Displaying publications 61 - 80 of 117 in total

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  1. Osman J, Tan SC, Lee PY, Low TY, Jamal R
    J Biomed Sci, 2019 May 22;26(1):39.
    PMID: 31118017 DOI: 10.1186/s12929-019-0535-8
    Sudden cardiac death (SCD) is a sudden, unexpected death that is caused by the loss of heart function. While SCD affects many patients suffering from coronary artery diseases (CAD) and heart failure (HF), a considerable number of SCD events occur in asymptomatic individuals. Certain risk factors for SCD have been identified and incorporated in different clinical scores, however, risk stratification using such algorithms is only useful for health management rather than for early detection and prediction of future SCD events in high-risk individuals. In this review, we discuss different molecular biomarkers that are used for early detection of SCD. This includes genetic biomarkers, where the majority of them are genomic variants for genes that encode for ion channels. Meanwhile, protein biomarkers often denote proteins that play roles in pathophysiological processes that lead to CAD and HF, notably (i) atherosclerosis that involves oxidative stress and inflammation, as well as (ii) cardiac tissue damage that involves neurohormonal and hemodynamic regulation and myocardial stress. Finally, we outline existing challenges and future directions including the use of OMICS strategy for biomarker discovery and the multimarker panels.
    Matched MeSH terms: Myocardium
  2. Zainudin H, Caszo BA, Knight VF, Gnanou JV
    Eurasian J Med, 2019 Jun;51(2):116-120.
    PMID: 31258349 DOI: 10.5152/eurasianjmed.2019.18106
    Objective: Regular moderate-intensity exercise has beneficial health effects, whereas regular strenuous exercise increases the production of oxidants that may lead to DNA, skeletal, and cardiac muscle damages. Triathletes experience strenuous muscular activity both during competition and training, being at risk of developing these tissue damages. The objective of the present study was to estimate DNA, skeletal, and cardiac muscle damages using blood biomarkers, 8-hydroxy-2'-deoxyguanosine (8-OHdG), myoglobin, and cardiac troponin I (cTnI) among young triathletes.

    Materials and Methods: Age-matched seven male and seven female triathletes were recruited for the study. They were on a standardized training regimen and on average competed in at least one endurance event every month for the past 3-4 years. Serum biomarkers were measured using enzyme-linked immunosorbent assay at the start and at end of the racing season.

    Results: Both male and female triathletes showed a statistically significant increase in 8-OHdG. A similar pattern of increase was seen with serum myoglobin, which was not statistically significant in both male and female triathletes. cTnI levels did not show any change in both sexes.

    Conclusion: Our study shows that there could be an increased evidence of DNA damage among triathletes. However, similar effects were not observed with skeletal and cardiac muscle biomarkers.

    Matched MeSH terms: Myocardium
  3. Wee Ling JL, Khan A, Saad B, Ab Ghani S
    Talanta, 2012 Jan 15;88:477-83.
    PMID: 22265529 DOI: 10.1016/j.talanta.2011.11.018
    A new poly(4-vinyl pyridine) (P4VP) based cadmium (Cd)-ion selective electrode (ISE) was developed. The 4-vinyl pyridine (4VP) was first polymerized electrochemically on the surface of graphite, later characterized by FTIR, SEM/EDX and then optimized as ISE for Cd. At optimal pH 6.4, slope of 27.7±0.8mVdecade(-1), linear concentration range of 1×10(-7) to 1.0×10(-1)M Cd(2+) and limit of detection (S/N=3) of 2.51×10(-8)M were obtained. The ISE was very selective towards Cd(2+), with K(pot)<1×10(-2) in the presence of the usual cations and anions in water samples. Response time and shelf life of less than 1min and 90 days, respectively, were observed. Its application was tested in various types of samples.
    Matched MeSH terms: Myocardium/chemistry
  4. Dayapala A, Kumar V
    Am J Forensic Med Pathol, 2009 Jun;30(2):171-4.
    PMID: 19465810 DOI: 10.1097/PAF.0b013e3181875a79
    Sudden deaths because of congenital heart diseases are infrequently referred to the forensic pathologist for autopsy. Many of such deaths, if already diagnosed are released directly from the hospital without autopsy. Even forensic pathologists face a few difficulties in performing the autopsy on such infrequent cases, as they are not always updated with the anatomy of anomalies. While dealing with such cases, the concerned forensic pathologist is compelled to refer literature and textbooks again to understand the nature of developmental defects. This is especially so when dealing with cases of situs inversus accompanied by transposition of great arteries and other congenital cardiac abnormalities and variants such as single ventricle, double outlet right ventricle, Taussig-Bing variety etc. In the present case also, situs inversus with transposition of great vessels and other anomalies have been noted and studied.
    Matched MeSH terms: Myocardium/pathology*
  5. Chan BT, Lim E, Chee KH, Abu Osman NA
    Comput Biol Med, 2013 May;43(4):377-85.
    PMID: 23428371 DOI: 10.1016/j.compbiomed.2013.01.013
    The heart is a sophisticated functional organ that plays a crucial role in the blood circulatory system. Hemodynamics within the heart chamber can be indicative of exert cardiac health. Due to the limitations of current cardiac imaging modalities, computational fluid dynamics (CFD) have been widely used for the purposes of cardiac function assessment and heart disease diagnosis, as they provide detailed insights into the cardiac flow field. An understanding of ventricular hemodynamics and pathological severities can be gained through studies that employ the CFD method. In this research the hemodynamics of two common myocardial diseases, dilated cardiomyopathy (DCM) and myocardial infarction (MI) were investigated, during both the filling phase and the whole cardiac cycle, through a prescribed geometry and fluid structure interaction (FSI) approach. The results of the research indicated that early stage disease identification and the improvement of cardiac assisting devices and therapeutic procedures can be facilitated through the use of the CFD method.
    Matched MeSH terms: Myocardium/pathology
  6. Wan Muhaizan WM, Swaminathan M, Daud MS
    Malays J Pathol, 2004 Jun;26(1):59-63.
    PMID: 16196153
    Cardiac sarcoidosis is a disease of young adults. In most cases it presents with sudden death, arrhythmias, conduction disorders, heart failure or cardiomyopathy. The authors describe two cases of myocardial involvement by sarcoidosis that lead to death of the patients. Case one was a 26-year-old Indian man who was previously well and presented with sudden death. Autopsy showed nodules of sarcoid granuloma involving the heart, lungs and lymph nodes. Case two was a 47-year-old Indian lady who complained of reduced effort tolerance. Echocardiography showed that she had restrictive hypertrophic cardiomyopathy with heart failure. Seven months after initial presentation, she developed worsening of heart failure and died. Autopsy revealed involvement of the heart, lungs and liver by sarcoidosis.
    Matched MeSH terms: Myocardium/pathology
  7. Looi LM
    Histopathology, 1981 Nov;5(6):615-22.
    PMID: 7319480
    Nineteen out of 121 consecutive cardiac biopsies from 107 patients were found to contain amyloid deposits on routine Congo red screening. Seventeen were left atrial appendages removed during mitral valvotomy for chronic rheumatic mitral valve disease while the remaining two were right atrial appendages excised during surgical repair of atrial septal defects. The distribution of amyloid deposits within the atria and their tinctorial characteristics are described. The high prevalence of atrial amyloidosis observed could not be attributed to generalized or senile amyloidosis. The possibility that this is a distinctive localized form of amyloidosis secondary to chronic heart disease is discussed.
    Matched MeSH terms: Myocardium/pathology*
  8. 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
  9. Fujimoto Y, Suzuki Y, Kanaiwa T, Amiya T, Hoshi K, Fujino S
    J. Pharmacobio-dyn., 1983 Feb;6(2):128-35.
    PMID: 6306201
    The present research is on a milky sap obtained from the Antiaris toxicaria tree (Moraceae) which is called Upas or Ipoh in Indonesia. The crude sap was administered to anesthetized rats, and changes in electrocardiogram (ECG) and systemic blood pressure was observed. Biologically and pharmacologically active components were extracted from the crude sap by means of water-acetone solution. Based on the strength of chemical qualitative detection tests of the sap extract (SE), cardiac glycosides are supposed to be the main components. The SE inhibited the Na+-, K+-ATPase (EC 3.6.1.3) which was partially purified from guinea pig heart muscle. When the SE and, concurrently, authentic ouabain were applied to isolated frog heart muscles, the fall of twitch tension was observed after the increased tension on mechanograms. These facts suggest that the main components of the milky sap are cardiac glycosides, and glycosides affect Na+, K+-ATPase activity of muscle membrane and heart muscle contraction.
    Matched MeSH terms: Myocardium/enzymology
  10. Lim WY, Thevarajah TM, Goh BT, Khor SM
    Biosens Bioelectron, 2019 Mar 01;128:176-185.
    PMID: 30685097 DOI: 10.1016/j.bios.2018.12.049
    The early detection of acute myocardial infarction (AMI) upon the onset of chest pain symptoms is crucial for patient survival. However, this detection is challenging, particularly without a persistent elevation of ST-segment reflected in an electrocardiogram or in blood tests. A majority of the available point-of-care testing devices allow accurate and rapid diagnosis of AMI. However, AMI diagnosis is reliable only at intermediate and later stages, with myocardial injury (> 6 h) and MI, based on the expression of specific cardiac biomarkers including troponin I or T (cTnI or cTnT), creatine kinase-MB (CK-MB), and myoglobin. Diagnosis at the early myocardial ischemia stage is not possible. To overcome this limitation, a sensitive and rapid microfluidic paper-based device (µPAD) was developed for the simultaneous detection of multiple cardiac biomarkers for the early and late diagnosis of AMI. The glycogen phosphorylase isoenzyme BB (GPBB) was detected during early (within first 4 h) ischemic myocardial injury. On the same µPAD platform, detection of prolonged elevation of levels of cTnT and CK-MB, which are only produced 6 h after the onset of chest pain in human serum, was possible. Sandwich immunoassay performed on the µPAD achieved reproducibility (RSD approximately 10% and intra-and inter-day precision (CV 10-20%, 99th percentile), as well as consistently stable test results for 28 days, with strong correlation (r2= 0.962), using the standard Siemens Centaur XPT Immunoassay system. The present findings indicate the potential of the µPAD platform as a point-of-care device for the early diagnosis and prognosis of AMI.
    Matched MeSH terms: Myocardium/pathology
  11. Teah YF, Abduraman MA, Amanah A, Adenan MI, Sulaiman SF, Tan ML
    Food Chem Toxicol, 2017 Sep;107(Pt A):293-301.
    PMID: 28689918 DOI: 10.1016/j.fct.2017.07.011
    Elephantopus scaber Linn and its major bioactive component, deoxyelephantopin are known for their medicinal properties and are often reported to have various cytotoxic and antitumor activities. This plant is widely used as folk medicine for a plethora of indications although its safety profile remains unknown. Human ether-a-go-go-related gene (hERG) encodes the cardiac IKr current which is a determinant of the duration of ventricular action potentials and QT interval. The hERG potassium channel is an important antitarget in cardiotoxicity evaluation. This study investigated the effects of deoxyelephantopin on the current, mRNA and protein expression of hERG channel in hERG-transfected HEK293 cells. The hERG tail currents following depolarization pulses were insignificantly affected by deoxyelephantopin in the transfected cell line. Current reduction was less than 40% as compared with baseline at the highest concentration of 50 μM. The results were consistent with the molecular docking simulation and hERG surface protein expression. Interestingly, it does not affect the hERG expression at both transcriptional and translational level at most concentrations, although higher concentration at 10 μM caused protein accumulation. In conclusion, deoxyelephantopin is unlikely a clinically significant hERG channel and Ikr blocker.
    Matched MeSH terms: Myocardium/metabolism*
  12. 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
  13. Fung SY, Tan NH, Liew SH, Sim SM, Aguiyi JC
    Trop Biomed, 2009 Apr;26(1):80-4.
    PMID: 19696731
    Seed of Mucuna pruriens (Velvet beans) has been prescribed by traditional medicine practitioners in Nigeria as a prophylactic oral antisnake remedy. In the present studies, we investigated the protective effects of M. pruriens seed extract (MPE) against histopathological changes induced by intravenous injection of Naja sputatrix (Malayan cobra) venom in rats pretreated with the seed extract. Examination by light microscope revealed that the venom induced histopathological changes in heart and blood vessels in liver, but no effect on brain, lung, kidney and spleen. The induced changes were prevented by pretreatment of the rats with MPE. Our results suggest that MPE pretreatment protects rat heart and liver blood vessels against cobra venom-induced damages.
    Matched MeSH terms: Myocardium/pathology*
  14. Giribabu N, Roslan J, Rekha SS, Salleh N
    Int J Cardiol, 2016 Nov 01;222:850-65.
    PMID: 27522389 DOI: 10.1016/j.ijcard.2016.07.250
    BACKGROUND: We hypothesized that consumption of Vitis vinifera seed by diabetics could help to ameliorate myocardial damage. Therefore, in this study, we investigated effects of V. vinifera seed methanolic extract (VVSME) on parameters related to myocardial damage in diabetes with or without myocardial infarction (MI).

    METHODS: Streptozotocin-nicotinamide induced diabetic rats received oral VVSME for 28days. MI was induced by intraperitoneal injection of isoproterenol on last two days. Prior to sacrifice, blood was collected and fasting blood glucose (FBG), glycated hemoglobin (HbA1c), lipid profile and insulin levels were measured. Levels of serum cardiac injury marker (troponin-I and CK-MB) were determined and histopathological changes in the heart were observed following harvesting. Levels of oxidative stress (LPO, SOD, CAT, GPx and RAGE), inflammation (NF-κB, TNF-α, IL-1β and IL-6) and cardiac ATPases (Na(+)/K(+)-ATPase and Ca(2+)-ATPase) were determined in heart homogenates. LC-MS was used to identify constituents in the extracts.

    RESULTS: Consumption of VVSME by diabetic rats with or without MI improved the metabolic profiles while decreased the cardiac injury marker levels with lesser myocardial damage observed. Additionally, VVSME consumption reduced the levels of LPO, RAGE, TNF-α, Iκκβ, NF-κβ, IL-1β and IL-6 while increased the levels of SOD, CAT, GPx, Na(+)/K(+)-ATPase and Ca(2+)-ATPase in the infarcted and non-infarcted heart of diabetic rats (p<0.05). LC-MS analysis revealed 17 major compounds in VVSME which might be responsible for the observed effects.

    CONCLUSIONS: Consumption of VVSME by diabetics helps to ameliorate damage to the infarcted and non-infarcted myocardium by decreasing oxidative stress, inflammation and cardiac ATPases dysfunctions.

    Matched MeSH terms: Myocardium/metabolism
  15. Cheah HY, Šarenac O, Arroyo JJ, Vasić M, Lozić M, Glumac S, et al.
    Nanotoxicology, 2017 03;11(2):210-222.
    PMID: 28098511 DOI: 10.1080/17435390.2017.1285071
    Conjugation of Doxorubicin (DOX) to N-(2-hydroxypropyl) methylacrylamide copolymer (HPMA) has significantly reduced the DOX-associated cardiotoxicity. However, the reports on the impact of HPMA-DOX conjugates on the cardiovascular system such as blood pressure (BP) and heart rate (HR) were in restrained animals using tail cuff and/or other methods that lacked the resolution and sensitivity. Herein, we employed radiotelemetric-spectral-echocardiography approach to further understand the in vivo cardiovascular hemodynamics and variability post administration of free DOX and HPMA-DOX. Rats implanted with radio-telemetry device were administered intravenously with DOX (5 mg/kg), HPMA-DOX (5 mg DOX equivalent/kg) and HPMA copolymer and subjected to continuous cardiovascular monitoring and echocardiography for 140 days. We found that DOX-treated rats had ruffled fur, reduced body weight (BW) and a low survival rate. Although BP and HR were normal, spectral analysis indicated that their BP and HR variabilities were reduced. All rats exhibited typical signs of cardiotoxicity at histopathology. In contrast, HPMA-DOX rats gained weight over time and survived. Although BP, HR and related variabilities were unaffected, the left ventricular end diastolic volume (EDV) of these rats, as well as of the HPMA copolymer-treated rats, was found increased at the end of observation period. Additionally, HPMA copolymer caused microscopic injury of the heart tissue. All of these suggest the necessity of caution when employing HPMA as carrier for prolonged drug delivery. The current study also indicates the potential of radiotelemetric-spectral-echocardiography approach for improved preclinical cardiovascular risk assessment of polymer-drug conjugate and other nano-sized-drug constructs.
    Matched MeSH terms: Myocardium/pathology
  16. 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
  17. Ng WH, Yong YK, Ramasamy R, Ngalim SH, Lim V, Shaharuddin B, et al.
    Int J Mol Sci, 2019 Nov 06;20(22).
    PMID: 31698679 DOI: 10.3390/ijms20225519
    Cardiac c-kit cells show promise in regenerating an injured heart. While heart disease commonly affects elderly patients, it is unclear if autologous cardiac c-kit cells are functionally competent and applicable to these patients. This study characterised cardiac c-kit cells (CCs) from aged mice and studied the effects of human Wharton's Jelly-derived mesenchymal stem cells (MSCs) on the growth kinetics and cardiac differentiation of aged CCs in vitro. CCs were isolated from 4-week- and 18-month-old C57/BL6N mice and were directly co-cultured with MSCs or separated by transwell insert. Clonogenically expanded aged CCs showed comparable telomere length to young CCs. However, these cells showed lower Gata4, Nkx2.5, and Sox2 gene expressions, with changes of 2.4, 3767.0, and 4.9 folds, respectively. Direct co-culture of both cells increased aged CC migration, which repopulated 54.6 ± 4.4% of the gap area as compared to aged CCs with MSCs in transwell (42.9 ± 2.6%) and CCs without MSCs (44.7 ± 2.5%). Both direct and transwell co-culture improved proliferation in aged CCs by 15.0% and 16.4%, respectively, as traced using carboxyfluorescein succinimidyl ester (CFSE) for three days. These data suggest that MSCs can improve the growth kinetics of aged CCs. CCs retaining intact telomere are present in old hearts and could be obtained based on their self-renewing capability. Although these aged CCs with reduced growth kinetics are improved by MSCs via cell-cell contact, the effect is minimal.
    Matched MeSH terms: Myocardium/cytology*
  18. 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*
  19. Sharma JN, Kesavarao U
    Immunopharmacology, 1996 Jun;33(1-3):341-3.
    PMID: 8856181 DOI: 10.1016/0162-3109(96)00104-x
    This study examined the effects of streptozotocin-induced diabetes on blood pressure and cardiac tissue kallikrein levels in WKYR and SHR. Streptozotocin-induced diabetes caused significant (p < 0.001) increase in SBP and DBP in WKYR and SHR as compared with their respective controls. We also observed that the active cardiac tissue kallikrein levels reduced greatly (p < 0.001) in diabetic WKYR and SHR than the normal rats. These findings suggest for the first time that the cardiac tissue kallikrein formation may have a greater role in the regulation of blood pressure and cardiac function.
    Matched MeSH terms: Myocardium/metabolism*
  20. Sharma JN, Uma K, Yusof AP
    Int J Cardiol, 1998 Feb 28;63(3):229-35.
    PMID: 9578349 DOI: 10.1016/s0167-5273(97)00329-x
    We investigated the cardiac tissue kallikrein and kininogen levels, left ventricular wall thickness and mean arterial blood pressure of Wistar Kyoto and spontaneously hypertensive rats with and without streptozotocin-induced diabetes. The mean arterial blood pressure was highly elevated (P<0.001) in Wistar Kyoto diabetic and spontaneously hypertensive diabetic rats as compared with their respective controls. The cardiac tissue kallikrein and kininogen levels were reduced significantly (P<0.001) in diabetic Wistar Kyoto, spontaneously hypertensive and diabetic spontaneously hypertensive compared with Wistar Kyoto control rats. In addition, the left ventricular thickness was found to be increased (P<0.001) in diabetic Wistar Kyoto and spontaneously hypertensive rats in the presence and in the absence of diabetes. Our results indicate that reduced activity of the kinin-forming system may be responsible for inducing left ventricular hypertrophy in the presence of raised mean arterial blood pressure in diabetic and hypertensive rats. Thus, the kinin-forming components might have a protective role against the development of left ventricular hypertrophy. The possible significance of these findings is discussed.
    Matched MeSH terms: Myocardium/chemistry
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