MyMedR

Solid-phase microextraction for determining twelve orange flavour compounds in a model beverage emulsion

Mirhosseini H, Tan CP, Yusof S, Hamid NS

Phytochem Anal, 2008 Sep-Oct;19(5):429-37.

Solid-phase microextraction (SPME) coupled to gas chromatography has been applied for the headspace analysis (HS) of 12 target flavour compounds in a model orange beverage emulsion. The main volatile flavour compounds studied were: acetaldehyde, ethyl acetate, alpha-pinene, ethyl butyrate, beta-pinene, myrcene, limonene, gamma-terpinene, octanal, decanal, linalool and citral (neral plus geranial). After screening the fibre type, the effect of other HS-SPME variables such as adsorption temperature (25-55 degrees C), extraction time (10-40 min), sample concentration (1-100% w/w), sample amount (5-10 g) and salt amount (0-30% w/w) were determined using a two-level fractional factorial design (2(5-2)) that was expanded further to a central composite design. It was found that an extraction process using a carboxen-polydimethylsiloxane fibre coating at 15 masculineC for 50 min with 5 g of diluted emulsion 1% (w/w) and 30% (w/w) of sodium chloride under stirring mode resulted in the highest HS extraction efficiency. For all volatile flavour compounds, the linearity values were accurate in the concentration ranges studied (r(2) > 0.97). Average recoveries that ranged from 90.3 to 124.8% showed a good accuracy for the optimised method. The relative standard deviation for six replicates of all volatile flavour compounds was found to be less than 15%. For all volatile flavour compounds, the limit of detection ranged from 0.20 to 1.69 mg/L.

Optimization of basic dye removal by oil palm fibre-based activated carbon using response surface methodology

Hameed BH, Tan IA, Ahmad AL

J Hazard Mater, 2008 Oct 30;158(2-3):324-32.

PMID: 18329169 DOI: 10.1016/j.jhazmat.2008.01.088

Oil palm fibre was used to prepare activated carbon using physiochemical activation method which consisted of potassium hydroxide (KOH) treatment and carbon dioxide (CO(2)) gasification. The effects of three preparation variables: the activation temperature, activation time and chemical impregnation (KOH:char) ratio on methylene blue (MB) uptake from aqueous solutions and activated carbon yield were investigated. Based on the central composite design (CCD), a quadratic model and a two factor interaction (2FI) model were respectively developed to correlate the preparation variables to the MB uptake and carbon yield. From the analysis of variance (ANOVA), the significant factors on each experimental design response were identified. The optimum activated carbon prepared from oil palm fibre was obtained by using activation temperature of 862 degrees C, activation time of 1h and chemical impregnation ratio of 3.1. The optimum activated carbon showed MB uptake of 203.83 mg/g and activated carbon yield of 16.50%. The equilibrium data for adsorption of MB on the optimum activated carbon were well represented by the Langmuir isotherm, giving maximum monolayer adsorption capacity as high as 400mg/g at 30 degrees C.

Improving diabetes care in a public hospital medical clinic: report of a completed audit cycle

Tan F, Liew SF, Chan G, Toh V, Wong SY

J Eval Clin Pract, 2011 Feb;17(1):40-4.

PMID: 20807297 DOI: 10.1111/j.1365-2753.2010.01367.x

RATIONALE, AIMS AND OBJECTIVES: To evaluate the impact of clinical audit on diabetes care provided to type 2 diabetic patients attending our hospital general medical clinics.
METHODS: Performances on diabetes-related process measures and intermediate outcome measures were evaluated through structured review of outpatient medical records. The results were fed back to the doctors and measures were implemented to improve care. The performance indicators were re-evaluated 2 years later to complete the audit cycle.
RESULTS: Annual testing rates improved for HbA1c (68.4% vs. 87.4%; P < 0.001) and lipid profile (91.8% vs. 97%; P = 0.027). Enquiry on smoking improved from 45.9% to 82.3% (P < 0.001), eye screening rates from 68.9% to 78.8% (P = 0.020) and foot examinations from 22.4% to 64.1% (P < 0.001). Prescription rates for insulin increased from 17.3% to 31.8% (P = 0.001) and statin from 83.2% to 94.4% (P < 0.001). The use of aspirin (80.6% vs. 83.8%; P =0.402) and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (92.3% vs. 88.9%; P = 0.239) remained high in both cycles. More patients achieved targets for HbA1c < 7% (38% vs. 26%; P = 0.006), blood pressure < 130/80 mmHg (43% vs. 32%; P = 0.071) and low-density lipoprotein cholesterol < 2.6 mmol/L (71% vs. 52%; P <0.001).
CONCLUSION: Clinical audit is a useful tool in improving diabetes care.
Study site: Outpatient clinic, Sarawak General Hospital, Kuching, Sarawak, Malaysia

Evaluation of the marginal fit of a zirconia ceramic computer-aided machined (CAM) crown system

Baig MR, Tan KB, Nicholls JI

J Prosthet Dent, 2010 Oct;104(4):216-27.

PMID: 20875526 DOI: 10.1016/S0022-3913(10)60128-X

The marginal fit of crowns is a concern for clinicians, and there is no conclusive evidence of any one margin configuration yielding better results than others in terms of marginal fit.

Purification of His-tagged hepatitis B core antigen from unclarified bacterial homogenate using immobilized metal affinity-expanded bed adsorption chromatography

Yap WB, Tey BT, Alitheen NB, Tan WS

J Chromatogr A, 2010 May 21;1217(21):3473-80.

PMID: 20388569 DOI: 10.1016/j.chroma.2010.03.012

Hepatitis B core antigen (HBcAg) is used as a diagnostic reagent for the detection of hepatitis B virus infection. In this study, immobilized metal affinity-expanded bed adsorption chromatography (IMA-EBAC) was employed to purify N-terminally His-tagged HBcAg from unclarified bacterial homogenate. Streamline Chelating was used as the adsorbent and the batch adsorption experiment showed that the optimal binding pH of His-tagged HBcAg was 8.0 with a binding capacity of 1.8 mg per ml of adsorbent. The optimal elution condition for the elution of His-tagged HBcAg from the adsorbent was at pH 7 in the presence of 500 mM imidazole and 1.5 M NaCl. The IMA-EBAC has successfully recovered 56% of His-tagged HBcAg from the unclarified E. coli homogenate with a purification factor of 3.64. Enzyme-linked immunosorbent assay (ELISA) showed that the antigenicity of the recovered His-tagged HBcAg was not affected throughout the IMA-EBAC purification process and electron microscopy revealed that the protein assembled into virus-like particles (VLP).

Description of Sinodiplectanotrema malayanum n. sp. (Monogenea: Diplectanidae), with comments on the taxonomic position of the genus

Lim LH, Tan WB, Gibson DI

Syst Parasitol, 2010 Jun;76(2):145-57.

PMID: 20437220 DOI: 10.1007/s11230-010-9242-2

Monogeneans identified as Sinodiplectanotrema malayanum n. sp. were collected from the fish Pennahia anea (Sciaenidae) off the west coast of Peninsular Malaysia. The new species is recognised on the basis of morphometrical differences in the anchors, marginal hooks and eggs and apparent differences in the 28S rDNA sequence data. The new species possesses features (ovary looping the intestinal caecum, body spines, a vagina and haptoral reservoirs) not noted in the original description of the type and only other species of the genus, S. argyrosomus Zhang, 2001, necessitating the re-assignment of the genus to the Diplectanidae Monticelli, 1903, a move which is supported by 28S rDNA evidence. Sinodiplectanotrema is redefined on the basis of the observation of several features not included in the original diagnosis.

Promethazine compared with metoclopramide for hyperemesis gravidarum: a randomized controlled trial

Tan PC, Khine PP, Vallikkannu N, Omar SZ

Obstet Gynecol, 2010 May;115(5):975-981.

PMID: 20410771 DOI: 10.1097/AOG.0b013e3181d99290

OBJECTIVE: To compare the effects of promethazine with those of metoclopramide for hyperemesis gravidarum.

METHODS: Women at their first hospitalization for hyperemesis gravidarum were approached when intravenous antiemetic therapy was needed. They were randomly assigned to receive 25 mg promethazine or 10 mg metoclopramide every 8 hours for 24 hours in a double-blind study. Primary outcomes were vomiting episodes by diary and well-being visual numerical rating scale score (10-point scale) in the 24-hour main study period. Participants also filled out an adverse-effects questionnaire at 24 hours and a nausea visual numerical rating scale score at recruitment and at 8, 16, and 24 hours.

RESULTS: A total of 73 and 76 women, randomized to metoclopramide and promethazine, respectively, were analyzed. Median vomiting episodes were one (range 0-26) compared with two (range 0-26) (P=.81), and well-being visual numerical rating scale scores were 8 (range 1-10) compared with 7 (range 2-10) (P=.24) for metoclopramide and promethazine, respectively. Repeat-measures analysis of variance of the nausea visual numerical rating scale scores showed no significant difference between study drugs (F score=0.842, P=.47). Reported drowsiness (58.6% compared with 83.6%, P=.001, number needed to treat to benefit [NNTb] 5), dizziness (34.3% compared with 71.2%, P

Clarithromycin resistance and point mutations in the 23S rRNA gene in Helicobacter pylori isolates from Malaysia

Ho SL, Tan EL, Sam CK, Goh KL

J Dig Dis, 2010 Apr;11(2):101-5.

PMID: 20402836 DOI: 10.1111/j.1751-2980.2010.00423.x

To determine the prevalence of primary clarithromycin resistance amongst Helicobacter pylori (H. pylori) strains in Malaysian patients with gastroduodenal diseases, by using restriction fragment length polymorphism (RFLP) in domain V of 23S rRNA.

In vitro modulation of naturally occurring flavonoids on cytochrome P450 2A6 (CYP2A6) activity

Tiong KH, Yiap BC, Tan EL, Ismail R, Ong CE

Xenobiotica, 2010 Jul;40(7):458-66.

PMID: 20402563 DOI: 10.3109/00498251003786749

1. The effect of flavonoids on coumarin 7-hydroxylation, an activity marker of an important human liver cytochrome P450 isoform, cytochrome P450 2A6 (CYP2A6), was investigated in this study. 2. Coumarin 7-hydroxylase activity was measured fluorometrically in reaction mixtures containing cDNA-expressed CYP2A6, nicotinamide adenine dinucleotide phosphate generating system and 10 uM coumarin, at various concentrations of flavonoids. 3. Among the 23 compounds tested, most of the active members were from flavonol group of hydroxylated flavonoids, with myricetin being the most potent inhibitor followed by quercetin, galangin, and kaempferol. 4. Further exploration of the inhibition mechanism of these compounds revealed that myricetin, galangin, and kaempferol exhibited mixed-type of inhibition pattern while quercetin was observed to exhibit competitive mode of inhibition. 5. Structure-function analyses revealed that degree of inhibition was closely related to the number and location of hydroxyl groups, glycosylation of the free hydroxyl groups, degree of saturation of the flavane nucleus as well as the presence of the alkoxylated function.

Fulltext Oral nifedipine versus intravenous labetalol for acute blood pressure control in hypertensive emergencies of pregnancy: a randomised trial

Raheem IA, Saaid R, Omar SZ, Tan PC

BJOG, 2012 Jan;119(1):78-85.

PMID: 21985500 DOI: 10.1111/j.1471-0528.2011.03151.x

To compare oral nifedipine with intravenous labetalol in their rapidity to control hypertensive emergencies of pregnancy.

Fulltext Paediatric ocular trauma in Kuching, Sarawak, Malaysia

Tan AK, Mallika PS, Asokumaran T, Mohamad Aziz S, Intan G

Malays Fam Physician, 2011;6(2-3):68-71.

PMID: 25606227 MyJurnal

To evaluate the demography, aetiology, type and outcome of paediatric ocular trauma in tertiary centre in Malaysia.

Fulltext Hypertension in a residential home for the elderly in Penang, Malaysia

Ong HT, Oung LS, Ong LM, Tan KP

Med J Malaysia, 2010 Mar;65(1):18-20.

PMID: 21265241 MyJurnal

A study of residents at the Silver Jubilee Home for the Aged was conducted to determine the prevalence, awareness and control of hypertension in this elderly community in Penang, Malaysia. Prevalence of hypertension was 36%, with 81% of patients being initially aware of this diagnosis. This relatively low hypertension prevalence rate may be because residents have a fairly sheltered lifestyle with less social stress and a daily routine that incorporates adequate exercise. Similarly, the high hypertension awareness rate compared to reported figures in the community may be because residents are more regularly monitored by the attending medical care-givers. At the beginning of the study, only 34% of hypertensive patients were well controlled with a blood pressure less than 140/90 mm Hg. This proportion rose to 53% at the end of study period. Compliance is better at a residential home because medication is served by their care-givers and cost is absorbed in this charitable organization. Our study suggests that hypertension awareness and control can be reasonable for the elderly in a residential home.

Fulltext Extending Asia Pacific bioinformatics into new realms in the "-omics" era

Ranganathan S, Eisenhaber F, Tong JC, Tan TW

BMC Genomics, 2009;10 Suppl 3:S1.

PMID: 19958472 DOI: 10.1186/1471-2164-10-S3-S1

The 2009 annual conference of the Asia Pacific Bioinformatics Network (APBioNet), Asia's oldest bioinformatics organisation dating back to 1998, was organized as the 8th International Conference on Bioinformatics (InCoB), Sept. 7-11, 2009 at Biopolis, Singapore. Besides bringing together scientists from the field of bioinformatics in this region, InCoB has actively engaged clinicians and researchers from the area of systems biology, to facilitate greater synergy between these two groups. InCoB2009 followed on from a series of successful annual events in Bangkok (Thailand), Penang (Malaysia), Auckland (New Zealand), Busan (South Korea), New Delhi (India), Hong Kong and Taipei (Taiwan), with InCoB2010 scheduled to be held in Tokyo, Japan, Sept. 26-28, 2010. The Workshop on Education in Bioinformatics and Computational Biology (WEBCB) and symposia on Clinical Bioinformatics (CBAS), the Singapore Symposium on Computational Biology (SYMBIO) and training tutorials were scheduled prior to the scientific meeting, and provided ample opportunity for in-depth learning and special interest meetings for educators, clinicians and students. We provide a brief overview of the peer-reviewed bioinformatics manuscripts accepted for publication in this supplement, grouped into thematic areas. In order to facilitate scientific reproducibility and accountability, we have, for the first time, introduced minimum information criteria for our pubilcations, including compliance to a Minimum Information about a Bioinformatics Investigation (MIABi). As the regional research expertise in bioinformatics matures, we have delineated a minimum set of bioinformatics skills required for addressing the computational challenges of the "-omics" era.

Fulltext Treatment outcome of superficial cerebral abscess: an analysis of two surgical methods

Tan WM, Adnan JS, Mohamad Haspani MS

Malays J Med Sci, 2010 Jan;17(1):23-9.

PMID: 22135522 MyJurnal

The purpose of the study is to compare the two surgical methods (burr hole and craniotomy) used as treatment for superficial cerebral abscess and its outcome in terms of radiological clearance on brain CT, improvement of neurological status, the need for repeated surgery, and survival and morbidity at three months after surgery. This report is a retrospective case review of the patients who were treated surgically for superficial cerebral abscess in Hospital Kuala Lumpur (HKL) and Hospital Sultanah Aminah (HSA) over a period of four years (2004 to 2007).

Fulltext 1-Benzoyl-3-(4-hy-droxy-phen-yl)thio-urea

Al-Abbasi AA, Tan SS, Kassim MB

Acta Crystallogr Sect E Struct Rep Online, 2010;66(Pt 12):o3181.

PMID: 21589476 DOI: 10.1107/S1600536810045988

In the title compound, C(14)H(12)N(2)O(2)S, the amino-phenol and the benzoyl groups adopt a syn-anti configuration with respect to the thiono C=S group across the thio-urea C-N. The dihedral angle between the mean planes of the benzoyl and hy-droxy-phenyl rings is 36.77 (8)°. The mol-ecules are stabilized by intra-molecular N-H⋯O hydrogen bonds. In the crystal, weak inter-molecular C-H⋯O, O-H⋯S and N-H⋯O hydrogen bonds link the mol-ecules into a chain along the c axis.

Factors associated with HER2 overexpression in breast cancer: Experience in an Asian developing country

Tan GH, Choo WY, Taib NA, Yip CH

Asian Pac J Cancer Prev, 2009;10(5):837-40.

PMID: 20104975

INTRODUCTION: The HER2 gene is amplified in up to 30% of human breast cancers, leading to overexpression of the HER2 protein on the cell surface. Overexpression of HER2 is associated with a more aggressive cancer and hence a poorer overall survival.

OBJECTIVE: To evaluate the association between clinico-pathological features and HER2 overexpression in breast cancer.

METHODS: This is a retrospective study conducted in the Department of Surgery, University Malaya Medical Centre. The association between HER2 overexpression, determined by immunohistochemistry, and other clinicopathological factors was evaluated in 996 patients with newly diagnosed breast cancer treated from 2005 to 2007 using univariate and multivariate logistic regression.

RESULTS: HER2 overexpression occurred in 30.3% of patients. On bivariate analysis, HER2 overexpression was inversely related to ER expression (p<0.01) and PR expression (p<0.01). This overexpression was associated with a higher tumour grade, lymphovascular positivity and infiltrating ductal carcinoma subtype. On multivariate analysis, HER2 overexpression was significantly associated with higher tumour grade (p= 0.018, CI 1.25-11.04), PR negativity (p= 0.002, CI 0.30-0.77) and lymphovascular positivity (p= 0.042, CI 1.01-2.12).

CONCLUSIONS: HER2 overexpression was observed in 30.3% of Malaysian female breast cancer patients. This group of patients represents a more aggressive subtype of breast cancer with higher tumour grade, PR negativity and lymphovascular positivity. No significant relationship was established between HER2 overexpression and age, race, lymph node, ER, pathology subtype and stage of disease from this study.

Securing the airway in a child with extensive post-burn contracture of the neck: a novel strategy

Wong TE, Lim LH, Tan WJ, Khoo TH

Burns, 2010 Aug;36(5):e78-81.

PMID: 20036061 DOI: 10.1016/j.burns.2009.10.016

Fulltext (E)-1-(2,4,6-Trihy-droxy-benzyl-idene)-4-ethyl-thio-semicarbazide dihydrate

Shawish HB, Tan KW, Maah MJ, Ng SW

Acta Crystallogr Sect E Struct Rep Online, 2010;66(Pt 9):o2230.

PMID: 21588600 DOI: 10.1107/S1600536810030783

In the title mol-ecule, C(10)H(13)N(3)O(3)S·2H(2)O, the thio-semi-carbazide =N-NH-C(=S)-NH- fragment [torsion angle = 0.2 (1)°] is nearly coplanar with the benzene ring [dihedral angle = 2.4 (1)°]. The benzene ring and semicarbazide moiety are located on opposite sites of the C=N bond, showing an E configuration. The hy-droxy, imino and water H atoms are engaged in extensive hydrogen bonding, forming a three-dimensional network.

Fulltext {2-[(2-Carbamothiol-ylhydrazin-1-yl-idene-κN,S)meth-yl]-6-hy-droxy-phenolato-κO}(triphenyl-phosphine-κP)nickel(II) chloride

Shawish HB, Tan KW, Maah MJ, Ng SW

Acta Crystallogr Sect E Struct Rep Online, 2010;66(Pt 9):m1074.

PMID: 21588494 DOI: 10.1107/S1600536810031065

The deprotonated Schiff base ligand in the title compound, [Ni(C(8)H(8)N(3)O(2)S)(C(18)H(15)P)]Cl, functions as an N,O,S-chelating anion to the phosphine-coordinated Ni atom, which exists in a distorted square-planar geometry. The hy-droxy group forms an intra-molecular O-H⋯O hydrogen bond. The two amino groups of the cation are hydrogen-bond donors to the chloride anion; the hydrogen bonds generate a chain structure running along the b axis.

Fulltext Hypertensive retinopathy and sensorineural hearing loss

Tan TY, Rahmat O, Prepageran N, Fauzi A, Noran NH, Raman R

Indian J Otolaryngol Head Neck Surg, 2009 Dec;61(4):275-9.

PMID: 23120650 DOI: 10.1007/s12070-009-0082-9

To determine the correlation between hypertensive retinopathy (which is the end-organ damage of the vessels due to chronic hypertension) with sensorineural hearing loss.

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