Displaying publications 101 - 120 of 144 in total

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  1. Fulltext KCNJ11: Genetic Polymorphisms and Risk of Diabetes Mellitus
    Haghvirdizadeh P, Mohamed Z, Abdullah NA, Haghvirdizadeh P, Haerian MS, Haerian BS
    J Diabetes Res, 2015;2015:908152.
    PMID: 26448950 DOI: 10.1155/2015/908152
    Diabetes mellitus (DM) is a major worldwide health problem and its prevalence has been rapidly increasing in the last century. It is caused by defects in insulin secretion or insulin action or both, leading to hyperglycemia. Of the various types of DM, type 2 occurs most frequently. Multiple genes and their interactions are involved in the insulin secretion pathway. Insulin secretion is mediated through the ATP-sensitive potassium (KATP) channel in pancreatic beta cells. This channel is a heteromeric protein, composed of four inward-rectifier potassium ion channel (Kir6.2) tetramers, which form the pore of the KATP channel, as well as sulfonylurea receptor 1 subunits surrounding the pore. Kir6.2 is encoded by the potassium inwardly rectifying channel, subfamily J, member 11 (KCNJ11) gene, a member of the potassium channel genes. Numerous studies have reported the involvement of single nucleotide polymorphisms of the KCNJ11 gene and their interactions in the susceptibility to DM. This review discusses the current evidence for the contribution of common KCNJ11 genetic variants to the development of DM. Future studies should concentrate on understanding the exact role played by these risk variants in the development of DM.
  2. Crouzon Syndrome: A Case Series of Craniomaxillofacial Distraction Osteogenesis for Functional Rehabilitation
    Hariri F, Abdul Rahman ZA, Bahuri NFA, Azmi MN, Abdullah NA, Ganesan D
    J Oral Maxillofac Surg, 2018 03;76(3):646.e1-646.e12.
    PMID: 29268076 DOI: 10.1016/j.joms.2017.11.029
    Crouzon syndrome (CS) is the most common craniosynostosis syndrome and requires a comprehensive management strategy for the optimization of care and functional rehabilitation. This report presents a case series of 6 pediatric patients diagnosed with CS who were treated with distraction osteogenesis (DO) to treat serious functional issues involving severe orbital proptosis, an obstructed nasopharyngeal airway, and increased intracranial pressure (ICP). Three boy and 3 girls were 8 months to 6 years old at the time of the operation. The mean skeletal advancement was 16.1 mm (range, 10 to 27 mm) with a mean follow-up of 31.7 months (range, 13 to 48 months). Reasonable and successful outcomes were achieved in most patients as evidenced by adequate eye protection, absence of signs and symptoms of increased ICP, and tracheostomy tube decannulation except in 1 patient. Complications were difficult fixation of external stabilizing pins in the distraction device (n = 1) and related to surgery (n = 4). Although DO can be considered very technical and can have potentially serious complications, the technique produces favorable functional and clinical outcomes in treating severe CS.
  3. Fulltext Efficient removal of pharmaceuticals from water using graphene nanoplatelets as adsorbent
    Rosli FA, Ahmad H, Jumbri K, Abdullah AH, Kamaruzaman S, Fathihah Abdullah NA
    R Soc Open Sci, 2021 Jan;8(1):201076.
    PMID: 33614065 DOI: 10.1098/rsos.201076
    Recently, pharmaceutical pollutants in water have emerged as a global concern as they give threat to human health and the environment. In this study, graphene nanoplatelets (GNPs) were used to efficiently remove antibiotics sulfamethoxazole (SMX) and analgesic acetaminophen (ACM) as pharmaceutical pollutants from water by an adsorption process. GNPs; C750, C300, M15 and M5 were characterized by high-resolution transmission electron microscopy, Raman spectroscopy, X-ray diffraction and Brunauer-Emmett-Teller. The effects of several parameters viz. solution pH, adsorbent amount, initial concentration and contact time were studied. The parameters were optimized by a batch adsorption process and the maximum removal efficiency for both pharmaceuticals was 99%. The adsorption kinetics and isotherms models were employed, and the experimental data were best analysed with pseudo-second kinetic and Langmuir isotherm with maximum adsorption capacity (Qm) of 210.08 mg g-1 for SMX and 56.21 mg g-1 for ACM. A regeneration study was applied using different eluents; 5% ethanol-deionized water 0.005 M NaOH and HCl. GNP C300 was able to remove most of both pollutants from environmental water samples. Molecular docking was used to simulate the adsorption mechanism of GNP C300 towards SMX and ACM with a free binding energy of -7.54 kcal mol-1 and -5.29 kcal mol-1, respectively, which revealed adsorption occurred spontaneously.
  4. Fulltext Renal targeting potential of a polymeric drug carrier, poly-l-glutamic acid, in normal and diabetic rats
    Chai HJ, Kiew LV, Chin Y, Norazit A, Mohd Noor S, Lo YL, et al.
    Int J Nanomedicine, 2017;12:577-591.
    PMID: 28144140 DOI: 10.2147/IJN.S111284
    BACKGROUND AND PURPOSE: Poly-l-glutamic acid (PG) has been used widely as a carrier to deliver anticancer chemotherapeutics. This study evaluates PG as a selective renal drug carrier.

    EXPERIMENTAL APPROACH: 3H-deoxycytidine-labeled PGs (17 or 41 kDa) and 3H-deoxycytidine were administered intravenously to normal rats and streptozotocin-induced diabetic rats. The biodistribution of these compounds was determined over 24 h. Accumulation of PG in normal kidneys was also tracked using 5-(aminoacetamido) fluorescein (fluoresceinyl glycine amide)-labeled PG (PG-AF). To evaluate the potential of PGs in ferrying renal protective anti-oxidative stress compounds, the model drug 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF) was conjugated to 41 kDa PG to form PG-AEBSF. PG-AEBSF was then characterized and evaluated for intracellular anti-oxidative stress efficacy (relative to free AEBSF).

    RESULTS: In the normal rat kidneys, 17 kDa radiolabeled PG (PG-Tr) presents a 7-fold higher, while 41 kDa PG-Tr shows a 15-fold higher renal accumulation than the free radiolabel after 24 h post injection. The accumulation of PG-AF was primarily found in the renal tubular tissues at 2 and 6 h after an intravenous administration. In the diabetic (oxidative stress-induced) kidneys, 41 kDa PG-Tr showed the greatest renal accumulation of 8-fold higher than the free compound 24 h post dose. Meanwhile, the synthesized PG-AEBSF was found to inhibit intracellular nicotinamide adenine dinucleotide phosphate oxidase (a reactive oxygen species generator) at an efficiency that is comparable to that of free AEBSF. This indicates the preservation of the anti-oxidative stress properties of AEBSF in the conjugated state.

    CONCLUSION/IMPLICATIONS: The favorable accumulation property of 41 kDa PG in normal and oxidative stress-induced kidneys, along with its capabilities in conserving the pharmacological properties of the conjugated renal protective drugs, supports its role as a potential renal targeting drug carrier.

  5. A taxonomic review of Odontogryllodes Chopard, 1969 (Gryllidae: Landrevinae)
    Tan MK, Muhammad AA, Abdullah NA, Japir R, Chung AYC
    Zootaxa, 2024 Feb 13;5410(2):267-279.
    PMID: 38480244 DOI: 10.11646/zootaxa.5410.2.7
    The taxonomy of the crickets from the genus Odontogryllodes Chopard, 1969 is reviewed. Two species new to science are described here, one from Peninsular Malaysia (part of Malay Peninsula) and another from East Malaysia (part of Borneo): Odontogryllodes undatus Tan, Muhammad & Abdullah sp. nov. from Panti Forest Reserve and Odontogryllodes magnus Tan, Japir & Chung sp. nov. from Tenompok Forest Reserve, respectively. We also present an updated key to the species of Odontogryllodes. In total, nine species are currently known.
  6. Thioredoxin system in colorectal cancer: Its role in carcinogenesis, disease progression, and response to treatment
    Abdullah NA, Md Hashim NF, Muhamad Zakuan N, Chua JX
    Life Sci, 2024 May 09;348:122711.
    PMID: 38734065 DOI: 10.1016/j.lfs.2024.122711
    The thioredoxin system is essential for many physiological processes, including the maintenance of redox signalling pathways. Alterations in the activity, expression and interactions with other signalling pathways can lead to protective or pathophysiological responses. Thioredoxin and thioredoxin reductase, the two main components of this system, are often overexpressed in cancer, including colorectal cancer. This overexpression is often linked with tumour progression and poor outcomes. This review discusses the role of the Trx system in driving colorectal carcinogenesis and disease progression, as well as the challenges of targeting this system. Additionally, the recent advancements in the development of novel and effective thioredoxin inhibitors for colorectal cancer are also explored.
  7. Fulltext Ectopic inferior vena cava thrombus secondary to a tubo-ovarian abscess
    Koh KS, Abdullah NA, Chong VH
    Med J Malaysia, 2014 Dec;69(6):293-5.
    PMID: 25934966
    Inferior vena cava (IVC) thrombosis typically arises distally from a thrombophlebitic extension in the pelvis or the lower extremities. It may also occur from propagation of an ovarian vein thrombosis as a result of gynaecological disorders such as pelvic inflammatory disease, endometritis or from pelvic surgeries. In this report, we present an interesting case of a tubo-ovarian abscess with an ectopic IVC thrombus. The approach to management in such cases is also highlighted.
  8. Sustainable complete remission in recurrence yolk sac tumor patient treated with tandem high-dose chemotherapy and autologous stem cell
    Abdullah NA, Wang PN, Huang KG, Adlan AS, Casanova J
    Eur. J. Gynaecol. Oncol., 2013;34(2):183-5.
    PMID: 23781595
    A 21-year-old lady diagnosed with Stage 3 ovarian yolk sac tumor (YST) underwent primary cytoreductive fertility sparing surgery, followed by conventional courses of platinum-based chemotherapy and etoposide. Recurrence at cul-da-sac was noted after a short period of remission and secondary debulking performed followed by four cycles of conventional chemotherapy. The patient's disease progressed despite courses of treatments. A joint team management including a hematologist was commenced following the failure of conventional chemotherapies. Two cycles of high-dose chemotherapy (HDCT) with ifosfamide/cisplatin/etoposide (ICE) regimen, followed by autologous stem cell transplantation (ASCT) were given. With this salvage treatment, she remained in complete remission and disease-free for more than 30 months, while maintaining her reproductive function. These approaches appear to be effective as a salvage treatment in selected cases of patients with ovarian germ cell tumor, especially those who failed primary conventional chemotherapy.
  9. Fulltext Effect of edaravone in diabetes mellitus-induced nephropathy in rats
    Varatharajan R, Lim LX, Tan K, Tay CS, Teoh YL, Akhtar SS, et al.
    Korean J. Physiol. Pharmacol., 2016 Jul;20(4):333-40.
    PMID: 27382349 DOI: 10.4196/kjpp.2016.20.4.333
    Edaravone, a synthetic-free radical scavenger, has been reported to reduce ischemia-reperfusion-induced renal injury by improving tubular cell function, and lowering serum creatinine and renal vascular resistance. The present study investigated the effect of edaravone in diabetes mellitus-induced nephropathy in rats. A single administration of streptozotocin (STZ, 55 mg/kg, i.p.) was employed to induce diabetes mellitus in rats. The STZ-administered diabetic rats were allowed for 10 weeks to develop nephropathy. Mean body weight, lipid alteration, renal functional and histopathology were analysed. Diabetic rats developed nephropathy as evidenced by a significant increase in serum creatinine and urea, and marked renal histopathological abnormalities like glomerulosclerosis and tubular cell degeneration. The kidney weight to body weight ratio was increased. Moreover, diabetic rats showed lipid alteration as evidenced by a signifi cant increase in serum triglycerides and decrease in serum high-density lipoproteins. Edaravone (10 mg/kg, i.p., last 4-weeks) treatment markedly prevented the development of nephropathy in diabetic rats by reducing serum creatinine and urea and preventing renal structural abnormalities. In addition, its treatment, without significantly altering the elevated glucose level in diabetic rats, prevented diabetes mellitus-induced lipid alteration by reducing serum triglycerides and increasing serum high-density lipoproteins. Interestingly, the renoprotective effect of edaravone was comparable to that of lisinopril (5 mg/kg, p.o, 4 weeks, standard drug). Edaravone prevented renal structural and functional abnormalities and lipid alteration associated with experimental diabetes mellitus. Edaravone has a potential to prevent nephropathy without showing an anti-diabetic action, implicating its direct renoprotection in diabetic rats.
  10. Fulltext Potential use of cord blood for Hb E hemoglobinopathy screening programme using capillary electrophoresis
    Wan Mohd Saman WA, Hassan R, Mohd Yusoff S, Che Yaakob CA, Abdullah NA, Ghazali S, et al.
    Malays J Pathol, 2016 Dec;38(3):235-239.
    PMID: 28028293 MyJurnal
    BACKGROUND: Thalassemia and hemoglobinopathies are inherited red blood cell disorders found worldwide. Hemoglobin (Hb) E disorder is one of the hemoglobinopathies known to have the high prevalence in South East Asia. Most of transfusion-dependent thalassemias were genotypically compound heterozygous Hb E/ β-thalassemia. In Malaysia, the national screening program for thalassemia was implemented for early pregnancy or secondary school girls; however many participants do not turn-up and missed the screening test. Screening for thalassemia using samples from cord blood is an alternative choice as it is a readily available source of blood and hence early detection of the disease. The purpose of this study was to determine the potential use of cord blood for the screening of HbE hemoglobinopathy by using capillary electrophoresis (CE).

    METHODS: Cord blood samples were collected from 300 newborns of healthy mothers. Hematological parameters were determined and hemoglobin quantitation for all cord blood samples were performed using capillary electrophoresis system (CES) and high performance liquid chromatography (HPLC).

    RESULTS: Majority of cord blood samples (63%) revealed Hb AF followed by Hb AFA2 (20%). Hb AFE was detected in 10.7% with the mean value of Hb E ranging from 2.3%-11.1%.

    CONCLUSION: Hemoglobin E was detected in cord blood using capillary electrophoresis system. It can be recommended in areas where Hb E/β is prevalent. Implementation of a screening strategy using CE on cord blood sampling will identify the disease early. With regular follow-up on these patients, the status of their disease can be determined earlier and appropriate management implemented.

  11. Fulltext Predictors of good glycemic controls among type 2 diabetes Mellitus patients in two primary health clinics, Kuala Selangor
    Abdullah NA, Ismail S, Shariff Ghazali S, Juni HF, Kadir Shahar H, Aziz NRA
    Malaysian Journal of Medicine and Health Sciences, 2019;15(203):58-64.
    MyJurnal
    Introduction: The objective of this study was to determine the factors and predictors of good glycaemic control among patients with Type 2 Diabetes Mellitus (T2DM) in two rural government health clinics in Kuala Selangor. Methods: This cross-sectional study involved 200 patients selected through systematic random sampling from a list of T2DM patients in two government health clinics in Kuala Selangor. Data was collected using a self-administered questionnaire while glycosylated haemoglobin (HbA1c) results were obtained from the patients’ blood results re- cord at the clinic. HbA1c of 6.5 % and below was categorized as good glycaemic control. The factors studied were socio-demographic characteristics (age, gender, ethnicity, level of education, occupation and household income), T2DM medical history (T2DM duration and type of treatment), diabetes knowledge, health literacy, adherence to treatment, body mass index (BMI) and physical activity. Pearson’s chi square test was used to test for associations and multiple logistic regressions were used to determine the predictors. Results: The response rate was 86.9%. The pro- portion of good glycaemic control was 34.0%. Level of glycaemic control was significantly associated with duration of being diagnosed with T2DM (p=0.006) and type of treatment (p=0.009). The probability of having good glycaemic control was 2.5 times more likely among respondents diagnosed with T2DM for less than 10 years (AOR=2.458, 95% of CI=1.504-14.282, p=0.037). Conclusion: Shorter duration of being diagnosed with T2DM has been found to be a predictor of good glycaemic control in this study population, thus warranting stricter monitoring among patients who have been diagnosed for a longer period.
  12. Fulltext Burden and Risk Factors of Melioidosis in Southeast Asia: A Scoping Review
    Selvam K, Ganapathy T, Najib MA, Khalid MF, Abdullah NA, Harun A, et al.
    Int J Environ Res Public Health, 2022 Nov 22;19(23).
    PMID: 36497549 DOI: 10.3390/ijerph192315475
    This scoping review aims to provide a comprehensive overview of human melioidosis in Southeast Asia as well as to highlight knowledge gaps in the prevalence and risk factors of this life-threatening disease using available evidence-based data for better diagnosis and treatment. Preferred Reporting Items for Systematic Review and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) was used as the guideline for this review. The literature search was conducted on 23 March 2022 through two electronic databases (PubMed and Scopus) using lists of keywords referring to the Medical Subject Headings (MeSH) thesaurus. A total of 38 articles related to human melioidosis were included from 645 screened articles. These studies were carried out between 1986 and 2019 in six Southeast Asian countries: Thailand, Cambodia, Malaysia, Myanmar, Singapore, and Vietnam. Melioidosis has been reported with a high disease prevalence among high-risk populations. Studies in Thailand (48.0%) and Cambodia (74.4%) revealed disease prevalence in patients with septic arthritis and children with suppurative parotitis, respectively. Other studies in Thailand (63.5%) and Malaysia (54.4% and 65.7%) showed a high seroprevalence of melioidosis among Tsunami survivors and military personnel, respectively. Additionally, this review documented soil and water exposure, diabetes mellitus, chronic renal failure, thalassemia, and children under the age of 15 as the main risk factors for melioidosis. Human melioidosis is currently under-reported in Southeast Asia and its true prevalence is unknown.
  13. Prevalence and Factors Associated With Oral and Hand Hygiene Practices Among Adolescents in Malaysia: Findings From the National Health and Morbidity Survey 2017
    Che Salleh N, Mohamad Anuar MF, Abdullah NA, Yaw SL, Ibrahim Wong N, Teck Pei T, et al.
    Asia Pac J Public Health, 2019 11;31(8_suppl):97S-104S.
    PMID: 31640393 DOI: 10.1177/1010539519880998
    This cross-sectional national survey aimed to determine the prevalence of oral and hand hygiene practices as well as associations between sociodemographic characteristics and oral and hygiene practice among adolescents aged 13 to 17 years during the past 30 days. A validated self-administered bilingual questionnaire adapted from the Malaysian Global School Health Survey with computer-scanable answer sheets was distributed to 30 823 adolescents attending government secondary schools in Malaysia; and 89.2% responded to the questionnaire given. More than 80% (87.1%; 95% confidence interval [CI] = 86.24-87.96) of the adolescents reported that they had brushed their teeth at least twice daily and had always washed their hands after using the toilet (86.6%; 95% CI = 85.85-87.36). The odds of adolescents who brushed their teeth at least 2 times daily and washed their hands after using the toilet was significantly associated with sociodemographic characteristics. This study highlights the need to further improve the effectiveness of current oral health promotion programs with consideration for sociodemographic characteristics.
  14. Silica exposure is associated with an increased risk of developing ACPA-positive rheumatoid arthritis in an Asian population: evidence from the Malaysian MyEIRA case-control study
    Yahya A, Bengtsson C, Larsson P, Too CL, Mustafa AN, Abdullah NA, et al.
    Mod Rheumatol, 2014 Mar;24(2):271-4.
    PMID: 24593203 DOI: 10.3109/14397595.2013.854076
    OBJECTIVES: Silica exposure has been associated with an increased risk of developing rheumatoid arthritis (RA), especially among smokers. In this study, we aimed at examining the association between silica exposure (and its interaction with smoking) and the risk of RA in the Malaysian population.
    METHODS: In total, 149 cases and 213 matched controls, all men, were included between August 2005 and December 2009. A case was defined as a person with early diagnosed RA using the 1987 American College of Rheumatology criteria for RA. Controls were randomly selected matched on sex, age and residential area. Silica exposure was defined as exposure to stone dust, rock drilling or stone crushing, and smoking status was categorized as ever/never cigarette smoking.
    RESULTS: An increased risk of anti-citrullinated protein antibody (ACPA)-positive RA (OR = 2.4, 95 % CI 1.0-5.6) was observed among those exposed to silica. Ever-smokers exposed to silica had a particularly high risk of developing ACPA-positive RA (OR = 7.5, 95 % CI 2.3-24.2), compared with never-smokers not exposed to silica. No association was found regarding ACPA-negative RA.
    CONCLUSION: Our data demonstrate that exposure to both silica and cigarette smoke comprise risks for developing RA in the Malaysian genetic context. The findings expand a link between environmental lung exposures and ACPA-positive RA to Asian populations.
  15. Silica exposure is associated with an increased risk of developing ACPA-positive rheumatoid arthritis in an Asian population: evidence from the Malaysian MyEIRA case-control study
    Yahya A, Bengtsson C, Larsson P, Too CL, Mustafa AN, Abdullah NA, et al.
    Mod Rheumatol, 2013 Apr 25.
    PMID: 23615838
    OBJECTIVES: Silica exposure has been associated with an increased risk of developing rheumatoid arthritis (RA), especially among smokers. In this study, we aimed at examining the association between silica exposure (and its interaction with smoking) and the risk of RA in the Malaysian population. METHODS: In total, 149 cases and 213 matched controls, all men, were included between August 2005 and December 2009. A case was defined as a person with early diagnosed RA using the 1987 American College of Rheumatology criteria for RA. Controls were randomly selected matched on sex, age and residential area. Silica exposure was defined as exposure to stone dust, rock drilling or stone crushing, and smoking status was categorized as ever/never cigarette smoking. RESULTS: An increased risk of anti-citrullinated protein antibody (ACPA)-positive RA (OR = 2.4, 95 % CI 1.0-5.6) was observed among those exposed to silica. Ever-smokers exposed to silica had a particularly high risk of developing ACPA-positive RA (OR = 7.5, 95 % CI 2.3-24.2), compared with never-smokers not exposed to silica. No association was found regarding ACPA-negative RA. CONCLUSION: Our data demonstrate that exposure to both silica and cigarette smoke comprise risks for developing RA in the Malaysian genetic context. The findings expand a link between environmental lung exposures and ACPA-positive RA to Asian populations.
  16. Genetic relationships among five varieties of Curcuma alismatifolia (Zingiberaceae) based on ISSR markers
    Taheri S, Abdullah TL, Abdullah NA, Ahmad Z
    Genet. Mol. Res., 2012;11(3):3069-76.
    PMID: 23007984
    The genus Curcuma is a member of the ginger family (Zingiberaceae) that has recently become popular for use as flowering pot plants, both indoors and as patio and landscape plants. We used PCR-based molecular markers (ISSRs) to assess genetic variation and relationships between five varieties of curcuma (Curcuma alismatifolia) cultivated in Malaysia. Sixteen ISSR primers generated 139 amplified fragments, of which 77% had high polymorphism among these varieties. These markers were used to estimate genetic similarity among the varieties using Jaccard's similarity coefficient. The similarity matrix was used to construct a dendrogram, and a principal component plot was developed to examine genetic relationships among varieties. Similarity coefficient values ranged from 0.40 to 0.58 (with a mean of 0.5) among the five varieties. The mean value of number of observed alleles, number of effective alleles, mean Nei's gene diversity, and Shannon's information index were 8.69, 1.48, 0.29, and 0.43, respectively.
  17. Fulltext COVID-19 screening test by using random oropharyngeal saliva
    Rao M, Rashid FA, Sabri FSAH, Jamil NN, Seradja V, Abdullah NA, et al.
    J Med Virol, 2021 Apr;93(4):2461-2466.
    PMID: 33393672 DOI: 10.1002/jmv.26773
    An optimal clinical specimen for accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by minimizing the usage of consumables and reduce hazard exposure to healthcare workers is an urgent priority. The diagnostic performance of SARS-CoV-2 detection between healthcare worker-collected nasopharyngeal and oropharyngeal (NP + OP) swabs and patient performed self-collected random saliva was assessed. Paired NP + OP swabs and random saliva were collected and processed within 48 h of specimen collection from two cohort studies which recruited 562 asymptomatic adult candidates. Real-time reverse-transcription polymerase chain reaction targeting Open reading frame 1a (ORF1a) and nucleocapsid (N) genes was performed and the results were compared. Overall, 65 of 562 (28.1%) candidates tested positive for COVID-19 based on random saliva, NP + OP swabs, or both testing techniques. The detection rate of SARS-CoV-2 was higher in random saliva compared to NP + OP testing (92.3%; 60/65 vs. 73.8%; 48/65; p 
  18. Fulltext Optimization of scanning electron microscope technique for amniotic membrane investigation: A preliminary study
    Shehadat SA, Gorduysus MO, Hamid SSA, Abdullah NA, Samsudin AR, Ahmad A
    Eur J Dent, 2018;12(4):574-578.
    PMID: 30369805 DOI: 10.4103/ejd.ejd_401_17
    OBJECTIVE: The objective of this study was to evaluate and compare the two scanning electron microscope (SEM) preparation protocols and determine the better SEM preparation technique to study stem cells on human amniotic membrane (hAM) scaffold.

    MATERIALS AND METHODS: Formaldehyde-based protocol and glutaraldehyde-based protocol were compared to evaluate the quality of SEM images for stem cells cultured on hAM scaffold.

    RESULTS: The results suggested that formaldehyde-based protocol is better than glutaraldehyde-based protocol in terms of showing clearer topography of the membrane as well as the boarders of the cells. To provide intact surface of the SEM sample and avoid possible ruptures of the hAM or the thin cell layer, it is recommended to perform the dehydration step using graded alcohol concentrations of 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%, one time for each and twice in 100% for 10 min each. Gold sputter-coating step is not recommended as it does not improve the image quality.

    CONCLUSIONS: To obtain clear SEM images, it is recommended to run a preliminary study to determine the better chemicals and conditions of sample preparation even when following preexisting protocols.

  19. Fulltext An efficient in vitro plantlet regeneration from shoot tip cultures of Curculigo latifolia, a medicinal plant
    Babaei N, Abdullah NA, Saleh G, Abdullah TL
    ScientificWorldJournal, 2014;2014:275028.
    PMID: 24723799 DOI: 10.1155/2014/275028
    A procedure was developed for in vitro propagation of Curculigo latifolia through shoot tip culture. Direct regeneration and indirect scalp induction of Curculigo latifolia were obtained from shoot tip grown on MS medium supplemented with different concentrations and combinations of thidiazuron and indole-3-butyric acid. Maximum response for direct regeneration in terms of percentage of explants producing shoot, shoot number, and shoot length was obtained on MS medium supplemented with combination of thidiazuron (0.5 mg L(-1)) and indole-3-butyric acid (0.25 mg L(-1)) after both 10 and 14 weeks of cultures. Indole-3-butyric acid in combination with thidiazuron exhibited a synergistic effect on shoot regeneration. The shoot tips were able to induce maximum scalp from basal end of explants on the medium with 2 mg L(-1) thidiazuron. Cultures showed that shoot number, shoot length, and scalp size increased significantly after 14 weeks of culture. Transferring of the shoots onto the MS medium devoid of growth regulators resulted in the highest percentage of root induction and longer roots, while medium supplemented with 0.25 mg L(-1) IBA produced more numbers of roots.
  20. Isolation and characterization of microsatellite markers and analysis of genetic variability in Curculigo latifolia Dryand
    Babaei N, Abdullah NA, Saleh G, Abdullah TL
    Mol Biol Rep, 2012 Nov;39(11):9869-77.
    PMID: 22752726
    Curculin, a sweet protein found in Curculigo latifolia fruit has great potential for the pharmaceutical industry. This protein interestingly has been found to have both sweet taste and taste-modifying capacities comparable with other natural sweeteners. According to our knowledge this is the first reported case on the isolation of microsatellite loci in this genus. Hence, the current development of microsatellite markers for C. latifolia will facilitate future population genetic studies and breeding programs for this valuable plant. In this study 11 microsatellite markers were developed using 3' and 5' ISSR markers. The primers were tested on 27 accessions from all states of Peninsular Malaysia. The number of alleles per locus ranged from three to seven, with allele size ranging from 141 to 306 bp. The observed and expected heterozygosity ranged between 0.00-0.65 and 0.38-0.79, respectively. The polymorphic information content ranged from 0.35 to 0.74 and the Shannon's information index ranged from 0.82 to 1.57. These developed polymorphic microsatellites were used for constructing a dendrogram by unweighted pair group method with arithmetic mean cluster analysis using the Dice's similarity coefficient. Accessions association according to their geographical origin was observed. Based on characteristics of isolated microsatellites for C. latifolia accessions all genotype can be distinguished using these 11 microsatellite markers. These polymorphic markers could also be applied to studies on uniformity determination and somaclonal variation of tissue culture plantlets, varieties identification, genetic diversity, analysis of phylogenetic relationship, genetic linkage maps and quantitative trait loci in C. latifolia.
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