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Displaying publications 21 - 35 of 35 in total

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Dental stem cells as an alternative source for cardiac regeneration

Xin LZ, Govindasamy V, Musa S, Abu Kasim NH

Med Hypotheses, 2013 Oct;81(4):704-6.
PMID: 23932760 DOI: 10.1016/j.mehy.2013.07.032

Dental tissues contains stem cells or progenitors that have high proliferative capacity, are clonogenic in vitro and demonstrate the ability to differentiate to multiple type cells involving neurons, bone, cartilage, fat and smooth muscle. Numerous experiments have demonstrated that the multipotent stem cells are not rejected by immune system and therefore it may be possible to use these cells in allogeneic settings. In addition, these remarkable cells are easily abundantly available couple with less invasive procedure in isolating comparing to bone marrow aspiration. Here we proposed dental stem cells as candidate for cardiac regeneration based on its immature characteristic and propensity towards cardiac lineage via PI3-Kinase/Aktsignalling pathway.
Retention Evaluation of Fissure Sealants Applied Using Self-Etch and Conventional Acid-Etch Techniques: A Randomized Control Trial Among Schoolchildren

Althomali YM, Musa S, Manan NM, Nor NAM

Pediatr Dent, 2022 Jul 15;44(4):249-254.
PMID: 35999682

Purpose: The purpose of this study was to evaluate the clinical retention capabilities of a self-etch adhesive system (experimental group) and conventional acid-etch (control group) techniques and compare the caries incidence within six months and 24 months of follow-up periods. Methods: A total of 47 healthy children with a mean age of 9.7 years and either sound or noncavitated erupted permanent first molars were included in the trial. A total of 188 molars were randomly assigned in a split-mouth design for the self-etch mode in the universal adhesive or conventional acid-etch. Differences in sealant retention and caries incidence were compared at six and 24 months after sealant placement using a chi-square test. Results: Within 24 months of follow-up, the retention of fissure sealant applied using conventional acid etching (41 out of 66; 62.1 percent) was significantly higher (P<0.05) than that of the fissure sealant applied using self-etching mode in the universal adhesive system (17 out of 66; 25.8 percent). There was no significant difference in caries incidence between the two groups up to 24 months after sealant placement. Conclusion: With 24 months of follow-up, the retention of the conventional acid-etching technique were superior to those of the self-etch technique.
Fulltext Synchronous reference frame fundamental method in shunt active power filter for mitigation of current harmonics

Musa, S., Radzi, M.A.M.

Pertanika Journal of Science & Technology, 2017;25(101):249-256.
MyJurnal

This research presents compensation of current harmonic disturbance in power system network using
shunt active power filter. In this paper, harmonic extraction using Synchronous Reference Frame
Fundamental technique (SRFF) was investigated for three phase 3-wire system. It proposes a method
based on direct current measurement of load currents using a band pass filter at low cut off frequencies
to improve the filtering ability in highly contaminated loads. The proposed filter consists of second
order low pass and high pass filters cascaded together at suitable frequencies, estimated based on the
output of these units to mitigate the current harmonics. The performance of the system was simulated
in Matlab Platform and evaluated considering total harmonic distortion of the source current in a threephase
balanced network. The simulation results show the ability of the proposed tracking scheme to
accurately estimate harmonics.
Fulltext A comparison study of dental pulp stem cells derived from healthy and orthodontically intruded human permanent teeth for mesenchymal stem cell characterisation

Lau MN, Kunasekaran W, On YY, Tan LJ, Zaharin NA, H A Ghani S, et al.

PLoS One, 2022;17(12):e0279129.
PMID: 36574419 DOI: 10.1371/journal.pone.0279129

The objective of this study was to compare the characteristics of Dental Pulp Stem Cells (DPSCs) derived from healthy human permanent teeth with those that were orthodontically-intruded to serve as potential Mesenchymal Stem Cells (MSC). Recruited subjects were treated with orthodontic intrusion on one side of the maxillary first premolar while the opposite side served as the control for a period of six weeks before the dental pulp was extracted. Isolated DPSCs from both the control and intruded samples were analyzed, looking at the morphology, growth kinetics, cell surface marker profile, and multilineage differentiation for MSC characterisation. Our study showed that cells isolated from both groups were able to attach to the cell culture flask, exhibited fibroblast-like morphology under light microscopy, able to differentiate into osteogenic, adipogenic and chondrogenic lineages as well as tested positive for MSCs cell surface markers CD90 and CD105 but negative for haematopoietic cell surface markers CD34 and HLA-DR. Both groups displayed a trend of gradually increasing population doubling time from passage 1 to passage 5. Viable DPSCs from both groups were successfully recovered from their cryopreserved state. In conclusion, DPSCs in the dental pulp of upper premolar not only remained viable after 6 weeks of orthodontic intrusion using fixed appliances but also able to develop into MSCs.
Fulltext The Forest Observation System, building a global reference dataset for remote sensing of forest biomass

Schepaschenko D, Chave J, Phillips OL, Lewis SL, Davies SJ, Réjou-Méchain M, et al.

Sci Data, 2019 10 10;6(1):198.
PMID: 31601817 DOI: 10.1038/s41597-019-0196-1

Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities.
Fulltext Quantification of mesenchymal stem cell growth rates through secretory and excretory biomolecules in conditioned media via Fresnel reflection

Ahmad H, Thambiratnam K, Zulkifli AZ, Lawrence A, Jasim AA, Kunasekaran W, et al.

Sensors (Basel), 2013 Sep 30;13(10):13276-88.
PMID: 24084118 DOI: 10.3390/s131013276

An efficient and low cost optical method for directly measuring the concentration of homogenous biological solutes is proposed and demonstrated. The proposed system operates by Fresnel reflection, with a flat-cleaved single-mode fiber serving as the sensor probe. A laser provides a 12.9 dBm sensor signal at 1,550 nm, while a computer-controlled optical power meter measures the power of the signal returned by the probe. Three different mesenchymal stem cell (MSC) lines were obtained, sub-cultured and trypsinized daily over 9 days. Counts were measured using a haemocytometer and the conditioned media (CM) was collected daily and stored at -80 °C. MSCs release excretory biomolecules proportional to their growth rate into the CM, which changes the refractive index of the latter. The sensor is capable of detecting changes in the number of stem cells via correlation to the change in the refractive index of the CM, with the measured power loss decreasing approximately 0.4 dB in the CM sample per average 1,000 cells in the MSC subculture. The proposed system is highly cost-effective, simple to deploy, operate, and maintain, is non-destructive, and allows reliable real-time measurement of various stem cell proliferation parameters.
Fulltext The promise of human induced pluripotent stem cells in dental research

Srijaya TC, Pradeep PJ, Zain RB, Musa S, Abu Kasim NH, Govindasamy V

Stem Cells Int, 2012;2012:423868.
PMID: 22654919 DOI: 10.1155/2012/423868

Induced pluripotent stem cell-based therapy for treating genetic disorders has become an interesting field of research in recent years. However, there is a paucity of information regarding the applicability of induced pluripotent stem cells in dental research. Recent advances in the use of induced pluripotent stem cells have the potential for developing disease-specific iPSC lines in vitro from patients. Indeed, this has provided a perfect cell source for disease modeling and a better understanding of genetic aberrations, pathogenicity, and drug screening. In this paper, we will summarize the recent progress of the disease-specific iPSC development for various human diseases and try to evaluate the possibility of application of iPS technology in dentistry, including its capacity for reprogramming some genetic orodental diseases. In addition to the easy availability and suitability of dental stem cells, the approach of generating patient-specific pluripotent stem cells will undoubtedly benefit patients suffering from orodental disorders.
Assessment of patients' level of satisfaction with cleft treatment using the Cleft Evaluation Profile

Noor SN, Musa S

Cleft Palate Craniofac J, 2007 May;44(3):292-303.
PMID: 17477746

OBJECTIVES: Determination of the psychosocial status and assessment of the level of satisfaction in Malaysian cleft palate patients and their parents.
DESIGN: Cross-sectional study.
PARTICIPANTS AND METHODS: Sixty cleft lip and palate patients (12 to 17 years of age) from Hospital Universiti Sains Malaysia and their parents were selected. The questionnaires used were the Child Interview Schedule, the Parents Interview Schedule, and the Cleft Evaluation Profile (CEP), administered via individual interviews.
RESULTS: Patients were teased because of their clefts and felt their self-confidence was affected by the cleft condition. They were frequently teased about cleft-related features such as speech, teeth, and lip appearance. Parents also reported that their children were being teased because of their clefts and that their children's self-confidence was affected by the clefts. Both showed a significant level of satisfaction with the treatment provided by the cleft team. There was no significant difference between the responses of the patients and their parents. The features that were found to be most important for the patients and their parents, in decreasing order of priority, were teeth, nose, lips, and speech.
CONCLUSIONS: Cleft lip and/or palate patients were teased because of their clefts, and it affected their self-confidence. The Cleft Evaluation Profile is a reliable and useful tool to assess patients' level of satisfaction with treatment received for cleft lip and/or palate and can identify the types of cleft-related features that are most important for the patients.
Fulltext Retrospective analysis of dental treatment under general anesthesia among children with early childhood caries in Malaysia

Ibrahim NA, Nor NAM, Azizi NZ, Hamzah TNNT, Dziaruddin N, Musa S

J Clin Pediatr Dent, 2023 Jul;47(4):46-53.
PMID: 37408346 DOI: 10.22514/jocpd.2023.034

Many children are affected by early childhood caries (ECC) with some requiring dental treatment under general anesthesia (GA). In pediatric dentistry, GA is one of the established methods of behavior management. GA data is useful for understanding the caries burden among young children. This study aimed to determine the trends, patient characteristics, and types of treatments conducted under GA among young children in a Malaysian dental hospital over a 7-year period. A retrospective study using pediatric patient records from 2013 to 2019 was conducted on children aged 2-6 years (24-71 months) having ECC. Relevant data were collected and analyzed. In total, 381 children with a mean age of 49.8 months were identified. Some of the ECC cases were associated with abscesses (32.5%) and multiple retained roots (36.7%). Over a 7-year period, there was an upward trend of preschool children receiving GA. Of the 4713 carious teeth treated, 55.1% were extracted, 29.9% were restored, 14.3% had preventive procedures, and 0.4% were pulp treated. Mean extractions were significantly higher among preschoolers compared to toddlers (p = 0.001), while preventive treatment was markedly higher among toddlers. In terms of the type of restorative materials, almost similar distribution was observed between the two age groups with 86.5% treated using composite restorations. Dental treatment under GA was more frequently used among preschoolers than in toddlers, with extractions and restoration with composite resin being the common treatment options. The findings can help decision-makers or relevant parties address the burden of ECC and enhance oral health promotion activities.
Fulltext Rapid diagnosis of leptospirosis by multiplex PCR

Ahmed SA, Sandai DA, Musa S, Hoe CH, Riadzi M, Lau KL, et al.

Malays J Med Sci, 2012 Jul;19(3):9-16.
PMID: 23610544 MyJurnal

Traditionally, the most common diagnostic approach used for diagnosing leptospirosis was the demonstration of immune-seroconversion in acute and convalescent patient serum samples. Recently, a variety of molecular techniques, including conventional and real-time polymerase chain reaction (PCR), have been developed for the specific detection of pathogenic bacteria from the genus Leptospira. PCR is a sensitive, specific, and rapid technique that has been successfully used to detect several microorganisms; including those of clinical significance.
A Prospective Interventional Study on LigaSureTM Haemorrhoidectomy as a Daycare Procedure

Elnaim ALK, Musa S, Wong MP, Sagap I

Malays J Med Sci, 2021 Oct;28(5):102-107.
PMID: 35115892 DOI: 10.21315/mjms2021.28.5.10

Objective: This study was designed as a prospective and interventional study that evaluated LigaSure™ haemorrhoidectomies with regional anaesthesia as a daycare procedure.
Methods: Patients with third- and fourth-degree haemorrhoids were recruited from the clinic from January 2018 to December 2019. The procedure was performed as a day case under regional anaesthesia. Using a LigaSureTM device, excisional haemorrhoidectomies (Milligan-Morgan haemorrhoidectomy) were performed without sutures or an anal sponge. We evaluated wound bleeding, pain and urinary retention per daycare protocols.
Results: A total of 264 patients were enrolled. There were 153 males (57.9%) with a median age of 30 years old (range 16 years old-80 years old). A total of 142 patients (54%) had third-degree haemorrhoids, while the rest had fourth-degree haemorrhoids. The median operating time was 8 min (range 4 min-17 min) and minimal blood loss was observed. During follow-up, the complications were one case (0.3%) had anal stenosis, one case (0.3%) had minimal bleeding and one case (0.3%) had urine retention. Upon discharge, four patients (1.5%) required additional analgesia and another four (1.5%) developed post-spinal headaches. No incontinence was encountered.
Conclusion: LigaSure™ excisional haemorrhoidectomy is a safe and effective daycare procedure with acceptable re-admission and complication rates.
The Malaysian experience in the typing of genetic variants of alpha-1-antitrypsin

Desa NM, Ismail Z, Beran Z, Musa SH

Southeast Asian J. Trop. Med. Public Health, 1995;26 Suppl 1:311-4.
PMID: 8629132

It is known that alpha1-antitrypsin deficiency is associated with emphysema in adults and liver cirrhosis in neonates. The phenotypes PiZZ and PiSZ are considered to be high risk groups. alpha1-antitrypsin deficiency is one of the most common lethal congenital disorders in Europe and the USA, occurring in approximately 1 in 2,000 caucasians of North European descent. Studies in Malaysia have found that the phenotypes PiZ and PiS are present in our population. Out of 950 samples analyzed, it was found that 10 samples were shown to be apparently Z homozygous phenotype. The phenotype is determined by high resolution isoelectrofocusing on an ultra-thin polyacrylamide gel embedded with narrow range Pi phamarlyte. The isoelectrofocused bands are confirmed by immunofixation and the plasma alpha1-antitrypsin levels determined by electroimmunoassay. The abnormal phenotypes are further confirmed by polymerase chain reaction using allele specific oligonucleotides.
Fulltext Comparative analysis of cardiovascular development related genes in stem cells isolated from deciduous pulp and adipose tissue

Loo ZX, Kunasekaran W, Govindasamy V, Musa S, Abu Kasim NH

ScientificWorldJournal, 2014;2014:186508.
PMID: 25548778 DOI: 10.1155/2014/186508

Human exfoliated deciduous teeth (SHED) and adipose stem cells (ASC) were suggested as alternative cell choice for cardiac regeneration. However, the true functionability of these cells toward cardiac regeneration is yet to be discovered. Hence, this study was carried out to investigate the innate biological properties of these cell sources toward cardiac regeneration. Both cells exhibited indistinguishable MSCs characteristics. Human stem cell transcription factor arrays were used to screen expression levels in SHED and ASC. Upregulated expression of transcription factor (TF) genes was detected in both sources. An almost equal percentage of >2-fold changes were observed. These TF genes fall under several cardiovascular categories with higher expressions which were observed in growth and development of blood vessel, angiogenesis, and vasculogenesis categories. Further induction into cardiomyocyte revealed ASC to express more significantly cardiomyocyte specific markers compared to SHED during the differentiation course evidenced by morphology and gene expression profile. Despite this, spontaneous cellular beating was not detected in both cell lines. Taken together, our data suggest that despite being defined as MSCs, both ASC and SHED behave differently when they were cultured in a same cardiomyocytes culture condition. Hence, vigorous characterization is needed before introducing any cell for treating targeted diseases.
Fulltext Diverse effects of lead nitrate on the proliferation, differentiation, and gene expression of stem cells isolated from a dental origin

Abdullah M, Rahman FA, Gnanasegaran N, Govindasamy V, Abu Kasim NH, Musa S

ScientificWorldJournal, 2014;2014:235941.
PMID: 24616615 DOI: 10.1155/2014/235941

Lead (Pb(2+)) exposure continues to be a significant public health problem. Therefore, it is vital to have a continuous epidemiological dataset for a better understanding of Pb(2+) toxicity. In the present study, we have exposed stem cells isolated from deciduous and permanent teeth, periodontal ligament, and bone marrow to five different types of Pb(2+) concentrations (160, 80, 40, 20, and 10 µM) for 24 hours to identify the adverse effects of Pb(2+) on the proliferation, differentiation, and gene expression on these cell lines. We found that Pb(2+) treatment altered the morphology and adhesion of the cells in a dose-dependent manner. There were no significant changes in terms of cell surface phenotypes. Cells exposed to Pb(2+) continued to differentiate into chondrogenesis and adipogenesis, and a severe downregulation was observed in osteogenesis. Gene expression studies revealed a constant expression of key markers associated with stemness (Oct 4, Rex 1) and DNA repair enzyme markers, but downregulation occurred with some ectoderm and endoderm markers, demonstrating an irregular and untimely differentiation trail. Our study revealed for the first time that Pb(2+) exposure not only affects the phenotypic characteristics but also induces significant alteration in the differentiation and gene expression in the cells.
Oral bacteria detection among children with cancer in a tertiary teaching hospital in Kuala Lumpur, Malaysia

Sidi Omar SFN, Ngui R, Ab Rahman SZ, Foo JC, Wang QY, Hassan NA, et al.

Trop Biomed, 2021 Sep 01;38(3):276-282.
PMID: 34362870 DOI: 10.47665/tb.38.3.068

This study sought to determine the prevalence of pathogenic and non-pathogenic bacteria in the oral cavities of children with cancer. There were 68 paediatric patients with cancer who were included in this study. Oral swab samples from the dorsum of tongues and mouth floors of these patients were subjected to culture, staining, and molecular methods to detect the bacteria. The overall prevalence of gram-positive and gram-negative bacteria was 79.4% (54/68; 95% CI = 68.4 - 87.3) and 25% (17/68; 95% CI = 16.2 - 36.4), respectively. Streptococcus salivarius and Streptococcus parasanguinis were the predominant pathogenic grampositive bacteria, while Neisseria subflava and Neisseria perflava were the most common pathogenic gram-negative bacteria. The results revealed that the number of bacteria isolates recovered in patients receiving cancer treatment was higher (55.9%) than those who had not received treatment (16.2%). Therefore, more isolated pathogenic bacteria were observed post-therapy (54.4%). Pathogenic organisms can have significant implications on patient health. Awareness of the types of bacteria inhabiting the oral cavity is essential to predict and prevent dental problems, and their associated systemic complications. Findings on the diversity of oral microflora can also provide a better understanding of the aetiology of oral diseases in paediatric patients receiving cancer treatment.

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