Displaying publications 61 - 80 of 434 in total

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  1. Ng MY, Tan WS, Abdullah N, Ling TC, Tey BT
    J Biotechnol, 2008 Nov 25;138(3-4):74-9.
    PMID: 18786579 DOI: 10.1016/j.jbiotec.2008.08.004
    Expanded bed adsorption chromatography (EBAC) is a single pass operation that has been used as primary capture step in various protein purifications. The most common problem in EBAC is often associated with successful formation of a stable fluidized bed during the absorption stage, which is critically dependent on parameters such as liquid velocity, bed height, particle (adsorbent) size and density as well as design of column and type of flow distributor. In this study, residence time distribution (RTD) test using acetone as non-binding tracer acetone was performed to evaluate liquid dispersion characteristics of the EBAC system. A high B(o) number was obtained indicating the liquid dispersion in the system employed is very minimal and the liquid flow within the bed was close to plug flow, which mimics a packed bed chromatography system. Evaluation on the effect of flow velocities and bed height on the performance of Streamline DEAE using feedstock containing heat-treated crude Escherichia coli homogenate of different biomass concentrations was carried out in this study. The advantages and disadvantages as well as the problems encountered during recovery of HBcAg with aforementioned parameters are also discussed in this paper.
  2. Misnan R, Murad S, Jones M, Taylor G, Rahman D, Arip M, et al.
    Asian Pac J Allergy Immunol, 2008 Dec;26(4):191-8.
    PMID: 19317337
    The purpose of this study was to characterize major allergens of Indian scad (Decapterus russelli) which is among the most commonly consumed fish in Malaysia. Raw and cooked extracts of the fish were prepared. Protein profiles and IgE binding patterns were produced by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using sera from subjects with fish allergy. The major allergens of the fish were then identified by two-dimensional electrophoresis (2-DE), followed by mass spectrometry of the peptide digests. The SDS-PAGE of the raw extract revealed 27 protein fractions over a wide molecular weight range, while the cooked extract demonstrated only six protein fractions. The 1-DE immunoblotting detected 14 IgE-binding proteins, with a molecular weight range from 90 to < 6.5 kDa. Three protein fractions with molecular weights of approximately 51, 46 and 12 kDa were identified as the major allergens of this fish. The approximately 12 kDa band was a heat-resistant protein while the approximately 51 and 46 kDa proteins were sensitive to heat. The 2-DE gel profile of the raw extract demonstrated > 100 distinct protein spots and immunoblotting detected at least 10 different major IgE reactive spots with molecular masses as expected and isoelectric point (pI) values ranging from 4.0 to 7.0. A comparison of the major allergenic spot sequences of the 12 kDa proteins with known protein sequences in databases revealed extensive similarity with fish parvalbumin. In conclusion, this study demonstrated that a parvalbumin which is similar to Gad c 1 is the major allergen of Indian scad. Interestingly, we also detected heat-sensitive proteins as major allergenic components in our fish allergy patients.
  3. Sidi H, Midin M, Puteh SE, Abdullah N
    Asia Pac J Public Health, 2008;20(4):298-306.
    PMID: 19124324 DOI: 10.1177/1010539508322810
    AIM: The aim of this study was to investigate the prevalence of orgasmic dysfunction and the potential risk factors that may be associated with orgasmic dysfunction among women at a primary care setting in Malaysia.
    METHODS: A validated questionnaire for sexual function was used to assess orgasmic function. A total of 230 married women aged 18 to 70 years participated in this study. Their sociodemographic and marital profiles were compared between those who had orgasmic dysfunction and those who did not, and the risk factors were examined.
    RESULTS: The prevalence of orgasmic dysfunction in the primary care population was 51.9%. Women with orgasmic dysfunction were found to be significantly higher in the following groups: age >45 years, being non-Malay, having lower academic status, married longer, having more children, married to an older husband, and being at menopausal state.
    CONCLUSION: Women with infrequent sexual intercourse are less likely to be orgasmic (odds ratio = 0.29, 95% confidence interval = 0.11-0.74).
  4. Abdulla MH, Sattar MA, Salman IM, Abdullah NA, Ameer OZ, Khan MA, et al.
    Auton Autacoid Pharmacol, 2008 Apr-Jul;28(2-3):87-94.
    PMID: 18598290 DOI: 10.1111/j.1474-8673.2008.00421.x
    1 This study was undertaken to characterize the renal responses to acute unilateral renal denervation in anaesthetized spontaneously hypertensive rats (SHR) by examining the effect of acute unilateral renal denervation on the renal hemodynamic responses to a set of vasoactive agents and renal nerve stimulation. 2 Twenty-four male SHR rats underwent acute unilateral renal denervation and the denervation was confirmed by significant drop (P < 0.05) in renal vasoconstrictor response to renal nerve stimulation along with marked diuresis and natriuresis following denervation. After 7 days treatment with losartan, the overnight fasted rats were anaesthetized (sodium pentobarbitone, 60 mg kg(-1) i.p.) and renal vasoconstrictor experiments were performed. The changes in the renal vasoconstrictor responses were determined in terms of reductions in renal blood flow caused by renal nerve stimulation or intrarenal administration of noradrenaline, phenylephrine, methoxamine and angiotensin II. 3 The data showed that there was significantly (all P < 0.05) increased renal vascular responsiveness to the vasoactive agents in denervated rats compared to those with intact renal nerves. In losartan-treated denervated SHR rats, there were significant (all P < 0.05) reductions in the renal vasoconstrictor responses to neural stimuli and vasoactive agents as compared with that of untreated denervated SHR rats. 4 The data obtained in denervated rats suggested an enhanced sensitivity of the alpha(1)-adrenoceptors to adrenergic agonists and possible increase of AT(1) receptors functionality in the renal vasculature of these rats. These data also suggested a possible interaction between sympathetic nervous system and renin-angiotensin system in terms of a crosstalk relationship between renal AT(1) and alpha(1)-adrenoceptor subtypes.
  5. Abdullah N, Lo KM, Tajuddin HA, Tee JT, Ng SW
    PMID: 21581455 DOI: 10.1107/S1600536808039858
    In the title Schiff base compound, C(23)H(30)N(2)O(2), the complete mol-ecule is generated by crystallographic twofold symmetry, with one C atom lying on the rotation axis. The nonane chain adopts a linear conformation and the hydr-oxy group forms an intra-molecular O-H⋯N hydrogen bond to the imine group.
  6. Kazi RN, Munavvar AS, Abdullah NA, Khan AH, Johns EJ
    Auton Autacoid Pharmacol, 2009 Jan;29(1-2):25-31.
    PMID: 19302553 DOI: 10.1111/j.1474-8673.2009.00428.x
    1 Increased renal vascular resistance is one renal functional abnormality that contributes to hypertension, and alpha(1)-adrenoceptors play a pivotal role in modulating this renal vascular resistance. This study investigates the functional contribution of alpha(1)-adrenoceptor subtypes in the renal cortical vasculature of Wistar-Kyoto rats on a normal sodium diet (WKYNNa) compared with those given saline to drink for 6 weeks (WKYHNa). 2 The renal cortical vascular responses to the adrenergic agonists noradrenaline (NA), methoxamine (ME) and phenylephrine (PE) were measured in WKYHNa and WKYNNa rats either in the absence (the control phase) or presence of chloroethylclonidine (CEC), an alpha(1B)-adrenoceptor antagonist, 5-methylurapidil (5-MeU), an alpha(1A) antagonist, or BMY7378, an alpha(1D) antagonist. 3 Results showed a greater renal cortical vascular sensitivity to NA, PE and ME in the WKYHNa compared with WKYNNa rats (P < 0.05). Moreover, 5-MeU and BMY7378 attenuated adrenergically induced renal cortical vasoconstriction in WKYHNa and WKYNNa rats; this response was largely blunted in CEC-treated WKYHNa rats (all P < 0.05) but not in CEC-treated WKYNNa rats. 4 The data suggest that irrespective of dietary sodium content, in Wistar-Kyoto rats alpha(1A)- and alpha(1D)-subtypes are the major alpha(1)-adrenoceptors in renal cortical vasculature; however, there appears to be a functional involvement of alpha(1B)-adrenoceptors in the WKYHNa rats.
  7. Kho YS, Vikineswary S, Abdullah N, Kuppusamy UR, Oh HI
    J Med Food, 2009 Feb;12(1):167-74.
    PMID: 19298211 DOI: 10.1089/jmf.2007.0568
    Auricularia auricula-judae is currently grown in Malaysia. In the present study, the methanolic extracts from fruit bodies (fresh, oven-dried, and freeze-dried) and mycelium of A. auricula-judae were evaluated for their antioxidant capacities based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity and ferric reducing antioxidant power (FRAP) assay. The total phenolic content in the extracts were also measured. The extract of freeze-dried fruit bodies of A. auricula-judae had potent DPPH free radical scavenging activity with a 50% effective concentration of 2.87 mg/mL, whereas the FRAP value of A. auricula-judae mycelium was 5.22 micromol of FeSO(4).7H(2)O equivalents/g of mycelium sample. Further, a positive correlation (R(2) = 0.7668) between FRAP level of A. auricula-judae extracts and the total phenolic contents was observed. Thus the method of processing of fresh fruit bodies had an effect on the antioxidant potential of A. auricula-judae.
  8. Kamal N, Sabaratnam V, Abdullah N, Ho AS, Teo SH, Lee HB
    Antonie Van Leeuwenhoek, 2009 Feb;95(2):179-88.
    PMID: 19125347 DOI: 10.1007/s10482-008-9301-8
    Photodynamic therapy (PDT) is a promising cancer treatment which involves activation of a photosensitizing drug with light to produce reactive oxygen species that kill tumors without causing damage to unirradiated normal tissues. To date, only Photofrin, Foscan and Levulan have been approved for clinical treatment of cancer. Tropical habitats such as those found in Malaysia are attractive sources of new therapeutic compounds as tremendous chemical diversity is found in a large number of plants, animals, marine- and micro-organisms. In our screening program for novel photosensitizers from nature, colorful strains of fungi (from Aspergillus and Penicillium genus) and bacteria (including actinomycetes and photosynthetic bacteria) were collected from various habitats in Peninsular Malaysia, such as coastal soil, peat soil, marine sponges and wastewater ponds. Methanolic extracts from a total of 85 different species were evaluated with a short-term cell viability assay for photo-cytotoxicity, where a promyelocytic leukemia cell-line, HL60 incubated with 20 microg/ml of extracts was irradiated with 9.6 J/cm(2) of a broad spectrum light. Two of these extracts, one from Rhodobacter sphaeroides (PBUM003) and one from Rhodopseudomonas palustris (PBUM001) showed moderate to strong photo-cytotoxicity. Subsequent bioassay guided isolation of the PBUM001 extract yielded known photosensitisers that are based on bacteriochlorophyll-a by comparing their molecular weight data, HPLC profiles and UV-vis absorption spectra with literature values, thereby demonstrating the validity of our screening approach.
  9. Abdulla MH, Sattar MA, Khan MA, Abdullah NA, Johns EJ
    Acta Physiol (Oxf), 2009 Mar;195(3):397-404.
    PMID: 19183357 DOI: 10.1111/j.1748-1716.2008.01895.x
    This study investigated the influence of angiotensin II (Ang II) receptor and adrenergic blockade on the renal vasoconstrictions caused by Ang II and adrenergic agonists in spontaneously hypertensive rats (SHR).
  10. Kuppusamy UR, Chong YL, Mahmood AA, Indran M, Abdullah N, Vikineswary S
    Indian J. Biochem. Biophys., 2009 Apr;46(2):161-5.
    PMID: 19517993
    Lentinula edodes (Berk) Pegler, commonly known as Shiitake mushroom has been used as medicinal food in Asian countries, especially in China and Japan and is believed to possess strong immunomodulatory property. In the present study, the methanolic extract of the fruit bodies of L. edodes was investigated for cytoprotective effect against H2O2-induced cytotoxicity in human peripheral blood mononuclear cells (PBMCs) by measuring the activities of xanthine oxidase (XO) and glutathione peroxidase (GPx) . H2O2 at a concentration of 5 microM caused 50% inhibition of PBMCs viability. The extract improved the PBMC viability and exerted a dose-dependent protection against H2O2-induced cytotoxicity. At 100 microg/ml of extract concentration, the cell viability increased by 60% compared with the PBMCs incubated with H2O2 alone. The extract also inhibited XO activity in PBMC, while showing moderate stimulatory effect on GPx. However, in the presence of H2O2 alone, both the enzyme activities were increased significantly. The GPx activity increased, possibly in response to the increased availability of H2O2 in the cell. When the cells were pretreated with the extract and washed (to remove the extract) prior to the addition of H2O2, the GPx and XO activities as well as the cell viability were comparable to those when incubated with the extract alone. Thus, it is suggested that one of the possible mechanisms via which L. edodes methanolic extract confers protection against H2O2-induced oxidative stress in PBMC is by inhibiting the superoxide-producing XO and increasing GPx activity which could rapidly inactivate H2O2.
  11. Rohana A, Hisham AN
    Asian J Surg, 2009 Apr;32(2):81-4.
    PMID: 19423453 DOI: 10.1016/S1015-9584(09)60015-4
    BACKGROUND: Acute life threatening presentations of thyroid disease are uncommon. The aim of this study was to review our experience of emergency thyroid surgery with regard to the incidence, management and outcome to this approach.
    METHODS: Forty patients who underwent emergency thyroid surgery from December 1998 to December 2007 were prospectively accrued in this study. There were 30 female and 10 male patients. The mean age was 63.8 years (range, 33-83 years). All patients had total thyroidectomy, except one patient who only had a right hemithyroidectomy for a dominant right multinodular goiter. Eight of the patients had been intubated before referring to our centre.
    RESULTS: The mean weight of specimen was 219 g (range, 32-800 g). A histopathology report confirmed 16 patients had multinodular goiters, eight patients had papillary thyroid carcinomas, seven patients had anaplastic cancers, four patients had follicular thyroid carcinomas, two patients had thyroid lymphoma, one patient had medullary carcinoma, one patient had sarcoma and one patient had thyroid abscess. A total of 28 patients were discharged well postoperatively.
    CONCLUSION: Acute life threatening presentations of thyroid disease are uncommon. However, early recognition of these problems is crucial and may life saving. Emergency thyroidectomy is important to release the critically obstructed airways. Nonetheless it is associated with higher risk of surgery and complication rate then any elective thyroid surgery.
  12. Rathore HA, Munavvar AS, Abdullah NA, Khan AH, Fathihah B, NurJannah MH, et al.
    Auton Autacoid Pharmacol, 2009 Oct;29(4):171-80.
    PMID: 19740088 DOI: 10.1111/j.1474-8665.2009.00445.x
    1 A raised cardiac workload activates neurohormones which will increase muscle mass and shift contractility to the right along the Frank-Starling curve. 2 This study examined the interaction between the SNS and RAS in contributing to vascular responsiveness following the development of cardiac hypertrophy due to aortic banding. 3 Sprague Dawley rats (180-200 g) were assigned to one of six groups; Normal, Sham-operated, Aortic Banded (AB), Aortic Banded treated with losartan (ABLOS), Aortic Banded treated with 6-hydroxydopamine (ABSYMP) and Aortic banded treated with both losartan and 6-hydroxydopamine (ABSYMPLOS). A constricting band was placed around the supra renal aorta on day zero with drug treatment from day 37 to day 44. Vasopressor responses to noradrenaline, phenylephrine, methoxamine and angiotensin II were measured on day 45. 4 The magnitudes of the MAP responses to all vasoactive agents, expressed as percentage changes, were similar in Normal and Sham groups, but reduced in the AB group. ABLOS group showed attenuated response to ANGII whereas all responses were enhanced in the ABSYM group. 5 A positive interaction between the two systems was observed with alpha(1A)-adrenoceptors identified as a major component of SNS and AT(1) receptors of RAS to induce vasopressor effects.
  13. Zain RB, Ghani WM, Razak IA, Latifah RJ, Samsuddin AR, Cheong SC, et al.
    Asian Pac J Cancer Prev, 2009 Jul-Sep;10(3):513-8.
    PMID: 19640201
    BACKGROUND: The rising burden of cancer in the developing world calls for a re-evaluation of the treatment strategies employed to improve patient management, early detection and understanding of the disease. There is thus an increasing demand for interdisciplinary research that integrates two or more disciplines of what may seemed to be highly unrelated and yet very much needed as strategies for success in research. This paper presents the processes and barriers faced in building partnerships in oral cancer research in a developing country.

    METHODS: A case study was undertaken in a developing country (Malaysia) to assess the strengths and weaknesses of the situation leading to the formation of a multidisciplinary research partnership in oral cancer. Following the formalization of the partnership, further evaluation was undertaken to identify measures that can assist in sustaining the partnership.

    RESULTS: The group identifies its strength as the existence of academia, research-intensive NGOs and good networking of clinicians via the existence of the government's network of healthcare provider system who are the policy makers. The major weaknesses identified are the competing interest between academia and NGOs to justify their existence due to the lack of funding sources and well trained human resources.

    CONCLUSIONS: With the growing partnership, the collaborative group recognizes the need to develop standard operating procedures (SOPs) and guidelines for the sharing and usage of resources in order to safeguard the interest of the original partners while also attending to the needs of the new partners.
  14. Razak AA, Saddki N, Naing NN, Abdullah N
    Asian Pac J Cancer Prev, 2009;10(6):1131-6.
    PMID: 20192598
    OBJECTIVE: The objective of this study was to identify the characteristics of oral cancer among Malay patients in Hospital Universiti Sains Malaysia (HUSM), Kelantan.

    METHODS: A retrospective record review was conducted from August to December 2006 in HUSM. Of 133 patients with oral cancer diagnosed from 1986 to 2005, 118 were Malay. Data on socio-demographic background, high-risk habits practiced, clinical and histological characteristics, and treatment profile of the patients were obtained.

    RESULTS: Malay patients with oral cancer were predominantly elderly, aged 60 years old and above (51.7%) at the time of diagnosis, with a mean age of 58.1 years (SD 16.81). Most patients were males (64.4%) and the majority of them were married (83.9%). More than half (58.5%) had been smokers, and of those who smoked, 89.9% were males. Some had a betel quid chewing habit (22.9%) but none ever consumed alcohol. The majority of the patients (77.1%) were diagnosed at stage IV. The tongue was the most usual site involved (37.3%) and squamous cell carcinoma was the most common histological type seen (75.4%).

    CONCLUSIONS: The prevalence of oral cancer among Malay patients in HUSM is high (88.7%). It is predominantly found in elderly males and the majority of cases present at advanced stage.

  15. Ramasamy K, Abdullah N, Wong MC, Karuthan C, Ho YW
    J Sci Food Agric, 2010 Jan 15;90(1):65-9.
    PMID: 20355013 DOI: 10.1002/jsfa.3780
    Bile salt deconjugation by Lactobacillus strains is often closely linked to bile tolerance and survival of the strains in the gut and lowering of cholesterol in the host. The present study investigated the deconjugation of bile salts and removal of cholesterol by 12 Lactobacillus strains in vitro. The 12 strains were previously isolated from the gastrointestinal tract of chickens.
  16. Rahman ZA, Abdullah N, Singh R, Sosroseno W
    J Oral Sci, 2010 Mar;52(1):133-6.
    PMID: 20339244
    The aim of the present study was to assess the levels of salivary cortisol, tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) before, during and after acute exercise. Acute exercise was induced using a standard treadmill test with Bruce protocol in ten physically active male participants. Unstimulated saliva was collected before, during and after exercise. The levels of salivary cortisol and TNF-alpha were assessed by enzyme immunoassays. Salivary NO was determined by the Griess reagent. The results showed that both salivary cortisol and TNF-alpha increased and peaked at 14 min during exercise and then decreased. The levels of NO were increased up to 1 h after exercise and subsequently lowered after 24 h. The results of the present study suggest that acute exercise may induce high levels of salivary cortisol, TNF-alpha and NO.
  17. Pau Ni IB, Zakaria Z, Muhammad R, Abdullah N, Ibrahim N, Aina Emran N, et al.
    Pathol Res Pract, 2010 Apr 15;206(4):223-8.
    PMID: 20097481 DOI: 10.1016/j.prp.2009.11.006
    Genomic and transcriptomic alterations that affect cellular processes, such as cell proliferation, differentiation, apoptosis and invasion, commonly occur in breast oncogenesis. Epidemiological evidence has proven that the risk of breast cancer predisposition varies among different ethnicities. This study aims to identify the transcriptome changes that commonly occur during the transition of normal breast epithelium to carcinoma in three local ethnic groups (Malays, Chinese and Indians). The gene expression patterns of 43 breast carcinomas with 43 patient-matched normal breast tissues were investigated using Affymetrix U133A GeneChip (containing 22,283 probe sets targeting approximately 18,400 different transcripts) and analyzed with GeneSpring GX10. Our findings revealed a total of 33 significantly differentially expressed genes, which showed>2-fold change at a 99.9% confidence interval level (p<0.001). The significantly differentially expressed genes included CD24, CD36, CD9, TACSTD1, TACSTD2, HBB, LEP, LPL, AKR1C1, AKR1C2 and AKR1C3. Our results indicate that the vast majority of gene expression changes, from normal breast epithelial to carcinoma, found in our three major ethnic populations are similar to those in the Caucasian population. Further study of the differentially expressed genes identified in our present study is needed to search for potential breast tumor biomarkers. This will eventually help to improve the therapeutic and treatment strategies for breast cancer patients in the future.
  18. Ozair LN, Abdullah N, Khaledi H, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2010 Apr 30;66(Pt 5):m589-90.
    PMID: 21579064 DOI: 10.1107/S1600536810015060
    The structure of the dinuclear title complex, [Cu(2)(C(5)H(9)O(2))(4)(C(5)H(5)N)(2)], represents a monoclinic polymorph of the previously reported triclinic form [Blewett et al. (2006 ▶). Acta Cryst. E62, m420-m422]. Each carboxyl-ate group is bidentate bridging and the distorted octa-hedral geometry about each Cu(II) atom is completed by a pyridine N atom and the other Cu atom [Cu⋯Cu = 2.6139 (7) Å]. In the crystal, mol-ecules are connected into supra-molecular chains via π-π inter-actions formed by the pyridine rings [centroid-centroid distance = 3.552 (3) Å] and these are connected into a two-dimensional array in the ac plane by C-H⋯π contacts. One of the tert-butyl groups is disordered over two orientations in a 0.734 (6):0.266 (6) ratio.
  19. Yadzir ZH, Misnan R, Abdullah N, Bakhtiar F, Arip M, Murad S
    PMID: 20578555
    Allergy to different classes of mollusks, including squid, which are members of the class Cephalopods has been reported. Tropomyosin, a major muscle protein, is the only well-recognized allergen in squid. The aim of this study was to characterize IgE-binding proteins of local Loligo edulis (white squid) consumed in Malaysia. Protein profiles and IgE-binding proteins were detected by sodium dodecyl sulfate-polyacrylamide gel-electrophoresis (SDS-PAGE) and immunoblotting using sera from 23 patients with positive skin prick test to raw squid extract. SDS-PAGE of the raw extract exhibited 21 protein bands (10-170 kDa) but those ranging from 19 to 29 kDa and 41 to 94 kDa were not found in the cooked extract. Immunoblotting of raw extract demonstrated 16 IgE-binding bands, ranging from 13 to 170 kDa. A heat-resistant 36 kDa protein, corresponding to squid tropomyosin, was identified as the major allergen of both extracts. In addition, a 50 kDa heat-sensitive protein was shown to be a major allergen of the raw extract. Our findings indicate that the allergen extract used for diagnosis of squid allergy should contain both the 36 kDa and 50 kDa proteins.
  20. Nooraee SE, Alimon AR, Ho YW, Abdullah N
    Lett Appl Microbiol, 2010 Jun 1;50(6):578-84.
    PMID: 20406377 DOI: 10.1111/j.1472-765X.2010.02836.x
    The aim of this study was to find suitable yeast isolates as potential microbial feed additives for ruminants.
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