Displaying publications 1 - 20 of 114 in total

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  1. Fulltext A Biochemical and Pharmacological Characterization of Phospholipase A2 and Metalloproteinase Fractions from Eastern Russell's Viper (Daboia siamensis) Venom: Two Major Components Associated with Acute Kidney Injury
    Chaisakul J, Khow O, Wiwatwarayos K, Rusmili MRA, Prasert W, Othman I, et al.
    Toxins (Basel), 2021 Jul 26;13(8).
    PMID: 34437392 DOI: 10.3390/toxins13080521
    Acute kidney injury (AKI) following Eastern Russell's viper (Daboia siamensis) envenoming is a significant symptom in systemically envenomed victims. A number of venom components have been identified as causing the nephrotoxicity which leads to AKI. However, the precise mechanism of nephrotoxicity caused by these toxins is still unclear. In the present study, we purified two proteins from D. siamensis venom, namely RvPLA2 and RvMP. Protein identification using LCMS/MS confirmed the identity of RvPLA2 to be snake venom phospholipase A2 (SVPLA2) from Thai D. siamensis venom, whereas RvMP exhibited the presence of a factor X activator with two subunits. In vitro and in vivo pharmacological studies demonstrated myotoxicity and histopathological changes of kidney, heart, and spleen. RvPLA2 (3-10 µg/mL) caused inhibition of direct twitches of the chick biventer cervicis muscle preparation. After administration of RvPLA2 or RvMP (300 µg/kg, i.p.) for 24 h, diffuse glomerular congestion and tubular injury with minor loss of brush border were detected in envenomed mice. RvPLA2 and RvMP (300 µg/kg; i.p.) also induced congestion and tissue inflammation of heart muscle as well as diffuse congestion of mouse spleen. This study showed the significant roles of PLA2 and SVMP in snake bite envenoming caused by Thai D. siamensis and their similarities with observed clinical manifestations in envenomed victims. This study also indicated that there is a need to reevaluate the current treatment strategies for Thai D. siamensis envenoming, given the potential for irreversible nephrotoxicity.
    Matched MeSH terms: Myocardium/pathology
  2. Fulltext A Potential Link between the C5a Receptor 1 and the β1-Adrenoreceptor in the Mouse Heart
    Khor KH, Moore TA, Shiels IA, Greer RM, Arumugam TV, Mills PC
    PLoS One, 2016;11(1):e0146022.
    PMID: 26727203 DOI: 10.1371/journal.pone.0146022
    PURPOSE: Inflammation may contribute to the pathogenesis of specific cardiovascular diseases, but it is uncertain if mediators released during the inflammatory process will affect the continued efficacy of drugs used to treat clinical signs of the cardiac disease. We investigated the role of the complement 5a receptor 1 (C5aR1/CD88) in the cardiac response to inflammation or atenolol, and the effect of C5aR1 deletion in control of baseline heart rate in an anesthetized mouse model.

    METHODS: An initial study showed that PMX53, an antagonist of C5aR1 in normal C57BL6/J (wild type, WT) mice reduced heart rate (HR) and appeared to have a protective effect on the heart following induced sepsis. C5aR1 knockout (CD88-/-) mice had a lower HR than wild type mice, even during sham surgery. A model to assess heart rate variability (HRV) in anesthetized mice was developed to assess the effects of inhibiting the β1-adrenoreceptor (β1-AR) in a randomized crossover study design.

    RESULTS: HR and LF Norm were constitutively lower and SDNN and HF Norm constitutively higher in the CD88-/- compared with WT mice (P< 0.001 for all outcomes). Administration of atenolol (2.5 mg/kg) reduced the HR and increased HRV (P< 0.05, respectively) in the wild type but not in the CD88-/- mice. There was no shift of the sympathovagal balance post-atenolol in either strains of mice (P> 0.05), except for the reduced LF/HF (Lower frequency/High frequency) ratio (P< 0.05) at 60 min post-atenolol, suggesting increased parasympathetic tone of the heart due to the effect of atenolol administration. The HR of the WT mice were lower post atenolol compared to the CD88-/- mice (P = 0.001) but the HRV of CD88-/- mice were significantly increased (P< 0.05), compared with WT mice.

    CONCLUSION: Knockout of the C5aR1 attenuated the effect of β1-AR in the heart, suggesting an association between the β1-AR and C5aR1, although further investigation is required to determine if this is a direct or causal association.

    Matched MeSH terms: Myocardium/metabolism*
  3. Fulltext A conducting polymer with enhanced electronic stability applied in cardiac models
    Mawad D, Mansfield C, Lauto A, Perbellini F, Nelson GW, Tonkin J, et al.
    Sci Adv, 2016 Nov;2(11):e1601007.
    PMID: 28138526 DOI: 10.1126/sciadv.1601007
    Electrically active constructs can have a beneficial effect on electroresponsive tissues, such as the brain, heart, and nervous system. Conducting polymers (CPs) are being considered as components of these constructs because of their intrinsic electroactive and flexible nature. However, their clinical application has been largely hampered by their short operational time due to a decrease in their electronic properties. We show that, by immobilizing the dopant in the conductive scaffold, we can prevent its electric deterioration. We grew polyaniline (PANI) doped with phytic acid on the surface of a chitosan film. The strong chelation between phytic acid and chitosan led to a conductive patch with retained electroactivity, low surface resistivity (35.85 ± 9.40 kilohms per square), and oxidized form after 2 weeks of incubation in physiological medium. Ex vivo experiments revealed that the conductive nature of the patch has an immediate effect on the electrophysiology of the heart. Preliminary in vivo experiments showed that the conductive patch does not induce proarrhythmogenic activities in the heart. Our findings set the foundation for the design of electronically stable CP-based scaffolds. This provides a robust conductive system that could be used at the interface with electroresponsive tissue to better understand the interaction and effect of these materials on the electrophysiology of these tissues.
    Matched MeSH terms: Myocardium*
  4. A myopathy associated with protozoan schizonts in chickens in commercial farms in peninsular Malaysia
    Opitz HM, Jakob HJ, Wiensenhuetter E, Devi VV
    Avian Pathol, 1982;11(3):527-34.
    PMID: 18770216
    A myopathy associated with elongated intramuscular protozoan schizonts of uncertain classification was observed in chickens in commercial farms. Of 152 affected fowls originating from 21 flocks in 12 farms, 149 were 24 weeks of age or older and 136 were broiler breeder birds. Both sexes were affected. The disease was only observed during the months of October, November and December, 1976 and 1977. The monthly mortality rate in affected adult flocks rose by 0.5% to 4% and the egg production declined by 5% to 15% during this period. Most affected birds were in good body condition or overweight. Gross lesions were usually present in all skeletal muscles and the cardiac muscle. They resembled nutritional myopathy, sarcosporidiosis, leucocytozoonosis or haemorrhagic syndrome. Microscopically visible elongated schizonts were demonstrated in skeletal muscles and the cardiac muscle in 49 of 55 birds examined histologically. The possible aetiology with respect to known parasites of muscles in fowls is discussed.
    Matched MeSH terms: Myocardium
  5. A novel automated diagnostic system for classification of myocardial infarction ECG signals using an optimal biorthogonal filter bank
    Sharma M, Tan RS, Acharya UR
    Comput Biol Med, 2018 11 01;102:341-356.
    PMID: 30049414 DOI: 10.1016/j.compbiomed.2018.07.005
    Myocardial infarction (MI), also referred to as heart attack, occurs when there is an interruption of blood flow to parts of the heart, due to the acute rupture of atherosclerotic plaque, which leads to damage of heart muscle. The heart muscle damage produces changes in the recorded surface electrocardiogram (ECG). The identification of MI by visual inspection of the ECG requires expert interpretation, and is difficult as the ECG signal changes associated with MI can be short in duration and low in magnitude. Hence, errors in diagnosis can lead to delay the initiation of appropriate medical treatment. To lessen the burden on doctors, an automated ECG based system can be installed in hospitals to help identify MI changes on ECG. In the proposed study, we develop a single-channel single lead ECG based MI diagnostic system validated using noisy and clean datasets. The raw ECG signals are taken from the Physikalisch-Technische Bundesanstalt database. We design a novel two-band optimal biorthogonal filter bank (FB) for analysis of the ECG signals. We present a method to design a novel class of two-band optimal biorthogonal FB in which not only the product filter but the analysis lowpass filter is also a halfband filter. The filter design problem has been composed as a constrained convex optimization problem in which the objective function is a convex combination of multiple quadratic functions and the regularity and perfect reconstruction conditions are imposed in the form linear equalities. ECG signals are decomposed into six subbands (SBs) using the newly designed wavelet FB. Following to this, discriminating features namely, fuzzy entropy (FE), signal-fractal-dimensions (SFD), and renyi entropy (RE) are computed from all the six SBs. The features are fed to the k-nearest neighbor (KNN). The proposed system yields an accuracy of 99.62% for the noisy dataset and an accuracy of 99.74% for the clean dataset, using 10-fold cross validation (CV) technique. Our MI identification system is robust and highly accurate. It can thus be installed in clinics for detecting MI.
    Matched MeSH terms: Myocardium
  6. Ablation of IL-33 gene exacerbate myocardial remodeling in mice with heart failure induced by mechanical stress
    Veeraveedu PT, Sanada S, Okuda K, Fu HY, Matsuzaki T, Araki R, et al.
    Biochem Pharmacol, 2017 Aug 15;138:73-80.
    PMID: 28450225 DOI: 10.1016/j.bcp.2017.04.022
    BACKGROUND AND PURPOSE: ST2 is one of the interleukin (IL)-1 receptor family members comprising of membrane-bound (ST2L) and soluble (sST2) isoforms. Clinical trials have revealed that serum sST2 levels predict outcome in patient with myocardial infarction or chronic heart failure (HF). Meanwhile, we and others have reported that ablation of ST2 caused exaggerated cardiac remodeling in both ischemic and non-ischemic HF. Here, we tested whether IL-33, the ligand for ST2, protects myocardium against HF induced by mechanical overload using ligand specific knockout (IL-33(-/-)) mice.

    METHODS AND RESULTS: Transverse aortic constriction (TAC)/sham surgery were carried out in both IL-33 and WT-littermates. Echocardiographic measurements were performed at frequent interval during the study period. Heart was harvested for RNA and histological measurements. Following mechanical overload by TAC, myocardial mRNA expressions of Th1 cytokines, such as TNF-α were enhanced in IL-33(-/-) mice than in WT mice. After 8-weeks, IL-33(-/-) mice exhibited exacerbated left ventricular hypertrophy, increased chamber dilation, reduced fractional shortening, aggravated fibrosis, inflammation, and impaired survival compared with WT littermates. Accordingly, myocardial mRNA expressions of hypertrophic (c-Myc/BNP) molecular markers were also significantly enhanced in IL-33(-/-) mice than those in WT mice.

    CONCLUSIONS: We report for the first time that ablation of IL-33 directly and significantly leads to exacerbate cardiac remodeling with impaired cardiac function and survival upon mechanical stress. These data highlight the cardioprotective role of IL-33/ST2 system in the stressed myocardium and reveal a potential therapeutic role for IL-33 in non-ischemic HF.

    Matched MeSH terms: Myocardium/immunology; Myocardium/metabolism*; Myocardium/pathology
  7. Acute myocarditis mimicking ST-elevation myocardial infarction: A diagnostic challenge for frontline clinicians
    Ang KP, Quek ZQ, Lee CY, Lu HT
    Med J Malaysia, 2019 12;74(6):561-563.
    PMID: 31929492
    The clinical presentation of acute myocarditis is highly variable ranging from no symptoms to cardiogenic shock. Despite considerable progress, it remains a challenge for frontline physicians to discriminate between acute myocarditis and myocardial infarction, especially in the early phase. Our case serves as a reminder that acute presentation of myocarditis could resemble ST elevation myocardial infarction potentially misdirecting the therapeutic decision. The clinical presentation, electrocardiographic and laboratory findings of the patient are not specific enough to distinguish acute myocarditis from myocardial infarction. The gold standard tests such coronary angiography and cardiovascular magnetic resonance (CMR) can reliably differentiate the two entities.
    Matched MeSH terms: Myocardium/pathology*
  8. Fulltext Age-dependent atrial arrhythmic phenotype secondary to mitochondrial dysfunction in Pgc-1β deficient murine hearts
    Valli H, Ahmad S, Chadda KR, Al-Hadithi ABAK, Grace AA, Jeevaratnam K, et al.
    Mech Ageing Dev, 2017 Oct;167:30-45.
    PMID: 28919427 DOI: 10.1016/j.mad.2017.09.002
    INTRODUCTION: Ageing and several age-related chronic conditions including obesity, insulin resistance and hypertension are associated with mitochondrial dysfunction and represent independent risk factors for atrial fibrillation (AF).

    MATERIALS AND METHODS: Atrial arrhythmogenesis was investigated in Langendorff-perfused young (3-4 month) and aged (>12 month), wild type (WT) and peroxisome proliferator activated receptor-γ coactivator-1β deficient (Pgc-1β-/-) murine hearts modeling age-dependent chronic mitochondrial dysfunction during regular pacing and programmed electrical stimulation (PES).

    RESULTS AND DISCUSSION: The Pgc-1β-/- genotype was associated with a pro-arrhythmic phenotype progressing with age. Young and aged Pgc-1β-/- hearts showed compromised maximum action potential (AP) depolarization rates, (dV/dt)max, prolonged AP latencies reflecting slowed action potential (AP) conduction, similar effective refractory periods and baseline action potential durations (APD90) but shortened APD90 in APs in response to extrasystolic stimuli at short stimulation intervals. Electrical properties of APs triggering arrhythmia were similar in WT and Pgc-1β-/- hearts. Pgc-1β-/- hearts showed accelerated age-dependent fibrotic change relative to WT, with young Pgc-1β-/- hearts displaying similar fibrotic change as aged WT, and aged Pgc-1β-/- hearts the greatest fibrotic change. Mitochondrial deficits thus result in an arrhythmic substrate, through slowed AP conduction and altered repolarisation characteristics, arising from alterations in electrophysiological properties and accelerated structural change.

    Matched MeSH terms: Myocardium/metabolism
  9. Altered cardiac tissue and plasma kininogen levels in hypertensive and diabetic rats
    Sharma JN, Kesavarao U, Yusof AP
    Immunopharmacology, 1999 Sep;43(2-3):129-32.
    PMID: 10596843 DOI: 10.1016/s0162-3109(99)00070-3
    The present investigation was aimed at evaluating the cardiac and total plasma kininogen levels, as well as LVWT in hypertensive and diabetic rats. STZ-induced diabetes produced a significant (P < 0.001) rise in mean arterial blood pressure (BP). The LVWT increased (P < 0.001) in SHR with and without diabetes) and diabetic WKYR. The cardiac tissue, as well as total plasma kininogen levels fell significantly (P < 0.001) in diabetic WKYR and SHR with and without diabetes compared to the control WKYR. These findings suggest that reduced kininogen levels may indicate a deficiency in kinin generation in the heart and in the peripheral circulation in diabetic and hypertensive rats. This effect may contribute to the development of LVH.
    Matched MeSH terms: Myocardium/chemistry*
  10. Amyloidosis in Malaysian aborigines (Orang Asli)
    Looi LM, Prathap K
    Pathology, 1979 Oct;11(4):575-82.
    PMID: 93739
    Material from 334 consecutive autopsies on Orang Asli subjects performed in the University Hospital, Kuala Lumpur between May 1967 and June 1978 was examined for amyloidosis. Nine positive cases were found, all in patients above 40 years of age, giving an age-corrected incidence of about 9%. In 6 cases, amyloidosis was probably secondary to tuberculosis. The remaining 3 cases exhibited a pericollagenous distribution characteristic of primary amyloidosis. Involvement of the heart and lungs was prominent. However, there were considerable similarities in the distribution and staining properties of the amyloid in the 2 groups. Though both the heart and kidney were frequently affected, the kidney was the most common organ to give rise to clinical symptoms. Infection probably plays a major contributory role in amyloidosis in the Orang Asli.
    Matched MeSH terms: Myocardium/pathology
  11. An integrated index for automated detection of infarcted myocardium from cross-sectional echocardiograms using texton-based features (Part 1)
    Sudarshan VK, Acharya UR, Ng EY, Tan RS, Chou SM, Ghista DN
    Comput Biol Med, 2016 Apr 1;71:231-40.
    PMID: 26898671 DOI: 10.1016/j.compbiomed.2016.01.028
    Cross-sectional view echocardiography is an efficient non-invasive diagnostic tool for characterizing Myocardial Infarction (MI) and stages of expansion leading to heart failure. An automated computer-aided technique of cross-sectional echocardiography feature assessment can aid clinicians in early and more reliable detection of MI patients before subsequent catastrophic post-MI medical conditions. Therefore, this paper proposes a novel Myocardial Infarction Index (MII) to discriminate infarcted and normal myocardium using features extracted from apical cross-sectional views of echocardiograms. The cross-sectional view of normal and MI echocardiography images are represented as textons using Maximum Responses (MR8) filter banks. Fractal Dimension (FD), Higher-Order Statistics (HOS), Hu's moments, Gabor Transform features, Fuzzy Entropy (FEnt), Energy, Local binary Pattern (LBP), Renyi's Entropy (REnt), Shannon's Entropy (ShEnt), and Kapur's Entropy (KEnt) features are extracted from textons. These features are ranked using t-test and fuzzy Max-Relevancy and Min-Redundancy (mRMR) ranking methods. Then, combinations of highly ranked features are used in the formulation and development of an integrated MII. This calculated novel MII is used to accurately and quickly detect infarcted myocardium by using one numerical value. Also, the highly ranked features are subjected to classification using different classifiers for the characterization of normal and MI LV ultrasound images using a minimum number of features. Our current technique is able to characterize MI with an average accuracy of 94.37%, sensitivity of 91.25% and specificity of 97.50% with 8 apical four chambers view features extracted from only single frame per patient making this a more reliable and accurate classification.
    Matched MeSH terms: Myocardium
  12. Fulltext An inverse finite element method for determining the tissue compressibility of human left ventricular wall during the cardiac cycle
    Hassaballah AI, Hassan MA, Mardi AN, Hamdi M
    PLoS One, 2013;8(12):e82703.
    PMID: 24367544 DOI: 10.1371/journal.pone.0082703
    The determination of the myocardium's tissue properties is important in constructing functional finite element (FE) models of the human heart. To obtain accurate properties especially for functional modeling of a heart, tissue properties have to be determined in vivo. At present, there are only few in vivo methods that can be applied to characterize the internal myocardium tissue mechanics. This work introduced and evaluated an FE inverse method to determine the myocardial tissue compressibility. Specifically, it combined an inverse FE method with the experimentally-measured left ventricular (LV) internal cavity pressure and volume versus time curves. Results indicated that the FE inverse method showed good correlation between LV repolarization and the variations in the myocardium tissue bulk modulus K (K = 1/compressibility), as well as provided an ability to describe in vivo human myocardium material behavior. The myocardium bulk modulus can be effectively used as a diagnostic tool of the heart ejection fraction. The model developed is proved to be robust and efficient. It offers a new perspective and means to the study of living-myocardium tissue properties, as it shows the variation of the bulk modulus throughout the cardiac cycle.
    Matched MeSH terms: Myocardium/metabolism
  13. An online open-source tool for automated quantification of liver and myocardial iron concentrations by T2* magnetic resonance imaging
    Git KA, Fioravante LA, Fernandes JL
    Br J Radiol, 2015 Sep;88(1053):20150269.
    PMID: 26118302 DOI: 10.1259/bjr.20150269
    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.
    Matched MeSH terms: Myocardium/metabolism; Myocardium/chemistry*
  14. Angiostrongylus malaysiensis (Nematoda: Metastrongylidae), a new species of rat lung-worm from Malaysia
    Bhaibulaya M, Cross JH
    Southeast Asian J. Trop. Med. Public Health, 1971 Dec;2(4):527-33.
    PMID: 5144154
    Matched MeSH terms: Myocardium/pathology
  15. Fulltext Angiotensin II Type I Receptor Antagonism Attenuates Nicotine-Induced Cardiac Remodeling, Dysfunction, and Aggravation of Myocardial Ischemia-Reperfusion Injury in Rats
    Ramalingam A, Budin SB, Mohd Fauzi N, Ritchie RH, Zainalabidin S
    Front Pharmacol, 2019;10:1493.
    PMID: 31920673 DOI: 10.3389/fphar.2019.01493
    Increased exposure to nicotine contributes to the development of cardiac dysfunction by promoting oxidative stress, fibrosis, and inflammation. These deleterious events altogether render cardiac myocytes more susceptible to acute cardiac insults such as ischemia-reperfusion (I/R) injury. This study sought to elucidate the role of angiotensin II type I (AT1) receptors in cardiac injury resulting from prolonged nicotine administration in a rat model. Male Sprague-Dawley rats were given nicotine (0.6 mg/kg ip) for 28 days to induce cardiac dysfunction, alone or in combination with the AT1 receptor antagonist, irbesartan (10 mg/kg, po). Vehicle-treated rats were used as controls. Rat hearts isolated from each experimental group at study endpoint were examined for changes in function, histology, gene expression, and susceptibility against acute I/R injury determined ex vivo. Rats administered nicotine alone exhibited significantly increased cardiac expression of angiotensin II and angiotensin-converting enzyme (ACE) in addition to elevated systolic blood pressure (SBP) and heart rate. Furthermore, nicotine administration markedly reduced left ventricular (LV) performance with concomitant increases in myocardial oxidative stress, fibrosis, and inflammation. Concomitant treatment with irbesartan attenuated these effects, lowering blood pressure, heart rate, oxidative stress, and expression of fibrotic and inflammatory genes. Importantly, the irbesartan-treated group also manifested reduced susceptibility to I/R injury ex vivo. These findings suggest that AT1 receptors play an important role in nicotine-induced cardiac dysfunction, and pharmacological approaches targeting cardiac AT1 receptors may thus benefit patients with sustained exposure to nicotine.
    Matched MeSH terms: Myocardium
  16. Fulltext Anterior Myocardial Infarction Associated with Myocardial Bridging in a Young Man
    Ngow, H.A., Wan Khairina, W.M.N.
    International Medical Journal Malaysia, 2010;9(2):67-70.
    MyJurnal
    A 43-year-old man presented with acute extensive anterior ST-segment elevation myocardial infarction. During coronary angiogram, a segment of myocardial bridging was noted in the mid-segment of left anterior descending artery. The association of myocardial bridging and an anterior ST segment elevation is rarely reported in the medical literature. Myocardial bridging is caused by systolic compression of a coronary artery by overlying myocardium tissue. It is a rare coronary artery anomaly, which usually has a benign prognosis despite some case reports of myocardial ischemia leading to myocardial infarction, lethal arrhythmias and sudden cardiac death. We report one such case of myocardial bridging that was complicated with acute extensive anterior myocardial infarction.
    Matched MeSH terms: Myocardium
  17. Fulltext Anterior penetrating chest injury with left ventricular thrombus
    Ruth Sabrina, S., Nik Azlan, N.M., Adi, O.
    Medicine & Health, 2013;8(1):28-32.
    MyJurnal
    Urban cities are synonym with a high incidence of penetrating chest injuries either from accidents or interpersonal violence. The outcome of penetrating chest wound can vary from immediate death to a prolonged morbidity. We here report a case of 39-year-gentleman who presented to Emergency Department Hospital Raja Permaisuri Bainun, Ipoh, Perak after being stabbed to the chest. His anterior penetrating chest wound was located at the 5th intercostal space medial to the midclavicular line. The stab wound penetrated the myocardium, causing minimal myocardial rupture. He also suffered from left haemothorax and hemopericardium. The haemothorax was drained with insertion of 32 French chest tube. The patient was admitted under the cardiothoracic team and discharged five days later without surgical intervention. He presented again to the Emergency Department with complains of shortness of breath and pleuritic pain. A left ventricular thrombus was detected via echocardiography. Unfortunately, he took his own discharge. Five days later he came again to Emergency Department with sporadic of loss of vision. The mural thrombus dislodged and embolized to the retinal artery causing amaurosis fugax. The patient was treated with aspirin 150mg and his symptoms subsequently resolved.
    Matched MeSH terms: Myocardium
  18. Fulltext Artifacts reduction in strain maps of tagged magnetic resonance imaging using harmonic phase
    Wang D, Fu Y, Ashraf MA
    Open Med (Wars), 2015;10(1):425-433.
    PMID: 28352731 DOI: 10.1515/med-2015-0074
    Tagged Magnetic Resonance Imaging (MRI) is a noninvasive technique for examining myocardial function and deformation. Tagged MRI can also be used in quasi-static MR elastography to acquire strain maps of other biological soft tissues. Harmonic phase (HARP) provides automatic and rapid analysis of tagged MR images for the quantification and visualization of myocardial strain. We propose a new artifact reduction method in strain maps. Image intensity of the DC component is estimated and subtracted from spatial modulation of magnetization (SPAMM) tagged MR images. DC peak interference in harmonic phase extraction is greatly reduced after DC component subtraction. The proposed method is validated using both simulated and MR acquired tagged images. Strain maps are obtained with better accuracy and smoothness after DC component subtraction.
    Matched MeSH terms: Myocardium
  19. Assessing regional left ventricular thickening dysfunction and dyssynchrony via personalized modeling and 3D wall thickness measurements for acute myocardial infarction
    Khalid A, Lim E, Chan BT, Abdul Aziz YF, Chee KH, Yap HJ, et al.
    J Magn Reson Imaging, 2019 04;49(4):1006-1019.
    PMID: 30211445 DOI: 10.1002/jmri.26302
    BACKGROUND: Existing clinical diagnostic and assessment methods could be improved to facilitate early detection and treatment of cardiac dysfunction associated with acute myocardial infarction (AMI) to reduce morbidity and mortality.

    PURPOSE: To develop 3D personalized left ventricular (LV) models and thickening assessment framework for assessing regional wall thickening dysfunction and dyssynchrony in AMI patients.

    STUDY TYPE: Retrospective study, diagnostic accuracy.

    SUBJECTS: Forty-four subjects consisting of 15 healthy subjects and 29 AMI patients.

    FIELD STRENGTH/SEQUENCE: 1.5T/steady-state free precession cine MRI scans; LGE MRI scans.

    ASSESSMENT: Quantitative thickening measurements across all cardiac phases were correlated and validated against clinical evaluation of infarct transmurality by an experienced cardiac radiologist based on the American Heart Association (AHA) 17-segment model.

    STATISTICAL TEST: Nonparametric 2-k related sample-based Kruskal-Wallis test; Mann-Whitney U-test; Pearson's correlation coefficient.

    RESULTS: Healthy LV wall segments undergo significant wall thickening (P Myocardium with thick infarct (ie, >50% transmurality) underwent remarkable wall thinning during contraction (thickening index [TI] = 1.46 ± 0.26 mm) as opposed to healthy myocardium (TI = 4.01 ± 1.04 mm). For AMI patients, LV that showed signs of thinning were found to be associated with a significantly higher percentage of dyssynchrony as compared with healthy subjects (dyssynchrony index [DI] = 15.0 ± 5.0% vs. 7.5 ± 2.0%, P 

    Matched MeSH terms: Myocardium/pathology
  20. Fulltext Autopsy findings in 35 cases of leprosy in Malaysia
    Jayalakshmi P, Looi LM, Lim KJ, Rajogopalan K
    Int. J. Lepr. Other Mycobact. Dis., 1987 Sep;55(3):510-4.
    PMID: 3655465
    The findings of autopsies performed on 35 leprosy subjects in the University Hospital, Kuala Lumpur, between January 1981 and December 1985 are presented. This is the first report based on autopsy findings from Malaysia. The patients were elderly subjects with a mean age of 74 years. Sixty-six percent had lepromatous leprosy. None had active skin lesions. The most common cause of death was pyogenic infection, particularly bronchopneumonia. Tuberculosis was noted in 25% of the cases. The other important causes of death included cardiac and renal failure. Renal lesions were evident in 71% of the cases, and the most common pathology was interstitial nephritis. Generalized amyloidosis complicated six (17%) patients.
    Matched MeSH terms: Myocardium/pathology
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