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  1. Wong, C. W., Angel Lee, P. L.
    MyJurnal
    The inhibitory effect of onion extract on cassava leaf polyphenol oxidase was investigated. The polyphenol oxidase from cassava leaves was strongly inhibited by various anti-browning agents such as L-ascorbic acid and L-cysteine. The percentage of inhibition increased with the increased of anti-browning agents concentrations. The addition of heated onion extract exhibited a stronger inhibitory effect on cassava leaf polyphenol oxidase than the fresh onion extract. The highest percentage of inhibition was exhibited with heated onion extract in the presence of glucose and glycine, which was 87.18%. The onion extract inhibited the cassava leaf polyphenol oxidase non-competitively.
  2. Pui, L. P., Ng. J. M. L., Wong, C. W.
    MyJurnal
    Spray drying is used widely for converting liquid food products into powder form as the dried powder is known to have a longer shelf life at ambient temperature, convenience to use and low transportation expenditure. In this study, the Sarawak pineapple puree was spray-dried and the characterization of the resulting powder was performed. The process of enzyme liquefaction was optimized with Pectinex® Ultra SP-L and Celluclast® 1.5 L (single and combined treatment) at different concentrations (0–2.5 %) and incubation time (0-2.5 hours). The combined treatment with both enzymes (1.5% v/w Pectinex® Ultra SP-L + 0.5% v/w Celluclast® 1.5 L, 1.5 hour) was found to be the best parameter, which produced purees with the lowest viscosity of 67.98 ± 4.27 cp. Optimization of spray drying process was carried out using different inlet temperatures (150-180°C) and maltodextrin concentrations (15-30 % w/w). Results indicated that the spraydried powder produced at 160°C with 15% w/w of maltodextrin has the highest yield (31.63 %). The spray-dried powder was further characterized for the moisture content (6.00 ± 0.63%), water activity (0.36 ± 0.01 Aw), hygroscopicity (17.35 ± 0.64%), bulk density (0.46 ± 0.04 g/ cm3 ) and solubility (87.33 ± 2.08 seconds). The fruit powder of this study can be incorporated into different fruit added –value products, such as fruit juice, yogurt, jelly and other beverages.
  3. Wong, C. W, Ding, K. Y., Anggraeni, V. S.
    MyJurnal
    Polyphenol oxidase (PPO) was extracted from lotus (Nelumbo nucifera) root and partially
    purified up to 11.51× with a 43.6% yield using aqueous two-phase separation system. The
    optimum pH was at 8.0 for both substrates; 4-methylcatechol and pyrogallol. PPO activities
    were maximally achieved at 50°C for pyrogallol, and 20°C for 4-methylcatechol. 84% and 71%
    loss of relative PPO activities were obtained for pyrogallol and 4-methylcatechol, respectively
    following heat inactivation at 90°C for 40 min. Inactivation rate constant (k) values ranged
    between 0.88 × 10-2 min-1 to 2.97 × 10-2 min-1 for pyrogallol, and 0.69 × 10-2 min-1 to 2.44 × 10-2min-1 for 4-methylcatechol. The activation energy (Ea) were 75.32 kJ mol-1 and 73.14 kJ mol-1
    for pyrogallol and 4-methylcatechol, respectively. PPO activity was strongly inhibited (> 79%)
    by ascorbic acid. SDS exhibited the greatest efficiency in activating lotus root PPO.
  4. Wong, C. W., Leow, R. K. S., Lim, W. Y., Siew, Z. Z.
    MyJurnal
    The present work was undertaken to investigate the effect of different packaging materials, namely polyethylene terephthalate (PET) and aluminium laminated polyethylene (ALP) on the physicochemical properties and microbiological stability of spray-dried honey jackfruit powder over seven weeks of storage at 38 ± 2°C and 90% relative humidity. The moisture content of honey jackfruit powder packaged in PET was doubled (12.32%) than of those packaged in ALP (5.31%). The water activity (aw) of the powders were lower than 0.6 for both packaging materials, thus considered shelf-stable. Hygroscopicity increased up to 42.44 and 39.84% for powder packaged in PET and ALP, respectively. The angle of repose for powders flowability increased to 19° (ALP) and 28° (PET), which indicated that the powders flowabili- ty significantly decreased upon storage. The degree of caking for powder packaged in ALP (43.69%) was much less severe than that of PET (84.51%). Powder packaged in ALP showed good solubility (81.07 - 99.01%) and satisfactory microbiological results (< log 2.58 CFU/g). The results recommended that ALP packaging was better suited for keeping spray-dried honey jackfruit powder.
  5. Chai SC, Wong CW
    Med J Malaysia, 2005 Jul;60 Suppl C:59-65.
    PMID: 16381286
    This retrospective study aims to evaluate the effectiveness of the modified regime for rehabilitation of Zone II flexor tendon injuries in Sibu Hospital. From January to December 2003, 8 patients with 15 injured digits were treated by using the combined method of dynamic traction and passive mobilization. According to Strickland's criteria, 14 (93.3%) digits achieved good to excellent outcomes and only 1 (6.7%) was rated as poor. No occurrence of tendon rupture was noted. The overall grip strength of the injured hand was 50.1% of the uninjured hand at 3 months after the repair. Our results compare favorably with the other published studies. We believed that this modified regime is as effective as other established regimes and suitable to be adopted in our setting. Further study with larger sample group will be required to consolidate our findings.
  6. Sthaneshwar P, Vethakkan SR, Wong CW
    Med J Malaysia, 2014 Aug;69(4):175-7.
    PMID: 25500845 MyJurnal
    INTRODUCTION: Glycohemoglobin (HbA1c) most accurately reflects the previous two to three months of glycaemic control. HbA1c should be measured regularly in all patients with diabetes, and values should be maintained below 7% to prevent the risk of chronic complications. Apart from the genetic variants of haemoglobins many other conditions also known to affect HbA1c measurements. In this study we evaluated the conditions that cause low HbA1c results.

    METHODS AND MATERIALS: The data was collected retrospectively HbA1c was measured in our laboratory by Biorad Variant II turbo 2.0. The method is based on chromatographic separation of HbA1c on a cation exchange cartridge. This method has been certified by National Glycohemoglobin Standardization Programme (NGSP). 58437 requests were received in a period of one year (January to December 2011). Medical records were reviewed to identify the conditions that might be associated with these low values.

    RESULTS: Among 58437 samples analysed, 53 patients had HbA1c levels < 4.0%. Fourteen patients had haemoglobinopathy. In 34 patients without Hb variants had conditions such as chronic liver disease, chronic kidney disease, haemolytic anaemia, pregnancy, and anaemia of chronic disease. Five non-pregnant individuals who were screened for diabetes mellitus had HbA1c levels < 4%.

    CONCLUSION: Our study underscores the importance of that both laboratories and the physicians should be aware of the factors that can influence the HbA1c results. The haematological status should be taken into consideration for proper interpretation of HbA1c results.
  7. Somchit N, Wong CW, Zuraini A, Ahmad Bustamam A, Hasiah AH, Khairi HM, et al.
    Drug Chem Toxicol, 2006;29(3):237-53.
    PMID: 16777703
    Itraconazole and fluconazole are potent wide spectrum antifungal drugs. Both of these drugs induce hepatotoxicity clinically. The mechanism underlying the hepatotoxicity is unknown. The purpose of this study was to investigate the role of phenobarbital (PB), an inducer of cytochrome P450 (CYP), and SKF 525A, an inhibitor of CYP, in the mechanism of hepatotoxicity induced by these two drugs in vivo. Rats were pretreated with PB (75 mg/kg for 4 days) prior to itraconazole or fluconazole dosing (20 and 200 mg/kg for 4 days). In the inhibition study, for 4 consecutive days, rats were pretreated with SKF 525A (50 mg/kg) or saline followed by itraconazole or fluconazole (20 and 200 mg/kg) Dose-dependent increases in plasma alanine aminotransferase (ALT), gamma-glutamyl transferase (gamma-GT), and alkaline phosphatase (ALP) activities and in liver weight were detected in rats receiving itraconazole treatment. Interestingly, pretreatment with PB prior to itraconazole reduced the ALT and gamma-GT activities and the liver weight of rats. No changes were observed in rats treated with fluconazole. Pretreatment with SKF 525A induced more severe hepatotoxicity for both itraconazole and fluconazole. CYP 3A activity was inhibited dose-dependently by itraconazole treatment. Itraconazole had no effects on the activity of CYP 1A and 2E. Fluconazole potently inhibited all three isoenzymes of CYP. PB plays a role in hepatoprotection to itraconazole-induced but not fluconazole-induced hepatotoxicity. SKF 525A enhanced the hepatotoxicity of both antifungal drugs in vivo. Therefore, it can be concluded that inhibition of CYP may play a key role in the mechanism of hepatotoxicity induced by itraconazole and fluconazole.
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