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Fulltext Development of Isocratic RP-HPLC Method for Separation and Quantification of L-Citrulline and L-Arginine in Watermelons

Ridwan R, Abdul Razak HR, Adenan MI, Md Saad WM

Int J Anal Chem, 2018;2018:4798530.
PMID: 29853897 DOI: 10.1155/2018/4798530

Watermelons (Citrullus lanatus) are known to have sufficient amino acid content. In this study, watermelons grown and consumed in Malaysia were investigated for their amino acid content, L-citrulline and L-arginine, by the isocratic RP-HPLC method. Flesh and rind watermelons were juiced, and freeze-dried samples were used for separation and quantification of L-citrulline and L-arginine. Three different mobile phases, 0.7% H3P04, 0.1% H3P04, and 0.7% H3P04 : ACN (90 : 10), were tested on two different columns using Zorbax Eclipse XDB-C18 and Gemini C18 with a flow rate of 0.5 mL/min and a detection wavelength at 195 nm. Efficient separation with reproducible resolution of L-citrulline and L-arginine was achieved using 0.1% H3P04 on the Gemini C18 column. The method was validated and good linearity of L-citrulline and L-arginine was obtained with R2 = 0.9956, y = 0.1664x + 2.4142 and R2 = 0.9912, y = 0.4100x + 3.4850, respectively. L-citrulline content showed the highest concentration in red watermelon of flesh and rind juice extract (43.81 mg/g and 45.02 mg/g), whereas L-arginine concentration was lower than L-citrulline, ranging from 3.39 to 11.14 mg/g. The isocratic RP-HPLC method with 0.1% H3P04 on the Gemini C18 column proved to be efficient for separation and quantification of L-citrulline and L-arginine in watermelons.
Fulltext Effects of different tube potentials and iodine concentrations on image enhancement, contrast-to-noise ratio and noise in micro-CT images: a phantom study

Abdul Razak HR, Shaffiq Said Rahmat SM, Md Saad WM

Quant Imaging Med Surg, 2013 Oct;3(5):256-61.
PMID: 24273743 DOI: 10.3978/j.issn.2223-4292.2013.10.04

The study aimed to investigate the effects of different tube potentials and concentrations of iodinated contrast media (CM) on the image enhancement, contrast-to-noise ratio (CNR) and noise in micro-computed tomography (µCT) images. A phantom containing of five polyethylene tube was filled with 2 mL of deionized water and iodinated CM (Omnipaque 300 mgI/mL) at four different concentrations: 5, 10, 15, and 20 mol/L, respectively. The phantom was scanned with a µCT machine (SkyScan 1176) using various tube potentials: 40, 50, 60, 70, 80, and 90 kVp, a fixed tube current; 100 µA, and filtration of 0.2 mm aluminum (Al). The percentage difference of image enhancement, CNR and noise of all images, acquired at different kVps and concentrations, were calculated. The image enhancement, CNR and noise curves with respect to tube potential and concentration were plotted and analysed. The highest image enhancement was found at the lowest tube potential of 40 kVp. At this kVp setting, the percentage difference of image enhancement [Hounsfield Unit (HU) of 20 mol/L iodine concentration over HU of deionized water] was 43%. By increasing the tube potential, it resulted with the reduction of HU, where only 17.5% different were noticed for 90 kVp. Across all iodine concentrations (5-20 M), CNR peaked at 80 kVp and then these values showed a slight decreasing pattern, which might be due insufficient tube current compensation. The percentage difference of image noise obtained at 40 and 90 kVp was 72.4%. Lower tube potential setting results in higher image enhancement (HU) in conjunction with increasing concentration of iodinated CM. Overall, the tube potential increment will substantially improve CNR and reduce image noise.
Fulltext Watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai) juice modulates oxidative damage induced by low dose X-ray in mice

Mohammad MK, Mohamed MI, Zakaria AM, Abdul Razak HR, Saad WM

Biomed Res Int, 2014;2014:512834.
PMID: 24877107 DOI: 10.1155/2014/512834

Watermelon is a natural product that contains high level of antioxidants and may prevent oxidative damage in tissues due to free radical generation following an exposure to ionizing radiation. The present study aimed to investigate the radioprotective effects of watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai) juice against oxidative damage induced by low dose X-ray exposure in mice. Twelve adult male ICR mice were randomly divided into two groups consisting of radiation (Rx) and supplementation (Tx) groups. Rx received filtered tap water, while Tx was supplemented with 50% (v/v) watermelon juice for 28 days ad libitum prior to total body irradiation by 100 μGy X-ray on day 29. Brain, lung, and liver tissues were assessed for the levels of malondialdehyde (MDA), apurinic/apyrimidinic (AP) sites, glutathione (GSH), and superoxide dismutase (SOD) inhibition activities. Results showed significant reduction of MDA levels and AP sites formation of Tx compared to Rx (P < 0.05). Mice supplemented with 50% watermelon juice restore the intracellular antioxidant activities by significantly increased SOD inhibition activities and GSH levels compared to Rx. These findings may postulate that supplementation of 50% watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai) juice could modulate oxidative damage induced by low dose X-ray exposure.
Fulltext Nanotoxic profiling of novel iron oxide nanoparticles functionalized with perchloric acid and SiPEG as a radiographic contrast medium

Mohamed MI, Mohammad MK, Abdul Razak HR, Abdul Razak K, Saad WM

Biomed Res Int, 2015;2015:183525.
PMID: 26075217 DOI: 10.1155/2015/183525

Emerging syntheses and findings of new metallic nanoparticles (MNPs) have become an important aspect in various fields including diagnostic imaging. To date, iodine has been utilized as a radiographic contrast medium. However, the raise concern of iodine threats on iodine-intolerance patient has led to search of new contrast media with lower toxic level. In this animal modeling study, 14 nm iron oxide nanoparticles (IONPs) with silane-polyethylene glycol (SiPEG) and perchloric acid have been assessed for toxicity level as compared to conventional iodine. The nanotoxicity of IONPs was evaluated in liver biochemistry, reactive oxygen species production (ROS), lipid peroxidation mechanism, and ultrastructural evaluation using transmission electron microscope (TEM). The hematological analysis and liver function test (LFT) revealed that most of the liver enzymes were significantly higher in iodine-administered group as compared to those in normal and IONPs groups (P < 0.05). ROS production assay and lipid peroxidation indicator, malondialdehyde (MDA), also showed significant reductions in comparison with iodine group (P < 0.05). TEM evaluation yielded the aberration of nucleus structure of iodine-administered group as compared to those in control and IONPs groups. This study has demonstrated the less toxic properties of IONPs and it may postulate that IONPs are safe to be applied as radiographic contrast medium.
Fulltext Establishment of CTPA Local Diagnostic Reference Levels with Noise Magnitude as a Quality Indicator in a Tertiary Care Hospital

Harun HH, Abdul Karim MK, Abd Rahman MA, Abdul Razak HR, Che Isa IN, Harun F

Diagnostics (Basel), 2020 Sep 09;10(9).
PMID: 32916913 DOI: 10.3390/diagnostics10090680

This study aimed to establish the local diagnostic reference levels (LDRLs) of computed tomography pulmonary angiography (CTPA) examinations based on body size with regard to noise magnitude as a quality indicator. The records of 127 patients (55 males and 72 females) who had undergone CTPAs using a 128-slice CT scanner were retrieved. The dose information, scanning acquisition parameters, and patient demographics were recorded in standardized forms. The body size of patients was categorized into three groups based on their anteroposterior body length: P1 (14-19 cm), P2 (19-24 cm), and P3 (24-31 cm), and the radiation dose exposure was statistically compared. The image noise was determined quantitatively by measuring the standard deviation of the region of interest (ROI) at five different arteries-the ascending and descending aorta, pulmonary trunk, and the left and right main pulmonary arteries. We observed that the LDRL values were significantly different between body sizes (p < 0.05), and the median values of the CT dose index volume (CTDIvol) for P1, P2, and P3 were 6.13, 8.3, and 21.40 mGy, respectively. It was noted that the noise reference values were 23.78, 24.26, and 23.97 HU for P1, P2, and P3, respectively, which were not significantly different from each other (p > 0.05). The CTDIvol of 9 mGy and dose length product (DLP) of 329 mGy∙cm in this study were lower than those reported by other studies conducted elsewhere. This study successfully established the LDRLs of a local healthcare institution with the inclusion of the noise magnitude, which is comparable with other established references.
Fulltext Prenatal ultrasound heating impacts on fluctuations in haematological analysis of Oryctolagus cuniculus

Ahmad Zaiki FW, Md Dom S, Abdul Razak HR, Hassan HF

Quant Imaging Med Surg, 2013 Oct;3(5):262-8.
PMID: 24273744 DOI: 10.3978/j.issn.2223-4292.2013.10.05

Prenatal Ultrasound (US) is commonly used as a routine procedure on pregnant women. It is generally perceived as a safe procedure due to the use of non-ionizing radiation. However, the neurotoxicity of diagnostic prenatal US was detected to have a correlation with high susceptibility to early developing fetus. This research involved in vivo experimental model by using 3(rd) trimester pregnant Oryctolagus cuniculus and exposing them to US exposures for 30, 60, and 90 minutes at their gestational day (GD) 28-29. The output power and intensities, spatial peak temporal average intensity (ISPTA) of US were varied from 0.4 to 0.7 W and 0.13 to 0.19 W/cm(2) respectively were tested initially in free-field, water. Haematological analysis was carried out to detect any changes in blood constituents. Statistically significant differences were detected in red blood cell (RBC) count (P<0.001), haemoglobin (Hb) concentration (P<0.001) and also platelet (PLT) count (P<0.001) in newborn of Oryctolagus cuniculus. These findings indicate the possibility of US heating in causing defects on studied animal.
Fulltext Estimation of kidneys and urinary bladder doses based on the region of interest in (18)fluorine-fluorodeoxyglucose positron emission tomography/computed tomography examination: a preliminary study

Mustapha FA, Bashah FAA, Yassin IM, Fathinul Fikri AS, Nordin AJ, Abdul Razak HR

Quant Imaging Med Surg, 2017 Jun;7(3):310-317.
PMID: 28811997 DOI: 10.21037/qims.2017.05.03

BACKGROUND: Kidneys and urinary bladder are common physiologic uptake sites of 18fluorine-fluorodeoxyglucose ((18)F-FDG) causing increased exposure of low energy ionizing radiation to these organs. Accurate measurement of organ dose is vital as (18)F-FDG is directly exposed to the organs. Organ dose from (18)F-FDG PET is calculated according to the injected (18)F-FDG activity with the application of dose coefficients established by International Commission on Radiological Protection (ICRP). But this dose calculation technique is not directly measured from these organs; rather it is calculated based on total injected activity of radiotracer prior to scanning. This study estimated the (18)F-FDG dose to the kidneys and urinary bladder in whole body positron emission tomography/computed tomography (PET/CT) examination by comparing dose from total injected activity of (18)F-FDG (calculated dose) and dose from organs activity based on the region of interest (ROI) (measured dose).
METHODS: Nine subjects were injected intravenously with the mean (18)F-FDG dose of 292.42 MBq prior to whole body PET/CT scanning. Kidneys and urinary bladder doses were estimated by using two approaches which are the total injected activity of (18)F-FDG and organs activity concentration of (18)F-FDG based on drawn ROI with the application of recommended dose coefficients for (18)F-FDG described in the ICRP 80 and ICRP 106.
RESULTS: The mean percentage difference between calculated dose and measured dose ranged from 98.95% to 99.29% for the kidneys based on ICRP 80 and 98.96% to 99.32% based on ICRP 106. Whilst, the mean percentage difference between calculated dose and measured dose was 97.08% and 97.27% for urinary bladder based on ICRP 80 while 96.99% and 97.28% based on ICRP 106. Whereas, the range of mean percentage difference between calculated and measured organ doses derived from ICRP 106 and ICRP 80 for kidney doses were from 17.00% to 40.00% and for urinary bladder dose was 18.46% to 18.75%.
CONCLUSIONS: There is a significant difference between calculated dose and measured dose. The use of organ activity estimation based on drawn ROI and the latest version of ICRP 106 dose coefficient should be explored deeper to obtain accurate radiation dose to patients.
Analytical GC-FID Method for the Determination of Organic Solvents in Radiopharmaceuticals

Hassan H, Othman MF, Zakaria ZA, Saad FFA, Abdul Razak HR

Curr Radiopharm, 2021;14(2):131-144.
PMID: 33115398 DOI: 10.2174/1874471013999201027215704

BACKGROUND: Organic solvents play an indispensable role in most of the radiopharmaceutical production stages. It is almost impossible to remove them entirely in the final formulation of the product.
OBJECTIVE: In this presented work, an analytical method by gas chromatography coupled with flame ionization detection (GC-FID) has been developed to determine organic solvents in radiopharmaceutical samples. The effect of injection holding time, temperature variation in the injection port, and the column temperature on the analysis time and resolution (R ≥ 1.5) of ethanol and acetonitrile was studied extensively.
METHODS: The experimental conditions were optimized with the aid of further statistical analysis; thence, the proposed method was validated following the International Council for Harmonisation (ICH) Q2 (R1) guideline.
RESULTS: The proposed analytical method surpassed the acceptance criteria including the linearity > 0.990 (correlation coefficient of R2), precision < 2%, LOD, and LOQ, accuracy > 90% for all solvents. The separation between ethanol and acetonitrile was acceptable with a resolution R > 1.5. Further statistical analysis of Oneway ANOVA revealed that the increment in injection holding time and variation of temperature at the injection port did not significantly affect the analysis time. Nevertheless, the variation in injection port temperature substantially influenced the resolution of ethanol and acetonitrile peaks (p < 0.05).
CONCLUSION: The proposed analytical method has been successfully implemented to determine the organic solvent in the [18F]fluoro-ethyl-tyrosine ([18F]FET), [18F]fluoromisonidazole ([18F]FMISO), and [18F]fluorothymidine ([18F]FLT).
The cytotoxicity effect of bismuth oxide particles synthesized hydrothermally using different reaction temperatures in vitro

Md Saad WM, Mohd Noor NA, Mohamad Salin NS, Mohd Z, Eshak Z, Abdul Razak HR

Med J Malaysia, 2024 Mar;79(Suppl 1):8-13.
PMID: 38555879

INTRODUCTION: Bismuth oxide (Bi2O3) particles gained attention in preclinical research especially in medical imaging. Bismuth oxide with its long circulation time is an alternative to the current iodine contrast media which directly possesses high X-ray attenuation coefficient. Exploration of bismuth compound is hampered owing to challenges in synthesizing control for in vivo stability.
MATERIALS AND METHODS: This study aimed are to characterize Bi2O3 particles synthesized at 60, 90 and 120 °C via hydrothermal method and investigated cytotoxicity of cell viability assay, cell morphology analysis, intracellular reactive oxygen species (ROS) assay and expression of ER stress genes by real-time PCR.
RESULTS: Results indicated that the size of rod-shaped Bi2O3 particles increased with rising synthesizing temperatures. The cytotoxicity of Bi2O3 particles in Chang liver cells was size-dependent. Bigger-sized Bi2O3 particles resulted in lesser toxicity effects. mRNA expressions of GRP78 and C/EBP homologous protein (CHOP) were down-regulated in all treated Chang liver cells due to the increasing size of Bi2O3 particles. Bi2O3 particles synthesized at 120 °C was found to be less toxic than iodine.
CONCLUSION: Data suggested that the response of Chang liver cells to Bi2O3 particle cytotoxicity has a significant relationship with its reaction temperatures. This outcome is important in hazard assessment of Bi2O3 particles as a new contrast media and provides better understanding in synthesizing control to enhance its biocompatibility.
Fulltext Ultrasound exposure during pregnancy affects rabbit foetal parathyroid hormone (PTH) level

Md Dom S, Abdul Razak HR, Ahmad Zaiki FW, Saat NH, Abd Manan K, Che Isa IN, et al.

Quant Imaging Med Surg, 2013 Feb;3(1):49-53.
PMID: 23483040 DOI: 10.3978/j.issn.2223-4292.2013.02.06

The aim of this study was to investigate the changes in parathyroid hormone (PTH) level of rabbit foetal bodies exposed to ultrasound at different gestational stages. A total of 9 pregnant rabbits (Oryctolagus cuniculus) were insonated for 60 minutes at the middle of 1(st), 2(nd) and 3(rd) gestational stages for group A (n=14 newborns), group B (n=7 newborns) and group C (n=24 newborns) respectively. Seven pregnant rabbits with 41 newborns severed as negative control group. Blood samples were withdrawn from each newborn rabbits for Parathyroid Hormone-Intact (PTH-I) test. Results of the independent samples t-test implied statistically significant differences (P<0.05) between the control group and the 1(st) stage (P=0.001), the 2(nd) stage (P<0.001) and the 3(rd) stage group (P<0.001). This in-vivo study revealed diagnostic ultrasound heating has the potential of affecting foetal PTH level. This study observed significantly low PTH level for all the treated groups. A further study should be instituted to determine whether this finding in rabbit may also occur in human by means of clinical trials.
Fulltext Preparation, Optimisation, and In Vitro Evaluation of [18F]AlF-NOTA-Pamidronic Acid for Bone Imaging PET

Hassan H, Othman MF, Abdul Razak HR, Zakaria ZA, Ahmad Saad FF, Osman MA, et al.

Molecules, 2022 Nov 17;27(22).
PMID: 36432069 DOI: 10.3390/molecules27227969

[18F]sodium fluoride ([18F]NaF) is recognised to be superior to [99mTc]-methyl diphosphate ([99mTc]Tc-MDP) and 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) in bone imaging. However, there is concern that [18F]NaF uptake is not cancer-specific, leading to a higher number of false-positive interpretations. Therefore, in this work, [18F]AlF-NOTA-pamidronic acid was prepared, optimised, and tested for its in vitro uptake. NOTA-pamidronic acid was prepared by an N-Hydroxysuccinimide (NHS) ester strategy and validated by liquid chromatography-mass spectrometry analysis (LC-MS/MS). Radiolabeling of [18F]AlF-NOTA-pamidronic acid was optimised, and it was ensured that all quality control analysis requirements for the radiopharmaceuticals were met prior to the in vitro cell uptake studies. NOTA-pamidronic acid was successfully prepared and radiolabeled with 18F. The radiolabel was prepared in a 1:1 molar ratio of aluminium chloride (AlCl3) to NOTA-pamidronic acid and heated at 100 °C for 15 min in the presence of 50% ethanol (v/v), which proved to be optimal. The preliminary in vitro results of the binding of the hydroxyapatite showed that [18F]AlF-NOTA-pamidronic acid was as sensitive as [18F]sodium fluoride ([18F]NaF). Normal human osteoblast cell lines (hFOB 1.19) and human osteosarcoma cell lines (Saos-2) were used for the in vitro cellular uptake studies. It was found that [18F]NaF was higher in both cell lines, but [18F]AlF-NOTA-pamidronic acid showed promising cellular uptake in Saos-2. The preliminary results suggest that further preclinical studies of [18F]AlF-NOTA-pamidronic acid are needed before it is transferred to clinical research.

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