chiang Mai University | Sawatdeechaikul P.,Chiang Mai University | Kummasook A.,Western University of Thailand | Khanthawong S.,Naresuan University | Vanittanakom N.,Chiang Mai University
Medical Mycology | Year: 2013

Penicillium marneffei is a significant opportunistic fungal pathogen in Southeast Asia and its ability to survive inside the host macrophages is believed to be important in the establishment of infection. Previously, we isolated a gene encoding a catalase- peroxidase (cpeA) from P. marneffei and showed that the cpeA transcript is specifically upregulated during yeast phase growth at 37°C. In this study, the cpeA transcript was found to be induced during the mycelium to yeast phase transition and during stress conditions induced by hydrogen peroxide treatment. Null mutation of cpeA reduced the fungal tolerance to hydrogen peroxide but not to heat stress. These results indicated that the CpeA plays a crucial role in this fungus' oxidative stress response. Western blot analysis demonstrated that the CpeA induced antibody production in P. marneffei-infected patients, including highly exposed-healthy people. This is the first report that the catalase-peroxidase possesses an immunogenic property in fungi. © 2013 ISHAM.


Kummasook A.,Chiang Mai University | Kummasook A.,Youngstown State University | Kummasook A.,Western University of Thailand | Cooper C.R.,Youngstown State University | And 4 more authors.
Fungal Genetics and Biology | Year: 2013

Penicillium marneffei is a thermally dimorphic fungus that is a highly significant pathogen of immune compromised persons living or having traveled in Southeast Asia. When cultured at 25. °C, the wild-type strain of P. marneffei exhibits a mycelial morphology that is marked by the development of specialized structures bearing conidia. Incubation of the wild type at 37. °C, however, promotes the development of a yeast form that divides by fission. Development of the yeast morphology in vivo appears to be requisite for pathogenesis. In a prior study using Agrobacterium-mediated transformation for random mutagenesis via T-DNA integration, we generated a morphological mutant (strain I6) defective in conidiation. The T-DNA insertion site in strain I6 was determined to be within the gene encoding S-adenosylmethionine decarboxylase (. sadA), an enzyme critical to spermidine biosynthesis. In the present study, we demonstrated that strain I6 was able to grow on rich media in either the mold or yeast forms at 25. °C and 37. °C, respectively. However, reduced growth of strain I6 was observed on minimal medium at either temperature. In addition, strain I6 produced mycelia with impaired conidiation on minimal medium at 25. °C. Supplementation of minimal medium with spermidine restored the ability of strain I6 to produce conidia at 25. °C and promoted yeast development at 37. °C. Moreover, conidia of strain I6 exhibited poor germination frequencies in the absence of this polyamine. All three of these processes (conidiogenesis, germination, and growth) were reinstated in strain I6 by complementation of the partially deleted of sadA gene by ectopic insertion of an intact wild-type copy. These results augment prior observations that spermidine biosynthesis is essential to normal growth, conidiogenesis, spore germination, and dimorphism in a variety of fungi. Given the presumption that P. marneffei infections are initiated following inhalation of conidia, and that pathogenesis is dependent upon yeast development, this study further suggests that the spermidine biosynthetic pathway may serve as a potential target for combating infections by this medically important fungus. © 2013 Elsevier Inc.


Somsak V.,Western University of Thailand | Srichairatanakool S.,Chiang Mai University | Uthaipibull C.,National Science and Technology Development Agency
International Food Research Journal | Year: 2016

Hypoglycemia has been reported during malaria infection in blood stage, and can cause of death in malaria endemic countries. Hence, in this study was aimed to evaluate anti-hypoglycemic effect of Siamese neem tree extract in P. berghei infected mice. The aqueous leaf extract of Siamese neem tree was freshly prepared and used for orally treatment. Groups of ICR mice were infected intraperitoneally with 6x106 infected erythrocytes of P. berghei ANKA, and subsequently given with the extract twice a day for 4 consecutive days. Blood glucose levels were then measured. Normal and untreated mice were used as healthy and disease controls, respectively. The results showed that hypoglycemia was developed during P. berghei ANKA infection in mice as indicated by decreasing of blood glucose level. However, blood glucose level in the extract treated mice was similar to normal group. It can be summarized that aqueous leaf extract of Siamese neem tree exhibited anti-hypoglycemic effect against P. berghei ANKA infected mice. © 2008 IFRJ.


Somsak V.,Western University of Thailand | Jaihan U.,Western University of Thailand | Srichairatanakool S.,Chiang Mai University | Uthaipibull C.,National Science and Technology Development Agency
Parasitology International | Year: 2013

Impairment of renal function from oxidative stress during malaria infection is one of the leading causes of death in endemic areas. Since blood urea nitrogen and creatinine levels in plasma can be used as markers for monitoring renal damage, this study investigated the effect of green tea extract on reduction of blood urea nitrogen and creatinine levels during malaria infection using Plasmodium berghei ANKA infected mice as in vivo model. For in vivo testing, ICR mice were infected with 1×107 parasitized erythrocytes and green tea extract was subsequently administered orally twice a day for 10 consecutive days. Parasitemia was estimated by standard microscopy, and blood urea nitrogen and creatinine levels in plasma were also measured. It was found that parasitemia kept increasing until animal death, and is strongly correlated with high blood urea nitrogen and creatinine. The highest levels of blood urea nitrogen and creatinine in plasma were found on day 10 after infection. However, blood urea nitrogen and creatinine levels in plasma were reduced and decreased significantly (p<0.01) in green tea extract treated mice, compared with untreated group. It can be concluded that green tea extract can protect and maintain renal function during malaria infection, and this extract can be developed for use as a supplement and combination therapy. © 2013 Elsevier Ireland Ltd.


Khobjai W.,Western University of Thailand | Jaihan U.,Western University of Thailand | Watcharasamphankul W.,Western University of Thailand | Somsak V.,Western University of Thailand
Parasitology Research | Year: 2014

This study was aimed to investigate the efficacy of Thunbergia laurifolia leaf extract to protect hemolysis in mice infected with Plasmodium berghei. Aqueous leaf extract of T. laurifolia was freshly prepared, and total polyphenol was then measured using Folin-Ciocalteu reagent method. For in vivo test, ICR mice were given intraperitoneally with this extract (1,000 mg/kg) once a day for four consecutive days and subsequently inoculated with 1×106 parasitized erythrocytes of P. berghei ANKA by intraperitoneal injection for 8 days. The results showed that hemolysis was inhibited as indicated by %hematocrit (%Hct) which was normal in infected mice treated with T. laurifolia extract. Untreated and pyrimethamine-treated controls showed decreasing %Hct. Moreover, no any toxic signs were observed in normal mice treated with this extract. We conclude that T. laurifolia leaf extract clearly protects hemolysis during P. berghei infection in mice. © 2014 Springer-Verlag.


PubMed | Western University of Thailand
Type: | Journal: Journal of pathogens | Year: 2016

Malaria is one of the most important infectious diseases in the world. The choice for the treatment is highly limited due to drug resistance. Hence, finding the new compounds to treat malaria is urgently needed. The present study was attempted to evaluate the antimalarial activity of the Annona muricata aqueous leaf extract in Plasmodium berghei infected mice. Aqueous leaf extract of A. muricata was prepared and tested for acute toxicity in mice. For efficacy test in vivo, standard 4-day suppressive test was carried out. ICR mice were inoculated with 10(7) parasitized erythrocytes of P. berghei ANKA by intraperitoneal injection. The extracts (100, 500, and 1000mg/kg) were then given orally by gavage once a day for 4 consecutive days. Parasitemia, percentage of inhibition, and packed cell volume were subsequently calculated. Chloroquine (10mg/kg) was given to infected mice as positive control while untreated control was given only distilled water. It was found that A. muricata aqueous leaf extract at doses of 100, 500, and 1000mg/kg resulted in dose dependent parasitemia inhibition of 38.03%, 75.25%, and 85.61%, respectively. Survival time was prolonged in infected mice treated with the extract. Moreover, no mortality to mice was observed with this extract up to a dose of 4000mg/kg. In conclusion, the A. muricata aqueous leaf extract exerted significant antimalarial activity with no toxicity and prolonged survival time. Therefore, this extract might contain potential lead molecule for the development of a new drug for malaria treatment.


PubMed | Western University of Thailand
Type: | Journal: Journal of tropical medicine | Year: 2016

Due to the emergence and spread of malaria parasite with resistance to antimalarial drugs, discovery and development of new, safe, and affordable antimalarial are urgently needed. In this respect, medicinal plant extracts are targets to optimize antimalarial actions and restore efficacy of standard antimalarial drugs. The present study was aimed at determining the antimalarial activities of

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