Displaying publications 2721 - 2740 of 8501 in total

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  1. Tan WS, McNae IW, Ho KL, Walkinshaw MD
    PMID: 17671358
    Hepatitis B core (HBc) particles have been extensively exploited as carriers for foreign immunological epitopes in the development of multicomponent vaccines and diagnostic reagents. Crystals of the T = 4 HBc particle were grown in PEG 20,000, ammonium sulfate and various types of alcohols. A temperature jump from 277 or 283 to 290 K was found to enhance crystal growth. A crystal grown using MPD as a cryoprotectant diffracted X-rays to 7.7 A resolution and data were collected to 99.6% completeness at 8.9 A. The crystal belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 352.3, b = 465.5, c = 645.0 A. The electron-density map reveals a protrusion that is consistent with the N-terminus extending out from the surface of the capsid. The structure presented here supports the idea that N-terminal insertions can be exploited in the development of diagnostic reagents, multicomponent vaccines and delivery vehicles into mammalian cells.
  2. Tan HJ, Suganthi C, Dhachayani S, Rizal AM, Raymond AA
    Med J Malaysia, 2007 Mar;62(1):56-8.
    PMID: 17682573 MyJurnal
    Migraine is associated with a variety of electroencephalographic (EEG) changes. Previous studies using analogue EEG and old diagnostic criteria may under or over report the prevalence of EEG changes in migraine. The objective of this study was to reevaluate the EEG changes in migraine patients diagnosed by applying the new International Classification of Headache Disorder -2 criteria. This was a case control study involving 70 migraine patients and 70 age and gender matched control who were subjected to scalp EEG. The EEG changes during hyperventilation (HV), which were significantly more common in the migraine group were theta activity (34 vs 22, p = 0.038) and frontal intermittent rhythmic delta activity (FIRDA) (10 vs 3, p = 0.042). Applying the new ICHD -2 diagnostic criteria and digital EEG, this study yielded previously unrecognized features including FIRDA during HV on EEG.
  3. Tan PC, Jacob R, Quek KF, Omar SZ
    J Obstet Gynaecol Res, 2007 Aug;33(4):457-64.
    PMID: 17688612
    To determine pregnancy outcome in hyperemesis gravidarum and the effect of metabolic, biochemical, hematological and clinical indicators of disease severity on outcome.
  4. Loo CY, Tan HJ, Teh HS, Raymond AA
    Singapore Med J, 2007 Sep;48(9):834-9.
    PMID: 17728965
    INTRODUCTION: Migraine is a common disabling condition that results in considerable socioeconomic loss. The role of non-steroidal anti-inflammatory drugs (NSAIDs) in acute migraine has been well-established. We compared the efficacy of the cyclooxygenase-2 inhibitor celecoxib with the NSAID, naproxen sodium, in the treatment of acute migraine.
    METHODS: This was a randomised, open label, controlled trial. We selected patients with a diagnosis of migraine, based on the International Headache Society revised criteria. 60 patients were randomised to either celecoxib 400 mg (30 patients) or naproxen sodium 550 mg (30 patients). Patients took the study medicine for the first acute migraine episode that occurred during the study period and reported the headache reduction based on a visual analogue score (VAS). Patients were reviewed after a month to check on VAS at one and two hours, compared to the baseline. Any side effects of the medication were also recorded.
    RESULTS: Of the 52 patients who completed the study, eight did not experience any headaches. The mean VAS in the celecoxib group improved significantly from baseline (6.48 +/- 1.53) to one hour (4.28 +/- 2.11) and two hours (2.24 +/- 2.57) (p-value is less than 0.0005). The mean VAS in the naproxen sodium group also improved significantly from baseline (7.30 +/- 1.66) to one hour (4.81 +/- 2.50) and two hours (2.63 +/- 2.65) (p-value is less than 0.0005). However, there was no significant difference between the magnitudes of improvement between the treatment groups. The incidence of gastric pain was significantly higher in the naproxen sodium group (p-value is equal to 0.029).
    CONCLUSION: In comparison with naproxen sodium, celecoxib was equally effective in relieving pain in acute migraine and caused significantly less gastric pain.

    Study site: neurology outpatient clinic in Pusat Perubatan
    Universiti Kebangsaan Malaysia (PPUKM)
  5. Yeo CC, Tan CL, Gao X, Zhao B, Poh CL
    Res. Microbiol., 2007 Sep;158(7):608-16.
    PMID: 17720458
    Pseudomonas alcaligenes NCIMB 9867 (strain P25X) is known to synthesize two isofunctional gentisate 1,2-dioxygenases (GDO; EC 1.13.11.4) as well as other enzymes involved in the degradation of xylenols and cresols via the gentisate pathway. The hbzE gene encoding what is possibly the strictly inducible gentisate 1,2-dioxygenase II (GDO-II) was cloned, overexpressed and purified as a hexahistidine fusion protein from Escherichia coli. Active recombinant GDO-II had an estimated molecular mass of 150kDa and is likely a tetrameric protein with a subunit mass of approximately 40kDa, similar to the previously characterized gentisate 1,2-dioxygenase I (GDO-I) encoded by xlnE. However, GDO-II was unable to utilize gentisate that is substituted at the carbon-4 position, unlike GDO-I which had broader substrate specificity. GDO-II also possessed different kinetic characteristics when compared to GDO-I. The hbzE-encoded GDO-II shared higher sequence identities (53%) with GDOs from Ralstonia sp. U2 and Polaromonas naphthalenivorans CJ2, compared with only 35% identity with the xlnE-encoded GDO-I. The hbzE gene was found to be part of a cluster of nine genes including the putative regulatory gene designated hbzR, which encodes an LysR-type regulator and is divergently transcribed from the other genes of the hbzHIJKLFED cluster.
  6. Mirhosseini H, Tan CP, Hamid NS, Yusof S
    J Agric Food Chem, 2007 Sep 19;55(19):7659-66.
    PMID: 17708646
    The possible relationships between the main emulsion components (namely, Arabic gum, xanthan gum, and orange oil) and the physicochemical properties of orange beverage emulsion were evaluated by using response surface methodology. The physicochemical emulsion property variables considered as response variables were emulsion stability, viscosity, fluid behavior, zeta-potential, and electrophoretic mobility. The independent variables had the most and least significant ( p < 0.05) effect on viscosity and zeta-potential, respectively. The quadratic effect of orange oil and Arabic gum, the interaction effect of Arabic gum and xanthan gum, and the main effect of Arabic gum were the most significant ( p < 0.05) effects on turbidity loss rate, viscosity, viscosity ratio, and mobility, respectively. The main effect of Arabic gum was found to be significant ( p < 0.05) in all response variables except for turbidity loss rate. The nonlinear regression equations were significantly ( p < 0.05) fitted for all response variables with high R (2) values (>0.86), which had no indication of lack of fit. The results indicated that a combined level of 10.78% (w/w) Arabic gum, 0.56% (w/w) xanthan gum, and 15.27% (w/w) orange oil was predicted to provide the overall optimum region in terms of physicochemical properties studied. No significant ( p > 0.05) difference between the experimental and the predicted values confirmed the adequacy of response surface equations.
  7. Yap CK, Chua BH, Teh CH, Tan SG, Ismail A
    Genetika, 2007 May;43(5):668-74.
    PMID: 17633561
    Genetic variation due to heavy metal contamination has always been an interesting topic of study. Because of the numerous contaminants being found in coastal and intertidal waters, there is always much discussion and argument as to which contaminant(s) caused the variations in the genetic structures of biomonitors. This study used a Single Primer Amplification Reaction (SPAR) technique namely Random Amplified Polymorphic DNA (RAPD) to determine the genetic diversity of the populations of the green-lipped mussel Perna viridis collected from a metal-contaminated site at Kg. Pasir Puteh and those from four relatively' uncontaminated sites (reference sites). Heavy metal levels (Cd, Cu, Pb and Zn) were also measured in the soft tissues and byssus of the mussels from all the sites. Cluster analyses employing UPGMA done based on the RAPD makers grouped the populations into two major clusters; the Bagan Tiang, Pantai Lido, Pontian and Kg. Pasir Puteh populations were in one cluster, while the Sg. Belungkor population clustered by itself. This indicated that the genetic diversity based on bands resulting from the use of all four RAPD primers on P. viridis did not indicate its potential use as a biomarker of heavy metal pollution in coastal waters. However, based on a correlation analysis between a particular metal and a band resulting from a specific RAPD primer revealed some significant (P < 0.01) correlations between the primers and the heavy metal concentrations in the byssus and soft tissues. Thus, the correlation between a particular metal and the bands resulting from the use of a specific RAPD primer on P. viridis could be used as biomonitoring tool of heavy metal pollution.
  8. Aziz HA, Peh KK, Tan YT
    Drug Dev Ind Pharm, 2007 Nov;33(11):1263-72.
    PMID: 18058323
    Curcumin, the main active constituent of turmeric herb (Curcuma longa L.) have been reported to possess many medicinal values. The application of curcumin in dermatological preparations is limited by their intense yellow color property, which stains the fabric and skin. The objectives of this study were to reduce the color staining effect and enhance the stability of curcumin via microencapsulation using gelatin simple coacervation method. As for curcumin, ethanol and acetone were used as coacervating solvents. Curcumin was dispersed in ethanol while dissolved in acetone. Irrespective of the types of coacervating solvents used, microencapsulation resolved the color-staining problem and enhanced the flow properties and photo-stability of curcumin. Nevertheless, it was found that more spherical curcumin microcapsules with higher yield, higher curcumin loading, and higher entrapment efficiency were obtained with acetone than ethanol. The in vitro release of curcumin after microencapsulation was slightly prolonged. Further evaluation of the effects of solubility of core materials in coacervating solvent or polymeric aqueous solution using six different drug compounds, namely, ketoconazole, ketoprofen, magnesium stearate, pseudoephedrine HCl, diclofenac sodium, and paracetamol, suggested that the solubility of core materials in aqueous polymeric solution determined the successful formation of microcapsules. Microcapsules could only be formed if the core materials were not dissolved in the aqueous polymeric solution while the core materials could either be dissolved or dispersed in the coacervating solvent. In summary, microencapsulation not only circumvents the color-staining problem but also improved the stability and flowability of curcumin. The solubility of core material in aqueous polymeric solution plays a pivotal role in determining the successful formation of microcapsules.
  9. Ahmad AL, Tan LS, Abd Shukor SR
    J Hazard Mater, 2008 Jun 15;154(1-3):633-8.
    PMID: 18055106
    This study examined the performance of nanofiltration membranes to retain atrazine and dimethoate in aqueous solution under different pH conditions. Four nanofiltration membranes, NF90, NF200, NF270 and DK are selected to be examined. The operating pressure, feed pesticide and stirring rate were kept constant at 6x10(5) Pa, 10 mg/L and 1000 rpm. It was found that increasing the solution's pH increased atrazine and dimethoate rejection but reduced the permeate flux performance for NF200, NF270 and DK. However, NF90 showed somewhat consistent performance in both rejection and permeate flux regardless of the solution's pH. NF90 maintained above 90% of atrazine rejection and approximately 80% of dimethoate rejection regardless of the changes in solution's pH. Thus, NF90 is deemed the more suitable nanofiltration membrane for atrazine and dimethoate retention from aqueous solution compared to NF200, NF270 and DK.
  10. Tan IA, Ahmad AL, Hameed BH
    J Hazard Mater, 2008 Jun 15;154(1-3):337-46.
    PMID: 18035483
    Adsorption isotherm and kinetics of methylene blue on activated carbon prepared from coconut husk were determined from batch tests. The effects of contact time (1-30 h), initial dye concentration (50-500 mg/l) and solution temperature (30-50 degrees C) were investigated. Equilibrium data were fitted to Langmuir, Freundlich, Temkin and Dubinin-Radushkevich isotherm models. The equilibrium data were best represented by Langmuir isotherm model, showing maximum monolayer adsorption capacity of 434.78 mg/g. The kinetic data were fitted to pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and was found to follow closely the pseudo-second-order kinetic model. Thermodynamic parameters such as standard enthalpy (DeltaH degrees), standard entropy (DeltaS degrees) and standard free energy (DeltaG degrees) were evaluated. The adsorption interaction was found to be exothermic in nature. Coconut husk-based activated carbon was shown to be a promising adsorbent for removal of methylene blue from aqueous solutions.
  11. Tan TY, Shashinder S, Subrayan V, Krishnan G
    Auris Nasus Larynx, 2008 Jun;35(2):285-7.
    PMID: 18024042
    Silent sinus syndrome is a rare clinical condition in which patients present with spontaneous enophthalmos and hypoglobus secondary to collapse of orbital floor due to chronic subclinical maxillary sinusitis. It is postulated that obstruction of the osteomeatal complex lead to negative antrum pressure which causes the maxillary sinus atelectasis.
  12. Tang KF, Abdullah MP, Yusoff K, Tan WS
    J Med Chem, 2007 Nov 15;50(23):5620-6.
    PMID: 17918821
    The core protein (HBcAg) of hepatitis B virus (HBV) has been shown to interact with the large surface antigen during HBV morphogenesis, and these interactions can be blocked by small peptides selected from either linear or constrained phage display peptide libraries. The association of HBcAg with peptide inhibitors was quantitatively evaluated by isothermal titration calorimetry. The thermodynamic data show that the interaction between HBcAg and peptide MHRSLLGRMKGA is enthalpy-driven and occurs at a 3:1 stoichiometry and dissociation constant (Kd) value of 79.4 muM. However, peptide WSFFSNI displays a higher binding affinity for HBcAg with a Kd value of 18.5 muM when compared to peptide MHRSLLGRMKGA. A combinatorial approach using chemical cross-linking and surface-enhanced laser desorption/ionization-time-of-flight-mass spectrometry shows that the Lys of peptide MHRSLLGRMKGA interacted either with D64, E77, or D78 of HBcAg.
  13. Tan GC, Shiran MS, Swaminathan M, Phang KS, Rohaizak M
    Asian J Surg, 2007 Oct;30(4):286-9.
    PMID: 17962134
    Parathyroid carcinoma is an uncommon cause of parathyroid hormone (PTH)-dependent hypercalcaemia, accounting for less than 1% of all cases of hyperparathyroidism. Parathyroid carcinoma is an indolent tumour with rather low malignant potential. Consideration of parathyroid carcinoma in the differential diagnosis of hypercalcaemic disorders is important because the morbidity and mortality are substantial and the best prognosis is associated with early recognition and surgical resection. Clinical indicators favouring parathyroid carcinoma over benign disease include markedly raised serum calcium levels, PTH and alkaline phosphatase. A palpable neck mass with both kidney and skeletal manifestations also give a high index of suspicion of parathyroid carcinoma. Histopathology alone is not sufficient to diagnose parathyroid cancer; it has to be correlated with the clinical findings. The initial and most effective treatment for parathyroid carcinoma is complete resection of the primary lesion, and repeated operations for recurrence are useful. The prognosis of parathyroid carcinomas is quite variable; 5-year survival rates vary from 40% to 86%, while the 10-year survival rate is approximately 49%. We report a case of parathyroid carcinoma occurring in a 55-year-old woman who presented with bone pain and hypercalcaemia.
  14. Tan IA, Ahmad AL, Hameed BH
    J Hazard Mater, 2008 May 1;153(1-2):709-17.
    PMID: 17935879
    Activated carbon was prepared from coconut husk using physicochemical activation method which consisted of potassium hydroxide (KOH) treatment and carbon dioxide (CO(2)) gasification. The effects of three preparation variables (CO(2) activation temperature, CO(2) activation time and KOH:char impregnation ratio) on the 2,4,6-trichlorophenol (2,4,6-TCP) uptake and activated carbon yield were investigated. Based on the central composite design, two quadratic models were developed to correlate the preparation variables to the two responses. From the analysis of variance (ANOVA), the most influential factor on each experimental design response was identified. The activated carbon preparation conditions were optimized by maximizing both the 2,4,6-TCP uptake and activated carbon yield. The predicted 2,4,6-TCP uptake and carbon yield from the models agreed satisfactorily with the experimental values. The optimum conditions for preparing activated carbon from coconut husk for adsorption of 2,4,6-TCP were found as follow: CO(2) activation temperature of 750 degrees C, CO(2) activation time of 2.29 h and KOH:char impregnation ratio of 2.91, which resulted in 191.73 mg/g of 2,4,6-TCP uptake and 20.16 % of activated carbon yield.
  15. Tan PC, Valiapan SD, Tay PY, Omar SZ
    BJOG, 2007 Jul;114(7):824-32.
    PMID: 17506788
    To compare concurrent oxytocin with dinoprostone pessary versus dinoprostone pessary in labour induction for nulliparas with an unfavourable cervix.
  16. Sim KS, Tso CP, Tan YY, Lim WK
    J Microsc, 2007 Jun;226(Pt 3):230-43.
    PMID: 17535262
    A proposal to assess the quality of scanning electron microscope images using mixed Lagrange time delay estimation technique is presented. With optimal scanning electron microscope scan rate information, online images can be quantified and improved. The online quality assessment technique is embedded onto a scanning electron microscope frame grabber card for real-time image processing. Different images are captured using scanning electron microscope and a database is built to optimally choose filter parameters. An optimum choice of filter parameters is obtained. With the optimum choice of scan rate, noise can be removed from real-time scanning electron microscope images without causing any sample contamination or increasing scanning time.
  17. Nazratun N, Mahmood AA, Kuppusamy UR, Ahmad TS, Tan SY
    Vasc Med, 2006 Nov;11(4):245-50.
    PMID: 17390548
    The excess accumulation of advanced glycation end products (AGEs) contributes to the chronic complications of type 2 diabetes mellitus (DM) and renal failure. Biopsy specimens (n = 184) of arterial (n = 92) and venous (n = 92) tissues were obtained (radial artery and cephalic vein) from end-stage renal disease (ESRD) patients with or without DM and normal healthy subjects (n = 12) requiring surgery (trauma patients). Immunohistochemical assessment of the blood vessels revealed the presence of pentosidine (AGE marker) in both veins and arteries in 72% of the ESRD patients. The percentage of arteries and veins that showed positive pentosidine staining in ESRD patients with type 2 DM alone was 100% and 92% respectively, in the non-diabetic ESRD patients it was < 70% (for arteries and veins), and in the ESRD patients with hypertension as an additional co-morbidity to type 2 DM it was 70% and 82%, respectively. The veins of ESRD patients with DM showed a strong (+++) positive staining and very strong (++++) positive staining was observed in the patients with DM and hypertension. Only mild (+) or moderate (++) pentosidine staining intensity was observed in the arteries of ESRD patients without or with comorbidities, respectively. The accumulation of AGE in the vein rather than the artery may be a better reflection of the extent of complications of ESRD.
  18. Tan HJ, Suganthi C, Dhachayani S, Rizal AM, Raymond AA
    Singapore Med J, 2007 Apr;48(4):307-10.
    PMID: 17384877
    Migraine is associated with a variety of personality traits. The objective of this study was to reevaluate the personality traits using Minnesota Multiphasic Personality Inventory-2 (MMPI-2) in migraine patients diagnosed by applying the new International Classification of Headache Disorders-2 criteria.
  19. Tan PC, Vallikkannu N, Suguna S, Quek KF, Hassan J
    Ultrasound Obstet Gynecol, 2007 May;29(5):568-73.
    PMID: 17444553
    To compare transvaginal sonography for cervical length measurement and digital examination for Bishop score assessment in women undergoing labor induction at term, to assess their tolerability (in terms of pain) and ability to predict need for Cesarean delivery.
  20. Fauziningtyas R, Chong MC, Setiawan HW, Tan MP
    J Multidiscip Healthc, 2023;16:3379-3392.
    PMID: 37964796 DOI: 10.2147/JMDH.S436766
    INTRODUCTION: Adverse incidents in nursing home (NH) may occur as the result of inadequate monitoring for signs of unobservable initial complications, medical errors, improper nursing interventions, lack of communication, and inadequate reporting.

    PURPOSE: This study explores incident types, causes, handling, and documentation in Indonesian NHs through a qualitative approach.

    PATIENTS AND METHODS: In-depth interviews were conducted with 23 NH staff members, including managers, nurses, and support staff.

    RESULTS: Five themes and 17 sub-themes emerged, with falls and resident-to-resident abuse as common adverse incidents. Causes included older adults' conditions, environment, and misunderstanding. Follow-up action included first aid, hospital referrals, and assertive communication. Adverse incidents were actively reported through verbal and written reports or WhatsApp groups. Reports and documentation remain unstructured, however, as there were no standard operating procedures regarding incident reporting, documentation, and the types of adverse incidents that staff should report.

    CONCLUSION: Improvements in management, documentation, and reporting adverse incidents are highlighted in this research. Practitioners, nurses, and social workers should develop guidelines for handling, reporting, and documenting adverse incidents in NHs.

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