Displaying publications 1 - 20 of 43 in total

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  1. Basri KN, Yazid F, Megat Abdul Wahab R, Mohd Zain MN, Md Yusof Z, Zoolfakar AS
    PMID: 34634732 DOI: 10.1016/j.saa.2021.120464
    Caries is one of the non-communicable diseases that has a high prevalence trend. The current methods used to detect caries require sophisticated laboratory equipment, professional inspection, and expensive equipment such as X-ray imaging device. A non-invasive and economical method is required to substitute the conventional methods for the detection of caries. UV absorption spectroscopy coupled with chemometrics analysis has emerged as a good potential candidate for such an application. Data preprocessing methods such as mean centre, autoscale and Savitzky-Golay smoothing were implemented to enhance the signal-to-noise ratio of spectra data. Various classification algorithms namely K-nearest neighbours (KNN), logistic regression (LR) and linear discriminant analysis (LDA) were implemented to classify the severity of dental caries into International Caries Detection and Assessment System (ICDAS) scores. The performance of the prediction model was measured and comparatively analysed based on the accuracy, precision, sensitivity, and specificity. The LDA algorithm combined with the Savitzky-Golay preprocessing method had shown the best result with respect to the validation data accuracy, precision, sensitivity and specificity, where each had values of 0.90, 1.00, 0.86 and 1.00 respectively. The area under the curve of the ROC plot computed for the LDA algorithm was 0.95, which indicated that the prediction algorithm was capable of differentiating normal and caries teeth excellently.
  2. Basri KN, Yazid F, Mohd Zain MN, Md Yusof Z, Abdul Rani R, Zoolfakar AS
    PMID: 38394882 DOI: 10.1016/j.saa.2024.124063
    Dental caries has high prevalence among kids and adults thus it has become one of the global health concerns. The current modern dentistry focused on the preventives measures to reduce the number of dental caries cases. The employment of machine learning coupled with UV spectroscopy plays a crucial role to detect the early stage of caries. Artificial neural network with hyperparameter tuning was employed to train spectral data for the classification based on the International Caries Detection and Assesment System (ICDAS). Spectra preprocessing namely mean center (MC), autoscale (AS) and Savitzky Golay smoothing (SG) were applied on the data for spectra correction. The best performance of ANN model obtained has accuracy of 0.85 with precision of 1.00. Convolutional neural network (CNN) combined with Savitzky Golay smoothing performed on the spectral data has accuracy, precision, sensitivity and specificity for validation data of 1.00 respectively. The result obtained shows that the application of ANN and CNN capable to produce robust model to be used as an early screening of dental caries.
  3. Al-Khateeb A, Al-Talib H, Mohamed MS, Yusof Z, Zilfalil BA
    Adv Clin Exp Med, 2013 Jan-Feb;22(1):57-67.
    PMID: 23468263
    BACKGROUND: Familial hypercholesterolemia and familial defective apo lipoprotein B are genetic disorders caused by defects in the low-density lipoprotein receptor gene and apo lipoprotein B 100 genes, respectively. The clinical phenotype of both diseases is characterized by increased plasma levels of total cholesterol and low density lipoprotein cholesterol, tendinous xanthomata, and premature coronary heart disease.
    OBJECTIVES: The aim of this study is to perform an association study between different gene sequence variants in low-density lipoprotein and apo lipoprotein B 100 genes to the clinical finding and lipid profile parameters of the study subjects.
    MATERIAL AND METHODS: A group of 164 familial hypercholesterolemic patients were recruited. The promoter region, exon 2-15 of the low density lipoprotein gene and parts of exon 26 and 29 of apo lipoprotein B 100 gene were screened by Denaturating Gradient High Performance Liquid Chromatography.
    RESULTS: For the apo lipoprotein B 100 gene, those with apo lipoprotein B 100 gene mutation have a significantly higher frequency of cardiovascular disease (P = 0.045), higher low density lipoprotein cholesterol and total cholesterol: high density lipoprotein cholesterol ratio than those without mutation (P = 0.03 and 0.02, respectively). For the low density lipoprotein gene defect those with frame shift mutation group showed the worst clinical presentation in terms of low density lipoprotein cholesterol level and cardiovascular frequency.
    CONCLUSIONS: There was a statistically significant association between mutations of low density lipoprotein gene and apo lipoprotein B 100 genes and history of cardiovascular disease, younger age of presentation, family history of hyperlipidemia, tendon xanthoma and low density lipoprotein cholesterol level.
    Study site: Cardiology Clinic, Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia
  4. Al-Khateeb AR, Mohd MS, Yusof Z, Zilfalil BA
    Biochem Genet, 2013 Oct;51(9-10):811-23.
    PMID: 23775634 DOI: 10.1007/s10528-013-9609-6
    Familial ligand-defective apolipoprotein B-100 is characterized by elevated plasma low-density lipoprotein levels and premature heart disease. This study aims to determine apolipoprotein B gene mutations among Malaysians with clinical diagnoses of familial hypercholesterolemia and to compare the phenotype of patients with apolipoprotein B gene mutations to those with a low-density lipoprotein receptor gene mutation. A group of 164 patients with a clinical diagnosis of familial hypercholesterolemia was analyzed. Amplicons in exon 26 and exon 29 of the apolipoprotein B gene were screened for genetic variants using denaturing gradient high-performance liquid chromatography; 10 variants were identified. Five novel mutations were detected (p.Gln2485Arg, p.Thr3526Ala, p.Glu3666Lys, p.Tyr4343CysfsX221, and p.Arg4297His). Those with familial defective apolipoprotein had a less severe phenotype than those with familial hypercholesterolemia. An apolipoprotein gene defect is present among Malaysian familial hypercholesterolemics. Those with both mutations show a more severe phenotype than those with one gene defect.
  5. Al-Khateeb A, Zahri MK, Mohamed MS, Sasongko TH, Ibrahim S, Yusof Z, et al.
    BMC Med Genet, 2011;12:40.
    PMID: 21418584 DOI: 10.1186/1471-2350-12-40
    Familial hypercholesterolemia is a genetic disorder mainly caused by defects in the low-density lipoprotein receptor gene. Few and limited analyses of familial hypercholesterolemia have been performed in Malaysia, and the underlying mutations therefore remain largely unknown.We studied a group of 154 unrelated FH patients from a northern area of Malaysia (Kelantan). The promoter region and exons 2-15 of the LDLR gene were screened by denaturing high-performance liquid chromatography to detect short deletions and nucleotide substitutions, and by multiplex ligation-dependent probe amplification to detect large rearrangements.
  6. Fong SW, Few LL, See Too WC, Khoo BY, Nik Ibrahim NN, Yahaya SA, et al.
    BMC Res Notes, 2015;8:679.
    PMID: 26576922 DOI: 10.1186/s13104-015-1677-8
    Biomarkers play a pivotal role in the diagnosis and management of patients with acute coronary syndrome. This study aimed to investigate the differences in level of several biomarkers, i.e. C-reactive protein, myeloperoxidase, soluble CD40 ligand and placental growth factor, between acute coronary syndrome and chronic stable angina patients. The relationship between these biomarkers in the coronary circulation and systemic circulation was also investigated.
  7. Mohd Idrus FN, Ahmad NS, Hoe CH, Azlan M, Norfuad FA, Yusof Z, et al.
    BMC Immunol, 2021 03 24;22(1):21.
    PMID: 33761885 DOI: 10.1186/s12865-021-00410-2
    BACKGROUND: Differential polarization of macrophage into M1 and M2 mediates atherosclerotic plaque clearance through efferocytosis. Higher expression of Mer proto-oncogene tyrosine kinase (MerTK) on M2 macrophage helps in maintaining macrophage efferocytic efficiency. In healthy individuals, macrophage polarization into M1 and M2 occurs in tissues in concomitance with the acquisition of functional phenotypes depending on specific microenvironment stimuli. However, whether the macrophage differential polarization and MerTK expression vary in coronary artery disease (CAD) patients remain unknown.

    OBJECTIVE: This study aimed to elucidate the polarization of M1 and M2 macrophage from CAD patients as well as to investigate the expression of MerTK in these macrophage phenotypes.

    METHODS: A total of 14 (n) CAD patients were recruited and subsequently grouped into "no apparent CAD", "non-obstructive CAD" and "obstructive CAD" according to the degree of stenosis. Thirty ml of venous blood was withdrawn to obtain monocyte from the patients. The M1 macrophage was generated by treating the monocyte with GMCSF, LPS and IFN-γ while MCSF, IL-4 and IL-13 were employed to differentiate monocyte into M2 macrophage. After 7 days of polarization, analysis of cell surface differentiation markers (CD86+/CD80+ for M1 and CD206+/CD200R+ for M2) and measurement of MerTK expression were performed using flow cytometry.

    RESULTS: Both M1 and M2 macrophage expressed similar level of CD86, CD80 and CD206 in all groups of CAD patients. MerTK expression in no apparent CAD patients was significantly higher in M2 macrophage compared to M1 macrophage [12.58 ± 4.40 vs. 6.58 ± 1.37, p = 0.040].

    CONCLUSION: Differential polarization of macrophage into M1 and M2 was highly dynamic and can be varied due to the microenvironment stimuli in atherosclerotic plaque. Besides, higher expression of MerTK in patients with the least coronary obstructive suggest its vital involvement in efferocytosis.

  8. Yusof ZA
    J. Periodontol., 1990 Dec;61(12):751-4.
    PMID: 2269916
    The objective of this report was to determine the radiographic patterns of alveolar bone loss in early-onset periodontitis (EOP) cases in a selected Malaysian population. The radiographs of 55 cases of EOP patients were examined and the radiographic patterns were classified as follows: Type I: bone destruction on first molars and/or incisors only; Type II: bone destruction on first molars and/or incisors and several additional teeth (less than 14 teeth); Type III: generalized bone destruction (greater than 14 teeth), but with involvement noticeably more extensive on the first molars and/or incisors; Type IV: generalized bone destruction (greater than 14 teeth), but with no more bone loss on the first molars and/or incisors than on other involved teeth. Sex, age, and missing teeth were also recorded. Out of 55 cases, 47 cases, 22 males and 25 females, were classified into the types mentioned above; the remaining 8 cases were excluded due to too many missing teeth. It was found that 7 (14.9%) were Type I; 12 (25.5%) were Type II; 7 (14.9%) were Type III; and 21 (44.7%) were Type IV. There was a predominance of first molar/incisor involvement in Types I, II, and III with the maxillary first molars most frequently involved followed by the mandibular central incisors. Type I occurred in the younger age group and Types II, III, and IV mainly in the older age group. It was concluded that EOP in this patient sample resembled that of western society.
  9. Al-Khateeb A, Mohamed MS, Imran K, Ibrahim S, Zilfalill BA, Yusof Z
    PMID: 21710862
    The aim of the present study was to evaluate Malaysian dyslipidemic patient treatment practices and outcomes. Factors contributing to success in reaching treatment goal were determined. A retrospective review of the records of dyslipidemic patients who attended the Universiti Sains Malaysia Hospital in 2007 was conducted. All the patients were receiving standard recommended doses of statins. Records were analysed for 890 patients. Patients were divided into three categories: 384 patients (43.1%) had coronary heart disease or coronary heart disease risk equivalents, 216 patients (24.3%) had moderate risk for coronary heart disease and 290 patients (32.6%) had low risk. Statins were the most commonly prescribed drug group (92%), of which atorvastatin was the most commonly prescribed drug (50.6%). The overall success rate for reaching goal was 64.2%. The percentages of patients achieving low-density lipoprotein cholesterol targets in the coronary heart disease and coronary heart disease risk equivalents, moderate, and low-risk groups were 50.5, 66.7, and 80.3%, respectively (p < 0.001). Multiple logistic regression showed achievement of therapeutic goal declined with increasing risk group. The baseline low-density lipoprotein cholesterol value was inversely related to therapeutic goal attainment. An inadequate proportion of dyslipidemic patients achieved the National Cholesterol Education Program therapeutic goals for low-density lipoprotein cholesterol, especially those in the coronary heart disease and coronary heart disease risk equivalent group. The achievement of this goal was dependent on baseline low-density lipoprotein cholesterol levels.
  10. Al-Khateeb A, Mohamed MS, Imran K, Ibrahim S, Zilfalil BA, Yusof Z
    Kobe J Med Sci, 2011;57(2):E38-48.
    PMID: 22926072
    The importance of serum lipids as cardiovascular risk factors is well recognized. However, most published studies have focused on western countries. The present study aimed to describe and analyze the lipid profile parameters in Malaysian dyslipidemic patients, and to identify concomitant clinical problems and risk factors associated with cardiovascular disease (CVD) among such patients.
  11. Yusof Z
    J Oral Rehabil, 1991 Jan;18(1):95-102.
    PMID: 2051253
    The aim of this study was to determine the periodontal status in relation to the quality of the adjacent proximal tooth surface. The gingival index (GI) and probable pocket depth (PD) were measured in 144 contra-lateral pairs of sound vs. restored and 95 contra-lateral pairs of sound vs. carious surfaces in 124 patients. The restorations studied were silver amalgams and tooth-coloured filling materials, the margins of which were supragingival or level with the gingival margins. The results showed that the GI and PD were greater for both restored and carious tooth surfaces than for the contra-lateral sound surfaces. When all the teeth were grouped together, the differences in the mean values of GI and PD were statistically significant at the P less than or equal to 0.05 level. A comparison between restored and carious (non-paired) tooth surfaces revealed higher mean values of GI and PD for the latter, which were highly significant at the P less than 0.001 level. Thus the present study shows that proximal tooth surface quality influences the health status of the adjacent periodontium.
  12. Isa Z, Yusof Z
    J Oral Rehabil, 1990 Nov;17(6):541-50.
    PMID: 2283549
    The aims of this study were to determine the dental and periodontal status and the associated treatment needs, other than that for prosthetic care, in patients who requested removable partial dentures. Forty-six patients who had never worn removable partial dentures before were examined for plaque index, tooth status, gingival index, loss of periodontal attachment and tooth mobility. Prior to prosthetic treatment, 15% of the teeth needed conservative treatment and 1% needed extractions. From the periodontal point of view, 65% of the teeth needed some form of related therapy, and 2% of the teeth were at risk of extraction due to advanced mobility.
  13. Johari MI, Besari AM, Wan Ghazali WS, Yusof Z
    BMJ Case Rep, 2019 May 09;12(5).
    PMID: 31076489 DOI: 10.1136/bcr-2018-226337
    A 47-year-old Malay man who presented with fever, poor oral intake and loss of weight for 1 month duration. Further work-up revealed evidence of disseminated Salmonella infection that was further complicated with pericardial and pleural empyema. Cultures from pericardial and pleural fluids grew Salmonella species with negative serial blood cultures. Contrast enhanced CT thorax showed pleural effusion with large pericardial effusion. The patient was treated with antibiotics and drainage of pericardial and pleural empyema was done and he was discharged well.
  14. Mustaffa N, Ibrahim S, Abdullah WZ, Yusof Z
    Blood Coagul Fibrinolysis, 2011 Sep;22(6):512-20.
    PMID: 21537159 DOI: 10.1097/MBC.0b013e32834740ba
    Rosiglitazone is an oral hypoglycaemic agent of the thiazolidinedione group. This study aimed to assess changes in the diabetic prothrombotic state via plasminogen activity and changes in surrogate markers of atherosclerotic burden via ankle-brachial pressure index (ABPI) measurements after rosiglitazone was added to a pre-existing type 2 diabetes mellitus treatment regime. A nonblinded interventional study was designed. Fifty-nine patients were enrolled. Rosiglitazone-naïve patients were prescribed oral rosiglitazone 4 mg daily for 10 weeks. ABPI, plasminogen activity, glycosylated haemoglobin (HbA1c) and fasting lipid profile were measured pretreatment and post-treatment. Forty-eight patients completed the study. At the end of this study, mean plasminogen activity improvement was nearly 16% (P<0.05), mean ABPI improvement was 0.01 (P=0.439), mean HbA1c reduction was 0.51% (P<0.05), mean total cholesterol (TC) increase was 0.36 mmol/l (P<0.05), mean high-density lipoprotein cholesterol (HDL-C) increase was 0.15 mmol/l (P<0.05) and mean low-density lipoprotein cholesterol increased by 0.19 mmol/l (P=0.098). Rosiglitazone significantly improved plasminogen activity. There was also significant HbA1c reduction, and rise in both TC and HDL-C. Thus, rosiglitazone potentially improves the atherosclerotic burden and prothrombotic state. In future, more studies are needed to confirm the relationship between rosiglitazone, fibrinolytic system and atheromatous reduction in type 2 diabetes mellitus.
  15. Wong DKC, Muhamad NS, Sobri SS, Amin WAM, Yusof Z
    Med J Malaysia, 2019 04;74(2):85-86.
    PMID: 31079134
    Metastasising pleomorphic adenoma is rare and may occur years after surgical excision of a pleomorphic adenoma (PA). We present a 61-year-old woman with a right infratemporal PA with metastases to the cervical lymph nodes after 30 years following a total parotidectomy. She was treated successfully with a resection of the tumour with combined neck and mandibulotomy approach along with postoperative radiotherapy given subsequently.
  16. Shahbuddin HMA, Hussin SA, W Isa WYH, Mamat AZ, Marzuki A, Yusof Z
    BMJ Case Rep, 2024 Mar 07;17(3).
    PMID: 38453227 DOI: 10.1136/bcr-2024-259675
    Diagnosing atrial myxoma in pregnancy is challenging because patients may present with non-specific symptoms that might be overlooked. The timing of non-obstetric operation usually depends on the nature of the disease, after careful consideration of feto-maternal safety, including the use of cardiopulmonary bypass and placental transfer of anaesthetic drug. A woman in her 30s at 18 weeks of pregnancy presented with recurring dizziness. She underwent successful myxoma excision at 20 weeks under general anaesthesia and cardiopulmonary bypass. The 6×5 cm myxoma was histologically confirmed as myxoma. Early detection of atrial myxoma in pregnancy is crucial, and a clinician has to consider the diagnosis of left atrial myxoma with mitral valve obstruction as a cause of severe dizziness. Optimal outcomes require multidisciplinary management. In this case, surgery during the second trimester of pregnancy enabled a full-term pregnancy with the patient's and foetal well-being and normal postprocedural echocardiography.
  17. Alarhabi AY, Mohamed MS, Ibrahim S, Hun TM, Musa KI, Yusof Z
    J Clin Hypertens (Greenwich), 2009 Jan;11(1):17-21.
    PMID: 19125854 DOI: 10.1111/j.1751-7176.2008.00061.x
    To determine whether pulse wave velocity (PWV) as a measure of arterial stiffness is a marker of coronary artery diseases (CAD), the authors did a cross-sectional study in 92 patients undergoing coronary angiography for suspected CAD. Arterial stiffness was assessed through recording PWV from the left carotid-right femoral arteries using an automated machine. The mean PWV was higher in patients with CAD than in those without CAD (11.13+/-0.91 vs 8.14+/-1.25 m/sec; P
  18. Yusof Z, Ramasamy S, Mahmood NZ, Yaacob JS
    Molecules, 2018 Jun 04;23(6).
    PMID: 29867000 DOI: 10.3390/molecules23061345
    This project studied the effect of vermicompost application on the composition of bioactive anthocyanin and phenolic compounds, and the antioxidant activity of Clinacanthus nutans. The correlation between the bioactive constituents and antioxidant capacity was also evaluated. In this project, a field study was conducted using a randomized complete block design (RCBD) with four treatment groups, including control plants (CC), plants supplied with chemical fertilizer (CF), plants supplied with vermicompost (VC), and plants supplied with mixed fertilizer (MF). The leaves of C. nutans from all treatment groups were harvested, subjected to solvent extraction, and used for quantification of total anthocyanin content (TAC), total phenolic content (TPC), and total flavonoid content (TFC). The initial antioxidant activity of the extracts was evaluated using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, as well as after two and four weeks of storage at -20 °C and 4 °C. Data analysis showed that CC plants contained the highest TAC (2180.14 ± 338.43 µg/g dry weight) and TFC (276.25 ± 3.09 mg QE/g dry weight). On the other hand, CF plants showed the highest TPC (181.53 ± 35.58 mg GAE/g dry weight). Moreover, we found that CC plants had the highest antioxidant potential against DPPH radicals whereas MF plants showed the lowest antioxidant potential. After four weeks of extract storage at -20 °C and 4 °C, the TPC, TFC, TAC, and antioxidant potential of the extracts decreased. Extracts from VC showed the lowest percentage of total phenolic and total flavonoid loss after extract storage at -20 °C and 4 °C compared with other plant extracts. At this juncture, it could be deduced that the application of vermicompost had little effect on the expression of phenolics, flavonoids, or anthocyanin in C. nutans. However, the extract from plants treated with vermicompost (VC and MF) showed better stability compared with CC and CF after extract storage at different temperatures.
  19. Khalid K, Ku Md Saad S, Soelar SA, Mohamed Yusof Z, Warijo O
    J Ethn Subst Abuse, 2023;22(1):121-132.
    PMID: 33784945 DOI: 10.1080/15332640.2021.1906816
    Kratom is a plant homogenous to Southeast Asia with a long history of traditional use as medicinal herbs. However, recent years have witnessed its pervasive infiltration into international audience with growing public health concern. This cross-sectional study was conducted from 1 August 2017 till 31 August 2018 aiming to explore the practice and perspectives of kratom use and misuse among adolescents in northwest Malaysia. The study involved a self-administered questionnaire that was designed for the purpose of the study. The instrument had undergone prior validation process with a good overall internal reliability for the knowledge domain (Cronbach's alpha = 0.728) and attitude domain (Cronbach's alpha = 0.700). The questionnaire was distributed to 135 respondents involving adolescents aged 13 to 19 years old via convenience (non-kratom user) and snowball sampling (kratom users). There were 65 (47.8%) kratom users, while 70 (51.5%) were kratom-naïve. Among the kratom users, peer influence was the most common reason for them to be first involved with kratom, 26 (41.3%) whereas the reasons for kratom use quoted were to improve physical stamina, 10 (16.4%), as painkiller, 9 (14.8%), and to be accepted by peers, 7 (11.5%). Multiple logistic regression found that older age (95% CI: 0.13, 0.58; p = 0.001) and being active smokers (95% CI: 39.33, 980.63; p 
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