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In the era of globalization, one of the key factors for manufacturing machine builders/suppliers to remain competitive is their capability to provide cost-effective and comprehensive machine service and maintenance for their clients at anytime, anywhere. Previous research has highlighted the role of virtual engineering tools in the design and development life cycle of manufacturing machinery systems. Virtual engineering models created during the development phase can potentially be used to provide valuable functions for many other tasks during the operational phase, including service and maintenance support. This paper introduces an innovative Internet-enabled three-dimensional-based virtual engineering framework that can be used for such purposes. Specifically, it addresses a system architecture that is designed to facilitate the tight integration between virtual engineering tools and a set of Internet-based reconfigurable modular maintenance supporting tools. This system architecture has been verified by implementations using different toolsets atop of various Internet technologies (e.g. XML Web services and LabView's Datasocket). Implementation details and successful industrial-based test cases are also provided in this paper. [ABSTRACT FROM AUTHOR]

Study Design: This study is a retrospective review of 39 patients with previous instrumented lumbar fusion who underwent secondary spine surgery for lumbar adjacent instability. To the authors' knowledge, this is the largest study of surgical treatment of lumbar adjacent instability in the literature to date., Object: This study evaluated the feasibility of adjacent instability treated with medial facetectomy, fusion with autologous bone grafting, and pedicle screw instrumentation., Summary of Background Data: The surgical treatment of adjacent instability has seldom been discussed. Revision spine fusions are challenged by high pseudarthrosis rates., Methods: Thirty-nine patients with previous lumbar fusion underwent second lumbar spine surgery for adjacent instability. All were treated with autogenous posterolateral arthrodesis and transpedicle screw fixation in addition to decompressive laminectomy. Medical records, radiographs, and pain scores were obtained., Results: The clinical results were excellent or good in 76.9% of patients, and the radiographic fusion was successful in 37 (94.9%) of patients. Flat back was noted in 8 (20.5%) of patients. In 5 patients (12.8%), neighboring segment breakdown again developed, and 2 of those patients underwent a third lumbar fusion. Dural tear during operation occurred in 2 patients. One patient experienced cauda equina syndrome but recovered bladder function 1 month later., Conclusion: Autogenous posterolateral arthrodesis combined with pedicle screw fixation led to successful radiologic and clinical outcome in patients with lumbar adjacent instability. Adequate decompression of the adjacent stenosis requires medial facetectomy, thus preventing aggressive nerve root manipulation and reducing the incidence of dural tear.

Background: Cirrhosis is characterized by the accumulation of collagen within the extracellular matrix (ECM) of the liver and progressive hepatocellular dysfunction. Since recent studies have shown that the ECM can modulate cellular function, we examined whether the ECM could contribute to hepatocellular dysfunction. To address this question we examined hepatocyte behavior in two different ECM environments., Materials and Methods: Primary rat hepatocytes were cultured as a monolayer on collagen or as multicellular aggregates (spheroids) within a laminin-rich ECM. Hepatocytes were then compared for viability, response to proinflammatory cytokines, and their capacity to activate a heat shock response and adopt a thermotolerant phenotype. In addition, we compared the ability of prior heat shock exposure to protect hepatocytes from tumor necrosis factor (TNF) alpha/actinomycin-D-induced apoptosis in the two different ECM environments., Results: Hepatocytes cultured as a monolayer on collagen exhibited decreased viability, underwent spontaneous apoptosis, and displayed an attenuated cytokine-stimulated nitric oxide production compared to hepatocytes cultured as spheroids. In response to heat, hepatocytes in both ECM environments expressed inducible heat shock protein 70 (hsp72). But, only the hepatocyte spheroids exhibited thermotolerance in response to a subsequent thermal challenge. In contrast to previous reports, induction of the heat shock response failed to protect hepatocytes against TNFalpha-induced apoptosis., Conclusions: These data demonstrate that the ECM can play an integral role in specific hepatocellular behaviors. Furthermore, the progressive deposition of collagen within the ECM, which is characteristic of fibrotic liver diseases, may directly contribute to the progressive hepatocellular dysfunction observed in cirrhosis. Hepatocellular viability, response to proinflammatory cytokines, heat shock response, and thermotolerance were all altered depending on the composition of the ECM. In contrast, TNFalpha-induced apoptosis was independent of the composition of the ECM., (Copyright 2000 Academic Press.)

Pulmonary embolism is a major cause of death in the United States. A high index of suspicion is required to achieve an accurate diagnosis. We report a case of a patient with syncope, ischemic electrocardiographic changes, and an elevated troponin I level, presenting just like acute myocardial infarction. The case highlights the value of an early use of 2-dimensional echocardiography in obtaining an accurate diagnosis, thus avoiding unnecessary and inappropriate treatment.

Anomalous origin of coronary arteries is rare, occurring in about 1% of patients undergoing cardiac catheterization. Coronary atherosclerosis is not uncommon in these patients. Percutaneous angioplasty of anomalous coronary arteries poses a particular technical challenge secondary to the vessel characteristics. Stenting of the anomalous coronary arteries has not been described previously. We report a 47-year-old man with unstable angina in whom a MULTI-LINK coronary stent was placed successfully in an anomalous circumflex coronary artery.

Coronary atherosclerosis is uncommon in patients with von Willebrand factor deficiency. Occurrence of acute myocardial infarction is even rarer in these patients. We report on a 69-year-old woman with a long-standing history of von Willebrand disease who presented with acute myocardial infarction. Thrombolytic therapy with rtPA, heparin, and aspirin, followed by percutaneous transluminal coronary angioplasty and coronary stenting, was performed without significant bleeding or other complications.

Erythromycin is a widely used antibiotic in today's armamentarium of antibiotics. Although erythromycin induced ventricular tachyarrhythmia is rare, this potentially life-threatening reaction should be kept in mind. The relative rarity of 'torsades de pointes' arrhythmia suggests that other predisposing factors contribute to the acquired long QT syndrome. Since more and more macrolide products have been approved by the Food and Drug Administration for use in the United States, the potential problem with 'torsades de pointes' may exist with each of the macrolide antibiotic. Until the exact mechanisms of the arrhythmia are worked out, close monitoring of rhythms and QT intervals of high risk patients who require erythromycin is certainly advisable. Only a heightened awareness among the physicians and medical personnel can the adverse outcome be minimized.

In conclusion, signal-averaged electrocardiography is a useful, noninvasive technique to identify patients after myocardial infarction at risk for future arrhythmic events, especially in conjunction to existing tools, such as 24 hour ambulatory monitoring, echocardiography, nucleotide angiography and coronary angiography. It has a limited positive predictive value, but has an excellent negative predictive value. The optimum time to do signal-averaged electrocardiograms after myocardial infarction is unclear, 6 to 14 days after myocardial infarction has the highest sensitivity. Time domain analysis remains the most common method used to record late potentials. The definition of late potential and the scoring of a high resolution electrocardiogram as normal and abnormal have not yet been resolved. The criteria proposed by the Task Force Committee of the European Society of Cardiology, the American Heart Association and the American College of Cardiology (see introduction) should be observed at present. Many studies on signal-averaging were done in the prethrombolytic era. In patients who have received thrombolytic therapy, the positive predictive value of signal-averaged electrocardiograms has decreased. There are other limitations in applying signal averaging technique. The faster the ventricular tachycardia is induced in electrophysiological studies, the shorter is the late potential. Thus, a faster tachycardia which causes sudden cardiac death may not be detected by late potentials. The management strategies for patients who have abnormal signal-averaged electrocardiograms after myocardial infarction have not be defined. One should note that any management strategy has to prove that it improves prognosis. More prospective, randomized clinical trials are required to address these issues.

Eosinophilia-myalgia syndrome (EMS) is characterized by intense eosinophilia and, very often, debilitating generalized myalgia in the absence of infectious or neoplastic causation. The Centers for Disease Control have established that the latter two features, along with an eosinophil count greater than 1000 cells per cu mm, are criteria for the syndrome. EMS has been reported in epidemic proportions over the last several months. Early data strongly suggested that in at least a small percentage of patients the syndrome leads to death. Epidemiological work in New Mexico, Minnesota, and Oregon has linked EMS most impressively to L-tryptophan-containing products (LTCPS).