Scopus 2001-2005
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Publication Metadata only Structural characterization of highly cis-1,4-polybutadiene: A comparing study in swollen and solid state using NMR technique(2001-08-31) Jitladda Sakdapipanich; Tippawan Kowitteerawut; Kawahara Seiichi; Yasuyuki Tanaka; Mahidol University; Nagaoka University of TechnologyCommercial highly cis-1,4-polybutadiene was cured out by benzoyl peroxide from 3 to 12 phr in toluene solution. The structural characterization of resulting gel fraction or cured rubber was carried out in both swollen- and solid-state 13C-NMR measurements. The assignment of observed chemical shift proposed by using a shift factor method and empirical calculation using HOSE method.Publication Metadata only Application of HIV-1-green fluorescent protein (GFP) reporter viruses in neutralizing antibody assays(2001-11-17) P. Auewarakul; V. Paungcharoen; S. Louisirirotchanakul; C. Wasi; Mahidol UniversityWe made reporter HIV-1 DNA constructs carrying green fluorescent protein (GFP) gene and exchangeable env of subtype E. The recombinant constructs were used to produce infectious reporter viruses, which induced infected cells to emit green fluorescent light and rendered them easily detectable at single cell level. Because the env in this construct can be easily exchanged, viruses with different antigenic epitopes can be made. We used these reporter viruses to set up a neutralizing antibody assay based on fluorescence reduction by flow cytometric measurement. The result of this new assay correlated with the standard infectivity reduction assay using primary isolates. Because this new assay is faster and much less costly than the standard assay using a p24 endpoint and can be performed in peripheral blood mononuclear cells (PBMC), it provides a useful tool for analysis of HIV-1 immune responses.Publication Metadata only Hair removal using a long-pulsed Nd:YAG Laser: Comparison at fluences of 50, 80, and 100 J/cm2(2001-05-24) David J. Goldberg; Sirunya Silapunt; Skin Laser and Surgery Specialists of NY and NJ; Icahn School of Medicine at Mount Sinai; Mahidol University;BACKGROUND. Unwanted hair is a widespread cosmetic problem. Many temporary methods of hair removal have proved unsatisfactory. A variety of laser systems with varying wave-lengths, pulse durations, and energy fluences are currently utilized for hair removal. Optimal laser parameters continue to require further investigation. OBJECTIVE. To evaluate the efficacy and safety of a long-pulse millisecond Nd:YAG hair removal laser utilizing fluences of either 50, 80, or 100 J/cm2. METHODS. Fifteen subjects were treated with a contact cooled 50 msec Nd:YAG laser at fluences 30, 50, or 100 J/cm2. Reduction in hair regrowth was measured at 3 months after treatment by comparing the terminal hair count to the baseline values. Potential complications were also evaluated. RESULTS. Average hair reduction at 3 months after treatment was 29%, 29%, and 27% in areas treated with a 50-msec Nd:YAG laser at fluences of 50, 80, and 100 J/cm2, respectively. Although short-term blistering was noted in two subjects, no hyperpimentation, hypopigmentation, or scarring was observed at 3 months after treatment. CONCLUSION. Long-pulse millisecond Nd:YAG laser hair removal with fluences of either 50, 80, or 100 J/cm2leads to similar efficacy with no significant adverse effects.Publication Metadata only Sacrococcygeal teratoma: 25 year experience(2001-02-01) Ravit Ruangtrakool; Att Nitipon; Mongkol Laohapensang; Danai Meekaewkunchorn; Surasak Sangkhathat; Chana Sathornkich; Polpatt Talalak; Mahidol University; Phayathai 3 HospitalWe retrospectively studied all thirty-five children (M 6, F 29) with sacrococcygeal teratomas admitted to Siriraj Hospital between 1974 and 1999. Although an abdominal delivery is recommended for lesions greater than 5 cm to avoid dystocia, the average diameter of masses which required interventions from dystocia (n = 3) was not different from vaginal delivery (n = 27). All except two first presented with sacral masses recognized at birth. One patient presented with an abdominal mass and the last one was diagnosed after suffering from difficulty in urination. Ninety-seven per cent of cases were completely excised initially (32 sacral, 2 abdomino-sacral approaches), however, six patients required other treatment for recurrent diseases. One mature teratoma recurrence was resected. Two patients who had malignant recurrences following complete benign excisions, died from advanced malignancy. Four presented with malignancy initially. Wound infection, bladder atony and UTI were the most common complications postoperatively. Advanced malignancy was the major cause of death. No patient died directly from the procedure.Publication Metadata only Cognitive status in the community dwelling Thai elderly(2001-03-01) Vorapun Senanarong; Niphon Poungvarin; Kanokrat Sukhatunga; Naraporn Prayoonwiwat; Rungsan Chaisewikul; Rattana Petchurai; Rungnirand Praditsuwan; Suthipol Udompunthurak; Adulya Viriyavejakul; Mahidol UniversityObjective : To survey the prevalence of cognitive impairment in the elderly and to estimate the prevalence of dementia in the community dwelling Thai population. To assess the psychometric property of Thai Mental State Examination (TMSE). Material and Method : We conducted a countrywide survey of 3,177 Thai elderly who were 60 years old and over from 1995 to 1997. Medical history and ability to carry out daily activities were taken by trained medical personnel. Thai Mental State Examination (TMSE) was used for cognitive study. Every elderly person involved in this study was examined by either an internist or a neurologist. Blood was taken for haematological and biochemical analysis. SPSS 6.0 was the main statistical analysis of the data. Results : Three thousand one hundred and seventy seven elderly people were enrolled in this study, thirty eight point eight per cent were male and sixty one point two per cent were female. There was correlation between age, education and TMSE (r=-0.345, r=0.473, p<0.001). We found no correlation between TMSE, mean arterial blood pressure (BP), systolic BP, diastolic BP, haematocrit, cholesterol, triglyceride, blood sugar and syphilitic serology. Multiple cut off points of TMSE was proposed to utilise the twenty fifth percentile in each five yearly age interval. Those who were under the 25thpercentile of TMSE and had impaired daily activities were diagnosed as dementia. The prevalence of dementia was 9.88 percentiles in our study. Conclusion : Dementia is a common problem in the Thai elderly. As treatment has become available for several etiologies of dementia, early detection and assessment of dementia with a cognitive screening test are essential. Public education to distinguish between dementia and old age needs to be emphasised.Publication Metadata only The efficacy of an aerobic exercise and health education program for treatment of chronic low back pain(2001-10-01) Tipawan Tritilanunt; Wiwat Wajanavisit; Mahidol UniversityLow back pain is one of the most common and important musculoskeletal disorders. In addition, chronic low back pain can deteriorate the patient's physical, psychosocial and socioeconomic status. The objective of this quasi-experimental research was to assess the efficacy of an aerobic exercise and health education program in the treatment of chronic low back pain. Seventy-two patients whose ages ranged from 30 to 50 years who had chronic low back pain were enrolled and randomly assigned into two groups. Eight men and 28 women in the experimental group participated in a series of 3 health education sessions and an aerobic exercise training pro-gram. Nine men and 27 women in the control group received regular health education and a lumbar flexion exercise program. After a 3-month period of treatment, the results revealed the experimental group had statistically significant improvement of pain score and resting pulse rates when compared to the values of the control group (p -value < 0.001 and < 0.01, respectively). The average serum High Density Lipoprotein-Cholesterol (HDL-C) in the experimental group was also significantly higher (p -value < 0.05) than that of the control group. This health education program is useful and may be applicable to patients with chronic low back pain as an alternative treatment.Publication Metadata only Effect of removal of the smear layer on apical microleakage(2001-01-01) Siriporn Timpawat; Mahidol UniversityIt has been shown previously that the smear layer created during instrumentation of the root canal promotes apical microleakage. The purpose of the present study was to investigate the effect of removal of the smear layer on apical microleakage, using the fluid filtration method. Thirty-six single-rooted human premolar teeth were used. Six of the teeth were selected randomly as controls, and the remaining 30 teeth were randomly divided into two groups of 15 teeth each. For the first group (group 1) teeth were irrigated with NaOCI only (smear layer not removed). In the second group (group 2) the teeth were irrigated with 15% EDTA, followed by NaOCI to remove the smear layer. Both groups were filled with thermoplasticized gutta-percha (Obtura II) using glass-ionomer cement as sealer. All teeth were stored at 37°C and 100% humidity for 2 days. Apical microleakage of the filled root canal was measured by the fluid filtration technique. Hydraulic conductance was measured by the movement of an air bubble in a capillary tube after a pressure of 200 mm Hg was applied to the system. The mean microleakage rate of group 1 and group 2 were 13.0 (SD ±5.1) and 16.9 (SD ± 15.3) nl/s, respectively. Removal of the smear layer caused significantly more apical microleakage (p < 0.05, Student's t test) than when the smear layer was left intact. Copyright © 2001 by The American Association of Endodontists.Publication Metadata only The IQCODE : An alternative screening test for dementia for low educated Thai elderly(2001-05-01) Vorapun Senanarong; Nopwan Sivasiriyanonds; Piyanuj Jamjumrus; Niphon Poungvarin; Sirichai Assavisaraporn; Thipawan Printarakul; Suthipol Udompunthuruk; Mahidol UniversityObjective : To explore an alternative method of screening for dementia in Thai elderly people who have a low educational level. The Informant Questionnaire on Cognitive Decline in the elderly (IQCODE) is used as the screening test. Material and Method : A community based population of elderly subjects in Bangkok including 87 normal subjects and 73 demented elderly people were studied. Their ages ranged from 52 to 85 years old. The majority of the elderly people had had four years or less of primaryeducation. Dementia was diagnosed independently by DSM IV criteria. A short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), a short form, was administered to informants of the elderly by trained medical personnel. The Thai Mini Mental State Examination (TMSE) was also administered to these subjects and compared with the IQCODE. SPSS 9.0 was used for statistical analysis. Results : The IQCODE showed a negative correlation with the TMSE (n=160, r=-0.679, p<0.001). The area under the receiver operating characteristic curve (ROC) of the IQCODE was larger than that of TMSE (0.928 vs 0.814). On logistic regression analysis, there were only three questions that contributed to the diagnosis that showed statistical significance. These questions are remembering what day and month it is, learning how to use a new gadget and handling other everyday arithmetic problems. Applying the new formula (z-score), these three questions showed a sensitivity of 84.90 per cent, and a specificity of 92 per cent for the diagnosis of dementia. Conclusion : Informants' perceptions of cognitive impairment of the elderly can be reliably applied as a screening instrument for dementia in the Thai population with a variety of educational levels. A short form of the IQCODE using selected questions can be administered with good diagnostic sensitivity and specificity.Publication Metadata only Roxithromycin, in prevention of acute coronary syndrome Associated with Chlamydia pneumoniae infection: A randomized placebo controlled trial(2001-12-01) Wattana Leowattana; Kieartijai Bhuripanyo; Lily Singhaviranon; Surank Akaniroj; Nithi Mahanonda; Manoon Samranthin; Sasikant Pokum; Mahidol UniversityThe role of Chlamydia pneumoniae infection in precipitating acute coronary syndrome (ACS) is unclear. Some studies have indicated that intervention with macrolide antibiotics might reduce coronary events in patients with ACS. A double blind, randomized, placebo-control trial was conducted on 84 ACS patients. Patients were randomized to 30 days of treatment with roxithromycin (150 mg, twice daily) or matching placebo. The follow-up period was 90 days, and the primary clinical end point included cardiovascular death, unplanned revascularization and recurrent angina/MI. Anti-C. pneumoniae IgG positive in 24 of 43 (55.8%) patients in the roxithromycin group and 23 of 41 (56.1%) patients in the placebo group. Anti-C pneumoniae IgA positive in 20 of 43 (46.5%) patients in the roxithromycin group and 13 of 41 (31.7%) patients in the placebo group. Thirty-three cardiac events occurred (2 cardiovascular deaths, 9 CABG, 12 PTCA and 10 recurrent angina/MI) with 17 events in the roxithromycin group and 16 events in the placebo group. There was no significant difference of cardiac events between the roxithromycin and placebo groups. The present study suggests that antibiotic therapy with roxithromycin is not associated with reduction of cardiac events as reported by other investigators. However, therapeutic interventions may need to be specifically targeted to a group of patients who are confirmed with chronic C. pneumoniae infection.Publication Metadata only Relationships among blending conditions, size of dispersed phase, and oil resistance in natural rubber and nitrile rubber blends(2001-10-31) Chakrit Sirisinha; Sauvarop Baulek-Limcharoen; Jarunee Thunyarittikorn; Mahidol University; The Institute of Science and Technology for Research and Development, Mahidol UniversityThe rheological properties, morphology, and oil resistance in natural rubber and nitrile-butadiene rubber (NR/NBR) blends are investigated as functions of the blending conditions. It is found that the Mooney viscosity of the blends depends more strongly on the blending time than the rotor speed. The size of the NR dispersed phase is approximately independent of the rotor speed, but it decreases with increasing blending time up to 25 min. With a further increase in the blending time the NR dispersed phase size decreases. The results for the relative tensile strength, which is an indicator of oil resistance, are in agreement with those of the blend morphology, indicating that the oil resistance in a 20/80 NR/NBR blend strongly depends on the phase morphology of the blend. The smaller the size of NR dispersed phase, the higher the blend resistance to oil.Publication Metadata only Structural basis for selectivity and toxicity of ribosomal antibiotics(2001-05-15) Erik C. Böttger; Burkhard Springer; Therdsak Prammananan; Yishak Kidan; Peter Sander; Medizinische Hochschule Hannover (MHH); ETH Zurich; Mahidol UniversityRibosomal antibiotics must discriminate between bacterial and eukaryotic ribosomes to various extents. Despite major differences in bacterial and eukaryotic ribosome structure, a single nucleotide or amino acid determines the selectivity of drugs affecting protein synthesis. Analysis of resistance mutations in bacteria allows the prediction of whether cytoplasmic or mitochondrial ribosomes in eukaryotic cells will be sensitive to the drug. This has important implications for drug specificity and toxicity. Together with recent data on the structure of ribosomal subunits these data provide the basis for development of new ribosomal antibiotics by rationale drug design.Publication Metadata only Association of adhesion molecule PECAM-1/CD31 polymorphism with susceptibility to cerebral malaria in Thais(2001-11-26) M. Kikuchi; S. Looareesuwan; R. Ubalee; O. Tasanor; F. Suzuki; Y. Wattanagoon; K. Na-Bangchang; A. Kimura; M. Aikawa; K. Hirayama; Saitma Medical University Faculty of Medicine; Mahidol University; Tokyo Medical and Dental University; Tokai University; Nagasaki UniversityAdhesion molecules on endothelial cells are known to be important ligands for malaria infected red blood cells (PRBC) [Mol Biochem Parasitol, 76, (1996) 1], and may be involved in the pathogenic process of cerebral malaria (CM) which is the most serious complication of falciparum malaria, through enhancing micro embolism or sequestration in the capillaries of the brain. PECAM-1/CD31 is one of these candidate ligands and is coded by a polymorphic gene. Two hundred and ten Thai malaria patients (43 cerebral, 89 severe and 78 uncomplicated) were analyzed for their genetic polymorphism of CD31 to examine the clinical relationship between the disease and specific genotypes. Four alleles were defined 125 valine (V)-563 asparagine (N); 125V-563 serine (S); 125 leucine (L)-563N; and 125L-563S. We found that the frequency of the 125 V/V 563 N/N genotype was significantly high in CM patients as compared with severe cases without CM (P<0.01, OR=2.92), suggesting that this genotype is one of the risk factors for CM. Copyright © 2001 Elsevier Science Ireland Ltd.Publication Metadata only A non-stop, single-tube, semi-nested pcr technique for grading the severity of white spot syndrome virus infections in penaeus monodon(2001-12-05) Wansika Kiatpathomchai; Vichai Boonsaeng; Anchalee Tassanakajon; Chainarong Wongteerasupaya; Sarawut Jitrapakdee; Sakol Panyim; Mahidol UniversityA single-tube, non-stop, semi-nested polymerase chain reaction (PCR) technique was developed for simultaneous detection and severity grading of white spot syndrome virus (WSSV) infections in the black tiger shrimp Penaeus monodon. The test uses 1 sense primer and 3 anti-sense primers that produce up to 3 PCR products (1100, 526 and 250 base pairs [bp]) depending upon the severity of infection. Specifically, heavy infections (≥2 × 104viral particles) of WSSV produce all 3 fragments, while moderate infections (around 2 × 103viral particles) produce 2 (526 and 250 bp) and light infections (20 to 200 viral particles) produce 1 (250 bp). In addition, the technique uses internal control primers that yield a shrimp characteristic fragment for non-infected samples and samples with a low quantity of viral target in order to assure integrity and reproducibility of the PCR assays. The non-stop, single-tube, semi-nested PCR technique is simple and convenient and can detect as little as 5 fg WSSV DNA (20 viral particles) in crude extracts of postlarval samples or extracts of pleopods and haemolymph from larger shrimp.Publication Metadata only An unusually large esophageal foreign body: A live whole fish(2001-12-01) Ong Art Janjarussin; Lalida Kasemsuwan; Mahidol UniversityPublication Metadata only HIV inhibitor from Thai bitter gourd(2001-07-09) W. Jiratchariyakul; C. Wiwat; M. Vongsakul; A. Somanabandhu; W. Leelamanit; I. Fujii; N. Suwannaroj; Y. Ebizuka; Mahidol University; University of TokyoThai bitter gourd protein (MRK29) was isolated from Momordica charantia ripe fruit and seed. The purification was performed by ammonium sulfate fractionation and gel filtration chromatography. MRK29 possessed one isoelectric point of (pl) ≥ 9, and the time of flight mass spectrum (TOFMS) indicated its molecular weight at 28.6 kD. The twenty amino acid sequence from the N-terminus was in the following order: 1Asp Val Asn Phe Arg Leu Ser Gly Ala 10Asp Pro Arg X Tyr Gly Met Phe lie Glu 20Asp. MRK29 inhibited the HIV-1 reverse transcriptase with 50% IR at the concentration of 18μg/ml. MRK29 was concentrated in the 30-60% salt precipitated fraction, at which the concentration of 0.175μg/ml exerted 82% reduction of viral core protein p24 expression in HIV-infected cells. MRK29 might have modulatory role on immune cells, because it increased 3-fold TNF activity.Publication Metadata only Hepatic arterial collaterals after transcatheter oily chemoembolization of hepatocellular carcinoma(2001-01-01) Charindr Eurvilaichit; Chamaree Chuapetcharasopon; Mahidol University; Smithivej HospitalFrom July 1989 to June 1999, 100 patients, 76 male and 24 female, were admitted for treatment of hepatocellular carcinoma (HCC) with transcatheier oily chemoembolization (TOCE) using lipiodol 10 ml mixed with an anticancer drug (mitomycin C 20 ml) and gelfoam particles, desc ribed by Nakamura H et al(1). The periodic follow-up angiogram showed hepatic collaterals which developed according to the mode of embolization. For peripheral hepatic arterial embolization such as segmental or lobar arterial embolization, the intrahepatic collaterals were commonly demonstrated. However, for more proximal hepatic arterial embolization of the tumor feeder arteries such as the proper hepatic artery and the common hepatic artery, the extrahepatic collaterals were commonly demonstrated with fine, small tortuous vasculatures, rendering a repeat TOCE more difficult. The hepatic collaterals are presented.Publication Metadata only Determination of lidocaine in dental pulp by high-performance liquid chromatography(2001-01-01) Somchart Kanjanawattana; Chutima Mangkornkarn; Prapin Wilairat; Noppakun Vongsavan; Mahidol University; Faculty of Dentistry; Faculty of Science;The purpose of this study was to develop a method for lidocaine detection in dental pulp by high-performance liquid chromatography. The amounts of lidocaine in dog pulps were quantitated after local injection to evaluate lidocaine recovery from pulp tissue with this technique. Comparison was also made between the amount of lidocaine found in upper and lower canines. The high-performance liquid chromatography system was shown to be a reliable and reproducible tool for lidocaine determination. Lidocaine extraction from the tissue showed recovery of 90%. The amount of lidocaine recovered from the upper canine (0.21 μg/mg) was higher than the lower canine (0.17 μg/mg). Copyright © 2001 by The American Association of Endodontists.Publication Metadata only Preparation of 5′-GMP-rich yeast extracts from spent brewer's yeast(2001-12-01) P. Sombutyanuchit; M. Suphantharika; C. Verduyn; Mahidol UniversitySpent brewer's yeast was autolysed and used as a raw material for the preparation of 5′-GMP-rich yeast extracts. Malt rootlets were used as a source of 5′-phosphodiesterase. The crude enzyme was extracted from malt rootlets and pretreated to inactivate 5′-nucleotidase. The optimum pretreatment conditions were heating at 65°C for 30 min or 70°C for 7 min. The effects of autolysis time, phosphodiesterase concentration and incubation period on 5′-GMP content were examined. The suitable autolysis time was 8 h. The preferable enzyme treatment period was in the range of 8-14 h. Longer autolysis and enzyme incubation periods caused a decrease in the 5′-GMP content from 0.7-0.9% (w/w) to 0.2-0.4% (w/w). The 5′-GMP content in extracts from debittered and non-debittered yeast was similar. The highest 5′-GMP content in yeast extract was 0.93% (w/w), obtained with a phosphodiesterase concentration of 1.6 unit/ml of yeast extract (5% solids content).Publication Metadata only A study of some physicochemical properties of high-crystalline tapioca starch(2001-11-01) Napaporn Atichokudomchai; Sujin Shobsngob; Pavinee Chinachoti; Saiyavit Varavinit; Mahidol University; University of MassachusettsTapioca starch was partially hydrolyzed in hydrochloric acid solution at room temperature for various lengths of time to obtain high-crystalline starches. RVA viscoamylograms of acid-modified starches demonstrated a very low viscosity as compared to that of native tapioca starch. The relative crystallinity of native and acid-modified tapioca starches were measured by X-ray diffraction ranging from 39.53% to 57.75%. The native and acid-modified tapioca starches were compressed into tablets using various compression forces. The % relative crystallinity of starch increased with the increase in hydrolysis time and the crushing strength of the tablet was also increased in line with the crystallinity while the amylose content decreased when the crystallinity increased. These results suggested that the erosion of amylose might cause the rearrangement of starch structure into a new more tightly packed form, which provided the higher crushing strength for the tablets.Publication Metadata only Irradiation of highly oriented polyethylene fibers in the atmosphere of some vinyl monomers: Effect on compressive strength(2001-03-01) Taweechai Amornsakchai; Supatra Wangsoub; Sauvarop Bualek-Limcharoen; Mahidol University; Naresuan UniversityHighly oriented polyethylene fibers have been modified by γ-irradiation in the presence of some vinyl monomer vapors, followed with further annealing in the atmosphere of the same monomer. Two types of vinyl monomers that are known to produce polymers with different glass transition temperatures, namely methyl methacrylate and vinyl acetate, were studied for their effect on the compressive strength of the fiber. It was found that a significant improvement in compressive strength, measured by tensile recoil test, was obtained. The level of improvement was affected by heat treatment and the presence of monomer during irradiation. Modification with vinyl acetate was found to be more effective than methyl methacrylate. These facts suggest that the improvement in compressive strength was attributable to several factors, including structural relaxation, the presence of graft copolymer, and energy dissipation ability of the graft copolymer. It is speculated that lateral integrity of the fiber is one of the key factors that prevents sliding of microfibril and possibly lateral or circumferential expansion of the fiber to accommodate kink band.