MyMedR

In vitro genotoxicity tests for polyhydroxybutyrate--a synthetic biomaterial

Ali AQ, Kannan TP, Ahmad A, Samsudin AR

Toxicol In Vitro, 2008 Feb;22(1):57-67.

The aims of this study are to determine the mutagenicity of a locally produced polyhydroxybutyrate (PHB) using Salmonella mutagenicity test and to find out if PHB altered the expression of p53 and c-myc proto-oncogenes and bcl-xl and bcl-xs anti-apoptotic genes in the human fibroblast cell line, MRC-5. Different concentrations of PHB were incubated with special genotypic variants of Salmonella strains (TA1535, TA1537, TA1538, TA98 and TA100) carrying mutations in several genes both with and without metabolic activation (S9) and the test was assessed based on the number of revertant colonies. The average number of revertant colonies per plate treated with PHB was less than double as compared to that of negative control. For the gene expression analyses, fibroblast cell lines were treated with PHB at different concentrations and incubated for 1, 12, 24 and 48 h separately. The total RNA was isolated and analysed for the expression of p53, c-myc, bcl-xl and bcl-xs genes. The PHB did not show over or under expression of the genes studied. The above tests indicate that the locally produced PHB is non-genotoxic and does not alter the expression of the proto-oncogenes and anti-apoptotic genes considered in this study.

Prevalence of Sleep-disordered Breathing and its Association with Obesity among Saudi Schoolchildren

Zreaqat M, Hassan R, Samsudin AR, Stas Y

J Contemp Dent Pract, 2020 Sep 01;21(9):1022-1026.

PMID: 33568590

AIM AND OBJECTIVE: Epidemiological studies of sleep disturbances are essential to promote awareness among families and educational officials and deliver appropriate treatment at a very early timing. The aim of this population-based study was to determine the frequency of sleep-disordered breathing (SDB) symptoms and its association with obesity among schoolchildren in West Saudi Arabia.

MATERIALS AND METHODS: This cross-sectional study comprised 2,000 schoolchildren aged 6-12 years. Sleep-disordered breathing symptoms were assessed with Arabic version of Pediatric Sleep Questionnaire (PSQ). Overweight/obesity was evaluated using body mass index (BMI) and their association with SDB was tested using a regression analysis model.

RESULTS: Overall, 23% of children were at high risk of SDB. Prevalence of habitual snoring was 15.9% and sleep apnea 4%. Boys were at higher risk of SDB than girls (p = 0.026), while age had no effect (p = 0.254). High-risk SDB had a strong association with sleep symptoms compared to low-risk SDB (p < 0.05). Sleep-disordered breathing increased significantly in overweight and obese children (p = 0.017 and p < 0.001, respectively).

CONCLUSION: Around 23% Saudi schoolchildren are at risk of SDB. Related symptoms were strongly associated with high risk of SDB. Overweight and obesity had a strong and progressive association with SDB.

CLINICAL SIGNIFICANCE: The results will help in identifying children at high risk of developing SDB and plan for early intervention to avoid the progression of SDB later in life.

Tonsil Size and Mallampati Score as Clinical Predictive Factors for Obstructive Sleep Apnea Severity in Children

Zreaqat M, Hassan R, Samsudin AR, Stas Y, Hanoun A

J Contemp Dent Pract, 2021 Jul 01;22(7):850-853.

PMID: 34615793

AIM AND OBJECTIVE: The aim of this study was to determine the clinical utility of body mass index (BMI), tonsil size, and Mallampati scoring in predicting both the presence of and severity of pediatric obstructive sleep apnea (OSA).

MATERIALS AND METHODS: This prospective cross-sectional study comprised 78 growing children in the age range of 11-14 years with polysomnography (PSG)-proven OSA and 86 non-OSA corresponding controls. BMI, tonsil size (Friedman grading scale), and Mallampati score were determined for both groups, and related differences were assessed with a t-test, while their independent association with OSA severity was tested with a regression analysis. Statistical significance was set at p <0.05.

RESULTS: Male gender, BMI, tonsil size, and Mallampati score were significantly higher in the OSA group (p < 0.05). A significant correlation was recorded between the Mallampati score and OSA severity (p < 0.01), but not with BMI or tonsil size (p > 0.05). For every 1-point increase in the Mallampati scale, the apnea-hypopnea index (AHI) increased by more than five events per hour in the bivariate analysis and by more than three events per hour in the multivariate analysis.

CONCLUSION: Male gender, increased BMI, high tonsil, and Mallampati scores were clinical indicators of the presence of OSA. However, only Mallampati scale had a significant association with OSA severity. Clinical diagnostic indicators should be established and encouraged especially in community-based studies.

CLINICAL SIGNIFICANCE: Clinical diagnostic indicators are very useful in examining and screening children who are at risk of developing OSA as PSG is expensive and unsuitable for universal use in the pediatric population.

Fulltext Surgical management of a massive facial hemangioma

Baharudin A, Samsudin AR, Halim AS, Shafie MA

Med J Malaysia, 2007 Aug;62(3):254-5.

PMID: 18246921 MyJurnal

Hemangiomas are the most common congenital lesions in man and occur predominantly in the head and neck region. Massive hemangioma especially near vital organs or structures pose a challenge to surgeons. With the availability of expertise in embolization of feeding vessel of the hemangioma and reconstructive techniques we were able to manage successfully a complicated case of massive facial hemangioma.

Successful commercialisation of locally fabricated bioceramics for clinical applications

Fazan F, Besar I, Osman A, Samsudin AR, Khalid KA

Med J Malaysia, 2008 Jul;63 Suppl A:49-50.

PMID: 19024978

This paper chronicled the development of a locally produced bone graft substitute based on calcium phosphate bioceramics called "GranuMaS--from concepts to clinics, and finally to its successful commercialization all within 5-year duration. It was a Prioritized Research (PR) collaborative project of 5 institutions namely SIRIM, ANM, USM, UKM and IIUM, funded by MOSTI to the amount of approximately RM2.5 millions under RM8. This paper also highlighted the requirements needed in terms of technical expertise/manpower, facilities and infrastructure, and government/institutional supports, as well as the challenge faced in developing and commercializing such product.

Fulltext Underlay myringoplasty: comparison of human amniotic membrane to temporalis fascia graft

Harvinder S, Hassan S, Sidek DS, Hamzah M, Samsudin AR, Philip R

Med J Malaysia, 2005 Dec;60(5):585-9.

PMID: 16515109

Human amniotic membrane as a homograft material was compared to temporalis fascia to close tympanic membrane perforations in 50 patients with chronic otitis media. Human amniotic membrane was used in 20 patients while temporalis fascia was used in the remaining 30. Anatomical closure of the perforation and reduction of the air-bone gap was measured. The graft uptake showed a 65% success rate for the amniotic membrane and 56.7% for the temporalis fascia at 3 months post-operatively. Significant closure of air-bone gap was observed in the human amniotic group. These results indicate comparable outcomes between human amniotic membrane and the temporalis fascia graft.

Coral--polyhydroxybutrate composite scaffold for tissue engineering: prefabrication properties

Al-Salihi KA, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:202-3.

PMID: 15468888

In this study the surface properties of two particulate coral and polyhydroxybutrate (PHB) were studied in order to characterize them prior to use in composite production. Coral powder and PHB particle were evaluated using scanning electron microscopy and confocal laser scanning microscopy, to measure surface porosity and pores size. The results showed that coral powder has multiple pleomorphic micropores cross each others give appearance of micro-interconnectivity. Some pore reached to 18 microm with an average porosity of 70%. PHB revealed multiple different size pores extended to the depth, with an average some times reach 25 microm and porosity 45%. These findings demonstrate that both coral and PHB have excellent pores size and porosity that facilitate bone in growth, vascular invasion and bone development. We believe that incorporation of coral powder into PHB will make an excellent composite scaffold for tissue engineering.

In vitro cytotoxicity evaluation of biomaterials on human osteoblast cells CRL-1543; hydroxyapatite, natural coral and polyhydroxybutarate

Shamsuria O, Fadilah AS, Asiah AB, Rodiah MR, Suzina AH, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:174-5.

PMID: 15468874

The aim of this study was to evaluate the in vitro cytotoxicity of biomaterials; Hydroxyapatite (HA), Natural coral (NC) and Polyhydroxybutarate (PHB). Three different materials used in this study; HA (Ca10(PO4)6(OH)2), NC (CaCO3) and PHB (Polymer) were locally produced by the groups of researcher from Universiti Sains Malaysia. The materials were separately extracted in the complete culture medium (100mg/ml) for 72h and introduced to the osteoblast cells CRL-1543. The viability of osteoblast CRL-1543 cultivated with these extraction materials after 72h incubation period was compared to negative control with neutral red assay by using spectrophotometer at 540nm. The results showed the non-cytotoxicity of the materials. After 72h of incubation period, HA showed 123% viable cells, NC was 99.43% and PHB was 176.75%. In this study, cytotoxicity test dealt mainly with the substances that leached out from the biomaterial. The results obtained showed that the materials were not toxic and also promoted cells growth in the sense of biofunctionality.

Locally produced bovine bone sponge as a haemostatic agent

Ang CY, Samsudin AR, Karima AM, Nizam A

Med J Malaysia, 2004 May;59 Suppl B:149-50.

PMID: 15468862

The aim of this study was to evaluate the morphological and biological properties of a locally produced "Bovine Bone Sponge" for use in dentistry. Bovine bone sponge was prepared from local calf bone. Endotoxin level and surface properties were investigated. The pore size and water uptake ability were measured and results were compared with the commercial haemostatic agent. The material was tested for its haemostatic property and its inhibition of alveolar bone resorption in a sheep model following dental extraction. Results revealed a significant difference in haemostatic effect, and a shorter bleeding time and a lower rate of alveolar bone resorption in bovine bone sponge compare to a commercial haemostatic agent.

Effect of powder to liquid ratio on tensile strength and glass transition temperature of alumina filled poly methyl methacrylate (PMMA) denture base material

Mohamed SH, Arifin A, Mohd Ishak ZA, Nizam A, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:147-8.

PMID: 15468861

The aim of this study was to evaluate the mechanical properties and glass transition temperature (Tg) of a denture base material prepared from high molecular weight poly methyl methacrylate (PMMA) and alumina (Al2O3). The glass transition temperature was studied by using differential scanning calorimetry (DSC). The effect of powder-to-liquid ratio was investigated. The result showed that the tensile properties and the Tg were slightly effected by the powder-to-liquid ratio. The ratio of 2.2:1 by weight of powder to liquid was found to be the best ratio for mixing the material to give the best result in this formulation.

Comparative study between dense and porous hydroxyapatite using light and scanning electron microscopy

Pohchi A, Suzina AH, Samsudin AR, Al-Salihi KA

Med J Malaysia, 2004 May;59 Suppl B:151-2.

PMID: 15468863

This in vivo study revealed that porous hydroxyapatite (PHA) and dense hydroxyapatite (DHA) are good implant materials that can accelerate bone healing and resorbed in acceptable time. But there were differences in the mechanism of the resorption of DHA and PHA due to variability in the physical properties and osteogenicity.

Chromosome aberration test for hydroxyapatite in sheep

Kannan TP, Nik Ahmad Shah NL, Azlina A, Samsudin AR, Narazah MY, Salleh M

Med J Malaysia, 2004 May;59 Suppl B:168-9.

PMID: 15468871

The present study is aimed at finding the mutagenicity and cytotoxicity of dense form of synthetic hydroxyapatite (Source: School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia) in the blood of sheep. The biomaterial was implanted in the tibia of Malin, an indigenous sheep breed of Malaysia. Blood was collected from the sheep before implantation of the biomaterial, cultured and a karyological study was made. Six weeks after implantation, blood was collected from the same animal, cultured and screened for chromosome aberrations. The mitotic indices and karyological analysis indicated that the implantation of synthetic hydroxyapatite (dense form) did not produce any cytotoxicity or chromosome aberrations in the blood of sheep.

Gene expressions screening of human cell line exposed to locally produced biomaterial

Azlina A, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:166-7.

PMID: 15468870

In Malaysia, the field of genomics in toxicology is still in infancy. The purpose of this study is to focus on the use of toxicogenomics for determination of gene expressions changes in cultured human fibroblast cells treated with genotoxicology free biomaterial (using Ames test), a locally produced hyroxyapatite. Dose and time response is similar to Ames test with time interval up to 21 days. mRNA is extracted, followed with RT-PCR and polyacrilamide gel electrophoresis. Changes of the gene expressions compared to the non-treated fibroblast mRNA would suggest some gene interactions in the molecule level associated with the exposure of the fibroblast cell line to the biomaterials. Further analysis (cloning & sequencing) shall be carried out to investigate the genes involved as simple changes might not signified toxicity.

Tensile strength and water absorption of alumina filled poly (methyl methacrylate) denture base material

Nizam A, Mohamed SH, Arifin A, Mohd Ishak ZA, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:145-6.

PMID: 15468860

The aim of this study was to evaluate the tensile properties and water absorption of denture base material prepared from high molecular weight poly methyl methacrylate (PMMA) and alumina (Al2O3) as particulate filler. Specimens for mechanical testing were prepared by adding composite powder to the monomer followed by hand mixing as in dental laboratory procedure. The tensile strength of the prepared denture base material was slightly higher than commercial denture base material, while the water absorption was almost the same for all formulation of denture base materials.

Biocompatibility test of polyhydroxybutyrate on human cell line

Raouf AA, Samsudin AR, Al-Joudi FS, Shamsuria O

Med J Malaysia, 2004 May;59 Suppl B:101-2.

PMID: 15468838

The human fibroblast MRC-5 cells incubated with PHB granules (TM) added at a final concentration of 4 mg/ml showed a time-course pattern of survival. The percentages of dead cells obtained were at the rate of 3.8% after 7 days, respectively. When the MRC-5 cells grown in different material, using the test concentration of 4 mg/ml PCM, they were found to show a similar time-course increasing pattern of death as that obtained with PHB. However, the death was noted in the cells incubated for 7 days, the death rates obtained was 40.54% respectively.

An in vivo study of a locally-manufactured hydroxyapatite-based material as bone replacement material

Abdul Razak NH, Al-Salihi KA, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:119-20.

PMID: 15468847

Defects were created in the mandible of a rabbit model whereby the right side was implanted with hydroxyapatite (HA) while the left side was left empty to act as control. Both the implant and control sites were evaluated clinically and histologically at 4,12,20,22 weeks. Decalcified sections were studied under confocal laser scanning microscope. No reactive cells were evident microscopically in all sections. There was bone ingrowth as early as 4 weeks when viewed by the topographic method. Enhancement of osteoconduction was evident by the presence of abundant capillaries, perivascular tissue and osteoprogenitor cells of the host. At 22 weeks, the implanted defect showed mature bone formation filling almost the whole field. This study demonstrated that the dense HA exhibits excellent biocompatibility as noted by the complete absence of reactive cells. It also promotes osteoconduction.

In vivo chromosome aberration test for hydroxyapetite in mice

Kannan TP, Nik Ahmad Shah NL, Azlina A, Samsudin AR, Narazah MY, Salleh M

Med J Malaysia, 2004 May;59 Suppl B:115-6.

PMID: 15468845

This study evaluates the cytotoxic and mutagenic effect of synthetic hydroxyapatite granules (source: School of Material and Mineral Resources Engineering, Universiti Sains Malaysia) in the bone marrow cells of mice. Mice are exposed to synthetic hydroxyapatite granules, the bone marrow cells are collected and observed for chromosome aberrations. No chromosome aberrations were noticed in the animals exposed to distilled water (negative control) and to the test substance, synthetic hydroxyapatite granules (treatment) groups. Chromosome aberrations were observed in the animals exposed to Mitomycin C (positive control group). There was no indication of cytotoxicity due to synthetic hydroxyapatite granules in the animals as revealed by the mitotic index. Hence, synthetic hydroxyapatite granules are considered non-mutagenic under the prevailing test conditions.

A comparative study of osseointegration phenomenon in coated and non-coated NiTi implants in a rabbit model

Najafpour HD, Suzina AH, Nizam A, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:121-2.

PMID: 15468848

There was a significant increased in Absolute Contact Length measurements of endosteal bone growth along the Nickel-Titanium (NiTi) implant coated with the natural coral powder and Hydroxyapatite (HA) compared to the non-calcium coated implants. This study demonstrated that coated implants seemed to show earlier and higher osseointergration phenomena compared to non coated ones. Furthermore, there was significantly greater bone-to-implant contact at the apical 1/3rd of the coated implants.

In vivo study of CORAGRAF: a preliminary results

Rosdan S, Al-Salihi KA, Suzina AH, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:111-2.

PMID: 15468843

The main objective of the study was to determine the biodegradability, resorption and osteoconductivity potency of coral implant. Coral blocks (CORAGRAF) were prepared from sea coral Porites species. The blocks were implanted in the right mandible of rabbit model. Implants were harvested at 2 and 4 weeks intervals and subjected for light and scanning electron microscopy. Dense hydroxyapatite (DHA) was implanted in the left mandible as a control. The results of this study demonstrated that CORAGRAF is a good implant material that can accelerates bone healing and be resorbed in an acceptable time. The mechanisms of the resorption seemed to be the same (crumbling process), a first step where the edge of the coral become powdery then a second step which could be phagocytosis and dissolution in extracellular fluid.

In vitro cytotoxicity testing on valued added hydroxyapatite as bone replacement material

Shaari R, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:109-10.

PMID: 15468842

The present in vitro evaluation indicated that the value added hydroxyapatite (HA) was more toxic than pure HA but the toxicity of value added HA was slight compared to the positive control. In this testing, the conclusion can be made that value added HA is less biocompatible than commercialized pure HA. This toxicity may be caused by both the particle size and degradation (leaching). Further studies should be carried out to determine whether there is particle size effect or leaching effect when using powder as compared to the block materials. The in vivo evaluation should be done to assess the reaction to this value added HA as compared to the pure HA.

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