MyMedR

Population education in Malaysian schools

Ahmad SH, Khoon YG

Bul Keluarga, 1973 May 7;58:1-2.

Fulltext Severe and fatal postoperative bronchospasm in a child with a pulmonary artery sling

Norzila MZ, Azizi BH, Mazeni A, Ahmad S, Devadass P, Lokman S

Med J Malaysia, 1994 Jun;49(2):182-4.

We report a case of left pulmonary artery sling in a child who also had duodenal atresia. He was admitted for respiratory failure requiring prolonged respiratory support due to a bronchiolitis-like illness at two months of age. Diagnostic procedures confirmed the presence of left pulmonary artery sling. He had a corrective procedure which relieved the compression. However postoperatively he had intermittent episodes of severe bronchospasm in addition to a persistent airway obstruction. Finally one such episode of severe bronchospasm did not respond to medical and resuscitative therapy and the baby succumbed. To our knowledge no case of left pulmonary artery sling has been described previously in a Malaysian child. This case also highlights the postoperative airway problems that may be encountered.

Research and development on functional foods in Malaysia

Ahmad S

Nutr Rev, 1996 Nov;54(11 Pt 2):S169-71.

PMID: 9110599

NETASA: neural network based prediction of solvent accessibility

Ahmad S, Gromiha MM

Bioinformatics, 2002 Jun;18(6):819-24.

PMID: 12075017

MOTIVATION: Prediction of the tertiary structure of a protein from its amino acid sequence is one of the most important problems in molecular biology. The successful prediction of solvent accessibility will be very helpful to achieve this goal. In the present work, we have implemented a server, NETASA for predicting solvent accessibility of amino acids using our newly optimized neural network algorithm. Several new features in the neural network architecture and training method have been introduced, and the network learns faster to provide accuracy values, which are comparable or better than other methods of ASA prediction.

RESULTS: Prediction in two and three state classification systems with several thresholds are provided. Our prediction method achieved the accuracy level upto 90% for training and 88% for test data sets. Three state prediction results provide a maximum 65% accuracy for training and 63% for the test data. Applicability of neural networks for ASA prediction has been confirmed with a larger data set and wider range of state thresholds. Salient differences between a linear and exponential network for ASA prediction have been analysed.

AVAILABILITY: Online predictions are freely available at: http://www.netasa.org. Linux ix86 binaries of the program written for this work may be obtained by email from the corresponding author.

Lipase-catalyzed esterification of palm-based 9,10-dihydroxystearic acid and 1-octanol in hexane--a kinetic study

Awang R, Basri M, Ahmad S, Salleh AB

Biotechnol Lett, 2004 Jan;26(1):11-4.

PMID: 15005144

The esterification of palm-based 9,10-dihydroxystearic acid (DHSA) and 1-octanol in hexane as catalyzed by lipase from Rhizomucor meihei (Lipozyme IM) followed Michaelis-Menten kinetics. The esterification reaction follows a Ping-Pong, Bi-Bi mechanism. The maximum rate was estimated to be 1 micromol min(-1) mg(-1) catalyst in hexane at 50 degrees C, and the Michaelis-Menten constants for DHSA and 1-octanol were 1.3 M and 0.7 M, respectively.

Distribution of radium in oil and gas industry wastes from Malaysia

Omar M, Ali HM, Abu MP, Kontol KM, Ahmad Z, Ahmad SH, et al.

Appl Radiat Isot, 2004 May;60(5):779-82.

PMID: 15082059

Radium concentrations in 470 samples of the various types of waste from oil and gas industries were analysed using gamma spectrometers. The results showed that the radium concentration varied within a wide range. The highest mean 226Ra and 228Ra concentrations of 114,300 and 130,120 Bq/kg, respectively, were measured in scales. Overall, 75% of the waste, mostly sludge and extraction residue lies within the normal range of radium concentration in soils of Malaysia. However, some platform sludge can have radium concentration up to 560 Bq/kg.

Solvent accessibility in native and isolated domain environments: general features and implications to interface predictability

Raih MF, Ahmad S, Zheng R, Mohamed R

Biophys Chem, 2005 Apr 1;114(1):63-9.

PMID: 15792862

A non-redundant database of 4536 structural domains, comprising more than 790,000 residues, has been used for the calculation of their solvent accessibility in the native protein environment and then in the isolated domain environment. Nearly 140,000 (18%) residues showed a change in accessible surface area in the above two conditions. General features of this change under these two circumstances have been pointed out. Propensities of these interfacing amino acid residues have been calculated and their variation for different secondary structure types has been analyzed. Actual amount of surface area lost by different secondary structures is higher in the case of helix and strands compared to coil and other conformations. Overall change in surface area in hydrophobic and uncharged residues is higher than that in charged residues. An attempt has been made to know the predictability of interface residues from sequence environments. This analysis and prediction results have significant implications towards determining interacting residues in proteins and for the prediction of protein-protein, protein-ligand, protein-DNA and similar interactions.

Solid waste collection and recycling in Nibong Tebal, Penang, Malaysia: a case study

Isa MH, Asaari FA, Ramli NA, Ahmad S, Siew TS

Waste Manag Res, 2005 Dec;23(6):565-70.

PMID: 16379126

The implementation of a suitable solid waste management programme with appropriate methods of recycling as an inherent element is vital to the alleviation of the problems associated with solid waste generation, handling and disposal, environmental conservation, public hygiene, etc. The present work is a case study on solid waste collection and recycling practices in Nibong Tebal town, Penang, Malaysia. The amount and types of domestic waste generated, household participation in recycling, identification of existing problems related to the implementation of the recycling programme, etc. formed the basis of this study. Surveys (interviews/questionnaires) and on-site observations were conducted to gather information on the solid waste collection and recycling practice of the residents. A focus group of 60 individuals was selected and their response to a questionnaire, prepared according to a Likert scale, was obtained and analysed. The majority of the respondents expressed concerns about recycling and wanted more to be done in this regard. Illegal collection, aesthetically displeasing sites and a lack of public awareness were problems of major concern. Issues related to inadequate funding and manpower as well as end market are also addressed and suggestions made.

Cardamonin, inhibits pro-inflammatory mediators in activated RAW 264.7 cells and whole blood

Ahmad S, Israf DA, Lajis NH, Shaari K, Mohamed H, Wahab AA, et al.

Eur J Pharmacol, 2006 May 24;538(1-3):188-94.

PMID: 16650843

Some chalcones, such as hydroxychalcones have been reported previously to inhibit major pro-inflammatory mediators such as nitric oxide (NO), prostaglandin E(2) (PGE(2)), tumor necrosis factor-alpha (TNF-alpha) and reactive oxygen species production by suppressing inducible enzyme expression via inhibition of the mitogen-activated protein kinase (MAPK) pathway and nuclear translocation of critical transcription factors. In this report, the effects of cardamonin (2',4'-dihydroxy-6'-methoxychalcone), a chalcone that we have previously isolated from Alpinia rafflesiana, was evaluated upon two cellular systems that are repeatedly used in the analysis of anti-inflammatory bioactive compounds namely RAW 264.7 cells and whole blood. Cardamonin inhibited NO and PGE(2) production from lipopolysaccharide- and interferon-gamma-induced RAW cells and whole blood with IC(50) values of 11.4 microM and 26.8 microM, respectively. Analysis of thromboxane B(2) (TxB(2)) secretion from whole blood either stimulated via the COX-1 or COX-2 pathway revealed that cardamonin inhibits the generation of TxB(2) via both pathways with IC(50) values of 2.9 and 1.1 microM, respectively. Analysis of IC(50) ratios determined that cardamonin was more COX-2 selective in its inhibition of TxB(2) with a ratio of 0.39. Cardamonin also inhibited the generation of intracellular reactive oxygen species and secretion of TNF-alpha from RAW 264.7 cells in a dose responsive manner with IC(50) values of 12.8 microM and 4.6 microM, respectively. However, cardamonin was a moderate inhibitor of lipoxygenase activity when tested in an enzymatic assay system, in which not a single concentration tested was able to cause an inhibition of more than 50%. Our results suggest that cardamonin acts upon major pro-inflammatory mediators in a similar fashion as described by previous work on other closely related synthetic hydroxychalcones and strengthens the conclusion of the importance of the methoxyl moiety substitution on the 4' or 6' locations of the A benzene ring.

Biological evaluation of curcumin and related diarylheptanoids

Abas F, Hui LS, Ahmad S, Stanslas J, Israf DA, Shaari K, et al.

Z Naturforsch C J Biosci, 2006 12 2;61(9-10):625-31.

PMID: 17137104

Nine derivatives of three natural diarylheptanoids, curcumin, demethoxycurcumin and bisdemethoxycurcumin, were prepared. Their antioxidant, free radical scavenging, nitric oxide (NO) inhibitory and cytotoxic activities were evaluated and compared with those of the respective natural compounds. Curcumin (1), demethoxycurcumin (2), demethyldemethoxy-curcumin (C3), diacetyldemethoxycurcumin (AC2) and triacetyldemethylcurcumin (AC5) exhibited higher antioxidant activity than quercetin while products from demethylation of 1 and 2 exhibited higher free radical scavenging activity. Compounds AC2 and AC5 were found to be most active in inhibiting breast cancer cells (MCF-7) proliferation with IC50 values of 6.7 and 3.6 microM, respectively. The activity of AC2 is almost doubled and of AC5 almost tripled as compared to curcumin. Their selectivity towards different cell lines is also more noticeable. Compounds AC2 and AC5 also showed increased activity against a human prostate cancer cell line (DU-145) and non-small lung cancer cell line (NCI-H460) with IC50 values of 20.4, 16.3 and 18.3, 10.7 microM, respectively.

Fulltext Reheating of soy oil is detrimental to bone metabolism in oestrogen deficient rats

Ima-Nirwana S, Ahmad SN, Yee LJ, Loh HC, Yew SF, Norazlina M, et al.

Singapore Med J, 2007 Mar;48(3):200-6.

PMID: 17342287

The short-term and long- term effects of heated soy oil on bone metabolism in ovariectomised Sprague-Dawley rats were studied.

The Vabra aspirator versus the Pipelle device for outpatient endometrial sampling

Naim NM, Mahdy ZA, Ahmad S, Razi ZR

Aust N Z J Obstet Gynaecol, 2007 Apr;47(2):132-6.

PMID: 17355303 DOI: 10.1111/j.1479-828X.2007.00699.x

OBJECTIVE: To compare the effectiveness of the Vabra aspirator and the Pipelle device as an outpatient endometrial assessment tool.
METHOD: This was a randomised, prospective trial conducted for a period of one year.
RESULTS: A total of 147 patients were recruited, of which 71 were in the Vabra group and 76 were in the Pipelle arm. The procedure success rate in the Pipelle group was significantly higher than the Vabra arm (98.7 vs 88.7%, P=0.02). Adequate tissue yield was also significantly more in the Pipelle arm (73.3 vs 52.4%, P=0.02). Cost-benefit analysis revealed a higher average cost per patient in the Vabra group compared to the Pipelle arm.
CONCLUSION: This study proved that the Vabra aspirator was not as effective as the Pipelle device in obtaining endometrial tissue for histological diagnosis. Despite its higher price per unit, the Pipelle device was a more cost-effective tool for outpatient endometrial assessment.
Study site: Medical clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia.

Cytotoxic caged-polyprenylated xanthonoids and a xanthone from Garcinia cantleyana

Shadid KA, Shaari K, Abas F, Israf DA, Hamzah AS, Syakroni N, et al.

Phytochemistry, 2007 Oct;68(20):2537-44.

PMID: 17602714

Phytochemical studies on the leaves and trunk bark of Garcinia cantleyana yielded five caged-xanthonoids including one tetra- and four tri-prenylated xanthones, cantleyanone A (1), 7-hydroxyforbesione (2) and cantleyanones B-D (4-6), as well as a simple xanthone, 4-(1,1-dimethylprop-2-enyl)-1,3,5,8-tetrahydroxyxanthone (3). Eight other known compounds, deoxygaudichaudione A, gaudichaudione H, friedelin, garbogiol, macranthol, glutin-5-en-3beta-ol, and a mixture of sitosterol and stigmasterol were also isolated. Their structures were elucidated by means of spectroscopic data and comparison of their NMR data with literature values. Significant cytotoxicity against MDA-MB-231, CaOV-3, MCF-7 and HeLa cancer cell-lines was demonstrated by cantleyanones B-D, 7-hydroxyforbesione, deoxygaudichaudione A and macranthol, with IC(50) values ranging from 0.22 to 17.17 microg/ml.

Advanced abdominal pregnancy resulting from late uterine rupture

Naim NM, Ahmad S, Siraj HH, Ng P, Mahdy ZA, Razi ZR

Obstet Gynecol, 2008 Feb;111(2 Pt 2):502-4.

PMID: 18239000 DOI: 10.1097/01.AOG.0000279451.51446.c1

Advanced abdominal pregnancy is rare, and one that occurs after uterine rupture with delivery of a viable fetus is exceptional.

Fulltext Colorectal cancer patients in a tertiary referral centre in Malaysia: a five year follow-up review

Rashid MR, Aziz AF, Ahmad S, Shah SA, Sagap I

Asian Pac J Cancer Prev, 2009;10(6):1163-6.

PMID: 20192604

BACKGROUND: Colorectal cancer (CRC) is one of the major malignancies in the world. In Malaysia, CRC is fast becoming the commonest cause of cancer death. Its etiology is complex, involving both environmental and genetic factors. This study looked at the profile and outcome of five-year follow-up of patients with CRC.

MATERIALS AND METHODS: Retrospective case review study done on CRC patients at University Kebangsaan Malaysia Medical Centre (UKMMC), Kuala Lumpur, Malaysia. Patientsandapos; socio-demographic characteristics, modalities of treatment, cancer characteristics and outcome at 5-year follow up were extracted from the case records.

RESULTS: A total of 107 case records of patients were analyzed. Peak age of CRC presentation was 40-69 years (71.1%). Male to female ratio was 1.2:1 with Chinese predominance (52.3%). Anaemia and its related symptoms including per rectal bleeding was the commonest clinical presentation. The median duration of clinical presentation was 13 weeks (IQR 21.8). More than two-thirds presented as non-emergency cases (69.2%). Most patients presented with Dukes C stage (40.2%). The overall 5-year survival rate was 40% with local recurrence rate of 19.6%. Metastasis after curative-intend treatment (surgery with adjuvant therapy) developed in 26% of patients. Lower recurrence (p = 0.016, OR = 0.205) and metastatic disease (p = 0.02, OR = 0.24) found among the Chinese patients. Almost half of the patients defaulted follow up care (43%), most often within the first year of treatment (22.4%) and the Chinese were the least likely to default (p= 0.04, OR = 0.45).

CONCLUSION: Socio-demographic profile of CRC patients in UKMMC is comparable to Asia pacific region. Apparent delay in seeking treatment gives rise to poor overall survival and local recurrence rates.

Fulltext Paravertebral Abscess Caused By Bukholderia Pseudomallei In

Ahmad, S., Azura, L., Duski, S., Aziz, M.Y.

Malays Orthop J, 2009;3(1):88-90.

MyJurnal

A 53-year-old Malay man was admitted with intestinal obstruction, fever and lower limb weakness. Initial clinical impression was myelitis causing paralytic ilues and paraperesis. Blood culture showed Burkholderia pseudomallei infection and subsequent MRI showed paravertebral abscess. This case highlights a rare manifestation of melioidosis involving the spine and difficulties in establishing the diagnosis.

Fulltext Melioidosis: A Retrospective Review of Orthopaedic manifestations

Ahmad, S., Azura, L., Duski, S., MAziz, M.Y.

Malays Orthop J, 2009;3(1):53-55.

MyJurnal

Melioidosis is an infectious disease which is associated with high rate of mortality. We reviewed 33 patients treated in our hospital over a period of 14 months. About half (55%) of these patient presented with one focus of infection while the rest had multifocal infections. 81% require drainage of abscess or arthrotomy. Four patients (12%) died as a result of septicaemia and the rate is lower than those reported in literature. We conclude that mortality of melioidosis can reduce with early diagnosis followed by appropriate and prolonged antibiotic therapy.

Fulltext Molybdate reduction by Pseudomonas sp. strain DRY2

Shukor MY, Ahmad SA, Nadzir MM, Abdullah MP, Shamaan NA, Syed MA

J Appl Microbiol, 2010 Jun;108(6):2050-8.

PMID: 19968732 DOI: 10.1111/j.1365-2672.2009.04604.x

To isolate and characterize a potent molybdenum-reducing bacterium.

Morphological comparison between adolescent and adult lumbar pedicles using computerised tomography scanning

Mughir AM, Yusof MI, Abdullah S, Ahmad S

Surg Radiol Anat, 2010 Jul;32(6):587-92.

PMID: 20047027 DOI: 10.1007/s00276-009-0612-x

To study the morphological difference between the lumbar pedicle in adolescent and adult groups as only less information is known about their pedicle morphology, especially in Malaysian population.

Fulltext Forced convection boundary layer flow over a moving thin needle

Arifin, N.M., Pop, I., Nazar, R., Ahmad, S.

ASM Science Journal, 2010;4(2):149-157.

MyJurnal

In this paper, the problem of steady laminar boundary layer flow of an incompressible viscous fluid over a moving thin needle is considered. The governing boundary layer equations were first transformed into non-dimensional forms. These non-dimensional equations were then transformed into similarity equations using the similarity variables, which were solved numerically using an implicit finite-difference scheme known as the Keller-box method. The solutions were obtained for a blunt-nosed needle. Numerical computations were carried out for various values of the dimensionless parameters of the problem which included the Prandtl number Pr and the parameter a representing the needle size. It was found that the heat transfer characteristics were significantly
influenced by these parameters. However, the Prandtl number had no effect on the flow characteristics due to the decoupled boundary layer equations.

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