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  1. Fulltext Effect of pentoxifylline on tumor necrosis factor-alpha and interleukin-6 levels in neonatal sepsis
    Selim K, Hüseyin C, Ibrahim KH, Hasan BU, Kazim U, Hüseyin K
    Med J Malaysia, 2004 Aug;59(3):391-4.
    PMID: 15727386
    Several pharmacological agents have been found to alter systemic concentrations and/or the activity of different cytokines via a variety of mechanisms, including changes in biosynthesis, secretion, and/or stability. Pentoxifylline (PTX), which is a methylxanthine derivative for example, has multiple effects on the immune system, but inhibition of pro-inflammatory cytokine release predominates. In this study we aimed to evaluate the influence of PTX on plasma levels of tumor necrosis factor (TNF) alpha and interleukin (IL)-6 in newborn infants with sepsis. The study included 20 infants with neonatal sepsis. In all subjects blood samples for serum C-reactive protein, TNF alpha and IL-6 determinations were received before giving PTX and at the 12th and 24th hours following PTX. In addition, white blood cell was counted before giving PTX and on the 3rd and 7th day following PTX. The infants were randomly divided into two groups. Firstly, PTX was used in infants who were successively admitted to the clinic and the subsequent infants were accepted as a control group. Of 20 infants, 13 infants received PTX and seven infants did not. We did not find any difference in the leukocyte count, serum C-reactive protein level, TNF alpha and IL-6 levels between the two groups of patients (P>0.05). While three infants died in the group of receiving PTX, death was not recorded in the group of non-receiving PTX (P>0.05). Our findings showed that PTX treatment did not affect leukocyte counts, serum CRP levels, TNF alpha and IL-6 levels and death ratio in newborn infants with sepsis. The last result may be due to the fact that the number of patients in the study was very small. We think that more extensive and controlled studies should be performed about this subject.
  2. Fulltext A clinical appraisal of patients with psoriasis treated in Seremban General Hospital, Malaysia
    Siow KY, Mohd Safdar NA, Chong KH, Chua KB
    Med J Malaysia, 2004 Aug;59(3):330-4.
    PMID: 15727378 MyJurnal
    A prospective clinical study of 181 patients with psoriasis seen in Seremban General Hospital showed the incidence of psoriasis among dermatology outpatients was 2.15%. A significantly higher proportion of male patients were affected, with a male to female ratio of 1.7:1. Within the racial groups; 63 were Malays, 37 Chinese, and 81 Indians. There was a significantly higher proportion of Indians affected as compared with the races. The mean age of patients in this study was 43.7 years old but the mean age of onset of psoriasis in these patients was 33.1 years old. Thirty-one (17.1%) patients gave a positive family history of psoriasis and the mean age of onset of psoriasis was lower (29.3 years old) for patients with a positive family history. Plaque psoriasis was the commonest type of clinical presentation with the scalp being the commonest site affected. Psoriatic arthropathy was seen in 35 (19.3%) patients. Ninety-five (52.5%) patients gave a positive history of factors exacerbating their pre-existing disease and stress was singled out as the most common exacerbating factor.
    Study site: Skin clinic, Hospital Tuanku Jaafar, Seremban, Negeri Sembilan, Malaysia
  3. Bioavailability and pharmacokinetics of acyclovir tablet preparation
    Yuen KH, Peh KK, Billa N, Chan KL, Toh WT
    Drug Dev Ind Pharm, 1998 Feb;24(2):193-6.
    PMID: 15605452
    The bioavailability of a generic preparation of acyclovir (Avorax) was compared with the innovator product, Zovirax. Twelve healthy volunteers participated in the study, conducted according to a randomized, two-way crossover design. The preparations were compared using the parameters area under the plasma concentration time curve (AUC(0-infinity), peak plasma concentration (Cmax), and time to reach peak plasma concentration (Tmax). No statistically significant difference was observed between the Tmax or the logarithmic transformed AUC(0-infinity) and C(max) values of the two preparations. In addition, the 90% confidence interval for the ratio of the logarithmic transformed AUC(0-infinity) values of Avorax over those of Zovirax was found to lie between 0.85 and 1.06, while that of the logarithmic transformed Cmax values was between 0.95 and 1.25, being within the bioequivalence limit of 0.80-1.25. Moreover, the elimination rate constant (k(e)), elimination half-life (t(1/2)), and apparent volume of distribution (Vd) values obtained with the two preparations were comparable and not significantly different statistically.
  4. Interaction between insulin-like growth factor-1 with other growth factors in serum depleted culture medium for human cartilage engineering
    Chua KH, Aminuddin BS, Fuzina NH, Ruszymah BH
    Med J Malaysia, 2004 May;59 Suppl B:7-8.
    PMID: 15468792
    The regulation roles of insulin-like growth factor-1 (IGF-1) with basic fibroblast growth factor (bFGF) and transforming growth factor beta 2 (TGFbeta2) in human nasal septum chondrocytes monolayer culture and cartilage engineering was investigated in this study. The role of IGF-1 with bFGF and TGFbeta2 was investigated by measuring chondrocyte growth kinetic and collagen genes expression. IGF-1 together with bFGF and TGFbeta2 promote cartilage tissue engineering, increase type II collagen expression and enhance the histological features of engineered cartilage.
  5. An unsuspected ameloblastoma in the subpontic region of the mandible with consideration of pathogenesis from the radiographic course
    Siar CH, Nakano K, Chelvanayagam PI, Ng KH, Nagatsuka H, Kawakami T
    Eur J Med Res, 2010 Mar 30;15(3):135-8.
    PMID: 20452900
    The purpose of this report is to document a case of unsuspected ameloblastoma involving the right man dibular subpontic region in a 38-year-old Cambodian female patient. This lesion was purportedly preceded by multiple radiolucencies which were diagnosed as radicular cysts and treated a few times in the past years by enucleation followed by endodontic therapy of the affected teeth. Bridgework restoration of the partially edentulous area was performed. This case report demonstrates radiographic changes that occurred in the periods before and after the diagnosis of ameloblastoma. The case may represent an example of radicular cysts and ameloblastoma occurring as a collision phenomenon, or the ameloblastoma may have arisen as a result of neoplastic transformation of the lining epithelium in an inflammatory odontogenic epithelial cyst.
  6. Lactobacillus gasseri [corrected] CHO-220 and inulin reduced plasma total cholesterol and low-density lipoprotein cholesterol via alteration of lipid transporters
    Ooi LG, Ahmad R, Yuen KH, Liong MT
    J Dairy Sci, 2010 Nov;93(11):5048-58.
    PMID: 20965319 DOI: 10.3168/jds.2010-3311
    This randomized, double-blind, placebo-controlled, and parallel-designed study was conducted to investigate the effect of a synbiotic product containing Lactobacillus gasseri [corrected] CHO-220 and inulin on lipid profiles of hypercholesterolemic men and women. Thirty-two hypercholesterolemic men and women with initial mean plasma cholesterol levels of 5.7±0.32 mmol/L were recruited for the 12-wk study. The subjects were randomly allocated to 2 groups; namely the treatment group (synbiotic product) and the control group (placebo), and each received 4 capsules of synbiotic or placebo daily. Our results showed that the mean body weight, energy, and nutrient intake of the subjects did not differ between the 2 groups over the study period. The supplementation of synbiotic reduced plasma total cholesterol and low-density lipoprotein (LDL)-cholesterol by 7.84 and 9.27%, respectively, compared with the control over 12 wk. Lipoproteins were subsequently subfractionated and characterized. The synbiotic supplementation resulted in a lower concentration of triglycerides in the very low, intermediate, low, and high-density lipoprotein particles compared with the control over 12 wk. The concentration of triglycerides in lipoproteins is positively correlated with an increased risk of atherosclerosis. Our results showed that the synbiotic might exhibit an atheropreventive characteristic. Cholesteryl ester (CE) in the high-density lipoprotein particles of the synbiotic group was also higher compared with the control, indicating greater transport of cholesterol in the form of CE to the liver for hydrolysis. This may have led to the reduced plasma total cholesterol level of the synbiotic group. The supplementation of synbiotic also reduced the concentration of CE in the LDL particles compared with the control, leading to the formation of smaller and denser particles that are more easily removed from blood. This supported the reduced LDL-cholesterol level of the synbiotic group compared with the control. Our present study showed that the synbiotic product improved plasma total- and LDL-cholesterol levels by modifying the interconnected pathways of lipid transporters. In addition, although Lactobacillus gasseri [corrected] CHO-220 could deconjugate bile, our results showed a statistically insignificant difference in the levels of conjugated, deconjugated, primary, and secondary bile acids between the synbiotic and control groups over 12 wk, indicating safety from bile-related toxicity.
  7. Squamous odontogenic tumor of the mandible: a case report demonstrating immunoexpression of Notch1, 3, 4, Jagged1 and Delta1
    Siar CH, Nakano K, Ng KH, Tomida M, Nagatsuka H, Kawakami T
    Eur J Med Res, 2010 Apr 08;15(4):180-4.
    PMID: 20554499
    BACKGROUND: Squamous odontogenic tumor (SOT) is a rare benign odontogenic epithelial neoplasm. A slow-growing painless expansive swelling is the common presenting symptom. Histopathologically, SOT can be easily misdiagnosed as an acanthomatous ameloblastoma. Although Notch receptors and ligands have been shown to play a role in cell fate decisions in ameloblastomas, the role of these cell signaling molecules in SOT is unknown.

    CASE REPORT: This paper describes a case of SOT affecting the anterior mandible of a 10-year-old Indian female. The patient was treated by local surgical excision and there has been no follow-up clinical record of recurrence 5 years after primary treatment. Histo?pathological examination revealed a solid, locally-infiltrative neoplasm composed of bland-looking squamatoid islands scattered in a mature fibrous connective tissue stroma and the diagnosis was SOT. Immunohistochemical evaluation showed positive reactivity of varying intensity in the neoplastic epithelial cells for Notch1, Notch3, Notch4, and their ligands Jagged1 and Delta1. Expression patterns showed considerable overlap. No immunoreactivity was detected for Notch2 and Jagged2.

    CONCLUSIONS: Present findings suggest that Notch receptors and their ligands play differential roles in the cytodifferentiation of SOT.

  8. Fulltext Basic fibroblast growth factor with human serum supplementation: enhancement of human chondrocyte proliferation and promotion of cartilage regeneration
    Chua KH, Aminuddin BS, Fuzina NH, Ruszymah BH
    Singapore Med J, 2007 Apr;48(4):324-32.
    PMID: 17384880
    The objectives of this study were to determine the optimum concentration of basic fibroblast growth factor (bFGF) in foetal bovine serum (FBS) or human serum (HS) supplemented medium for adult human nasal septum chondrocyte culture and to evaluate the potential of cartilage regeneration.
  9. Fulltext Managing congestive heart failure in a general hospital in Malaysia. Are we keeping pace with evidence?
    Chin SP, Sapari S, How SH, Sim KH
    Med J Malaysia, 2006 Aug;61(3):278-83.
    PMID: 17240575 MyJurnal
    Evidence-based heart failure management now includes beta-blockers and spironolactone in addition to diuretics and angiotensin-converting enzyme inhibitors. We aim to determine if these recommendations had been applied in practice for acute and chronic stable heart failure, and what difficulties there might be. Data from 80 consecutive patients hospitalized for decompensated heart failure ('acute') between May and July 2003 were analyzed at admission, upon discharge and at 12 weeks follow-up; along with 74 cardiology clinic out-patients with stable congestive heart failure ('chronic'- no decompensation or admission in previous six months). Less than half of study patients with prior left ventricular dysfunction were on ACE-inhibitors (47%), diuretics (39%), ATII antagonists, spironolactone or digoxin (5% each). All 'acute' patients were commenced on diuretics and ACE-inhibitors in hospital. Six patients died or transferred to another center. Compliance with clinic appointment at 12 weeks was 85% despite telephone reminders. Drug prescription at 12 weeks was significantly lower for diuretics and ACE-inhibitors compared to prescription at discharge (all p < 0.05) but higher compared to patients with chronic HF. Diuretics and ACE inhibitors remain under-utilized for patients with recurrent heart failure. Use of spironolactone and beta-blocker is slow due to limited medical experience and funding. Clinic non-attendance is significant and due to patient factors.
  10. A new genus and species of Scirtothrips genus-group (Thysanoptera, Thripidae), with two new species of Scirtothrips, from Dipterocarp Forest canopy in Malaysia
    Ng YF, Ain N, Rafti NS, Lau KH
    Zootaxa, 2023 Jun 23;5306(5):586-594.
    PMID: 37518665 DOI: 10.11646/zootaxa.5306.5.6
    A new genus and three new species are described from the canopy of Dipterocarp forest in Pasoh Forest Research in Malaysia: Daunothrips gen. n., D. striatus sp. n., Scirtothrips convexum sp. n. and Scirtothrips longifacies sp. n. The morphological characters of these new members of the Scirtothrips genus-group are discussed and illustrated.
  11. Assays to Study Hypoxia-Inducible Factor Prolyl Hydroxylase Domain 2 (PHD2), a Key Human Oxygen Sensing Protein
    Chan YY, Mbenza NM, Chan MC, Leung IKH
    Methods Mol Biol, 2023;2648:187-206.
    PMID: 37039992 DOI: 10.1007/978-1-0716-3080-8_12
    Molecular oxygen is essential for all multicellular life forms. In humans, the hypoxia-inducible factor (HIF) prolyl hydroxylase domain-containing enzymes (PHDs) serve as important oxygen sensors by regulating the activity of HIF, the master regulator that mediates cellular oxygen homeostasis, in an oxygen-dependent manner. In normoxia, PHDs catalyze the prolyl hydroxylation of HIF, which leads to its degradation and prevents cellular hypoxic response to be triggered. PHDs are current inhibition targets for the potential treatments of a number of diseases. In this chapter, we discuss in vitro and cell-based methods to study the modulation of PHD2, the most important human PHD isoform in normoxia and mild hypoxia. These include the production and purification of recombinant PHD2, the use of mass spectrometry to follow PHD2-catalyzed reactions and the studies of HIF stabilization in cells by immunoblotting.
  12. Contractile function of smooth muscle retained after overnight storage
    Loong BJ, Tan JH, Lim KH, Mbaki Y, Ting KN
    Naunyn Schmiedebergs Arch Pharmacol, 2015 Oct;388(10):1061-7.
    PMID: 26051407 DOI: 10.1007/s00210-015-1140-3
    The functional responses of different overnight-stored in vitro tissues are not clearly described in any animal model. The influence of overnight storage in an animal model may vary between tissue types. We employed Sprague-Dawley rat as our animal model and investigated the functional changes of rat aorta, trachea, bronchus and bladder that were used (i) immediately after surgical removal (denoted as fresh) and (ii) after storage in aerated (95% O2, 5% CO2) Krebs-Ringer bicarbonate solution at 4 °C for 24 h (denoted as stored). The aorta ring was pre-contracted with phenylephrine, and the functional response of the tissue was investigated using isoprenaline, forskolin and carbachol. Carbachol was also used to increase the tone in trachea, bronchus rings and bladder strips. A clear reduced function of endothelium, with a minor if any effect in the smooth muscle function in rat aorta was observed after overnight storage. The contractile response of overnight-stored rat airway (trachea and bronchus) and bladder smooth muscles remained unchanged. Among all tested tissues, only bronchus showed a reduced response rate (only 40% responded) after storage. In vitro rat tissues that are stored in Krebs solution at 4 °C for 24 h can still be used to investigate smooth muscle responses, however, not endothelium-mediated responses for aorta. The influence of overnight storage on different tissues from an animal model (Sprague-Dawley rat in our study) also provides an insight in maximising the use of sacrificed animals.
  13. Fulltext Development and evaluation of a Multiplex Polymerase Chain Reaction for the detection of Salmonella species
    Thong KL, Teh CS, Chua KH
    Trop Biomed, 2014 Dec;31(4):689-97.
    PMID: 25776594 MyJurnal
    The present study aims to develop a system which consists of four pairs of primers that specifically detects Salmonella spp., Salmonella serovar Typhi and Salmonella serovar Paratyphi A with an internal amplification control. The system, when applied in Polymerase Chain Reaction (PCR) under specific conditions, reaction mixture and cycling temperatures produced four bands; 784 bp, 496 bp, 332 bp and 187 bp. The DNA band 784 bp is present in all Salmonella spp., while the bands of 496 bp and 332 bp are only present in S. Paratyphi A and S. Typhi, respectively. An internal amplification control as indicated by the 187 bp shows the system is working in optimum condition in all the tests. This multiplex PCR was evaluated on 241 bacterial cultures and 691 naturally contaminated samples. Overall, this multiplex PCR detection system provides a single step for simultaneous detection of DNAs of Salmonella spp., S. Typhi and S. Paratyphi A.
  14. Myocardial collagen deposition and inflammatory cell infiltration in cats with pre-clinical hypertrophic cardiomyopathy
    Khor KH, Campbell FE, Owen H, Shiels IA, Mills PC
    Vet J, 2015 Feb;203(2):161-8.
    PMID: 25573453 DOI: 10.1016/j.tvjl.2014.11.018
    The histological features of feline hypertrophic cardiomyopathy (HCM) have been well documented, but there are no reports describing the histological features in mild pre-clinical disease, since cats are rarely screened for the disease in the early stages before clinical signs are apparent. Histological changes at the early stage of the disease in pre-clinical cats could contribute to an improved understanding of disease aetiology or progression. The aim of this study was to evaluate the histological features of HCM in the left ventricular (LV) myocardium of cats diagnosed with pre-clinical HCM. Clinically healthy cats with normal (n = 11) and pre-clinical HCM (n = 6) were identified on the basis of echocardiography; LV free wall dimensions (LVFWd) and/or interventricular septal wall (IVSd) dimensions during diastole of 6-7 mm were defined as HCM, while equivalent dimensions <5.5 mm were defined as normal. LV myocardial sections were assessed and collagen content and inflammatory cell infiltrates were quantified objectively. Multifocal areas of inflammatory cell infiltration, predominantly lymphocytes, were observed frequently in the left myocardium of cats with pre-clinical HCM. Tissue from cats with pre-clinical HCM also had a higher number of neutrophils and a greater collagen content than the myocardium of normal cats. The myocardium variably demonstrated other features characteristic of HCM, including arteriolar mural hypertrophy and interstitial fibrosis and, to a lesser extent, myocardial fibre disarray and cardiomyocyte hypertrophy. These results suggest that an inflammatory process could contribute to increased collagen content and the myocardial fibrosis known to be associated with HCM.
  15. Fulltext High-frequency hearing loss among mobile phone users
    Velayutham P, Govindasamy GK, Raman R, Prepageran N, Ng KH
    Indian J Otolaryngol Head Neck Surg, 2014 Jan;66(Suppl 1):169-72.
    PMID: 24533378 DOI: 10.1007/s12070-011-0406-4
    The objective of this study is to assess high frequency hearing (above 8 kHz) loss among prolonged mobile phone users is a tertiary Referral Center. Prospective single blinded study. This is the first study that used high-frequency audiometry. The wide usage of mobile phone is so profound that we were unable to find enough non-users as a control group. Therefore we compared the non-dominant ear to the dominant ear using audiometric measurements. The study was a blinded study wherein the audiologist did not know which was the dominant ear. A total of 100 subjects were studied. Of the subjects studied 53% were males and 47% females. Mean age was 27. The left ear was dominant in 63%, 22% were dominant in the right ear and 15% did not have a preference. This study showed that there is significant loss in the dominant ear compared to the non-dominant ear (P 
  16. AMP-activated protein kinase mediates insulin-like and lipo-mobilising effects of β-glucan-rich polysaccharides isolated from Pleurotus sajor-caju (Fr.), Singer mushroom, in 3T3-L1 cells
    Kanagasabapathy G, Chua KH, Malek SN, Vikineswary S, Kuppusamy UR
    Food Chem, 2014 Feb 15;145:198-204.
    PMID: 24128468 DOI: 10.1016/j.foodchem.2013.08.051
    Mushrooms have been used to treat various diseases for thousands of years. In the present study, the effects of Pleurotus sajor-caju mushroom on lipogenesis, lipolysis and oxidative stress in 3T3-L1 cells were investigated. The β-glucan-rich polysaccharides (GE) from P. sajor-caju stimulated lipogenesis and lipolysis but attenuated protein carbonyl and lipid hydroperoxide levels in 3T3-L1 cells. This extract caused an increase in the expression of 5'-AMP-activated protein kinase subunit γ-2 (PKRAG2) and 5'-AMP-activated protein kinase subunit γ-3 (PKRAG3) when compared to control (untreated) cells. Moreover, GE induced the expressions of hormone-sensitive lipase, adipose triglyceride lipase enzymes, leptin, adiponectin and glucose transporter-4 in 3T3-L1 cells which may have contributed to the lipolytic and insulin-like activities observed in this study. These findings suggest that GE is a novel AMPK activator that may be valuable in the formulation of nutraceuticals and functional food for the prevention and treatment of diabetes mellitus.
  17. Fulltext The use of radiochromic EBT2 film for the quality assurance and dosimetric verification of 3D conformal radiotherapy using Microtek ScanMaker 9800XL flatbed scanner
    Sim GS, Wong JH, Ng KH
    J Appl Clin Med Phys, 2013 Jul 08;14(4):4182.
    PMID: 23835383 DOI: 10.1120/jacmp.v14i4.4182
    Radiochromic and radiographic films are widely used for radiation dosimetry due to the advantage of high spatial resolution and two-dimensional dose measurement. Different types of scanners, including various models of flatbed scanners, have been used as part of the dosimetry readout procedure. This paper focuses on the characterization of the EBT2 film response in combination with a Microtek ScanMaker 9800XL scanner and the subsequent use in the dosimetric verification of a 3D conformal radiotherapy treatment. The film reproducibility and scanner uniformity of the Microtek ScanMaker 9800XL was studied. A three-field 3D conformal radiotherapy treatment was planned on an anthropomorphic phantom and EBT2 film measurements were carried out to verify the treatment. The interfilm reproducibility was found to be 0.25%. Over a period of three months, the films darkened by 1%. The scanner reproducibility was ± 2% and a nonuniformity was ±1.9% along the direction perpendicular to the scan direction. EBT2 measurements showed an underdose of 6.2% at high-dose region compared to TPS predicted dose. This may be due to the inability of the treatment planning system to predict the correct dose distribution in the presence of tissue inhomogeneities and the uncertainty of the scanner reproducibility and uniformity. The use of EBT2 film in conjunction with the axial CT image of the anthropomorphic phantom allows the evaluation of the anatomical location of dose discrepancies between the EBT2 measured dose distribution and TPS predicted dose distribution.
  18. Monoterpenes: Novel insights into their biological effects and roles on glucose uptake and lipid metabolism in 3T3-L1 adipocytes
    Tan XC, Chua KH, Ravishankar Ram M, Kuppusamy UR
    Food Chem, 2016 Apr 1;196:242-50.
    PMID: 26593489 DOI: 10.1016/j.foodchem.2015.09.042
    Various strategies have been adopted to combat complications caused by Type 2 diabetes mellitus and controlled diet is one of them. Monoterpenes, major constituents of essential oils, are synthesized and widely used as artificial food flavors. A series of twelve monoterpenes were assessed in the present study. Monoterpenes, exhibited low 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity even at high concentrations. Some monoterpenes inhibited α-amylase and α-glucosidase activity and stimulated glucose uptake and lipolysis. Monoterpenes such as (R)-(+)-limonene stimulated both glucose uptake (17.4%) and lipolysis (17.7%); the mRNA expression of glucose transporter 1 (GLUT1) was upregulated but glucose transporter 4 (GLUT4) was unaffected, and adipose triglyceride lipase (ATGL) was suppressed. Taken together, the selected monoterpenes may not confer strong protection against free radicals but nevertheless, their positive influence on lipid and glucose metabolism may have potential in the control of obesity and Type 2 diabetes mellitus.
  19. Development and dosimetric evaluation of a low-cost 3D-Printed PLA head CTDI phantom and CT parameter comparison with commercial phantom for CT quality assurance
    Hariyanto AP, Endarko E, Mardat MD, Almira L, Ng KH
    Radiography (Lond), 2026 Oct;32(7):103543.
    PMID: 42648226 DOI: 10.1016/j.radi.2026.103543
    INTRODUCTION: Commercial polymethyl methacrylate (PMMA) computed tomography dose index (CTDI) phantoms are widely used for CT dose assessment, but their cost and limited availability may restrict routine quality assurance, especially in resource-limited settings. This study evaluated the feasibility of a low-cost 3D-printed polylactic acid (PLA) head CTDI phantom as a complementary to commercial PMMA phantoms for CT dosimetry.

    METHODS: A 160-mm-diameter PLA head CTDI phantom with five dosimetry holes was fabricated using fused deposition modeling. Its elemental composition, density, effective atomic number, electron density, Hounsfield units (HU), and CT dosimetry parameters were characterized. Measurements were performed on 128-slice Ingenuity Philips and GE Discovery scanners, at 80, 120, and 140 kV. CTDI was measured at two different times and then compared with PMMA.

    RESULTS: PLA showed properties close to PMMA, with differences of 5.08% in density, -0.015% in effective atomic number, and -4.46% in electron density. PLA HU values were lower than PMMA, ranging from 22.5 to 45.3 HU on Philips and 25.1-49.1 HU on GE. CTDIvol deviations between PLA and PMMA ranged from -9.00% to -2.82% in November 2025 and from -5.78% to -3.83% in June 2026. These deviations remained within <10%, which was generally considered acceptable for comparative phantom-based CT dosimetry.

    CONCLUSION: The PLA CTDI phantom showed good effective atomic number, electron density, and dosimetric agreement with the standard PMMA phantom across two CT systems and two measurement time points.

    IMPLICATIONS FOR PRACTICE: 3D-printed PLA CTDI phantom could offer a practical, low-cost complementary tool for comparative CTDI measurement, education, protocol optimization, and quality assurance.

  20. ß-blockers in congestive heart failure
    Teh BT, Wan Azman WA, Thuraisingham S, Choy AM, Tan KH, Jesudason P, et al.
    JUMMEC, 1999;4:26-33.
    Activation of the synlpathetic nervous system (SNS) and renin-angiotensin system (RAS) plays a pivotal role in the pathophysiology and progression of the disease in chronic heart failure (CHF). Blocking the activation of the RAS with angiotensin converting enzyme inhibitors not only improves sylnptonls but also prolongs life in symptomatic CHF. Does a similar analogy hold true for the use of ß-blockers in CHF? Evidence from a number of small trials and several recent large prospective trials show that b-blockers may improve ventricular function and symptoms in CHF. In a combination of trials investigating the use of carvedilol (an α, and ß-blocker) in congestive heart failure a mortality benefit appears to be evident. There are still a number of key questions that relnaill unanswered regarding the tolerability, patient type and stage of CHF in which ß-blockers should be advocated. Several large scale trials are in progress to answer some of these questions and also to add further information regarding its efficacy and impact on survival. KEYWORDS: Beta-adrenoreceptor antagonist, congestive heart failure.
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