The aim of this study was to evaluate properties of normoxic polymer gel 2-Hydroxyethyl methacrylate monomer (HEMAG)
as a point dosimeter by using optical properties evaluation techniques. HEMAG were prepared from seven different
radiation dose within five different depths of HEMAG dosimeters. These HEMAG dosimeters were irradiated by linear
accelerator with 6 MV photon beams. The absorption spectra were measured by using a UV-visible spectrophotometer in
the wavelength range from 300 to 800 nm. Then, the data was analysed to determine the optical energy band gap (Eg
)
and Urbach’s energy (∆E). The result showed that Eg
and ∆E were dependent on radiation dose and percentage of depth
dose (PDD). In additional, Eg
with indirect transition of HEMAG decreased as radiation dose increased and increased
with traversing of depth. ∆E of HEMAG increased as the dose increased and decreased with traversing depth of monomer.
There was a shift in the Eg
values towards lower energy as the dose increased and led to a shift of the ∆E value towards
the higher energy with increasing dose. This observation supported the increase of structured disorder of the polymer
with increasing radiation dose, which resulted in the lower energy transitions that was feasible and reduced the values
of Eg
. In conclusion, HEMAG has a potential to be used as a dosimeter at low radiation dose in the clinical radiotherapy
Nine local plant species were picked randomly and their aqueous extracts have been screened to know their effects on the phagocytic capability and intracellular killing of StapllylococclIs al/rellS bacteria by mouse peritoneal macrophages. Macrophage cultures were incubated with different concentration of each plant extracts forI hour. Among these aqueous extracts, Ageratum conyzoides and Malastoma melabathricum inhibited the phagocytic capability and intracellular killing of Stapllylococclls aureus compared with controls. Elicited (activated) cells have more phagocytic capability and intracellular killing than the resident (normal) macrophages. There were no differences in the viability of cells between treated cells (with extracts) and controls (without extracts). KEYWORDS: Aqueous plant extracts, murine macrophage, phagocytosis.
Widespread evidence has demonstrated the negative effects of tobacco smoking in patients with diabetes. Although many studies have explored the prevalence of tobacco smoking in the general population, data are lacking regarding its prevalence in a specific population with a chronic disease such as diabetes.
Objectives: This study aims to determine the prevalence of tobacco smoking among patients with diabetes in Hospital Pulau Pinang, Malaysia.
Methods: A cross-sectional survey was conducted to study diabetic patients who attended the endocrine clinic at Hospital Pulau Pinang in Malaysia from March to August 2012. All the diabetic patients who attended the endocrine clinic during that period were asked about their smoking status, and their medical records were reviewed. A total of 1,118 patients with diabetes were reviewed to determine the prevalence of tobacco smoking in diabetic patients at the endocrine clinic of Hospital Pulau Pinang.
Results: The majority of the study population was male, with Malay and Chinese patients in almost equal proportions and a smaller proportion of Indian patients. Most of these patients had started smoking before they were diagnosed with diabetes. Among the 1,118 diabetic patients, only 108 patients smoked; therefore, the prevalence of tobacco smoking in our patients with diabetes was 9.66%.
Conclusions: A low prevalence of tobacco smoking was estimated in this study. This prevalence is close to the corresponding value in the general population in Malaysia.
Study site: Endocrine clinic, Hospital Pulau Pinang, Malaysia
Chitinases are glycosyl hydrolases that cleave the β-1,4-glycosidic linkages between N-acetylglucosamine residues in chitin which is a major component of fungal cell wall. Plant chitinases hydrolyze fungal chitin to chitin oligosaccharides that serve as elicitors of plant defense system against fungal pathogens. However, plants synthesize many chitinase isozymes and some of them are not pathogenesis-related. In this study, three full-length cDNA sequences encoding a putative chitinase (EgChit3-1) and two chitinase-like proteins (EgChit1-1 and EgChit5-1) have been cloned from oil palm (Elaeis guineensis) by polymerase chain reaction (PCR). The abundance of these transcripts in the roots and leaves of oil palm seedlings treated with Ganoderma boninense (a fungal pathogen) or Trichoderma harzianum (an avirulent symbiont), and a combination of both fungi at 3, 6 and 12 weeks post infection were profiled by real time quantitative reverse-transcription (qRT)-PCR. Our findings showed that the gene expression of EgChit3-1 increased significantly in the roots of oil palm seedlings treated with either G. boninense or T. harzianum and a combination of both; whereas the gene expression of EgChit1-1 in the treated roots of oil palm seedlings was not significantly higher compared to those of the untreated oil palm roots. The gene expression of EgChit5-1 was only higher in the roots of oil palm seedlings treated with T. harzianum compared to those of the untreated oil palm roots. In addition, the gene expression of EgChit1-1 and EgChit3-1 showed a significantly higher gene expression in the leaf samples of oil palm seedlings treated with either G. boninense or T. harzianum.
Studies of genetic mutations that have been used in predicting glioma prognosis have revealed a complex relationship between clinical and genetic factors. Epidermal growth factor (EGF) and the NAT2 gene play a central role in carcinogenesis. An adenine (A) to guanine (G) single nucleotide polymorphism at position 61 in the 5'-untranslated region (5'-UTR) of the EGF gene has been found to be associated with levels of EGF production, and the mutations in the NAT2 gene have been postulated as a risk factor for cancer. We investigated EGF and the NAT2 gene in 13 glioma tissue samples and 12 normal controls. In the EGF 5'-UTR 61G polymorphism, the heterozygote GA was the most common genotype in the glioma patients. In the NAT2 polymorphism at nucleotide position 857G/A, the G allele and the GG genotype were the most prevalent forms in both the glioma and normal samples. We did not find any homozygous AA genotypes in the glioma patients. Based on this preliminary evidence, the EGF 5'-UTR at position 61 and the NAT2 SNP at position 857 polymorphisms are associated with increased risk for glioma.
Ageing is associated with geometrical changes in muscle fascicles that may lead to deteriorations in physical functions. The purpose of this study was to study the effects of ageing on fibre orientation and strength of the lumbar extensor muscles.
This study was designed to identify surface and subsurface microscopic changes in different carious lesions by using Confocal Laser Scanning Microscope (CLSM) and Image analyzer (light microscopy). Thirty extracted carious posterior teeth were fixed, embedded and polymerized in plastic fixation medium. The final thin sections (80mm) were stained with H&E and Masson Goldner's Tricome while others were left unstained. Under Confocal, marked differences between control sound enamel and dentin, and carious area of the samples were observed which illustrated that a correlation existed between the zone of autofluoresence, demineralization and carious enamel and dentin. Compared to CLSM, Image Analyzer only produce two-dimensional images but the histopathological changes were better appreciated by using various staining methods.
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.
Nasopharyngeal carcinoma (NPC) and other head and neck cancer (HNCA) types show a great epidemiological variation in different regions of the world. NPC has multifactorial etiology and many interacting risk factors are involved in NPC development mainly Epstein Barr virus (EBV). There is a need to scrutinize the complicated network of risk factors affecting NPC and how far they are different from that of other HNCA types.
To highlight therapeutic controversies, and present a critical review of the most recent evidence on the management of heparin-induced thrombocytopenia (HIT).
Runoff quality draining from 17.14 km2 urban catchment in Johor Bahru, Malaysia, was analysed. The land-use consists of residential (30.3%), agricultural (27.3%), open space (27.9%), industrial (8.1%) and commercial (6.4%) areas. Three storm events were sampled in detail. These storms produced stormflow between 0.84 mm and 27.82 mm, and peakflow from 2.19 m3/s to 42.36 m3/s. Water quality showed marked variation during storms especially for TSS, BOD and COD with maximum concentrations of 778 mg/l, 135 mg/l and 358 mg/l, respectively. Concentrations of TOC, DOC, NH3-N, Fe and level of colour were also high. In general, the river quality is badly polluted and falls in Class V based on the Malaysian Interim National Water Quality Standards. Event Mean Concentrations (EMC) for various parameters varied considerably between storms. The largest storm produced higher EMC for TSS, NO3-N and SS whereas the smaller storms tend to register higher EMC for BOD, COD, NH3-N, TOC, Ca, K, Mg, Fe and Zn. Such variations could be explained in terms of pollutant availability and the effects of flushing and dilution. Based on a three-month average recurrence interval (ARI) of rainfall, the estimated event loadings (ton/ha) of TSS, BOD, COD, TOC, NH3-N and NO3-N were 0.055, 0.016, 0.012, 0.039, 0.010, 0.0007 and 0.0002, respectively. Heavy metals present in trace quantities. Storms with 3 months ARI could capture about 70% of the total annual loads of major pollutants.
A descriptive prospective study of 16 children with injuries inflicted by bicycle spokes and chain was undertaken to identify the demographic profiles of such injuries. Aspects of preventive measures are proposed.
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.
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.
This study is to qualitatively evaluate a locally produced hydroxyapatite (HA), made by AMREC-SIRIM in an experimental animal bone defect using New Zealand White (NZW) rabbits. HA cylindrical blocks measuring 2.5 mm (D) x 1.0 mm (H) were implanted in the rabbits' left tibia. The tibias were harvested within one to three weeks post-implantation. The implantion site was cut into thin undecalcified sections of about 30 microm to 60 microm and stained with Toluidine Blue and Goldner's Masson Trichrome. Microscopic examinations using standard light microscopy of these slides were performed.
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.
Hydroxyapatite is a calcium phosphate bioceramic that has been shown by many authors to be biocompatible with bioactive properties. It is widely accepted as the best synthetic material available for surgical use as a bone graft substitute. HA granules produced by AMREC-SIRIM from local materials underwent 5 types of sterilisation techniques with different ageing periods. Samples were tested for chemical and phase composition and microbial contamination before and after being sterilised. From the microbiological tests done, none of the unsterilised positive control yielded a positive culture. Results from X-Ray diffraction studies found that all the sterilisation techniques did not chemically degrade or structurally change the HA granules significantly.
Ionic liquids have been objects of extensive research for physical sorption of CO2 and a number of myths have been perpetuated in the literature, for lack of a critical analysis, concerning their potential for CO2 capture. This study carries a critical analysis of a number of widely accepted ideas and others not so well accepted that have been repeatedly expressed in the literature concerning the CO2 physical sorption in ionic liquids. Using the CO2 solubility in eicosane as benchmark, it will be shown that there is no evidence that ILs display a physical sorption of CO2 larger than n-alkanes when analyzed in adequate concentration units; the fluorination of the ions has no impact on the CO2 solubility and the oxygenation will marginally contribute to a decrease of the solubility. Ionic liquid-based deep eutectic systems are also shown to have a poor CO2 solubility. Although these widely used approaches to physically enhance the CO2 solubility in ILs do not seem to have any positive influence, this does not mean that other types of interaction cannot provide enhanced CO2 solubility as in the case of the anion [B(CN)4] confirmed here by a critical analysis of the published data. The mechanism of CO2 physical sorption in ionic liquids is discussed based on the results analyzed, supported by spectroscopic measurements and molecular simulations previously reported and further suggestions of possibilities for enhanced physical sorption based on fluorinated aromatic rings, other cyano based anions, mixtures with other ILs or solvents or the use of porous liquids are proposed.
To assess whether an online open-source tool would provide accurate calculations of T2(*) values for iron concentrations in the liver and heart compared with a standard reference software.
Individuals who report their sensitivity to electromagnetic fields often undergo cognitive impairments that they believe are due to the exposure of mobile phone technology. The aim of this study is to clarify whether short-term exposure at 1 V/m to the typical Global System for Mobile Communication and Universal Mobile Telecommunications System (UMTS) affects cognitive performance and physiological parameters (body temperature, blood pressure and heart rate). This study applies counterbalanced randomizing single blind tests to determine if sensitive individuals experience more negative health effects when they are exposed to base station signals compared with sham (control) individuals. The sample size is 200 subjects with 50.0% Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI-EMF) also known as sensitive and 50.0% (non-IEI-EMF). The computer-administered Cambridge Neuropsychological Test Automated Battery (CANTAB eclipse(TM)) is used to examine cognitive performance. Four tests are chosen to evaluate Cognitive performance in CANTAB: Reaction Time (RTI), Rapid Visual Processing (RVP), Paired Associates Learning (PAL) and Spatial Span (SSP). Paired sample t-test on the other hand, is used to examine the physiological parameters. Generally, in both groups, there is no statistical significant difference between the exposure and sham exposure towards cognitive performance and physiological effects (P's > 0.05).