120 results on '"Alexander Black"'
Search Results
2. Hearing loss and a supportive tactile signal in a navigation system: Effects on driving behavior and eye movements
- Author
-
Birgitta Thorslund, Björn Peters, Nicholas Herbert, Kenneth Holmqvist, Björn Lidestam, Alexander Black, and Björn Lyxell
- Subjects
hearing loss ,tactile support ,navigation system ,eye movements ,driving behavior ,Human anatomy ,QM1-695 - Abstract
An on-road study was conducted to evaluate a complementary tactile navigation signal on driving behaviour and eye movements for drivers with hearing loss (HL) compared to drivers with normal hearing (NH). 32 participants (16 HL and 16 NH) performed two preprogrammed navigation tasks. In one, participants received only visual information, while the other also included a vibration in the seat to guide them in the correct direction. SMI glasses were used for eye tracking, recording the point of gaze within the scene. Analysis was performed on predefined regions. A questionnaire examined participant's experience of the navigation systems. Hearing loss was associated with lower speed, higher satisfaction with the tactile signal and more glances in the rear view mirror. Additionally, tactile support led to less time spent viewing the navigation display.
- Published
- 2013
- Full Text
- View/download PDF
3. VADER: Video Alignment Differencing and Retrieval.
- Author
-
Alexander Black 0001, Simon Jenni, Tu Bui, Md. Mehrab Tanjim, Stefano Petrangeli, Ritwik Sinha, Viswanathan Swaminathan 0001, and John P. Collomosse
- Published
- 2023
- Full Text
- View/download PDF
4. DECORAIT - DECentralized Opt-in/out Registry for AI Training.
- Author
-
Kar Balan, Andrew Gilbert, Alexander Black 0001, Simon Jenni, Andy Parsons, and John P. Collomosse
- Published
- 2023
- Full Text
- View/download PDF
5. Audio-Visual Contrastive Learning with Temporal Self-Supervision.
- Author
-
Simon Jenni, Alexander Black 0001, and John P. Collomosse
- Published
- 2023
- Full Text
- View/download PDF
6. Deep Image Comparator: Learning To Visualize Editorial Change.
- Author
-
Alexander Black 0001, Tu Bui, Hailin Jin, Vishy Swaminathan, and John P. Collomosse
- Published
- 2021
- Full Text
- View/download PDF
7. VPN: Video Provenance Network for Robust Content Attribution.
- Author
-
Alexander Black 0001, Tu Bui, Simon Jenni, Viswanathan (Vishy) Swaminathan, and John P. Collomosse
- Published
- 2021
- Full Text
- View/download PDF
8. Compositional Sketch Search.
- Author
-
Alexander Black 0001, Tu Bui, Long Mai, Hailin Jin, and John P. Collomosse
- Published
- 2021
- Full Text
- View/download PDF
9. SImProv: Scalable Image Provenance Framework for Robust Content Attribution.
- Author
-
Alexander Black 0001, Tu Bui, Simon Jenni, Zhifei Zhang, Viswanathan Swaminanthan, and John P. Collomosse
- Published
- 2022
- Full Text
- View/download PDF
10. Topical Ophthalmic Anesthetic Use for Sterile Corneal Abrasion in the Emergency Department
- Author
-
Alexander Black, Kathryn Boswell, and Daniel Montenegro
- Subjects
Ophthalmology - Abstract
Investigate current treatment and prescription practices of topical ophthalmic anesthetic agents (TOAAs) in emergency departments (EDs) across the United States to understand how these encounters may affect ocular health.A six question survey regarding the use of topical ophthalmic anesthetics was completed by 73 emergency medicine (EM) physicians across 34 states through the American College of Emergency Physicians (ACEP) Emergency Medicine Practices Research Network (EMPRN).The survey was completed by 73 EM physicians. The majority indicated treating eye-related complaints frequently and comfort using (TOAAs) for pain control in sterile corneal abrasion. Over half of respondents indicated never discharging a patient from the ED with a prescription for TOAAs. The consensus for patient instructions included offering a short course (48 hr) of treatment. Furthermore, 96% of respondents indicated that they would not prescribe refills for TOAAs, mostly due to concern regarding corneal damage.Despite demonstrable concern regarding the use of TOAAs and risk of corneal damage, a minority of EM physicians continue to prescribe these agents in the treatment of sterile corneal abrasion, which poses risks to visual health. Ophthalmologists have begun to advocate for decreased availability of TOAAs in settings such as the ED.
- Published
- 2022
- Full Text
- View/download PDF
11. Severe hyponatremia in the setting of mediastinal neuroblastoma in an elderly male
- Author
-
Sankarabharan Kanikireddy, Nishant Gohel, and Alexander Black
- Subjects
General Materials Science - Abstract
Introduction: Neuroblastomas are rare neoplasms with the potential to express paraneoplastic syndromes. Case Report: We report the case of a 77-year-old male with biopsy-confirmed unresectable anterior mediastinal neuroblastoma with symptomatic hyponatremia likely due to paraneoplastic syndrome of inappropriate antidiuretic hormone (SIADH). He had multiple inpatient admissions for symptomatic hyponatremia over the 3-year period that we examined, with a paucity of admissions during chemoreduction with adjuvant radiation therapy. Due to the rarity of this tumor, there is no standard treatment protocol and the literature regarding these neoplasms exists primarily as case reports. Conclusion: This case report adds to the existing literature detailing paraneoplastic SIADH in the setting of mediastinal neuroblastoma in adults and highlights the importance for oncologists to be cognizant of this syndrome as a complication of a particular rare malignancy.
- Published
- 2022
- Full Text
- View/download PDF
12. A Unified Method for the Recovery of Metals from Chalcogenides
- Author
-
Francesca Bevan, Magali Perez, Gawen R.T. Jenkin, Alexander Black, Jörg Feldmann, Ioanna M. Pateli, Andrew P. Abbott, Hanaa Galeb, Jennifer Hartley, Jack Allen, and Robert C. Harris
- Subjects
Primary (chemistry) ,Materials science ,Renewable Energy, Sustainability and the Environment ,Metal chalcogenides ,Chalcogenide ,General Chemical Engineering ,Extraction (chemistry) ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Deep eutectic solvent ,chemistry.chemical_compound ,chemistry ,Environmental Chemistry ,0210 nano-technology ,Tellurium ,Selenium - Abstract
Metal chalcogenides are ubiquitous starting materials for the extraction of metals from both primary and secondary sources. In this study, it is shown that chalcogenide compounds are electrochemica...
- Published
- 2021
- Full Text
- View/download PDF
13. Fair splittings by independent sets in sparse graphs
- Author
-
Linus Setiabrata, Umur Cetin, Florian Frick, Alexander Black, Alexander Pacun, and Çetin, Umur
- Subjects
Euclidean space ,General Mathematics ,010102 general mathematics ,0102 computer and information sciences ,Disjoint sets ,01 natural sciences ,Coincidence ,Vertex (geometry) ,Combinatorics ,Corollary ,010201 computation theory & mathematics ,Symmetric group ,FOS: Mathematics ,Mathematics - Combinatorics ,Partition (number theory) ,Equivariant map ,Combinatorics (math.CO) ,0101 mathematics ,05C69, 05C15, 52A35 ,Mathematics - Abstract
Given a partition $V_1 \sqcup V_2 \sqcup \dots \sqcup V_m$ of the vertex set of a graph, we are interested in finding multiple disjoint independent sets that contain the correct fraction of vertices of each $V_j$. We give conditions for the existence of $q$ such independent sets in terms of the topology of the independence complex. We relate this question to the existence of $q$-fold points of coincidence for any continuous map from the independence complex to Euclidean space of a certain dimension, and to the existence of equivariant maps from the $q$-fold deleted join of the independence complex to a certain representation sphere of the symmetric group. As a corollary we derive the existence of $q$ pairwise disjoint independent sets accurately representing the $V_j$ in certain sparse graphs for $q$ a power of a prime., 14 pages
- Published
- 2020
- Full Text
- View/download PDF
14. A History of the City of Brooklyn and Kings County, Volume II.
- Author
-
Stephen M. Ostrander, Alexander Black
- Published
- 2013
15. An on-road examination of daytime and evening driving on rural roads: physiological, subjective, eye gaze, and driving performance outcomes
- Author
-
Christopher N, Watling, Grégoire S, Larue, Joanne M, Wood, and Alexander, Black
- Subjects
Male ,Automobile Driving ,Humans ,Female ,Fixation, Ocular ,Wakefulness - Abstract
Experiencing sleepiness when driving is associated with increased crash risk. An increasing number of studies have examined on-road driver sleepiness; however, these studies typically assess the effect of sleepiness during the late night or early morning hours when sleep pressure is approaching its greatest. An on-road driving study was performed to assess how a range of physiological and sleepiness measures are impacted when driving during the daytime and evening when moderate sleepiness is experienced. In total, 27 participants (14 women and 13 men) completed a driving session in a rural town lasting approximately 60 minutes, while physiological sleepiness (heart rate variability), subjective sleepiness, eye tracking data, vehicle kinematic data and GPS speed data were recorded. Daytime driving sessions began at 12:00 or 14:00, with the evening sessions beginning at 19:30 or 20:30; only a subset of participants (n = 11) completing the evening sessions (daytime and evening order counterbalanced). The results suggest reductions in the horizontal and vertical scanning ranges occurred during the initial 40 minutes of driving for both daytime and evening sessions, but with evening sessions reductions in scanning ranges occurred across the entire driving session. Moreover, during evening driving there was an increase in physiological and subjective sleepiness levels. The results demonstrate meaningful increases in sleepiness and reductions in eye scanning when driving during both the daytime and particularly in the evening. Thus, drivers need to remain vigilant when driving during the daytime and the evening.
- Published
- 2021
16. Compositional Sketch Search
- Author
-
Alexander Black, Hailin Jin, Long Mai, Tu Bui, and John Collomosse
- Subjects
Visual search ,FOS: Computer and information sciences ,Similarity (geometry) ,business.industry ,Computer science ,Computer Vision and Pattern Recognition (cs.CV) ,Computer Science - Computer Vision and Pattern Recognition ,Pattern recognition ,Object (computer science) ,Convolutional neural network ,Sketch ,Metric (mathematics) ,Artificial intelligence ,business ,Representation (mathematics) ,Image retrieval - Abstract
We present an algorithm for searching image collections using free-hand sketches that describe the appearance and relative positions of multiple objects. Sketch based image retrieval (SBIR) methods predominantly match queries containing a single, dominant object invariant to its position within an image. Our work exploits drawings as a concise and intuitive representation for specifying entire scene compositions. We train a convolutional neural network (CNN) to encode masked visual features from sketched objects, pooling these into a spatial descriptor encoding the spatial relationships and appearances of objects in the composition. Training the CNN backbone as a Siamese network under triplet loss yields a metric search embedding for measuring compositional similarity which may be efficiently leveraged for visual search by applying product quantization., Comment: ICIP 2021 camera-ready version
- Published
- 2021
- Full Text
- View/download PDF
17. VPN: Video Provenance Network for Robust Content Attribution
- Author
-
Alexander Black, Tu Bui, Viswanathan Swaminathan, Simon Jenni, and John Collomosse
- Subjects
FOS: Computer and information sciences ,Matching (statistics) ,Information retrieval ,Artificial neural network ,Computer science ,Emoji ,Computer Vision and Pattern Recognition (cs.CV) ,Computer Science - Computer Vision and Pattern Recognition ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Inverted index ,Embedding ,Codec ,CLIPS ,computer ,Invariant (computer science) ,computer.programming_language - Abstract
We present VPN - a content attribution method for recovering provenance information from videos shared online. Platforms, and users, often transform video into different quality, codecs, sizes, shapes, etc. or slightly edit its content such as adding text or emoji, as they are redistributed online. We learn a robust search embedding for matching such video, invariant to these transformations, using full-length or truncated video queries. Once matched against a trusted database of video clips, associated information on the provenance of the clip is presented to the user. We use an inverted index to match temporal chunks of video using late-fusion to combine both visual and audio features. In both cases, features are extracted via a deep neural network trained using contrastive learning on a dataset of original and augmented video clips. We demonstrate high accuracy recall over a corpus of 100,000 videos., Comment: CVMP2021 camera-ready version
- Published
- 2021
- Full Text
- View/download PDF
18. Captain Kodak A Camera Story
- Author
-
Alexander Black and Alexander Black
- Subjects
- Boys--Juvenile fiction
- Abstract
Captain Kodak: A Camera Story is a children's book written by Alexander Black and published in 1899. The story follows a young boy named Harry Hastings who is passionate about photography and dreams of becoming a great photographer like his hero, Captain Kodak. After receiving a camera as a gift from his uncle, Harry sets out on a series of adventures with his friends, using his camera to document their journeys and capture the beauty of the world around them. Along the way, Harry learns valuable lessons about perseverance, creativity, and the power of imagination. As Harry's photography skills grow, he becomes increasingly determined to enter a photography contest and win the grand prize: a trip to Europe with Captain Kodak himself. With the help of his friends and his trusty camera, Harry embarks on a journey full of excitement and discovery, and ultimately learns that the most important thing is not the destination, but the journey itself.'Captain Kodak: A Camera Story'is a charming and engaging tale that celebrates the joy of creativity and the power of imagination. Through Harry's adventures, young readers are inspired to pursue their own passions and to never give up on their dreams, no matter how challenging they may seem. The book also serves as a reminder of the magic of photography and its ability to capture the beauty of the world around us.
- Published
- 2023
19. Fabrication of Blood-Derived Elastogenic Vascular Grafts Using Electrospun Fibrinogen and Polycaprolactone Composite Scaffolds for Pediatric Applications
- Author
-
Stefan Jockenhoevel, Ian G. Woods, Alexander Black, Thomas C. Flanagan, Eleanor J. Molloy, AMIBM, RS: FSE AMIBM, Sciences, RS: FSE Sciences, Biobased Materials, and RS: FSE Biobased Materials
- Subjects
Scaffold ,Swine ,Polyesters ,Myocytes, Smooth Muscle ,CELL INFILTRATION ,nanofibre ,Nanofibers ,Biomedical Engineering ,Medicine (miscellaneous) ,elastin ,Fibrinogen ,Umbilical cord ,Umbilical Cord ,Transforming Growth Factor beta1 ,Biomaterials ,Extracellular matrix ,congenital heart defect ,medicine ,Animals ,Humans ,Child ,electrospinning ,ARTERY ,Tissue Engineering ,Tissue Scaffolds ,biology ,Chemistry ,vascular graft ,MORTALITY ,DIAMETER ,VEIN ,MECHANICAL-PROPERTIES ,Blood Vessel Prosthesis ,Extracellular Matrix ,medicine.anatomical_structure ,TISSUE ,Cord blood ,Nanofiber ,biology.protein ,UMBILICAL-CORD BLOOD ,fibrinogen ,Elastin ,Biomedical engineering ,medicine.drug ,Artery - Abstract
The development of tissue-engineered vascular grafts (TEVGs) for pediatric applications must consider unique factors associated with this patient cohort. While the increased elastogenic potential of neonatal cells offers an opportunity to overcome the long-standing challenge of in vitro elastogenesis, neonatal patients have a lower tolerance for autologous tissue harvest and require grafts that exhibit growth potential. The purpose of this study was to apply a multi-pronged strategy to promote elastogenesis in conjunction with umbilical cord-derived materials in the production of a functional pediatric TEVG. An initial proof-of-concept study was performed to extract fibrinogen from human umbilical cord blood samples and, through electrospinning, to produce a nanofibrous fibrinogen scaffold. This scaffold was seeded with human umbilical cord artery-derived smooth muscle cells (hUASMCs) and neotissue formation within the scaffold was examined using immunofluorescence microscopy. Subsequently, a polycaprolactone (PCL)-reinforced porcine blood-derived fibrinogen scaffold (isolated using the same protocol as cord blood fibrinogen) was used to develop a rolled-sheet graft which employed topographical and biochemical guidance cues to promote elastogenesis and cellular orientation. This approach resulted in a TEVG with robust mechanical properties, and biomimetic arrangement of extracellular matrix (ECM) with rich expression of elastic-fiber related proteins (EFRPs). The results of this study hold promise for further development of pediatric TEVGs and the exploration of the effects of scaffold micro- and nanostructure on vascular cell function and ECM production.
- Published
- 2020
20. SOURCES OF MERCURY DURING LARGE IGNEOUS PROVINCE EMPLACEMENT: THE CENTRAL ATLANTIC MAGMATIC PROVINCE AND SIBERIAN TRAPS
- Author
-
David S. Jones, Benjamin Alexander Black, Felix Alexandre Edwards, and Anna M. Martini
- Subjects
chemistry ,Siberian Traps ,Large igneous province ,Geochemistry ,chemistry.chemical_element ,Geology ,Mercury (element) - Published
- 2020
- Full Text
- View/download PDF
21. SC28 ‘Simdaver’ – A blended-learning programme using simulation-based education with cadaveric dissection to contextualise anatomy for first year medical students
- Author
-
Eoghan O’Connor, Dara Byrne, Bronwyn Reid-McDermott, Áine de Bhulbh, Senan Maher, and Alexander Black
- Subjects
Blended learning ,Dissection ,media_common.quotation_subject ,Preparedness ,Learning environment ,education ,Context (language use) ,Anatomy ,Prosection ,Function (engineering) ,Psychology ,Curriculum ,media_common - Abstract
Background Cadaveric dissections are used to teach anatomy in the early phase of the undergraduate medical curriculum, while the learning of procedural skills is part of the later phase of the curriculum. However, the lack of clinical exposure in early phase, limits students’ ability to understand the significance of anatomical structures. Research has identified challenges in the delivery of anatomy teaching, with recommendations made to tailor learning to increase students’ preparedness to function effectively in a clinical role.1 Simulation-Based Education (SBE) may offer a solution in providing opportunities for early phase learners to perform procedural skills in a safe environment and apply anatomical knowledge in a clinical context. Summary of educational programme or project ‘Simdaver’– a 12-week Special Study Module (SSM) was designed by a team of simulationists, anatomists and doctors from ICAPSS. A blended-learning approach was employed which focused on contextualising what was being taught in anatomy by using SBE to teach core procedural skills. The teaching of each skill involved three elements: ‘Dissecting the Skill’: a brief lecture explained the relevant indications, complications and equipment considerations. Both prosection and dissection were used on a soft–fix cadaver to identify anatomical structures of significance. Students performed elements of the skill on the cadaver with equipment used in clinical practice. Technical skills practice: Repeated practice of the skill took place in the simulation laboratory where students applied their anatomical knowledge of structures to performing the learned core skills on a simulator. They received feedback on performance. Students completed an assessment, a written reflection and a post-SSM evaluation survey. Summary of results All students (n=6) agreed that their learning was greater with this blended-learning approach and that using simulation helped improve their understanding of anatomy. Students’ written reflections identified that the module helped provide insight into the clinical significance of anatomy and motivated them to learn. There was a demand for increased simulation in the early years of the undergraduate curriculum and awareness of the importance of a safe learning environment for both students and patients. Students also reflected that the module allowed them to build confidence and work on non-technical skills in a team-based setting. Discussion, conclusions and recommendations: SBE is an effective means of improving delivery of, and providing a clinical context to, cadaveric anatomy in undergraduate medicine. References Sbayeh, A., Qaedi Choo, M. A., Quane, K. A., Finucane, P., McGrath, D., O’Flynn, S., … O’Tuathaigh, C. M. Relevance of anatomy to medical education and clinical practice: perspectives of medical students, clinicians, and educators. Perspectives on medical education 2016.5(6), 338–346. doi:10.1007/s40037-016-0310-4
- Published
- 2019
- Full Text
- View/download PDF
22. Quantification of the regional bioarchitecture in the human aorta
- Author
-
Peter E. McHugh, Alexander Black, J. Concannon, Sherif Sultan, Kevin M. Moerman, Peter Dockery, J. P. McGarry, and Niamh Hynes
- Subjects
0301 basic medicine ,Male ,Histology ,Myocytes, Smooth Muscle ,Muscle, Smooth, Vascular ,03 medical and health sciences ,0302 clinical medicine ,Cadaver ,medicine.artery ,Ascending aorta ,medicine ,Humans ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,Aorta ,Aged ,Human aorta ,Aged, 80 and over ,biology ,Chemistry ,Abdominal aorta ,Biomechanics ,Cell Biology ,Anatomy ,Original Articles ,Elastin ,030104 developmental biology ,biology.protein ,cardiovascular system ,Female ,Collagen ,Cadaveric spasm ,030217 neurology & neurosurgery ,Developmental Biology - Abstract
Regional variance in human aortic bioarchitecture responsible for the elasticity of the vessel is poorly understood. The current study quantifies the elements responsible for aortic compliance, namely, elastin, collagen and smooth muscle cells, using histological and stereological techniques on human tissue with a focus on regional heterogeneity. Using donated cadaveric tissue, a series of samples were excised between the proximal ascending aorta and the distal abdominal aorta, for five cadavers, each of which underwent various staining procedures to enhance specific constituents of the wall. Using polarised light microscopy techniques, the orientation of collagen fibres was studied for each location and each tunical layer of the aorta. Significant transmural and longitudinal heterogeneity in collagen fibre orientations were uncovered throughout the vessel. It is shown that a von Mises mixture model is required accurately to fit the complex collagen fibre distributions that exist along the aorta. Additionally, collagen and smooth muscle cell density was observed to increase with increasing distance from the heart, whereas elastin density decreased. Evidence clearly demonstrates that the aorta is a highly heterogeneous vessel which cannot be simplistically represented by a single compliance value. The quantification and fitting of the regional aortic bioarchitectural data, although not without its limitations, including mean cohort age of 77.6 years, facilitates the development of next-generation finite element models that can potentially simulate the influence of regional aortic composition and microstructure on vessel biomechanics.
- Published
- 2019
23. Identifying Nanotoxicity at the Cellular Level Using Electron Microscopy
- Author
-
Kerry Thompson, Emma McDermott, Alexander Black, Peter Dockery, and Alanna Stanley
- Subjects
law ,Chemistry ,Nanotoxicology ,Biophysics ,Cellular level ,Electron microscope ,law.invention - Published
- 2019
- Full Text
- View/download PDF
24. Development and Evaluation of a Tissue-Engineered Fibrin-based Canine Mitral Valve Three-dimensional Cell Culture System
- Author
-
C. C. Lu, Mengmeng Liu, David J. Argyle, Alexander Black, S Jockenhovel, Brendan Corcoran, Thomas C. Flanagan, and Anne French
- Subjects
Pathology ,medicine.medical_specialty ,Endothelium ,040301 veterinary sciences ,Cell Culture Techniques ,030204 cardiovascular system & hematology ,Matrix metalloproteinase ,Fibrin ,Pathology and Forensic Medicine ,0403 veterinary science ,Extracellular matrix ,03 medical and health sciences ,0302 clinical medicine ,Dogs ,Tissue engineering ,Mitral valve ,medicine ,Animals ,Dog Diseases ,General Veterinary ,biology ,Tissue Engineering ,Chemistry ,04 agricultural and veterinary sciences ,Embryonic stem cell ,Coculture Techniques ,medicine.anatomical_structure ,Cell culture ,biology.protein ,Mitral Valve - Abstract
Myxomatous mitral valve disease is the most common cardiac disease of the dog, but examination of the associated cellular and molecular events has relied on the use of cadaveric valve tissue, in which functional studies cannot be undertaken. The aim of this study was to develop a three-dimensional (3D) cell co-culture model as an experimental platform to examine disease pathogenesis. Mitral valve interstitial (VIC) and endothelial (VEC) cells were cultured from normal and diseased canine (VIC only) valves. VICs were embedded in a fibrin-based hydrogel matrix and one surface was lined with VECs. The 3D static cultures (constructs) were examined qualitatively and semiquantitatively by light microscopy, immunofluorescence microscopy and protein immunoblotting. Some constructs were manipulated and the endothelium damaged, and the response examined. The construct gross morphology and histology demonstrated native tissue-like features and comparable expression patterns of cellular (α-smooth muscle actin [SMA] and embryonic smooth muscle myosin heavy chain [SMemb]) and extracellular matrix associated markers (matrix metalloproteinase [MMP]-1 and MMP-3), reminiscent of diseased valves. There were no differences between constructs containing normal valve VICs and VECs (type 1) and those containing diseased valve VICs and normal valve VECs (type 2). Mechanical manipulation and endothelial damage (type 3) tended to decrease α-SMA and SMemb expression, suggesting reversal of VIC activation, but with retention of SMemb+ cells adjacent to the wounded endothelium consistent with response to injury. Fibrin-based 3D mitral valve constructs can be produced using primary cell cultures derived from canine mitral valves, and show a phenotype reminiscent of diseased valves. The constructs demonstrate a response to endothelial damage indicating their utility as experimental platforms.
- Published
- 2017
25. UTILIZING NASA EARTH OBSERVATIONS TO DETECT CHANGES IN ANNUAL SNOWPACK COVERAGE IN INTERMOUNTAIN NATIONAL PARKS
- Author
-
Brooke Elizabeth Colley, Alexander Black, James Michael Brooke, Robert D. VanGundy, Aubrey Hilte, and Kimberly Berry
- Subjects
Geography ,Meteorology ,Earth (chemistry) ,Snowpack - Published
- 2017
- Full Text
- View/download PDF
26. Cardiovascular Medication Use Following Percutaneous Coronary Intervention: The Australian Experience
- Author
-
Gishel New, Alexander Black, Nick Andrianopoulos, Justin Cole, James Shaw, Bryan P. Yan, Stephen J. Duffy, P. Loane, Andrew E. Ajani, Matias Yudi, Christopher M. Reid, David J Clark, and Angela Brennan
- Subjects
Male ,medicine.medical_specialty ,Time Factors ,Victoria ,medicine.medical_treatment ,Coronary Artery Disease ,Coronary artery disease ,Drug Utilization Review ,Percutaneous Coronary Intervention ,Risk Factors ,Internal medicine ,Secondary Prevention ,medicine ,Humans ,Pharmacology (medical) ,Prospective Studies ,Registries ,Myocardial infarction ,Practice Patterns, Physicians' ,Prospective cohort study ,Aged ,Pharmacology ,business.industry ,Percutaneous coronary intervention ,Cardiovascular Agents ,General Medicine ,Clopidogrel ,medicine.disease ,Surgery ,Treatment Outcome ,Practice Guidelines as Topic ,Cardiovascular agent ,Conventional PCI ,Cohort ,Female ,Guideline Adherence ,Cardiology and Cardiovascular Medicine ,business ,medicine.drug - Abstract
Summary Aims Despite the guidelines, a “treatment gap” exists in the delivery of pharmacotherapy for secondary prevention. We aimed to analyze the trend in guideline-based medication usage following percutaneous coronary intervention (PCI) using the Melbourne Interventional Group (MIG) registry over a 6-year period (2005–2010). Methods The MIG registry prospectively collects demographical, clinical, and procedural characteristics of consecutive patients undergoing PCI. We assessed medication use (aspirin, clopidogrel, ACE inhibitors, angiotensin receptor blockers, beta-blockers, and lipid-lowering agents) at 30 days and 12 months in patients alive and able to provide the information. Results The cohort consists of 12,813 patients who underwent 14,787 consecutive interventional procedures. They comprised 76% males: 22% were elderly (≥75 years), 23% had diabetes, 2% had severe renal impairment, 2% had severe left ventricular dysfunction, 26% presented with STEMI, and 44% of patients received drug-eluting stent. Follow-up was complete for 97.8% of the cohort at 30 days (2.2% mortality) and 89.1% at 12 months (4% mortality). From 2005 to 2010, the percentage of patients taking all five classes of medications increased each year. In 2010 at 30 days, nearly 60% of patients took all five classes of medications, and by 12 months, 75% of patients were taking four or five classes of medications. Conclusion In conclusion, while the increasing use of cardiovascular medicines in an “at-risk” Australian cohort is encouraging, a treatment gap appears to still exist.
- Published
- 2014
- Full Text
- View/download PDF
27. Morphological changes to endothelial and interstitial cells and to the extra-cellular matrix in canine myxomatous mitral valve disease (endocardiosis)
- Author
-
S.A. Kempson, Richard I Han, Anne French, Alexander Black, C H Clark, Brendan Corcoran, and Geoff Culshaw
- Subjects
Pathology ,medicine.medical_specialty ,Endothelium ,Stereology ,Biology ,Myxomatous degeneration ,Extracellular matrix ,Dogs ,Mitral valve ,medicine ,Animals ,Dog Diseases ,Endocardiosis ,Cell Shape ,Mitral Valve Prolapse ,General Veterinary ,Endothelial Cells ,Anatomy ,medicine.disease ,Heart Valves ,Extracellular Matrix ,medicine.anatomical_structure ,Pleomorphism (microbiology) ,Animal Science and Zoology ,Collagen ,Myofibroblast - Abstract
Morphological and functional changes in endothelial and interstitial cells are considered central to myxomatous degeneration of the canine mitral valve (endocardiosis). The aim of this study was to describe and quantify changes in valve endothelial cells (VECs), interstitial cells (VICs) and the extra-cellular matrix (ECM) of the sub-endothelial zone of diseased valves using a combination of transmission electron microscopy, stereology and computer-aided image analysis. Marked degradation of the endothelium was evident in diseased valves, which coincided with significant degradation of the local ECM (P
- Published
- 2013
- Full Text
- View/download PDF
28. Acute intrathoracic intestinal strangulation diagnosed by transthoracic echocardiography
- Author
-
Elizabeth Ryan, Om Narayan, Alan Appelbe, Catherine Liew, John Amerena, and Alexander Black
- Subjects
Hernia, Diaphragmatic ,Male ,Pulmonary and Respiratory Medicine ,3RD DEGREE AV BLOCK ,medicine.medical_specialty ,Unusual case ,Vomiting ,Pleural effusion ,business.industry ,Left hemithorax ,Nausea ,medicine.disease ,Computed tomographic ,Pleural Effusion ,Echocardiography ,Internal medicine ,Bradycardia ,medicine ,Cardiology ,Humans ,Radiology ,Cardiology and Cardiovascular Medicine ,business ,Aged - Abstract
Transthoracic echocardiography plays a central role in diagnosing a variety of cardiac and pericardial disorders. However its use in identifying extra-cardiac thoracic pathology is less well recognised. We describe an unusual case of intrathoracic intestinal strangulation detected by transthoracic echocardiography. The recognition of bowel loops within the left hemithorax enabled rapid confirmatory computed tomographic imaging and subsequent life-saving surgery. This case demonstrates the utility of bedside echocardiography in the assessment of intrathoracic pathology and emphasises the need for cardiologists to be familiar with the echocardiographic appearance of these disorders.
- Published
- 2012
- Full Text
- View/download PDF
29. Development of the venom ducts in the centipedeScolopendra: an example of recapitulation
- Author
-
Luke Hayden, Alexander Black, Wallace Arthur, and Michel M. Dugon
- Subjects
biology ,Extant taxon ,Arthropod Venoms ,Scolopendra ,Scolopendra subspinipes mutilans ,Venom ,Biological evolution ,Anatomy ,biology.organism_classification ,Centipede ,Ecology, Evolution, Behavior and Systematics ,Developmental Biology - Abstract
In contrast to previous claims that (a) there is a law of recapitulation and, conversely, (b) recapitulation never happens, the evolutionary repatterning of development can take many forms, of which recapitulation is one. Here, we add another example to the list of case studies of recapitulation. This example involves the development of the venom claws (forcipules) in the centipede Scolopendra subspinipes mutilans, and in particular the development of the duct through which venom flows from the gland that produces it (proximal) to the opening called the meatus (distal) through which it is injected into prey. Most of the information we present is from early postembryonic stages--these have been neglected in previous work on centipede development. We show that the venom ducts arise from sutures that are invaginations of the cuticle. In S. s. mutilans, the invagination in each forcipule forms into a tubular structure that detaches itself from the exoskeleton and moves toward the center of the forcipule. This is in contrast to extant Scutigera, and also, probably, Scolopendra's extinct Scutigera-like ancestors, where the duct remains attached to the cuticle of throughout development. Thus, S. s. mutilans exhibits a recapitulatory repatterning of development.
- Published
- 2012
- Full Text
- View/download PDF
30. Usefulness of Transient and Persistent No Reflow to Predict Adverse Clinical Outcomes Following Percutaneous Coronary Intervention
- Author
-
Dion Stub, Gishel New, David J Clark, Christopher M. Reid, Angela Brennan, Alexander Black, William Chan, James Shaw, Nick Andrianopoulos, Anthony M. Dart, Andrew E. Ajani, and Stephen J. Duffy
- Subjects
Male ,medicine.medical_specialty ,Acute coronary syndrome ,medicine.medical_treatment ,Myocardial Infarction ,Shock, Cardiogenic ,Coronary Artery Disease ,Platelet Glycoprotein GPIIb-IIIa Complex ,Prosthesis Design ,Severity of Illness Index ,Cohort Studies ,Coronary artery disease ,Internal medicine ,Angioplasty ,Outcome Assessment, Health Care ,Humans ,Medicine ,Hospital Mortality ,Registries ,cardiovascular diseases ,Myocardial infarction ,Acute Coronary Syndrome ,Angioplasty, Balloon, Coronary ,Intra-Aortic Balloon Pumping ,business.industry ,Cardiogenic shock ,Australia ,Percutaneous coronary intervention ,Stroke Volume ,Acute Kidney Injury ,Middle Aged ,medicine.disease ,Creatinine ,Retreatment ,No reflow phenomenon ,cardiovascular system ,Cardiology ,No-Reflow Phenomenon ,Platelet aggregation inhibitor ,Female ,Stents ,Cardiology and Cardiovascular Medicine ,business ,Platelet Aggregation Inhibitors ,Follow-Up Studies - Abstract
The no reflow phenomenon is reported to occur in >2% of all percutaneous coronary interventions (PCIs) and portends a poor prognosis. We analyzed data from 5,286 consecutive patients who underwent PCI from the Melbourne Interventional Group (MIG) registry from April 2004 through January 2008 who had 30-day follow-up completed. Patients without no reflow (normal reflow, n = 5,031) were compared to 255 (4.8%) with no reflow (n = 217 for transient no reflow, n = 38 for persistent no reflow). Patients with transient or persistent no reflow were more likely to present with ST-elevation myocardial infarction (MI) or cardiogenic shock (p
- Published
- 2012
- Full Text
- View/download PDF
31. Sa1523 - Impact of Pre-Transplant Vitamin and Mineral Deficiencies and Malnutrition on Outcomes after Liver Transplantation
- Author
-
Andrew P. Keaveny, Omar Y. Mousa, Jordan J. Cochuyt, Alexander Black, Surakit Pungpapong, Andree Koop, and Michael G. Heckman
- Subjects
Vitamin ,medicine.medical_specialty ,Hepatology ,business.industry ,medicine.medical_treatment ,Gastroenterology ,Liver transplantation ,medicine.disease ,Malnutrition ,chemistry.chemical_compound ,chemistry ,Internal medicine ,Medicine ,business - Published
- 2018
- Full Text
- View/download PDF
32. Polymer-Free Biolimus A9-Coated Stent Demonstrates More Sustained Intimal Inhibition, Improved Healing, and Reduced Inflammation Compared With a Polymer-Coated Sirolimus-Eluting Cypher Stent in a Porcine Model
- Author
-
Gordon Grant, Alexander Black, John E. Shulze, Saibal Kar, Shih-Horng Su, Norio Tada, Doug Savage, Uwe Christians, Renu Virmani, Ron Betts, Lauren Bartlett, and Claudia F. Clavijo
- Subjects
Neointima ,medicine.medical_specialty ,Intimal hyperplasia ,Swine ,medicine.medical_treatment ,Urology ,Giant Cells ,Fibrin ,Coronary Restenosis ,Restenosis ,Cypher stent ,medicine ,Animals ,Cell Proliferation ,Inflammation ,Sirolimus ,Wound Healing ,Granuloma ,biology ,business.industry ,Stent ,Drug-Eluting Stents ,medicine.disease ,Thrombosis ,Surgery ,biology.protein ,Swine, Miniature ,Tunica Intima ,Cardiology and Cardiovascular Medicine ,business ,medicine.drug - Abstract
Background— Drug-eluting stents effectively reduce restenosis but may increase late thrombosis and delayed restenosis. Persistent polymer, the drug, or a combination of both could be responsible. Local delivery of Biolimus A9, a rapamycin derivative, from a polymer-free BioFreedom stent (Biosensors International) may prevent these complications. Methods and Results— We compared high-dose (HD) (225 μg/14 mm Biolimus A9) and low-dose (LD) (112 μg/14 mm Biolimus A9) BioFreedom stents with a polymer-coated sirolimus-eluting Cypher stent (SES) and a bare-metal stent (BMS) at 28 days and 180 days in an overstretch coronary mini-swine model with histomorphometric and histological analysis. At 28 days, there was a reduction in neointimal proliferation by HD, LD, and SES compared with BMS (neointimal thickness: HD, 0.080�0.032; LD, 0.085�0.038; SES, 0.064�0.037; BMS, 0.19�0.111 mm; P HD/LD/SES). At 180 days, both BioFreedom stents were associated with reduced neointimal proliferation, whereas SES exhibited increased neointima (neointimal thickness: HD, 0.12�0.034; LD, 0.10�0.040; SES, 0.20�0.111; BMS, 0.17�0.099 mm; P HD/LD; BMS > LD). At 180 days, BioFreedom stents showed decreased fibrin and inflammation, including granuloma and giant cells, compared with SES. Conclusions— The polymer-free Biolimus A9-coated stent demonstrates equivalent early and superior late reduction of intimal proliferation compared with SES in a porcine model. After implantation of BioFreedom stent, delayed arterial healing was minimal, and there was no increased inflammation at 180 days compared with SES implantation. The use of polymer-free stents may have a potential long-term benefit over traditional polymeric-coated drug-eluting stents.
- Published
- 2010
- Full Text
- View/download PDF
33. The effect of intended duration of clopidogrel use on early and late mortality and major adverse cardiac events in patients with drug-eluting stents
- Author
-
Brian P Yan, Alexander Black, Gishel New, David Eccleston, Greg Szto, Anthony M. Dart, Angela Brennan, Stephen J. Duffy, Nick Andrianopoulos, James Shaw, David J Clark, Michelle J. Butler, Andrew E. Ajani, and Christopher M. Reid
- Subjects
Male ,medicine.medical_specialty ,Ticlopidine ,Time Factors ,Victoria ,medicine.medical_treatment ,Drug Administration Schedule ,Risk Factors ,Internal medicine ,Myocardial Revascularization ,medicine ,Humans ,Hospital Mortality ,cardiovascular diseases ,Myocardial infarction ,Aged ,Retrospective Studies ,business.industry ,Coronary Stenosis ,Graft Occlusion, Vascular ,Percutaneous coronary intervention ,Stent ,Drug-Eluting Stents ,Middle Aged ,Planned Duration ,medicine.disease ,Clopidogrel ,Surgery ,Survival Rate ,Treatment Outcome ,Drug-eluting stent ,Cardiology ,Platelet aggregation inhibitor ,Female ,Cardiology and Cardiovascular Medicine ,business ,Platelet Aggregation Inhibitors ,Follow-Up Studies ,medicine.drug - Abstract
The optimal duration of clopidogrel use for prevention of stent thrombosis with drug-eluting stent (DES) use is uncertain. Our objective was to determine whether the planned duration of clopidogrel at the time of percutaneous coronary intervention affected patient outcomes.We analyzed data from 2,980 patients who underwent percutaneous coronary intervention in the Melbourne Interventional Group registry who had 12-month follow-up. We compared outcomes at 30 days and 12 months according to planned duration of clopidogrel use.Twelve-month mortality was significantly lower in patients with a DES with a longer (or=12 months) planned duration of clopidogrel when compared with a shorter (or=6 months) planned duration (2.8% vs 5.3%, P = .012). However, myocardial infarction, target-vessel revascularization, and overall major adverse cardiac events were similar in the longer- and shorter-duration clopidogrel strategies. In contrast, in patients receiving a bare-metal stent, mortality at 12 months was similar among the clopidogrel-duration strategies. Kaplan-Meier analysis demonstrated improved cumulative survival with planned clopidogrel use ofor=12 months (log rank P = .017), and the propensity score-adjusted odds ratio was 0.59 (95% confidence interval 0.35-0.99, P = .04). Premature cessation of clopidogrel in DES patients was documented in 5.2% of patients alive at 30-day follow-up, and these patients had increased 12-month mortality (10.6% vs 1.4%, P.0001) and major adverse cardiac events (22.4% vs 12.0%, P = .005).These data suggest that in patients treated with DES, longer (or=12 months) planned duration of clopidogrel results in reduced 12-month mortality and that premature cessation of clopidogrel results in significantly higher event rates. Randomized studies are urgently needed to address this issue.
- Published
- 2009
- Full Text
- View/download PDF
34. Short-, mid-, and long-term effects of a polymer-free tacrolimus-eluting stent in a porcine coronary model
- Author
-
S. Gaggianesi, V. Lolli, Marco Galloni, Alexander Black, C. Vignolini, A. Santarelli, and Marco Prunotto
- Subjects
medicine.medical_specialty ,Surface Properties ,Swine ,medicine.medical_treatment ,Biomedical Engineering ,Polymer free ,Water insoluble ,Tacrolimus ,Drug eluthing stent ,Coronary artieries ,Coronary Restenosis ,Biomaterials ,Coated Materials, Biocompatible ,Restenosis ,Internal medicine ,Materials Testing ,medicine ,Animals ,Angioplasty, Balloon, Coronary ,Neointimal hyperplasia ,Hyperplasia ,business.industry ,Metals and Alloys ,Stent ,Drug-Eluting Stents ,medicine.disease ,Macrolide immunosuppressant ,Coronary Vessels ,Stenosis ,Ceramics and Composites ,Cardiology ,Swine, Miniature ,Tunica Intima ,business ,Immunosuppressive Agents - Abstract
Stent-based delivery of tacrolimus has shown neointimal hyperplasia and restenosis reduction; FK506 is a water insoluble macrolide immunosuppressant. The purpose of this study was to evaluate acute and chronic tissue response to a polymer-free FK506 drug-eluting stent implantation in a porcine coronary artery model. Seventy-eight nonatherosclerotic minipigs underwent successful placement of 134 stents (control n = 56; FK506 (1.5 μg/mm2) n = 44; FK506 (2.6 μg/mm2) n = 34) at 7, 15, 30, 90, or 180 days. Endothelialisation was almost complete at 7 days, complete at 15 days. At 30 and 90 days, mean neointimal thickness, neointimal area, and % stenosis was significantly less for drug-eluting stents compared with controls. At 180 days, histomorphometric values were similar for eluting and control stents. The FK506-eluting stent allows for a complete re-endothelialisation at 15 days and favorably moderate neointimal hyperplasia at 30 and 90 days in the porcine coronary model. Because of a possible limited bioavailability of FK506, long-term inhibition of neointimal formation was not sustained at the considered follow-up. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
- Published
- 2009
- Full Text
- View/download PDF
35. Survival of Elderly Patients Undergoing Percutaneous Coronary Intervention for Acute Myocardial Infarction Complicated by Cardiogenic Shock
- Author
-
Kerrie Charter, H.M. Omar Farouque, Gishel New, Angela Brennan, Melanie Freeman, Nick Andrianopoulos, C.C.S. Lim, Bryan P. Yan, Andrew E. Ajani, Christopher M. Reid, Han S. Lim, Alexander Black, Stephen J. Duffy, and David J Clark
- Subjects
Male ,Aging ,medicine.medical_specialty ,medicine.medical_treatment ,Myocardial Infarction ,Shock, Cardiogenic ,Kaplan-Meier Estimate ,Revascularization ,Internal medicine ,Angioplasty ,Confidence Intervals ,Odds Ratio ,medicine ,Humans ,Hospital Mortality ,Registries ,cardiovascular diseases ,Myocardial infarction ,Angioplasty, Balloon, Coronary ,Aged ,Aged, 80 and over ,business.industry ,Cardiogenic shock ,Age Factors ,Percutaneous coronary intervention ,Middle Aged ,medicine.disease ,Clinical trial ,Logistic Models ,Shock (circulatory) ,Multivariate Analysis ,Conventional PCI ,Cardiology ,Female ,medicine.symptom ,Cardiology and Cardiovascular Medicine ,business - Abstract
We sought to assess clinical outcomes of elderly patients (ageor=75 years) undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (MI) complicated by cardiogenic shock (CS) in a contemporary multicenter PCI registry.Although benefits of early PCI have been shown in younger groups, few studies have reported on clinical outcomes in elderly shock patients using current PCI techniques.We analyzed baseline characteristics and procedural and clinical outcomes in 143 consecutive patients presenting with MI and CS who underwent PCI from the Melbourne Interventional Group registry between 2004 and 2007.Of the 143 patients, 31.5% (n = 45) were elderly and 68.5% were younger (age75 years). Elderly patients were more likely to be female (46.7% vs. 22.4%, p0.01) and have hypertension (77.8% vs. 46.4%, p0.01), previous MI (31.1% vs. 15.5%, p = 0.03), renal failure (24.4% vs. 11.3%, p0.05) and multivessel coronary artery disease (93.1% vs. 68.3%, p0.01). Stent (86.7% vs. 94.8%, p = 0.09), glycoprotein IIb/IIIa inhibitor (68.9% vs. 65.3%, p = 0.67), and intra-aortic balloon pump (57.8% vs. 58.2%, p = 0.97) use were similar in both groups. In-hospital, 30-day, and 1-year mortality in the elderly group versus the younger group were 42.2% vs. 33.7% (p = 0.32), 43.2% vs. 36.1% (p = 0.42), and 52.6% vs. 46.8% (p = 0.56), respectively.In this study, the 1-year survival of elderly patients with acute MI complicated by CS undergoing PCI was comparable to younger patients. These data suggest that in elderly patients presenting with CS, benefit is possible with selective use of early revascularization and merits further investigation.
- Published
- 2009
- Full Text
- View/download PDF
36. Outcomes after percutaneous coronary intervention in contemporary Australian practice: insights from a large multicentre registry
- Author
-
Jeffery Lefkovits, Ronen Gurvitch, James Shaw, Andrew E. Ajani, Gishel New, Christopher M. Reid, Angela Brennan, Alexander Black, Bryan P. Yan, Nick Andrianopoulos, A. Al-Fiadh, R. Lew, Stephen J. Duffy, and David J Clark
- Subjects
Adult ,Male ,Acute coronary syndrome ,medicine.medical_specialty ,Pediatrics ,Ticlopidine ,Victoria ,medicine.medical_treatment ,Myocardial Infarction ,Comorbidity ,Internal medicine ,medicine ,Humans ,Hospital Mortality ,Registries ,Myocardial infarction ,Acute Coronary Syndrome ,Angioplasty, Balloon, Coronary ,Practice Patterns, Physicians' ,Aged ,Retrospective Studies ,business.industry ,Mortality rate ,Percutaneous coronary intervention ,Drug-Eluting Stents ,Retrospective cohort study ,General Medicine ,Middle Aged ,medicine.disease ,Clopidogrel ,Treatment Outcome ,Cohort ,Platelet aggregation inhibitor ,Female ,Stents ,business ,Platelet Aggregation Inhibitors ,Mace - Abstract
OBJECTIVE: To examine short- and medium-term outcomes of percutaneous coronary interventions (PCIs), with a focus on comparing drug-eluting stents (DESs) with bare-metal stents (BMSs). DESIGN, SETTING AND PARTICIPANTS: Retrospective analysis of data from the Melbourne Interventional Group (MIG) registry, a large multicentre Australian registry. The study cohort consisted of 6364 consecutive patients undergoing 7167 PCIs between April 2004 and August 2007. MAIN OUTCOME MEASURES: Clinical events including death, myocardial infarction (MI), target lesion revascularisation (TLR), target vessel revascularisation (TVR) and major adverse cardiac events (MACE) (a composite of death, MI and TVR), at 30 days and at 12 months. RESULTS: The cohort was predominantly male (74%), with a mean age of 64.7 years (SD, 12.0 years). DESs were used in 3482 (51.4%) of PCIs. In the overall cohort, rates of clinical events were low at 30 days: mortality (1.9%), MI (2.4%), TLR (2.0%), TVR (2.4%) and MACE (5.7%). At 12 months, event rates were: mortality (5.2%), MI (6.0%), TLR (5.8%), TVR (8.2%) and MACE (16.2%). Patients receiving DESs had similar mortality rates to those receiving BMSs (4.0% v 6.0%; P = 0.62 [propensity score-adjusted]); late thrombosis rates were also similar in the two groups (0.8% v 1.1%; P = 0.38). The proportion of patients receiving DESs fell significantly over time, from 54.9% in the first 24 months to 44.7% in the last 15 months of the study period (P < 0.01). Independent predictors of 12-month mortality included diabetes, renal failure, ST-segment-elevation MI and cardiogenic shock. CONCLUSION: Our clinical event rates were comparable with international registry outcomes. Rates of mortality and stent thrombosis were no higher in patients with DESs than those with BMSs. Although DESs were used in about half the procedures (preferentially for higher-risk lesions), recent trends suggest their use is in decline.
- Published
- 2008
- Full Text
- View/download PDF
37. Body esteem as a moderator of cardiovascular stress responses in anatomy students viewing cadaver dissections
- Author
-
Alexander Black and Brian M. Hughes
- Subjects
Adult ,Male ,Students, Medical ,Time Factors ,education ,Blood Pressure ,Terror management theory ,Heart Rate ,Cadaver ,Adaptation, Psychological ,Mortality salience ,Heart rate ,Body Image ,Humans ,Dissection ,Anatomy ,Moderation ,Self Concept ,Pulse pressure ,Psychiatry and Mental health ,Clinical Psychology ,Blood pressure ,Visual Perception ,Female ,Psychology ,Stress, Psychological - Abstract
Objective: Anatomy training requires students to take courses involving the dissection of human cadavers. It is suspected that such tuition is stressful for some students more than for others. Terror management theory suggests that the mortality salience presented by cadaver dissections would heighten stress among those students with positive self-images. The present study sought to investigate the association between body esteem (BE) and cardiovascular stress reactivity to cadaver dissections. Methods: The study involved the measurement of cardiovascular stress responses in 36 anatomy students during a dissection class. Psychometric assessments of BE and other variables were taken. Results: Students with high BE had lower heart rate (P=.011) and exhibited greater decreases in systolic blood pressure (P=.008) and pulse pressure (P=.003) throughout the session, suggestive of maladaptive stress response. Conclusions: As findings are consistent with theories linking BE with stress in occupations that require workers to view dead bodies, the consideration of BE may be an effective component in stress reduction interventions.
- Published
- 2006
- Full Text
- View/download PDF
38. Use of drug‐eluting stents in Victorian public hospitals
- Author
-
Andrew E. Ajani, Martin Sebastian, Mark Horrigan, Jeffery Lefkovits, Christopher M. Reid, Greg Szto, Bryan P. Yan, David J Clark, David Eccleston, Gishel New, Stephen J. Duffy, Alexander Black, Anthony Walton, and Angela Brennan
- Subjects
Male ,Risk ,medicine.medical_specialty ,Percutaneous ,Victoria ,medicine.medical_treatment ,Coronary Restenosis ,Coronary artery disease ,Drug Delivery Systems ,Restenosis ,Angioplasty ,Humans ,Medicine ,Prospective Studies ,Angioplasty, Balloon, Coronary ,Practice Patterns, Physicians' ,Prospective cohort study ,Hospitals, Public ,business.industry ,Patient Selection ,General Medicine ,Middle Aged ,medicine.disease ,Surgery ,Drug-eluting stent ,Relative risk ,Practice Guidelines as Topic ,Utilization Review ,Conventional PCI ,Female ,Stents ,Guideline Adherence ,business - Abstract
Objective: We aimed to assess the pattern of use of drug-eluting stents (DESs) in patients undergoing percutaneous coronary interventions (PCIs) in Victorian public hospitals. Design, setting and patients: Prospective study comparing the use of one or more DESs versus bare-metal stents (BMSs) only, in consecutive patients undergoing 2428 PCIs with stent implantation from 1 April 2004 to 31 December 2005 at seven Victorian public hospitals. Main outcome measures: Adherence to current Victorian Department of Human Services guidelines which recommend DES use in patients with high-risk features for restenosis (diabetes, small vessels, long lesions, in-stent restenotic lesions, chronic total occlusions and bifurcation lesions). Results: Of the 2428 PCIs performed, at least one DES was implanted in 1101 (45.3%) and BMSs only were implanted in 1327 (54.7%). In 87.7% (966/1101) of PCI with DESs, there was at least one criterion for high risk of restenosis. DESs were more likely to be used in patients with diabetes (risk ratio [RR], 2.45; 95% CI, 2.02–2.97), small vessels (RR, 3.35; 95%CI, 2.35–4.76), long lesions (RR, 3.87; 95% CI, 3.23–4.65), in-stent restenotic lesions (RR, 3.98; 95%CI, 2.67–6.06), chronic total occlusions (RR, 1.30; 95% CI, 0.51–2.88) and bifurcation lesions (RR, 2.23; 95%CI, 1.57–3.17). However, 66.2% (1608/2428) of all PCIs were in patients eligible for DESs according to Victorian guidelines, and in 39.9% (642/1608) of these PCIs, a BMS was used. Conclusion: In Victorian public hospitals, DESs have been largely reserved for patients at high risk of restenosis in accordance with Department of Human Services guidelines. However, many patients with high-risk criteria for restenosis did not receive DESs. Greater use of DESs in these patients may improve outcomes by reducing the need for
- Published
- 2006
- Full Text
- View/download PDF
39. A collagen-glycosaminoglycan co-culture model for heart valve tissue engineering applications
- Author
-
Terence James Smith, Stefan Jockenhoevel, Alexander Black, Brendan Wilkins, Thomas C. Flanagan, and Abhay Pandit
- Subjects
Materials science ,Swine ,Biophysics ,Biocompatible Materials ,Bioengineering ,Models, Biological ,Biomaterials ,Extracellular matrix ,Laminin ,Mitral valve ,Materials Testing ,medicine ,Animals ,Heart valve ,Cells, Cultured ,Glycosaminoglycans ,Basement membrane ,Tissue Engineering ,biology ,Endothelial Cells ,Hydrogels ,Coculture Techniques ,Extracellular Matrix ,Cell biology ,medicine.anatomical_structure ,Mechanics of Materials ,Self-healing hydrogels ,Ceramics and Composites ,biology.protein ,Mitral Valve ,Collagen ,Elastin ,Type I collagen ,Biomedical engineering - Abstract
In order to develop efficient design strategies for a tissue-engineered heart valve, in vivo and in vitro models of valvular structure and cellular function require extensive characterisation. Collagen and glycosaminoglycans (GAGs) provide unique functional characteristics to the heart valve structure. In the current study, type I collagen-GAG hydrogels were investigated as biomaterials for the creation of mitral valve tissue. Porcine mitral valve interstitial cells (VICs) and endothelial cells (VECs) were isolated and co-cultured for 4 weeks in hydrogel constructs composed of type I collagen. The metabolic activity and tissue organisation of mitral valve tissue constructs was evaluated in the presence and absence of chondroitin sulphate (CS) GAG, and comparisons were made with normal mitral valve tissue. Both collagen and collagen-CS mitral valve constructs contracted to form tissue-like structures in vitro. Biochemical assay demonstrated that over 75% of CS was retained within collagen-CS constructs. Morphological examination demonstrated enhanced VEC surface coverage in collagen-CS constructs compared to collagen constructs. Ultrastructural analysis revealed basement membrane synthesis and cell junction formation by construct VECs, with an increased matrix porosity observed in collagen-CS constructs. Immunohistochemical analyses demonstrated enhanced extracellular matrix production in collagen-CS constructs, including expression of elastin and laminin by VICs. Both native valve and collagen-CS construct VECs also expressed the vasoactive molecule, eNOS, which was absent from collagen construct VECs. The present study demonstrates that collagen gels can be used as matrices for the in vitro synthesis of tissue structures resembling mitral valve tissue. Addition of CS resulting in a more porous model was shown to positively influence the bioactivity of seeded valve cells and tissue remodelling. Collagen-GAG matrices may hold promise for a potential use in heart valve tissue engineering and improved understanding of heart valve biology.
- Published
- 2006
- Full Text
- View/download PDF
40. The Foundation and Launch of the Melbourne Interventional Group: A Collaborative Interventional Cardiology Project
- Author
-
Greg Szto, Christopher M. Reid, Martin Sebastian, Angela Brennan, Roderic Warren, Jonathan E. Shaw, Bryan P. Yan, David Eccleston, David J Clark, Mark Horrigan, Stephen J. Duffy, Antony Walton, Adam David Meehan, R. Lew, Gishel New, Alexander Black, Andrew E. Ajani, Henry Krum, Derek P. Chew, and Jeffrey Lefkovits
- Subjects
Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Victoria ,Interventional cardiology ,business.industry ,medicine.medical_treatment ,MEDLINE ,Psychological intervention ,Percutaneous coronary intervention ,medicine.disease ,Clinical trial ,Angioplasty ,Conventional PCI ,Epidemiology ,medicine ,Humans ,Organizational Objectives ,Registries ,Medical emergency ,Angioplasty, Balloon, Coronary ,Cardiology and Cardiovascular Medicine ,business - Abstract
The Melbourne Interventional Group (MIG) is a voluntary collaborative venture of interventional cardiologists practicing at 12 major public and private hospitals in Victoria, designed to record data pertaining to percutaneous coronary interventions (PCI) and perform long-term follow-up. The potential advantages of collaboration involve large-scale analysis of current interventional strategies (e.g. drug-eluting stents, evaluation of new technologies and cost-effective analysis), provide a basis for multi-centred clinical trials and allow comparison of clinical outcomes with cardiac surgery. The established registry documents demographic, clinical and procedural characteristics of consecutive patients undergoing PCI and permits analysis of those characteristics at 30 days and 12 months. The registry is co-ordinated by the Centre of Clinical Research Excellence (CCRE), a research body within the Department of Epidemiology and Preventive Medicine (Monash University, Melbourne). The eventual goal of MIG is to provide a contemporary appraisal of Australian interventional cardiology practice, with opportunities to improve in-hospital and long-term outcomes of patients with coronary artery disease.
- Published
- 2006
- Full Text
- View/download PDF
41. Reference Models for Mitral Valve Tissue Engineering Based on Valve Cell Phenotype and Extracellular Matrix Analysis
- Author
-
Margaret O'Brien, Alexander Black, Thomas C. Flanagan, Abhay Pandit, and Terry J. Smith
- Subjects
Male ,Histology ,Swine ,medicine.medical_treatment ,Extracellular matrix ,Mice ,Type IV collagen ,Laminin ,Mitral valve ,medicine ,Animals ,Humans ,Vimentin ,Heart valve ,Cells, Cultured ,Basement membrane ,Mitral valve repair ,Tissue Engineering ,biology ,Reverse Transcriptase Polymerase Chain Reaction ,Chemistry ,Chondroitin Sulfates ,Endothelial Cells ,Anatomy ,Immunohistochemistry ,Actins ,Elastin ,Extracellular Matrix ,Fibronectins ,Cell biology ,Fibronectin ,medicine.anatomical_structure ,cardiovascular system ,biology.protein ,Mitral Valve ,Female ,Collagen ,Nitric Oxide Synthase - Abstract
The advance of mitral valve repair techniques through tissue engineering is impeded by the lack of information regarding the cellular and extracellular components of the mitral valve. The present study aims to expand our understanding of the mitral valve structure by analysing the synthesis of extracellular matrix (ECM) proteins and the expression of nitric oxide synthase (NOS). Valvular endothelial cells (VECs) and valvular interstitial cells (VICs) were isolated from porcine mitral valves. Immunochemical staining of ECM components, including type I, II, III, IV and V collagen, laminin, fibronectin, elastin and chondroitin sulphate (CS), was performed on both mitral valve tissue and cell cultures. Reverse transcription polymerase chain reaction and immunochemistry were used to analyse NOS expression in native valve and in culture. Both VECs and VICs synthesised the basement membrane components, laminin and type IV collagen both in vivo and in vitro, amongst other fibrous ECM proteins. Synthesis of type I collagen and CS was absent in VEC cultures. Each cell type had a characteristic profile of NOS expression. VECs synthesised endothelial NOS both in vivo and in vitro, with a minority of VICs expressing neuronal NOS in vitro. The present study reports newly recognised aspects of the mitral valve structure and the in vitro behaviour of mitral valve cell populations based on ECM synthesis and NOS expression. The presented profiles can be used as base tools for the generation of data necessary for the selection of ideal cell sources and for the design of appropriate scaffolds for the development of effective tissue-engineered mitral valves.
- Published
- 2006
- Full Text
- View/download PDF
42. Identification of surface morphologic changes in the mitral valve leaflets and chordae tendineae of dogs with myxomatous degeneration
- Author
-
Joanna Dukes Mcewan, Anne French, Heather Anderson, Paul Smith, Alexander Black, Craig Devine, and Brendan Corcoran
- Subjects
Basement membrane ,Endocarditis ,General Veterinary ,Endothelium ,business.industry ,Hemodynamics ,General Medicine ,Anatomy ,medicine.disease ,Myxomatous degeneration ,Pathogenesis ,Dogs ,medicine.anatomical_structure ,Mitral valve ,Microscopy, Electron, Scanning ,cardiovascular system ,medicine ,Animals ,Chordae Tendineae ,Mitral Valve ,Mitral valve prolapse ,Dog Diseases ,cardiovascular diseases ,Chordae tendineae ,business - Abstract
Objective—To describe structural changes in the left atrioventricular (mitral) valve complex of dogs with endocardiosis by use of scanning electron microscopy. Animals—5 clinically normal dogs and 4 dogs with mitral valve endocardiosis. Procedure—The mitral valve complex from each dog was fixed and prepared for examination via scanning electron microscopy. Findings in valves from clinically normal and affected dogs were compared to identify surface changes associated with endocardiosis. Results—Compared with findings in valves from clinically normal dogs, endocardiosis-affected mitral valve complexes had several morphologic abnormalities. Tissue swelling on the edge of valve leaflets, chordae tendineae, and the chordal-papillary muscle junction was evident. Damage to the valve complex endothelium was unevenly distributed; in some areas, denudation of endothelial cells had exposed the basement membrane or subendothelial valve collagen matrix. This damage was most noticeable on the leaflet edges and extended more to the ventricular aspect of the valve than the atrial side. Cell loss also extended to the chordae tendineae but was less apparent at the chordal-papillary muscle junction. The remaining endothelial cells on affected valves were arranged in less-ordered rows and had more plasmalemmal microappendages, compared with cells on unaffected valves. Conclusions and Clinical Relevance—Morphologic changes associated with mitral valve endocardiosis in dogs were similar to those observed in humans with mitral valve prolapse. In dogs with mitral valve endocardiosis, gross changes in the valve complex may affect hemodynamics in the heart; alterations in the leaflet and chordal endothelium may contribute to pathogenesis of this disease. (Am J Vet Res 2004; 65:198–206)
- Published
- 2004
- Full Text
- View/download PDF
43. Unprotected left main coronary artery stenting
- Author
-
Rémi Choussat, Jean Fajadet, Alexander Black, Jean Marco, R. Cortina, and Irene Bossi
- Subjects
medicine.medical_specialty ,Ejection fraction ,business.industry ,medicine.medical_treatment ,Stent ,Revascularization ,Surgery ,Left coronary artery ,medicine.anatomical_structure ,Bypass surgery ,Angioplasty ,Internal medicine ,medicine.artery ,Coronary stent ,medicine ,Cardiology ,Cardiology and Cardiovascular Medicine ,business ,Artery - Abstract
OBJECTIVES The study served to present the in-hospital and six-month clinical outcome and also the long-term survival data of a consecutive series of patients undergoing stenting for unprotected left main coronary artery (LMCA) disease. BACKGROUND Revascularization with coronary bypass surgery has been generally recommended for treatment of left main coronary stenosis. Improvements in angioplasty and coronary stent techniques and equipment may result in the wider applicability of a percutaneous approach. METHODS A total of 92 consecutive patients underwent unprotected LMCA stenting between March 1994 and December 1998. For the initial 39 patients (group I) angioplasty was performed only when surgical revascularization was contraindicated. The remaining 53 patients (group II) also included patients in whom surgery was feasible. Patients were followed for 7.3 ± 5.8 months (median 239 days; range 49 to 1,477 days). RESULTS Compared to group I, group II patients had higher left ventricular ejection fraction (60 ± 12% vs. 51 ± 16%, p CONCLUSIONS Coronary stenting can be performed safely in high-risk individuals with acceptable intermediate-term outcome. It may be feasible to broaden the application of this technique in selected patients needing revascularization for left main coronary disease.
- Published
- 2001
- Full Text
- View/download PDF
44. Long-term clinical outcome after endoluminal reconstruction of diffusely degenerated saphenous vein grafts with less-shortening wallstents
- Author
-
Rémi Choussat, T. Joseph, Jean Fajadet, Alexander Black, Jean Marco, and Irene Bossi
- Subjects
Adult ,Male ,medicine.medical_specialty ,Percutaneous ,medicine.medical_treatment ,Coronary Disease ,Constriction, Pathologic ,Balloon ,Coronary Angiography ,Constriction ,Lesion ,Postoperative Complications ,Angioplasty ,medicine ,Humans ,Saphenous Vein ,Angioplasty, Balloon, Coronary ,Coronary Artery Bypass ,Survival analysis ,Aged ,Aged, 80 and over ,business.industry ,Middle Aged ,Survival Analysis ,Surgery ,Treatment Outcome ,Bypass surgery ,Retreatment ,Female ,Stents ,Radiology ,medicine.symptom ,business ,Cardiology and Cardiovascular Medicine ,TIMI - Abstract
OBJECTIVES This study was designed to evaluate the immediate and long-term clinical results of patients undergoing endoluminal reconstruction in diffusely degenerated saphenous vein grafts (SVGs) with elective implantation of one or more less-shortening Wallstents. BACKGROUND The optimal treatment strategy for patients with diffusely degenerated SVGs is controversial. Endoluminal reconstruction by stent implantation is one proposed strategy; however, there are few data regarding long-term clinical outcome. METHODS Between May 1995 and September 1998, 6,534 consecutive patients underwent angioplasty in our institution, including 440 who were treated for SVG lesions. Of these, 126 (115 men, 11 women, median age 69.5 years, range: 33–86 years) with old SVGs (mean age: 13 ± 5 years) diffusely degenerated stenosed or occluded (mean lesion length: 27 ± 12 mm) were treated electively with implantation of one or multiple (total 197) less-shortening Wallstents. RESULTS Before discharge, 13 patients (10.3%) sustained at least one major cardiovascular event, including 4 deaths (3.2%), 11 myocardial infarctions (MI) (8.7%), and 3 repeat revascularizations (target vessel = 1, nontarget vessel = 2, 2.4%). Surviving patients were followed for 22 ± 11 months: 13 patients (11.1%) died, 11 (9.4%) sustained an MI, 37 underwent angioplasty (31.6%), and 4 (3.4%) underwent bypass surgery. The estimated three-year event-free survival rates (freedom from death, and freedom from death/MI/target vessel revascularization) were (mean ± SE) 81.1 ± 7.8% and 43.2 ± 18.5%, respectively. CONCLUSIONS The long-term clinical outcome of patients undergoing endoluminal reconstruction in diffusely degenerated SVG is relatively poor, mainly because of a high incidence of death or MI and the frequent need for repeat angioplasty. It is unlikely that percutaneous intervention alone will provide a satisfactory or definitive solution for these patients.
- Published
- 2000
- Full Text
- View/download PDF
45. In-stent restenosis: long-term outcome and predictors of subsequent target lesion revascularization after repeat balloon angioplasty
- Author
-
M. Bernies, Alexander Black, Catherine Klersy, B. Cassagneau, Remi Choussat, R. Cortina, Christian Jordan, Jean Fajadet, Jean Marco, Jean Pierre Laurent, Jean Claude Laborde, and Irene Bossi
- Subjects
Male ,medicine.medical_specialty ,Percutaneous ,medicine.medical_treatment ,Coronary Disease ,Balloon ,Lesion ,Restenosis ,Recurrence ,Internal medicine ,Angioplasty ,medicine ,Humans ,Myocardial infarction ,Angioplasty, Balloon, Coronary ,Target lesion revascularization ,Aged ,business.industry ,Middle Aged ,medicine.disease ,Surgery ,Radiography ,Survival Rate ,Retreatment ,Cardiology ,Equipment Failure ,Female ,Stents ,medicine.symptom ,In stent restenosis ,business ,Cardiology and Cardiovascular Medicine ,Follow-Up Studies - Abstract
We sought to evaluate the long-term clinical outcome of patients undergoing successful balloon angioplasty for in-stent restenosis, and to determine correlates of the need for subsequent target lesion revascularization (TLR).In-stent restenosis can be safely treated by repeat percutaneous intervention. Reported subsequent TLR rates have varied from 20% to 80% and seem related to the type of restenotic lesion.The study population comprised 234 patients with follow-up data who were successfully treated with repeat balloon angioplasty for in-stent restenosis in 257 lesions between May 1995 and January 1998 at our institution.Clinical follow-up was available at 459 (286 to 693) days after the repeat procedure. Event-free survival was 78.5% and 74.6% at 12 and 24 months, respectively. Recurrent events occurred in 58 patients (24.8%), including 6 deaths (2.6%), 4 myocardial infarction (1.7%) and repeat target vessel revascularization in 50 patients (21.4%). Independent predictors of repeat TLR were time to in-stent restenosis90 days (Hazard ratio 4.67, p0.001), minimal luminal diameter after repeat procedure (Hazard ratio 0.38, p = 0.034) and the angiographic pattern of in-stent restenosis (Hazard ratio 1.65, p = 0.036).Balloon angioplasty is an effective means of treating in-stent restenosis. The long-term results are acceptable particularly for focal restenotic lesions. Further restenosis is more common in patients with early initial recurrence, more proliferative lesions and a poorer angiographic result from repeat angioplasty.
- Published
- 2000
- Full Text
- View/download PDF
46. Development of the venom ducts in the centipede Scolopendra: an example of recapitulation
- Author
-
Michel M, Dugon, Luke, Hayden, Alexander, Black, and Wallace, Arthur
- Subjects
Microscopy, Fluorescence ,Microscopy, Electron, Scanning ,Animals ,Arthropods ,Biological Evolution ,Arthropod Venoms - Abstract
In contrast to previous claims that (a) there is a law of recapitulation and, conversely, (b) recapitulation never happens, the evolutionary repatterning of development can take many forms, of which recapitulation is one. Here, we add another example to the list of case studies of recapitulation. This example involves the development of the venom claws (forcipules) in the centipede Scolopendra subspinipes mutilans, and in particular the development of the duct through which venom flows from the gland that produces it (proximal) to the opening called the meatus (distal) through which it is injected into prey. Most of the information we present is from early postembryonic stages--these have been neglected in previous work on centipede development. We show that the venom ducts arise from sutures that are invaginations of the cuticle. In S. s. mutilans, the invagination in each forcipule forms into a tubular structure that detaches itself from the exoskeleton and moves toward the center of the forcipule. This is in contrast to extant Scutigera, and also, probably, Scolopendra's extinct Scutigera-like ancestors, where the duct remains attached to the cuticle of throughout development. Thus, S. s. mutilans exhibits a recapitulatory repatterning of development.
- Published
- 2012
47. Cardiovascular readmissions and excess costs following percutaneous coronary intervention in patients with chronic kidney disease: data from a large multi-centre Australian registry
- Author
-
Cheng-Hon Yap, Stephen J. Duffy, Zanfina Ademi, Bryan P. Yan, David J Clark, Baki Billah, Gishel New, Andrew E. Ajani, Alexander Black, Christopher M. Reid, Thathya V. Ariyaratne, Angela Brennan, and Nick Andrianopoulos
- Subjects
Male ,medicine.medical_specialty ,Pediatrics ,medicine.medical_treatment ,Renal function ,Patient Readmission ,Indirect costs ,Percutaneous Coronary Intervention ,Postoperative Complications ,medicine ,Humans ,Registries ,Risk factor ,Renal Insufficiency, Chronic ,Adverse effect ,Dialysis ,Aged ,business.industry ,Australia ,Percutaneous coronary intervention ,Middle Aged ,medicine.disease ,Cardiovascular Diseases ,Conventional PCI ,Emergency medicine ,Costs and Cost Analysis ,Female ,Cardiology and Cardiovascular Medicine ,business ,Kidney disease - Abstract
Background Chronic kidney disease (CKD) is a well-established risk factor for adverse events in patients undergoing percutaneous coronary intervention (PCI). However, few data exists on the subsequent healthcare resource use and related incremental costs in this patient subgroup. The present study compares the rates of cardiac-related hospitalisations and the associated direct costs, post-PCI in patients with and without CKD. Methods Healthcare costs were estimated for 12,998 PCI patient-procedures from the Melbourne Interventional Group (MIG) registry, collected between February 2004 and October 2010. Information collected included the use of cardiovascular drugs and cardiac-related hospitalisations from those that completed 12-month follow-up. Individual patients were assigned unit costs based on published data from the National Hospital Cost Data Collection for Admissions in Victoria (2008–2009) and the Pharmaceutical Benefit Scheme (PBS) schedule (2011–2012). Bootstrap multiple linear regression was used to estimate the direct excess healthcare costs, adjusting for age and gender and relevant comorbidities. Results Excess cardiac-related readmissions occurred among patients with "severe CKD or dialysis" (estimated glomerular filtration rate (eGFR): 2 ; n=330; 35%), compared to "moderate CKD" (eGFR: 30–60ml/min/1.73m 2 ; n=2648; 28%), or the "referent CKD status" (eGFR: ≥60ml/min/1.73m 2 ; n=10,020; 24%). On average, excess (95%CI) overall direct costs were significantly higher in patients with severe CKD or dialysis compared to those with referent CKD status [$AUD 2206 ($AUD 1148 to 3688)]. Conclusions From the healthcare payer's perspective, PCI patients with severe CKD compared to no-CKD imposed significantly higher burden on subsequent healthcare resources. Hospitalisations accounted for the majority of these expenditures.
- Published
- 2012
48. Cell maceration scanning electron microscopy and computer-derived porosity measurements in assessment of connective tissue microstructure changes in the canine myxomatous mitral valve
- Author
-
Richard I Han, Geoff Culshaw, G Impoco, Anne French, Alexander Black, and Brendan Corcoran
- Subjects
Materials science ,General Veterinary ,Scanning electron microscope ,Cell ,Maceration (bone) ,Connective tissue ,Mitral Valve Insufficiency ,Anatomy ,Matrix (biology) ,Microstructure ,Extracellular matrix ,medicine.anatomical_structure ,Dogs ,Connective Tissue ,medicine ,Microscopy, Electron, Scanning ,Animals ,Mitral Valve ,Animal Science and Zoology ,sense organs ,Dog Diseases ,skin and connective tissue diseases ,Porosity - Abstract
Canine myxomatous mitral valve disease is associated with changes in the valve extracellular matrix (ECM). The aim of this study was to examine the use of cell macerated scanning electron microscopy (CMSEM) in evaluating ECM changes in a small sample of valves and to quantify these changes using computer-aided image analysis of sample porosity (a measure of structural disorganisation and collagen loss). The distinct layered structure of the de-cellularised matrix could be seen in the normal valve and there were marked changes in layers and ECM organisation as the disease progressed. Clearly visible and quantifiable, statistically significant changes were found in valve porosity across the entire leaflet thickness and particularly in the valve mid and distal zones. All of these changes are presumed to affect the mechanical function of the valve. In conclusion, CMSEM with computed image analysis can be used to visualise and measure tissue structural changes in a quasi-3-dimensional manner in normal and diseased tissues.
- Published
- 2012
49. Pravastatin reduces marfan aortic dilation
- Author
-
Vilhelmiina Huuskonen, Harry C. Dietz, Sinead Kearney, Darren McLoughlin, Jonathan McGuinness, Hester McAllister, Elaine W. Kay, Alexander Black, J. Mark Redmond, Arnold D.K. Hill, John Byrne, and E. Terzo
- Subjects
Male ,Marfan syndrome ,vessels ,losartan ,Stereology ,Endoplasmic Reticulum ,Muscle, Smooth, Vascular ,Marfan Syndrome ,Pathogenesis ,Mice ,prevention ,Pravastatin ,remodeling ,biology ,pathogenesis ,Treatment Outcome ,Losartan ,Cardiology ,cardiovascular system ,Tunica Media ,Cardiology and Cardiovascular Medicine ,events ,Dilatation, Pathologic ,medicine.drug ,medicine.medical_specialty ,mouse model ,Aortic Diseases ,metalloproteinases ,smooth-muscle-cells ,Aneurysm ,Physiology (medical) ,Internal medicine ,medicine.artery ,medicine ,Animals ,Aorta ,disease ,business.industry ,medicine.disease ,Mice, Mutant Strains ,Elastin ,Disease Models, Animal ,aorta ,inflammation ,biology.protein ,aneurysm ,pathology ,Hydroxymethylglutaryl-CoA Reductase Inhibitors ,business ,Angiotensin II Type 1 Receptor Blockers - Abstract
Background— The sequelae of aortic root dilation are the lethal consequences of Marfan syndrome. The root dilation is attributable to an imbalance between deposition of matrix elements and metalloproteinases in the aortic medial layer as a result of excessive transforming growth factor-beta signaling. This study examined the efficacy and mechanism of statins in attenuating aortic root dilation in Marfan syndrome and compared effects to the other main proposed preventative agent, losartan. Methods and Results— Marfan mice heterozygous for a mutant allele encoding a cysteine substitution in fibrillin-1 (C1039G) were treated daily from 6 weeks old with pravastatin 0.5g/L or losartan 0.6 g/L. The end points of aortic root diameter (n=25), aortic thickness, and architecture (n=10), elastin volume (n=5), dp/dtmax (maximal rate of change of pressure) (cardiac catheter; n=20), and ultrastructural analysis with stereology (electron microscopy; n=5) were examined. The aortic root diameters of untreated Marfan mice were significantly increased in comparison to normal mice (0.161±0.001 cm vs 0.252±0.004 cm; P P P P =0.01; normal mice 0.27±0.02). Ultrastructural analysis showed a reduction of rough endoplasmic reticulum in smooth muscle cells with pravastatin (0.022±0.004) and losartan (0.013±0.001) compared to untreated Marfan mice (0.035±0.004; P Conclusions— Statins are similar to losartan in attenuating aortic root dilation in a mouse model of Marfan syndrome. They appear to act through reducing the excessive protein manufacture by vascular smooth muscle cells, which occurs in the Marfan aorta. As a drug that is relatively well-tolerated for long-term use, it may be useful clinically.
- Published
- 2011
50. Survival in patients with myocardial infarction complicated by out-of-hospital cardiac arrest undergoing emergency percutaneous coronary intervention
- Author
-
Angela Brennan, Kerrie Charter, Omar Farouque, Christopher M. Reid, Chris C.S. Lim, Nick Andrianopoulos, James Shaw, William Chan, Alexander Black, Karen Smith, Andrew E. Ajani, Han S. Lim, Stephen J. Duffy, David J Clark, Dion Stub, and Gishel New
- Subjects
Male ,medicine.medical_specialty ,Emergency Medical Services ,medicine.medical_treatment ,Myocardial Infarction ,Cohort Studies ,Percutaneous Coronary Intervention ,Internal medicine ,Angioplasty ,medicine ,Emergency medical services ,Humans ,Myocardial infarction ,Cardiopulmonary resuscitation ,Registries ,Survival rate ,Aged ,business.industry ,Percutaneous coronary intervention ,Middle Aged ,medicine.disease ,Survival Rate ,Treatment Outcome ,Conventional PCI ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,business ,Out-of-Hospital Cardiac Arrest ,Cohort study ,Follow-Up Studies - Abstract
We sought to evaluate the clinical outcomes of patients with myocardial infarction (MI) complicated by out-of-hospital cardiac arrest (OHCA) undergoing percutaneous coronary intervention (PCI).Controversy remains regarding the benefit of early PCI in patients with MI complicated by OHCA.We analyzed the outcomes of 88 consecutive patients presenting with MI complicated by OHCA compared to 5101 patients with MI without OHCA who underwent PCI from the Melbourne Interventional Group registry between 2004 and 2009.Patients with OHCA had a higher proportion of ST-elevation MI presentations (90.9% vs. 50%, p0.01) and were more likely to be to be in cardiogenic shock (38.6% vs. 4.6%, p0.01). Procedural success was similar in the two groups (95.5% OHCA vs. 96.5% non-OHCA MI cohort, p=0.65). In-hospital, 30-day, and 1-year survival in the OHCA cohort versus the non-OHCA MI cohort were 62.5% vs. 97.2% (p0.01), 61.4% vs. 96.5% (p0.01), and 60.2% vs. 94.2% (p0.01), respectively. Within the OHCA cohort, presentation with cardiogenic shock (OR 7.2, 95% CI: 2.7-18.8; p0.01) was strongly associated with in-hospital mortality. Importantly, 1-year survival of patients discharged alive from hospital was similar between the two groups (96% vs. 97% p=0.8).Patients with MI complicated by OHCA remain a high-risk group associated with high mortality. However, high procedural success rates similar to non-OHCA patients can be attained. Survival rates better than previously reported were observed with an emergent PCI approach, with 1-year survival comparable to a non-OHCA cohort if patients survive to hospital discharge.
- Published
- 2011
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.