1.Performance evaluation of the Arkray Adams HA-8160 HbA1c analyser.
T Malathi Thevarajah ; Nordin Nani ; Y Y Chew
The Malaysian journal of pathology 2008;30(2):81-6
BACKGROUND: HbA1c measurement is currently routinely used to predict long term outcome of diabetes, thus playing a fundamental role in the management of diabetes. The relationship between HbA1c value and long term diabetic complications has been established by a randomised control Diabetes Control and Complications Trial (DCCT) which used high performance liquid chromatography (HPLC) as a reference method for HbA1c assay. To ensure that HbA1c results from a variety HbA1c assay methods are similar to the DCCT values, the American Diabetes Association (ADA) recommended that all laboratories should use methods certified by the National Glycohemoglobin Standardization Programme (NGSP) with interassay coefficient variation (CV) of < 5% (ideally < 3%). The International Federation of Clinical Chemistry (IFCC) working group on HbA1c standardisation has set a CV < 2.5% as a criteria for its reference laboratories. OBJECTIVES: To evaluate the performance of Arkray Adams HA-8160 HbA1c analyser which uses a cation exchange HPLC method and its correlation to HbA1c assay on Cobas Integra 800 which is an immunoturbidimetric method. METHODS: For the imprecision study, patient samples and control material of two levels were analysed on HA-8160 analyser 20 times in a single run (within-run imprecision) and twice a day on five consecutive days (between-run imprecision). For the recovery study, two samples each with high and low values were selected and mixed in ratios of 1:3, 1:1 and 3:1, and were analysed by HA-8160. Sixty samples were analysed by both Cobas Integra 800 and HA-8160 for method comparison study. Ten uraemic samples and ten thalassaemic samples were assayed on Cobas Integra 800 and HA 8160 for interference study. RESULTS: Within-run CVs were 0.6% and 0.7% for medium and high value samples respectively, 0.6% and 0.7% for low and high level controls respectively. Between-run CVs were 0.5% and 0.4% for medium and high value samples respectively, 0.5% and 0.6% for low and high level controls respectively. The mean recovery was 100.1%. A good correlation between the 2 methods (Adams = 1.00 Cobas - 0.11, r = 0.98) was observed. CONCLUSIONS: The Akray Adams HA-8160 HbA1c analyser performed within the target CV of < 2.5% and showed a good correlation with the Cobas Integra 800.
Glycosylated hemoglobin A
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Sjogren's syndrome B antibody
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Adams
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Performance
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cyclophosphamide/etoposide
2.Antibacterial property of locally produced hydroxyapatite.
Tin-Oo M.M. ; Gopalakrishnan V. * ; Samsuddin A.R. ; Al Salihi K.A. ; Shamsuria O.
Archives of Orofacial Sciences 2007;2(1):41-44
Use of synthetic hydroxyapatite (HA) in biomedical applications is well warranted. It has shown to have an excellent biocompatibility in human tooth and bones. Additionally it has been documented to possess antibacterial potentials. The present study was conducted to assess the presence of any such potential in locally produced (HA) using Streptococcus mutans, a common pathogen in the oral cavity. The study was carried out using 50, 100, 150, 200, 300, 400 and 800 mg/ml concentration of HA. The antibacterial property of HA was assessed using Miles and Misra method. Our studies showed that bacterial growth inhibitions of S. mutans occurred from 50 mg/ml, and complete inhibition was perceived at concentrations at 200mg/ml of HA. The antibacterial property HA should be used to good advantage as a bioactive biomaterial in dental and maxillofacial applications.
Sjogren's syndrome B antibody
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/mL
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Durapatite
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Antibacterial
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biomaterial compatibility
3.Comparative study of synthesised hyroxyapatite from pure chemicals and Malaysian natural limestone precursors.
S H Abu Bakar ; Z Hussein ; S L Hee ; F Fazan
The Medical journal of Malaysia 2004;59 Suppl F():81-2
Hydroxyapatite, (HA; Ca1O(PO4)6(OH)2) has been successfully applied in medical and dental applications for several years due to its excellent biocompatibility. The usage of HA in Malaysia, however, is limited due to the lack of availability. Therefore the aim of this work is to produce HA materials from both pure chemicals and from Malaysian natural limestone precursors, and to compare their bulk properties. However, parts of Malaysian natural limestone deposits actually consist of a combination of Ca(OH)2 and CaCO3. In order to utilise the limestone to produce HA material, the combination of these commercially pure chemicals as HA precursors should still work. In order to test this hypothesis, two HAs were produced by wet synthesis technique utilising (a) combination of Ca(OH)2 + CaCO3 from pure commercial chemicals [WCC] and (b) a local natural limestone [WL] precursors. The HAs produced; WCC and WL, were compacted into discs and sintered at 1250 degrees C. The characterisations and evaluations conducted were XRD, SEM-EDX, FTIR and shrinkage factor. The results indicate that WL gives slightly better bulk properties compared to WCC.
Sjogren's syndrome B antibody
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MALAYSIAN
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hydroxyl group
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Calcium measurement
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Work
4.The synthesis of hydroxyapatite through the precipitation method.
Rizal K Shah ; M N Fahmi ; Akil H Mat ; Arifin A Zainal
The Medical journal of Malaysia 2004;59 Suppl F():75-6
Hydroxyapatite (HA) has been earmarked as suitable for implantation within the human of its chemical makeup to human bone. In this paper, HA powders were synthesized via the precipitation method where phosphoric acid (H3PO4) was titrated into calcium hydroxide solution [Ca(OH)2]. Two parameters such as temperature and stirring rate were identified as factors that influenced the amount and purity of HA powder. Phase identification of the synthesized powder was done using X-Ray Diffraction (XRD). The results show that HA phase can be synthesized from this titration process of Ca(OH)2 and H3PO4 with yield amount of HA powder around 45 - 61 grams but with less than hundred percent purity. In order to study the effect of heat treatment to HA crystals structure, HA powder was calcined at 850 degrees C for 2 hours. It's found that the degree of crystallinity increases after calcination because of lattice expansion when the materials were heated at higher temperature
Sjogren's syndrome B antibody
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Powders
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Durapatite
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Precipitation
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hydroxyl group
5.Hydroxapatite and tricalcium phosphate prepared by precipitation method.
C H Cik Rohaida ; B Idris ; Y Mohd Reusmaazran ; M Rusnah ; A M Fadzley Izwan
The Medical journal of Malaysia 2004;59 Suppl F():156-7
A mixture with different compositions of HA and TCP were synthesize in this work by precipitation method using Ca(NO3)2 4H2 and (NH4)2HPO4 as the starting materials. A mixture with HA and TCP phases in different ratios were produced. The powders were sintered from 1000 degrees C to 1250 degrees C. The phase compositions of the mixtures were then studied via XRD. This work shows that the pH value determines the different phase compositions of the HA-TCP mixture. Chemical analyses were carried out by FTIR. The microstructure was observed under SEM.
Sjogren's syndrome B antibody
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Tritolyl Phosphates
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Precipitation
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degrees C
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calcium phosphate, tribasic
6.The fundamentals of tissue engineering: new scaffolds.
L Di Silvio ; N Gurav ; R Sambrook
The Medical journal of Malaysia 2004;59 Suppl F():89-90
The ability to regenerate new bone for skeletal use is a major clinical need. In this study, two novel porous calcium phosphate materials pure HA and biphasic HA/beta-Tricalcium phosphate (HA/beta -TCP) were evaluated as potential scaffolds for cell-seeded bone substitutes using human osteoblast-like cells (HOS) and primary human mesenchymal stem cells (hMSCs). A high rate of proliferation was observed on both scaffolds. A greater increase in alkaline phosphatase (ALP- an indicator of osteoblast differentiation) was observed on HA/beta -TCP compared to HA. This observation indicates that HA/TCP may play a role in inducing osteoblastic differentiation. Although further evaluation is required both materials show potential as innovative synthetic substitutes for tissue engineered scaffolds.
Sjogren's syndrome B antibody
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Tritolyl Phosphates
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differentiation
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Tissue Engineering
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Skeletal bone