Displaying publications 201 - 209 of 209 in total

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  1. Faizal Mohamed
    MyJurnal
    The effects of radiation on tissue have generally been investigated in the context of therapeutic
    irradiations, radiation protection and exposure to solar radiation. Typically attention has
    concentrated primarily on cells, less consideration being given to the extracellular matrix (ECM).
    ECM consists of collagen and elastin fibers immersed in a viscoelastic gel composed principally of
    hyaluronan (HA) and proteoglycans. The present study examines changes in the physical properties of
    the principle matrix micromolecules due to exposure to ionizing radiation. Freeze-dried rooster-comb
    HA (Sigma) were used to give doses of 10-100 Gy for HA, to cover the range of irradiation exposure
    during radiotherapy. The viscosity of HA (at 1.25% and 0.125% w/v) was measured by both cone and
    plate and capillary viscometry, the former providing measurement at uniform shear rate and the latter
    providing a more sensitive indication of changes. The Raman microspectrometry was employed to
    characterize these changes on ECM molecular conformation. In regard to the viscometry, both
    techniques (cone and plate and capillary viscometry) reveal a dose-dependent reduction in viscosity
    (from 340 ± 194 cP for controls to 1500 ± 88 cP at a shear rate of 2 s-1 and dose of 75 Gy), again
    suggesting depolymerisation.
  2. Faizal Mohamed
    MyJurnal
    The extracellular matrix (ECM) is a complex structural entity surrounding and supporting cells that
    are found within mammalian tissue. This study presents the effect of ionizing radiation on the physical
    properties of elastin which is usually found within arteries, lung, skin, ligantum nuchae, vocal chords
    and elastic cartilage as a function of their composition and organization or architecture. X-ray from
    an electron linac were used to give doses of 10-50Gy to cover the range of irradiation exposure during
    radiotherapy. A uniaxial mechanical testing protocol was used to characterize the fibrous protein. For
    pericardial the major change was an increase in the elastic modulus in the toe region of the curve (≤
    20% strain), from 23±18 kPa for controls to 57±22 kPa at a dose of 10 Gy (p=0.01, α=0.05). At a
    larger strain (≤ 20%), the elastic modulus in the region decreased from 1.92±0.70 MPa for control
    pericardium tissue to 1.31±0.56 MPa (p=0.01, α=0.05) for 10 Gy X-irradiated sample. For elastin,
    the stress-strain relationship was linear up to 30% strain, but the elastic modulus decreased
    significantly with irradiation (controls 626±65 kPa, irradiated 474±121 kPa (p=0.02, α=0.05). The
    results suggest that for elastin chain scissions are the primary effect of irradiation. The Raman
    microspectrometry was employed to characterize these changes on ECM conformation.
  3. Zainah Adam, Shafii Khamis, Amin Ismail, Muhajir Hamid
    MyJurnal
    Ficus deltoidea or locally known as Mas cotek is one of the common medicinal plants used in
    Malaysia. Our previous studies showed that this plant have blood glucose lowering effect. Glucose
    uptake into muscle and adipocytes cells is one of the known mechanisms of blood glucose lowering
    effect. This study was performed to evaluate the effect of Ficus deltoidea on glucose uptake activity
    into muscle cells. The cells were incubated with Ficus deltoidea extracts either a,lone or combination
    with insulin. Amount of glucose uptake by L6 myotubes was determined using glucose tracer, 2-deoxy-
    [l-:-Hj-glucose. The results showed that Ficus deltoidea extracts at particular doses enhanced basal or
    insulin-mediated glucose uptake into muscle cells significantly. Hot aqueous extract enhanced glucose
    uptake at the low concentration (10 pg/ml) whereas methanolic extract enhanced basal glucose uptake
    at high concentrations (500 and 1000 fig/ml). Meanwhile, ethanolic extract enhanced glucose uptake at
    low and high concentrations. Methanolic extract also mimicked insulin activity during enhancing
    glucose uptake into L6 muscle cells. Glucose uptake activity of Ficus deltoidea could be attributed by
    the phenolic compounds presence in the plant. This study had shown that Ficus deltoidea has the
    ability to enhance glucose uptake into muscle cells which is partly contributed the antidiabetic activity
    of this plant.
  4. Muhammad Fakhrurazi Ahmad Fadzil, Ng Yen, Siti Najila Mohd Janib, Noor Hasnah M. Khairullah, Mohd Khairul Najah
    MyJurnal
    PET/CT Scan with obGa-labelled analogs is of increasing interest in Nuclear Medicine and currently
    is being performed all over the world. However, such labeling procedure requires high purity and
    concentrated solutions of°sGa. Here we report the purification and concentration of the eluate of
    SnOi-Based obGe/obGa generators via the anion exchange method. Three different anion columns were
    selected to purify and concentrate the6SGa eluat.es which are Chromafix, Oasis WAX and AG 1-X8
    columns. The different anion columns were compared and evaluated in terms of their capability in
    adsorption and desorption of ""Ga from, the generator. While the optimum molarity of Hydrocholric
    Acid (HCl) for highest 6dGa retention was also determined starting from the ranges of fM to 7M of
    HCl. The results showed that the percentage of 68Ga retention or adsorption .started to be plateau at
    molarity of 5.5M for all three anion cartridges. One-way ANOVA analysis proved that there is no
    significant difference between 5.5M with 6.0M, 6.5M and 7.0M which means that the retention of
    gallium-68 is equal at those molarities. At 5.5M, Chromafix and Oasis WAX cartridges showed the
    highest retention of gallium-68 which is 98.30%. The lowest 6"Ga retention was gained by AG 1-X8
    column which is 97.07%'. While for desorption of 6bGa, the highest percentage was obtained by using
    Oasis WAX cart/ridges which, is 70.f9% followed by Chromafix which, is 70.36%. The lowest desorption
    of gallium-68 was obtained by using AG 1-X8 column which is only 58.56%. Therefore, from this
    study, the most suitable cartridge and HCl molarity that should be applied in purification and
    concentration of Gallium-68 eluate fromÿ a SnOs Based °*Ge/*Ga generator is Oasis® WAX column
    with a HCl molarity of 5.5M respectively.
  5. Chee, Fuei Pien, Saafie Salleh, Afishah Alias, Haider F. Abdul Amir, Abu Hassan Husin
    MyJurnal
    The most sensitive part of a metal-oxide-semiconductor (MOS) structure to ionizing radiation is the
    oxide insulating layer. When ionizing radiation passes through the oxide, the energy deposited creates
    electron/hole pairs. Oxide trapped charge causes a negative shift in capacitance-voltage (C-V)
    characteristics. These changes are the results of, firstly, incre using trapped positive charge in the
    oxide, which causes a parallel shift of the curve to more negative voltages, and secondly, increasing
    interface trap density, which causes the curve to stretch-out.
  6. Mohd Rafi Mohd Solleh, Abdul Aziz Mohamed, Abd. Aziz Tajuddin, Faridah Idris, Mohamad Hairie Rabir, Muhammad Rawi Md Zin, et al.
    MyJurnal
    Thermal neutron beam from thermal column was selected for a Boron Neutron Capture Therapy
    (BNCT) system utilizing the Malaysian TRIGA MARK II reactor. Determination of shielding
    materials for fast and epithermal neutron was conducted. The materials selected were polyethylene,
    paraffin and water. For gamma-ray shielding, lead was used. The objective of this paper is to present
    the simulation and verification of an optimal design of BNCT collimation at a beam. line viewing the
    thermal column. A collimator was made from polyethylene pipe with 8 cm of diameter filled with
    paraffin.
  7. Muhammad Afiq Khairil Anuar, Siti Zanariah Ab Aziz, Raizulnasuha Abdul Rashid, Safri Zainal Abidin, Norhayati Dollah, Wan Nordiana A. Abd Rahman
    MyJurnal
    Radiotherapy has become the most important modality in treating cancer with approximately 50% of
    cancer patient undergo the treatment. However, more improvement to the radiotherapy treatment
    efficacy is required to deprive cancer. Assessment of tumor progress during treatment is important, to
    accommodate the changes that occur during the fractionation course. The objective of this study is to
    assess tumor cell damage after external beam radiotherapy by using technetium-99m
    pertechnetate (99mTcOf) as a tracer. In this study, HeLa cells were irradiated with 6 MVphoton beam
    with different radiation dose ranging from 0.5 Gy to 10 Gy. The irradiated cells were recultured in 6-
    well plates and incubated for 10 days. After that, 2 mCi of 99mTcOf were prescribed to each cell
    colonies. The viable cells were separated from the rest, and measured for 99mTcOf uptake using singlehead
    gamma camera with LEHR collimation. As results, the cells survival, fractions clearly indicate
    diminishing effect, to the cells at, higher dose of irradiation. Good correlation were observed between
    mmTcGi uptake and survival, fraction for cells irradiated at, lower dose and less significant, correlation
    were indicated at higher dose. In conclusion, there is potential for the efficacy of external beam
    radiotherapy in treating cancer to be assessed by using radioisotope as a non-invasive tracer. In this
    case, technetium-99m, pertechnetate (99mTcOjt) could be attached to the specific antibody so that, better
    correlation, between, the cells uptake and possible cell damages could be observed.
  8. Safri Zainal Abidin, Raizulnasuha Abdul Rashid, Muhammad Afiq Khairil Anuar, Wan Nordiana A. Abd Rahman
    MyJurnal
    The purpose of this study is to determine the technetium-99m pertechnetate (99mTcO4) intercellular uptake by different types of cell lines. HeLa, human fetal
    osteoblast (hFOB), glial and glioma cell lines grown in 6-wells culture plates were incubated with 99mTcO4 of activity of 200, 400, 600. 800 and 1000
    pCi for 30 minutes at 3T°C and 5% ( '< - humidified atmosphere. After incubation, the cells were washed 3 times with phosphate buffer saline to remove the
    extracellular traces of 99mTcO4. Measurements of the intercellular Q9mTcOjt radioactivity were performed using single head gamma
    camera and the percentage uptake of the yUwTcGpinto the cells was calculated. The intercellular uptake
    0fyUmTcO_( was found to be inversely correlate to the radioactivity HeLa cell shows the highest uptake
    followed by hFOB, glial and glioma cell lines. Comparison of uptake between normal and cancer cells
    present indistinguishable results. The findings of this study suggest that the intercellular uptake of
    yymTcOjt is highly dependent on the type of cells despite no significant different of uptake was found
    between normal and cancer cell lines. The level of radioactivity is also an important determinant
    factor that influence the uptake ofyUmTcG) into the cells. This study will be the first precedent toward
    understanding the cellular characteristic and pharmacokinetic of non-invasive imaging tracer for
    future molecular imaging and therapy.
  9. Muhammad Fakhrurazi Ahmad Fadzil, Siti Selina Abdul Hamid, Siti Najila Mohd Janib, Azahari Kasbollah, Syed Asraf Fahlawi Wafa
    MyJurnal
    Medical radioisotope is a small quantity of radioactive substance used in safe, cost effective, for the
    purpose of diagnostic and therapy of various diseases. In Malaysia, the emerging of new nuclear
    medicine centers or institutions in both government and private sectors rose abruptly for the past few
    years. Currently, there are no data available on the usage and demand of medial radioisotope or
    radiopharmaceuticals. Understanding the usage trending and demand of radiopharmaceuticals and
    medical radioisotope is essential when related to technology changes in order to meet the market size
    of these radiopharmaceuticals. Survey result found out that the highest demand and the highest usage
    among all radioisotopes are Technetium-99m and Radioiodine isotopes such as the Iodine-131, Iodine-
    131 MIBG, Iodine-123 and Iodine-123 MIBG. Currently, most of the medical isotopes and
    radiopharmaceuticals are currently imported. Technetium-99m is the backbone of nuclear medicine
    whereby more than 80% of Nuclear Medicine services utilize this radioisotope. Technetium-99m supply
    chain is unstable globally and in coming future, two main reactors (Canada & Holland) that produces
    60% of world Molybdenum-99 will shut down the operation and supply of Molybdenum-99 will be
    disrupted. As for radioiodine services, currently, Iodine-123 can't be obtained in Malaysia and
    neighboring countries due to its short half-life. Iodine-123 is useful in diagnostic of thyroid related
    diseases. As for PET services, the highest demands are F-18 FDG and Gallium-68 Generator for the
    moment. However the survey data still did not, include most of the PET centers in the Klang Valley,
    northern area (Penang) and the new upcoming PET center in Southern Region (Malacca and Johor).
    It is important for Malaysia to self-produced medical radioisotope and radiopharmaceuticals to meet
    the market and local demand of these medical isotopes.
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