Displaying publications 1 - 20 of 96 in total

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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 CT, Saha N
    Ann Nutr Metab, 1985;29(5):267-73.
    PMID: 4051449
    The concentrations of non-haem iron, ferritin and ferritin-iron were measured in the livers of 137 adults and children collected at necropsy. The concentrations of non-haem and ferritin iron were found to be 146.6 +/- 95.2 micrograms/g and 61.6 +/- 32.4 micrograms/g, respectively, in males and 108.0 +/- 61.7 micrograms/g and 60.6 +/- 26.4 micrograms/g, respectively, in females. The values for males in Singapore were lower than those reported in developed Western countries. No correlation was observed between storage iron and age, or ferritin concentration and age. Concentrations of non-haem iron and ferritin were similar for persons dying from accident and coronary heart disease. The non-haem iron concentration in Chinese (187.9 +/- 101.0 micrograms/g) was significantly greater than that in Indians (103.1 +/- 65.8 micrograms/g), while the ferritin concentration in Chinese (6.18 +/- 2.37 mg/g) was significantly greater than either Malays (3.81 +/- 1.8 mg/g) or Indians (3.52 +/- 1.6 mg/g). A significant positive correlation was observed between the non-haem iron and ferritin and also ferritin-iron in Chinese males (r values of 0.678 and 0.598, respectively) and Indian males (r values of 0.576 and 0.612, respectively). However, the correlation between these indices was not significant in the case of Malay males. In premenopausal women the non-haem iron correlated well with ferritin (r = 0.737) and ferritin iron (r = 0.826) while the correlation was lacking in postmenopausal women.
  5. Wong CK, Bernardo R
    Theor Appl Genet, 2008 Apr;116(6):815-24.
    PMID: 18219476 DOI: 10.1007/s00122-008-0715-5
    Oil palm (Elaeis guineensis Jacq.) requires 19 years per cycle of phenotypic selection. The use of molecular markers may reduce the generation interval and the cost of oil-palm breeding. Our objectives were to compare, by simulation, the response to phenotypic selection, marker-assisted recurrent selection (MARS), and genomewide selection with small population sizes in oil palm, and assess the efficiency of each method in terms of years and cost per unit gain. Markers significantly associated with the trait were used to calculate the marker scores in MARS, whereas all markers were used (without significance tests) to calculate the marker scores in genomewide selection. Responses to phenotypic selection and genomewide selection were consistently greater than the response to MARS. With population sizes of N = 50 or 70, responses to genomewide selection were 4-25% larger than the corresponding responses to phenotypic selection, depending on the heritability and number of quantitative trait loci. Cost per unit gain was 26-57% lower with genomewide selection than with phenotypic selection when markers cost US $1.50 per data point, and 35-65% lower when markers cost $0.15 per data point. With population sizes of N = 50 or 70, time per unit gain was 11-23 years with genomewide selection and 14-25 years with phenotypic selection. We conclude that for a realistic yet relatively small population size of N = 50 in oil palm, genomewide selection is superior to MARS and phenotypic selection in terms of gain per unit cost and time. Our results should be generally applicable to other tree species that are characterized by long generation intervals, high costs of maintaining breeding plantations, and small population sizes in selection programs.
  6. 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.
  7. Irfan, M., Wong,C. Y., Nik Fariza, H., Maha, K., Nor Hayati, O.
    MyJurnal
    Mucoepidermoid carcinoma and squamous cell carcinoma are tumors found predominantly in the elderly. Most of the cases reported were from patients of more than 50 years old. In our case, it affects a young patient, a 26 year old lady who has a history of a severely burnt and scarred face since childhood. She represents a rare case of a high grade aggressive tumor involving her right eyelid and right parotid gland.
  8. 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.
  9. Peh KK, Wong CF
    J Pharm Pharm Sci, 1999 May-Aug;2(2):53-61.
    PMID: 10952770
    To investigate the suitability of an SCMC (sodium carboxymethyl cellulose/polyethylene glycol 400/carbopol 934P) and an HPMC (hydroxypropylmethyl cellulose/polyethylene glycol 400/carbopol 934P) films as drug vehicle for buccal delivery.
  10. Peh KK, Wong CF
    Drug Dev Ind Pharm, 2000 Jul;26(7):723-30.
    PMID: 10872090
    Controlled-release grade hydroxypropylmethylcellulose (HPMC) or xanthan gum (XG) and microcrystalline cellulose (MCC) were employed to prepare controlled-release diltiazem hydrochloride tablets. The similarity factor f2 was used for dissolution profile comparison using Herbesser 90 SR as a reference product. Drug release could be sustained in a predictable manner by modifying the content of HPMC or XG. Moreover, the drug release profiles of tablets prepared using these matrix materials were not affected by pH and agitation rate. The f2 values showed that only one batch of tablets (of diltiazem HCl, HPMC or XG, and MCC in proportions of 3.0:3.0:4.0) was considered similar to that of the reference product, with values above 50. The unbiased similarity factor f2* values were not much different from the f2 values, ascribing to a small dissolution variance of the test and reference products. The amount of HPMC or XG incorporated to produce tablets with the desired dissolution profile could be determined from the curves of f2 versus polymer content. Hence, the f2 values can be applied as screening and optimization tools during development of controlled-release preparations.
  11. 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.
  12. Ongkudon CM, Kansil T, Wong C
    J Sep Sci, 2014 Mar;37(5):455-64.
    PMID: 24376196 DOI: 10.1002/jssc.201300995
    To date, the number of published reports on the large-volume preparation of polymer-based monolithic chromatography adsorbents is still lacking and is of great importance. Many critical factors need to be considered when manufacturing a large-volume polymer-based monolith for chromatographic applications. Structural integrity, validity, and repeatability are thought to be the key factors determining the usability of a large-volume monolith in a separation process. In this review, we focus on problems and solutions pertaining to heat dissipation, pore size distribution, "wall channel" effect, and mechanical strength in monolith preparation. A template-based method comprising sacrificial and nonsacrificial techniques is possibly the method of choice due to its precise control over the porous structure. However, additional expensive steps are usually required for the template removal. Other strategies in monolith preparation are also discussed.
  13. Wong C, Phang H, Cheong M, Ramiah R
    Malays Orthop J, 2012 Nov;6(3):54-6.
    PMID: 25279060 MyJurnal DOI: 10.5704/MOJ.1207.007
    We present the case of a patient with multiple atraumatic osteoporotic vertebral fractures in an adolescent with suprasellar germinoma and also review of relevant literature. The patient suffered from a rare adolescent brain tumour with common complications which are often overlooked and give rise to significant morbidity. Suprasellar germinoma is an intracranial neoplasm, that in addition to its rarity, has variable clinical presentation. Despite appropriate treatment and good outcome, tumour related morbidity is still of concern for these patients.
  14. Siow SL, Wong CM, Sohail M
    Med J Malaysia, 2009 Jun;64(2):168-9.
    PMID: 20058581 MyJurnal
    Gastric outlet obstruction and in particular, pyloric stenosis, is relatively common in developing countries. Acute clinical presentation is often the manifestation of biochemical and electrolyte changes. The presence of metabolic alkalosis in combination with acute renal failure should alarm us to the possibility of adult pyloric stenosis. We report a case of adult pyloric stenosis that presented as acute renal failure and discuss its pathophysiology.
  15. Wong CC, Ting F, Wong B, Lee PI
    Med J Malaysia, 2005 Jul;60 Suppl C:35-40.
    PMID: 16381281
    Pedicle screw system has increasingly been used for correction of thoracic scoliosis. It offers several biomechanical advantages over hook system as it controls all three-column of the spine with enhanced stability. Of many techniques of pedicle screw placement in the thoracic spine, the funnel technique has been used in Sarawak General Hospital since 2002. This prospective study aims to assess the accuracy of the placement of thoracic pedicle screws using the funnel technique in the corrective surgery of idiopathic scoliosis. A total of 88 thoracic pedicle screws were inserted into the T4 to T12 vertebrae of 11 patients. Post-operative CT-scan was performed to evaluate the position of the pedicle screw. Seventy six (86.4%) screws were noted to be totally within the pedicle. There was no screw with medial violation of the pedicle, 8 (9.1%) screws breeching the lateral wall of the pedicle and 4 (4.5%) screws with anterior and lateral penetration of the vertebral body. No clinical sequel with the mal-positioned screws was noted. In conclusion, the funnel technique enabled simple, accurate and reliable insertion of pedicle screw even in the scoliotic thoracic spine without the need of any imaging guidance. It is however imperative for the surgeon to have a thorough knowledge of the thoracic spine anatomy, and to be familiar with the technique to insert these screws diligently.
  16. Ujang Z, Wong CL, Manan ZA
    Water Sci Technol, 2002;46(11-12):77-84.
    PMID: 12523736
    Industrial wastewater minimization can be conducted using four main strategies: (i) reuse; (ii) regeneration-reuse; (iii) regeneration-recycling; and (iv) process changes. This study is concerned with (i) and (ii) to investigate the most suitable approach to wastewater minimization for an old textile industry plant. A systematic water networks design using water pinch analysis (WPA) was developed to minimize the water usage and wastewater generation for the textile plant. COD was chosen as the main parameter. An integrated design method has been applied, which brings the engineering insight using WPA that can determine the minimum flowrate of the water usage and then minimize the water consumption and wastewater generation as well. The overall result of this study shows that WPA has been effectively applied using both reuse and regeneration-reuse strategies for the old textile industry plant, and reduced the operating cost by 16% and 50% respectively.
  17. Liam CK, Lim KH, Wong CM
    Respirology, 2001 Sep;6(3):259-64.
    PMID: 11555386
    This study aimed to investigate the microbial aetiology of community-acquired pneumonia (CAP) in patients requiring hospitalization.
  18. Liam CK, Lim KH, Wong CM
    Asian Pac J Allergy Immunol, 2000 Sep;18(3):135-40.
    PMID: 11270467
    This study aimed to evaluate dry powder inhaler naive asthmatic patients' perception and preference of the Accuhaler, a multidose dry powder inhaler and the pressurized metered dose inhaler (pMDI). After the first instruction, 66.7% of 48 patients enrolled in the study could demonstrate the correct use of the Accuhaler. When the patients were asked to compare the pMDI and the Accuhaler after using the Accuhaler to administer salmeterol for 4 weeks, the Accuhaler scored significantly better than the pMDI for the following features: knowing how many doses are left, presence of an attached cover, taste, instruction for use, attractiveness, ease of use, ease of holding, shape, and comfortable mouthpiece. The pMDI scored better to the Accuhaler in terms of size. More patients preferred the Accuhaler than the pMDI; the presence of a dose counter and perceived ease of use were the main reasons cited for their preference for the Accuhaler.
    Study site: Asthma Clinic, University of Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
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