Displaying publications 1 - 20 of 28 in total

Abstract:
Sort:
  1. Chan KS, Chuang YC, Lin TY, Shaw SW
    J Formos Med Assoc, 2021 Jun;120(6):1394-1399.
    PMID: 33583701 DOI: 10.1016/j.jfma.2021.01.022
    Acardiac twin or twin reversed arterial perfusion (TRAP) sequence is a rare medical complication of Monozygotic twins. Taiwanese Obstetricians usually treat TRAP sequence conservatively. Occasionally, repeated amnio-reduction is performed to decompress the polyhydramnios caused by the TRAP sequence, even though there was no correction of the pathophysiologic mechanism. Radiofrequency ablation is a minimally invasive, percutaneous technique that can effectively obliterate blood supply to an acardiac twin to preserve and protect the pump twin. This recent technique has never been used before for the treatment of the TRAP sequence in Taiwan. This article reported the first-hand experience of acardiac twin management with RFA in Taipei Chang Gung Memorial Hospital.
    Matched MeSH terms: Perfusion
  2. Ahmad Helmy AK, Salmah Jalaluddin WM, Ab Rahman IG
    Malays J Med Sci, 2010 Oct;17(4):51-6.
    PMID: 22135561 MyJurnal
    Brain ischaemia and infarction are the leading factors in morbidity and mortality of traumatic brain injury. This study aimed to determine the perfusion status of pericontusional hypodense areas in traumatic cerebral contusion
    Matched MeSH terms: Perfusion
  3. Ayavoo T, Murugesan K, Gnanasekaran A
    PMID: 33829056 DOI: 10.21037/sci-2020-027
    Wound healing phases comprise of highly synchronized process that begins due to a damage and restores the integrity of the injured tissues. Wound healing reduces the damage in tissue and supply sufficient oxygen and tissue perfusion, provide proper nourishment and humid wound healing atmosphere to re-establish the essential status of exaggerated parts. The untreated wound becomes susceptible for pus development, bacterial infection and complications like sepsis. Traditional and modern approaches are in practice to treat acute, open and chronic injuries, however, present wound care management has met with challenges and minimal positive effects. Stem cells have possible wound healing capability to overwhelm restrictions of the current wound care practices as it produces faster tissue regeneration in wound repair. Stem cells are unspecialized cells derived from adult body tissues and embryos that differentiate into any cell of an organism and capable of self-regeneration. The understanding on molecular mechanisms of stem cells has become the central and promising field in scientific study. This review focuses on the pre-existing traditional and modern treatments for wound healing, and types and roles of stem cells in wound care management. This review also focuses on the fundamental molecular characterization and factors influencing the molecular mechanisms of stem cells in wound healing.
    Matched MeSH terms: Perfusion
  4. Shahida Saharudin, Norlelawati A. Talib, Nor Zamzila Abdullah, Jamalludin Ab. Rahman, Zunariah Buyong
    MyJurnal
    Liver perfusion has been the standard method to digest and isolate liver
    cells including liver sinusoidal endothelial cells (LSEC). Poor cannulating skills through
    portal vein results in a waste of animal resource. Familiarization of both liver perfusion
    technique and adhering strictly to aseptic technique during cell handling ensure high
    cell yield, minimum morphology disruption and cell contamination. We aimed to present
    a method of liver perfusion procedure followed by the isolation of LSEC. (Copied from article).
    Matched MeSH terms: Perfusion
  5. Belqes Abdullah, A. T., Yvonne, T. G. B., Ahmad, S. H., Abdul Aziz, A. S. I., Aida, H. G. R.
    MyJurnal
    Introduction: Iontophoresis of vasoactive substances such as acetylcholine (ACh) and sodium nitroprusside (SNP) combined with Laser Doppler fluximetry (LDF) is a non-invasive tool used to determine microvascular endothelial function. This study aims to test the effect of sodium chloride on
    non-specific vasodilatation when used as a vehicle in the process of iontophoresis. This study also aims to define the number of current pulses needed to get the maximum effect during iontophoresis with ACh and SNP using low current strength. Methods: The experiment was conducted in five healthy females. Baseline skin perfusion was taken before administration of seven current pulses. Current strength of 0.007 mA and current density of 0.01 mA/cm2 were used. Acetylcholine was used to assess endothelial dependent vasodilatation, while SNP was used to assess endothelial independent vasodilatation. The mean skin perfusion (AU) responses to the iontophoresis of ACh at the anodal and SNP at the cathode leads were recorded. Sodium chloride (0.9%) was used as a vehicle to obtain concentration of 1% for both ACh and SNP. Iontophoresis of pure vehicle (NaCl) was conducted on a separate day to observe the effect of vehicle only on the iontophoresis process at both anode and cathode. Results: Iontophoresis of NaCl showed no significant increase in perfusion compared to baseline at both anode and cathode. Significant increases in skin perfusion were observed with SNP and ACh; a plateau of ACh was reached from the 3rd pulse onwards; while the plateau of SNP was reached from the 4th pulse onwards. Conclusion: NaCl could be used as a vehicle for Ach and SNP during iontophoresis as it did not cause non-specific vasodilatation. Using five current pulses are adequate for iontophoresis of ACh and SNP to assess microvascular endothelial function.
    Matched MeSH terms: Perfusion
  6. Mohd Radzi A, Boey CY, Amir Hassan SZ
    Clin Nucl Med, 2023 Aug 01;48(8):727-728.
    PMID: 37220239 DOI: 10.1097/RLU.0000000000004700
    We report a case of a 33-year-old woman who underwent stress and rest myocardial perfusion scintigraphy (MPS) to exclude coronary artery disease. MPS images showed an apparent dextrocardia with a right-sided septal wall uptake. The electrocardiograph showed a right axis deviation with dominant R waves at leads aVR and V1. Upon retrieval of the patient's medical records, she had an underlying transposition of great arteries and underwent a Senning atrial switch surgery. Hence, the MPS images demonstrated a prominent right ventricular wall due to its function as the "systemic" ventricle with minimal uptake in the "pulmonary" left ventricle.
    Matched MeSH terms: Perfusion Imaging
  7. Ghani AA, Nayan SAM, Kandasamy R, Ghani ARI, Rosman AK
    Malays J Med Sci, 2017 Feb;24(1):47-58.
    PMID: 28461780 DOI: 10.21315/mjms2017.24.1.6
    BACKGROUND: Intracranial aneurysms may rupture and are typically associated with high morbidity and mortality, commonly due to vasospasm after rupture. Once the aneurysm ruptures, the patient's cerebral blood flow may be disturbed during the acute phase, affecting cerebral circulation and thus cerebral perfusion prior to the onset of vasospasm. Fisher and Navarro scores are used to predict vasospasm, while World Federation of Neurosurgical Societies (WFNS) scores are used to predict patient outcomes. Several score modifications are available to obtain higher sensitivity and specificity for the prediction of vasospasm development, but these scores are still unsuccessful. Alternatively, cerebral CT perfusion scan (CTP) is a non-invasive method for measuring cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in regions of interests (ROI) to obtain the cerebral perfusion status as well as detecting vasospasm.

    METHODS: A total of 30 patients' data with clipped anterior circulation intracranial aneurysms admitted to the hospital between 1 January 2013 and 30 June 2014, were collected from the hospital's electronic database. The data collected included patients' admissions demographic profiles, Fisher, Navarro and WFNS scores; and their immediate pre- and post-operative CTP parameters.

    RESULTS: This study found a significant increase in post-operative MTT (pre- and post-operative MTT) were 9.75 (SD = 1.31) and 10.44 (SD = 1.56) respectively, (P < 0.001)) as well as a significant reduction in post-operative CBF (pre- and post-operative mean CBF were 195.29 (SD = 24.92) and 179.49 (SD = 31.17) respectively (P < 0.001)). There were no significant differences in CBV. There were no significant correlations between the pre- and post-operative CTP parameters and Fisher, Navarro or WFNS scores.

    CONCLUSION: Despite the interest in using Fisher, Navarro and WFNS scores to predict vasospasm and patient outcomes for ruptured intracranial aneurysms, this study found no significant correlations between these scores in either pre- or post-operative CTP parameters. These results explain the disagreement in the field regarding the multiple proposed grading systems for vasospasm prediction. CTP measures more than just anatomical structures; therefore, it is more sensitive towards minor changes in cerebral perfusion that would not be detected by WFNS, Fisher or Navarro scores.

    Matched MeSH terms: Perfusion
  8. Khoo CS, Kim SE, Lee BI, Shin KJ, Ha SY, Park J, et al.
    Eur Neurol, 2020;83(1):56-64.
    PMID: 32320976 DOI: 10.1159/000506591
    INTRODUCTION: Seizures as acute stroke mimics are a diagnostic challenge.

    OBJECTIVE: The aim of the study was to characterize the perfusion patterns on perfusion computed tomography (PCT) in patients with seizures masquerading as acute stroke.

    METHODS: We conducted a study on patients with acute seizures as stroke mimics. The inclusion criteria for this study were patients (1) initially presenting with stroke-like symptoms but finally diagnosed to have seizures and (2) with PCT performed within 72 h of seizures. The PCT of seizure patients (n = 27) was compared with that of revascularized stroke patients (n = 20) as the control group.

    RESULTS: Among the 27 patients with seizures as stroke mimics, 70.4% (n = 19) showed characteristic PCT findings compared with the revascularized stroke patients, which were as follows: (1) multi-territorial cortical hyperperfusion {(73.7% [14/19] vs. 0% [0/20], p = 0.002), sensitivity of 73.7%, negative predictive value (NPV) of 80%}, (2) involvement of the ipsilateral thalamus {(57.9% [11/19] vs. 0% [0/20], p = 0.007), sensitivity of 57.9%, NPV of 71.4%}, and (3) reduced perfusion time {(84.2% [16/19] vs. 0% [0/20], p = 0.001), sensitivity of 84.2%, NPV of 87%}. These 3 findings had 100% specificity and positive predictive value in predicting patients with acute seizures in comparison with reperfused stroke patients. Older age was strongly associated with abnormal perfusion changes (p = 0.038), with a mean age of 66.8 ± 14.5 years versus 49.2 ± 27.4 years (in seizure patients with normal perfusion scan).

    CONCLUSIONS: PCT is a reliable tool to differentiate acute seizures from acute stroke in the emergency setting.

    Matched MeSH terms: Perfusion Imaging/methods*
  9. Mashori GR, Tariq AR, Shahimi MM, Suhaimi H
    Singapore Med J, 1996 Jun;37(3):278-81.
    PMID: 8942229
    Treatment of hypertension has reduced the incidence of stroke, heart failure and renal failure. However, the incidence of coronary heart disease is not reduced to the same degree. Many of the drugs advocated as first-line drugs in the step-wise therapy have been shown to cause carbohydrate intolerance and it is an independent risk factor in the development of coronary heart disease. It is thus important to identify the antihypertensive drugs that may cause deterioration in glucose tolerance. Cicletanine, the first derivative of the furopyridines, is a new class of antihypertensive agents. It acts directly on vascular endothelium cells by increasing prostacyclin synthesis. It also decreases intracytosolic calcium levels in smooth muscles. The purpose of this study is to evaluate the effects of Cicletanine on insulin release in rat isolated pancreas by the perfusion technique adapted from Loubatieres and co-workers (1972). Doses used were based on therapeutic peak plasma concentration. Diazoxide was used as a positive control ie a known insulin suppressant. Cicletanine at 1/10 and equivalent therapeutic concentrations (0.5 microgram/mL and 5.0 micrograms/mL) did not suppress insulin release. However, at concentration exceeding 10X its therapeutic levels (50 micrograms/mL) it begins to suppress insulin release. In conclusion, Cicletanine did not inhibit insulin release at concentrations within the therapeutic range.
    Matched MeSH terms: Perfusion/methods
  10. Mahaletchumy T, Muhamad M, Mohammad Kazmin NE, Kori N, Periyasamy P
    Clin Nucl Med, 2021 Jul 01;46(7):e360-e362.
    PMID: 33443945 DOI: 10.1097/RLU.0000000000003513
    Severe COVID-19 infection is associated with significant coagulopathy. We would like share a case of an asymptomatic 26-year-old man who tested positive for COVID-19 and had elevated d-dimer levels. Because of inconclusive CTPA findings, V/Q (ventilation/perfusion) SPECT/CT was performed, which confirmed the presence of pulmonary embolism. This case highlights the fact that pulmonary embolism should not be overlooked in a COVID-19 patient who has raised d-dimer levels, even in the absence of symptoms. It also highlights the importance of performing a V/Q study when CTPA results are inconclusive or when there are contraindications for iodinated contrast media.
    Matched MeSH terms: Ventilation-Perfusion Ratio*
  11. Nogueiro J, Fathi NQ, Guaglio M, Baratti D, Kusamura S, Deraco M
    Eur J Surg Oncol, 2023 Oct;49(10):107020.
    PMID: 37597284 DOI: 10.1016/j.ejso.2023.107020
    BACKGROUND: Gastrointestinal leak is one of the most feared complications after cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) and harbors significant postoperative morbidity and mortality. We aim to identify risk-factors for anastomotic leak (AL) and gastrointestinal perforation (GP) to optimize postoperative outcomes of this population.

    METHODS: We performed a retrospective analysis of 1043 consecutive patients submitted to CRS in a single institution. Potential risk factors for AL and GP, both related to patient overall condition, disease status and surgical technique were reviewed.

    RESULTS: Anastomotic leaks were identified in 5.2% of patients, and GPs in 7.0%. The independent risk-factors for AL were age at surgery (OR1.40; CI95% 1.10-1.79); peritoneal cancer index (PCI) (OR1.04, CI95% 1.01-1.07); Cisplatin dose >240 mg during HIPEC (OR3.53; CI95% 1.47-8.56) and the presence of colorectal (CR) or colo-colic (CC) anastomosis (OR5.09; CI95% 2.71-9.53, and 4.58; CI95% 1.22-17.24 respectively). Male gender and intraoperative red blood cell transfusions were the only independent risk factors for GP identified (OR1.70; CI95% 1.04-2.78 and 1.06; CI95% 1.01-1.12, respectively). Regarding 30-day and 90-day postoperative mortality, independent risk-factors were mainly related to patient's overall condition.

    CONCLUSION: Gastrointestinal leaks are a frequent source of postoperative morbidity, mainly at the expense of GP. A careful and systematic intraoperative revision of all potential gastrointestinal injuries is equally critical to perfecting anastomotic fashioning techniques to decrease gastrointestinal complication rates. We identified multiple risk-factors for AL and GP related to disease status and patient condition. Our study suggests that patient-related conditions are of paramount relevance, highlighting the importance of patient selection and preoperative patient optimization.

    Matched MeSH terms: Chemotherapy, Cancer, Regional Perfusion/adverse effects
  12. Jayasinghe R, Weerasooriya S, Kapadia N
    Med J Malaysia, 2012 Apr;67(2):236-9; quiz 240.
    PMID: 22822658
    How does one decide on the best non-invasive test to investigate stable coronary ischaemia? This is a very common question faced by many medical practitioners. Chronic stable angina is a common presentation encountered in general practitice. Upon clinical assessment and risk stratification the patient needs to be investigated further to confirm the diagnosis. The first investigational modality involves a non-invasive test. It is important that practitioners possess a practical knowledge of the array of different tests that are available so that the best suited one for each patient can be chosen. This article aims to compare the efficacy and accuracy and the practical utility of the different non-invasive tests for coronary ischaemia and aid the practitioner in making sound decisions in this regard.
    Matched MeSH terms: Myocardial Perfusion Imaging
  13. Shahida S, Nor Zamzila A, Norlelawati AT, Jamalludin AR, Azliana AF, Zunariah Buyong
    MyJurnal
    Introduction: Over the decades, organic arsenic has been thought to be less toxic than inorganic arsenic.
    Monosodium methylarsonate (MSMA) is a potent organoarsenical herbicide that is still being used in most
    Asian countries. Reported studies on the effects of organic arsenic are mainly to the gastrointestinal system,
    however there are limited research on its impacts to the liver. Therefore, this study aimed to investigate the
    effect of MSMA exposure on hepatocytes and liver sinusoidal endothelial cells (LSEC). Materials and Methods:
    Fourteen Sprague Dawley rats (n=14) were divided equally into arsenic-exposed (n=7) and control (n=7)
    groups. The rats in arsenic-exposed group were given MSMA at 63.20 mg/kg daily for 6 months through oral
    gavage. While the rats in control group were given distilled water ad libitum. At the end of the duration,
    they were euthanized and underwent liver perfusion for tissue preservation. Liver tissues were harvested and
    processed for light microscopy, scanning and transmission electron microscopy. The findings were analysed
    descriptively. Results: MSMA had caused necrotic and apoptotic changes to the liver. Normal organelles
    morphology were loss in the hepatocytes while LSEC revealed defenestration. Conclusion: In this study,
    chronic low dose organic arsenic exposure showed evidence of toxicity to hepatocytes. Interestingly, LSEC
    demonstrated capillarization changes.
    Matched MeSH terms: Perfusion
  14. Thinakaran T, Nor M, Duncan MT, Chan OL, Klissouras V
    Med J Malaysia, 1974 Sep;29(1):24-8.
    PMID: 4282626
    Matched MeSH terms: Ventilation-Perfusion Ratio
  15. Li Y, Li S, Wang Y, Zhou J, Yang J, Ma J
    J Fr Ophtalmol, 2021 Dec;44(10):1596-1604.
    PMID: 34454773 DOI: 10.1016/j.jfo.2021.05.005
    BACKGROUND: The main risks for glaucoma are increased intraocular pressure (IOP) and decreased ocular perfusion pressure (OPP). This review aims to examine the potential impact of lower limb isometric resistance exercise on intraocular pressure and ocular perfusion pressure.

    METHOD: A meta-analysis was conducted to determine the potential impact of isometric exercise on IOP and OPP. The literature on the relationship between isometric resistance exercise and IOP was systematically searched according to the "Cochrane Handbook" in the databases of Pubmed, Web of Science, EBSCO, and Scopus through December 31, 2020. The search terms used were "exercise," "train," "isometric," "intraocular pressure," and "ocular perfusion pressure," and the mean differences of the data were analyzed using the Stata 16.0 software, with a 95% confidence interval.

    RESULTS: A total of 13 studies, which included 268 adult participants consisting of 162 men and 106 women, were selected. All the exercise programs that were included were isometric resistance exercises of the lower limbs with intervention times of 1min, 2min, or 6min. The increase in IOP after intervention was as follows: I2=87.1%, P=0.001 using random-effects model combined statistics, SMD=1.03 (0.48, 1.59), and the increase in OPP was as follows: I2=94.5%, P=0.001 using random-effects model combined statistics, SMD=2.94 (1.65, 4.22), with both results showing high heterogeneity.

    CONCLUSION: As isometric exercise may cause an increase in IOP and OPP, therefore, people with glaucoma and related high risk should perform isometric exercise with caution.

    Matched MeSH terms: Perfusion
  16. Anderson I, Kumar R, Patankar T, Tyagi A
    BMJ Case Rep, 2014;2014.
    PMID: 25257888 DOI: 10.1136/bcr-2014-205736
    We present the case of a 24-year-old man who presented with vertigo and right-sided weakness. Subsequent imaging demonstrated a lateral ventricle haemangioblastoma. This is the first case ever to be treated with surgical excision augmented by preoperative endovascular embolisation, as illustrated with perfusion CT scanning performed pre-embolisation and postembolisation. We present the case followed by a summary of the previously published cases and a discussion of the advantages of perfusion scanning and endovascular embolisation in these highly vascular (and therefore potentially dangerous) lesions.
    Matched MeSH terms: Perfusion Imaging*
  17. Yapp JH, Kamil R, Rozi M, Mohtarrudin N, Loqman MY, Ezamin AR, et al.
    J Tissue Viability, 2017 Aug;26(3):196-201.
    PMID: 28438463 DOI: 10.1016/j.jtv.2017.03.002
    Tissue recovery is important in preventing tissue deterioration, which is induced by pressure and may lead to pressure ulcers (PU). Reactive hyperaemia (RH) is an indicator used to identify people at risk of PU. In this study, the effect of different recovery times on RH trend is investigated during repetitive loading. Twenty-one male Sprague-Dawley rats (seven per group), with body weight of 385-485 g, were categorised into three groups and subjected to different recovery times with three repetitive loading cycles. The first, second, and third groups were subjected to short (3 min), moderate (10 min), and prolonged (40 min) recovery, respectively, while fixed loading time and pressure (10 min and 50 mmHg, respectively). Peak hyperaemia was measured in the three cycles to determine trends associated with different recovery times. Three RH trends (increasing, decreasing, and inconsistent) were observed. As the recovery time is increased (3 min vs. 10 min vs. 40 min), the number of samples with increasing RH trend decreases (57% vs. 29% vs. 14%) and the number of samples with inconsistent RH trend increases (29% vs. 57% vs. 72%). All groups consists of one sample with decreasing RH trend (14%). Results confirm that different recovery times affect the RH trend during repetitive loading. The RH trend may be used to determine the sufficient recovery time of an individual to avoid PU development.
    Matched MeSH terms: Perfusion/standards*
  18. Man K, Kareem AM, Ahmad Alias NA, Shuaib IL, Tharakan J, Abdullah JM, et al.
    Singapore Med J, 2006 Mar;47(3):194-7.
    PMID: 16518552
    Computed tomography (CT) perfusion is a new method to diagnose ischaemic stroke especially in developing countries. It identifies the area and is useful to predict the size of final infarction. The aim of this study was to assess cerebral ischaemia with CT perfusion (CTP) among patients with acute ischaemic stroke in Hospital Universiti Sains Malaysia, a tertiary referral centre in a rural setting.
    Matched MeSH terms: Perfusion*
  19. Sabarudin A, Yusof MZ, Mohamad M, Sun Z
    Radiat Prot Dosimetry, 2014 Dec;162(3):316-21.
    PMID: 24255172 DOI: 10.1093/rpd/nct280
    A study on the radiation dose associated with cerebral CT angiography (CTA) and CT perfusion (CTP) was conducted on an anthropomorphic phantom with the aim of estimating the effective dose (E) and entrance skin dose (ESD) in the eyes and thyroid gland during different CTA and CTP protocols. The E was calculated to be 0.61 and 0.28 mSv in CTA with 100 and 80 kV(p), respectively. In contrast, CTP resulted in an estimated E of 2.74 and 2.07 mSv corresponding to 40 and 30 s protocols, respectively. The eyes received a higher ESD than the thyroid gland in all of these protocols. The results of this study indicate that combining both CTA and CTP procedures are not recommended in the stroke evaluation due to high radiation dose. Application of modified techniques in CTA (80 kV(p)) and CTP (30 s) is highly recommended in clinical practice for further radiation dose reduction.
    Matched MeSH terms: Perfusion
  20. Malhotra N
    Curr Stem Cell Res Ther, 2019;14(4):351-366.
    PMID: 30636614 DOI: 10.2174/1574888X14666190111105504
    OBJECTIVES: A variety of bioreactors and related approaches have been applied to dental tissues as their use has become more essential in the field of regenerative dentistry and dental tissue engineering. The review discusses the various types of bioreactors and their potential application in dentistry.

    METHODS: Review of the literature was conducted using keywords (and MeSH) like Bioreactor, Regenerative Dentistry, Fourth Factor, Stem Cells, etc., from the journals published in English. All the searched abstracts, published in indexed journals were read and reviewed to further refine the list of included articles. Based on the relevance of abstracts pertaining to the manuscript, full-text articles were assessed.

    RESULTS: Bioreactors provide a prerequisite platform to create, test, and validate the biomaterials and techniques proposed for dental tissue regeneration. Flow perfusion, rotational, spinner-flask, strain and customize-combined bioreactors have been applied for the regeneration of bone, periodontal ligament, gingiva, cementum, oral mucosa, temporomandibular joint and vascular tissues. Customized bioreactors can support cellular/biofilm growth as well as apply cyclic loading. Center of disease control & dip-flow biofilm-reactors and micro-bioreactor have been used to evaluate the biological properties of dental biomaterials, their performance assessment and interaction with biofilms. Few case reports have also applied the concept of in vivo bioreactor for the repair of musculoskeletal defects and used customdesigned bioreactor (Aastrom) to repair the defects of cleft-palate.

    CONCLUSIONS: Bioreactors provide a sterile simulated environment to support cellular differentiation for oro-dental regenerative applications. Also, bioreactors like, customized bioreactors for cyclic loading, biofilm reactors (CDC & drip-flow), and micro-bioreactor, can assess biological responses of dental biomaterials by simultaneously supporting cellular or biofilm growth and application of cyclic stresses.

    Matched MeSH terms: Perfusion
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links