52 research outputs found

    Assessment of cardiovascular function by combining clinical data with a computational model of the cardiovascular system

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    ObjectiveA sufficient understanding of patients’ cardiovascular status is necessary for doctors to make the best decisions with regard to the treatment of cardiovascular disease; however, it is often not available because of the limitation of clinical measurements. The objective of this study was to examine whether cardiovascular function can be assessed quantitatively and for specific patients by combining clinical data with a computational model of the cardiovascular system.MethodsSeven consecutive patients undergoing off-pump coronary artery bypass grafting were enrolled in this study. The clinical data were collected both during the preoperative diagnosis and during the operation. Sensitivity analysis was performed to select the major model parameters most relevant to the measured data. The major model parameters were then estimated through a data-fitting procedure, enabling a patient-specific quantitative assessment of various aspects of cardiovascular function.ResultsThe results revealed the prevalence of left ventricular diastolic dysfunction in the patients, although the severity of dysfunction exhibits significant interpatient variability (the estimated left ventricular passive elastance varies from 194% to 540% of its reference value). Moreover, 4 of the 7 patients studied had impaired left ventricular systolic function.ConclusionsThe current study demonstrates the feasibility of assessing cardiovascular function quantitatively by combining clinical data with a cardiovascular model. In particular, the assessment utilizes the measurements already in use or available in clinical settings, enhancing the clinical potential of the proposed method

    Off-pump waffle procedure using an ultrasonic scalpel for constrictive pericarditis †

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    Abstract Radical pericardiectomy alone is not effective in patients with constrictive pericarditis accompanied by epicardial constriction. However, a waffle procedure is very effective in these patients, as we demonstrate in this paper. Firstly, we performed a radical pericardiectomy via a median sternotomy. We used an ultrasonic scalpel for this procedure, and an apical suction device was useful for lifting the heart. This technique is similar to that used in off-pump coronary artery bypass grafting. After the whole heart was dissected from the markedly thickened parietal pericardium, a waffle procedure was performed on the left ventricle first. Multiple longitudinal and transverse incisions were made on the thickened epicardium using an ultrasonic scalpel. After the left ventricle was fully relieved of constriction, the same procedure was performed on the right ventricle. Thereafter, a remarkable improvement of our patient's haemodynamic status was obtained. The whole procedure can be done without cardiopulmonary bypass. We describe tips for performing the waffle procedure without cardiopulmonary bypass using an ultrasonic scalpel and apical suction device, as well as pitfalls to avoid

    Solitary mandibular metastasis as an initial manifestation of hepatocellular carcinoma.

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    Oral metastases from hepatocellular carcinoma are very rare. We encountered a case of hepatocellular carcinoma with a solitary metastasis to the mandible as an initial manifestation. The patient was a 76-year-old man who was admitted for left mandibular swelling. A biopsy specimen of mandible was suspected to be a metastatic tumor. The histological findings, abdominal computed tomography, bone scintigraphy, and F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) revealed it to be a solitary metastasis from hepatocellular carcinoma. As a result, he was diagnosed to have liver cirrhosis due to a hepatitis C virus infection and hepatocellular carcinoma with a solitary metastasis to the mandible. The primary lesion was treated with transcatheter arterial embolization (TAE), and the metastasis to the mandible was surgically resected. The patient survived for 9 months after treatment without recurrence

    Histopathological Study on the Distribution of Langerhans Cells in Oral Mucosa

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    Background & Aims: Some oral mucosal diseases display clear predispositions toward certain sites of occurrence. Oral lichen planus is one such disease, and is thought to have some relationships with cell-mediated immunity leading to a tendency to develop on the buccal mucosa. The aim of this study was to investigate the distribution of Langerhans cells in various sites of oral mucosa. Methods: Immunohistochemical examination using an anti-S100 antibody was performed for 47 samples of healthy oral mucosa and skin. Results: S100-positive cells were more frequent in lining mucosa than in masticatory mucosa. Significantly more S100-positive cells were found in buccal mucosa than in other sites. Conclusions: Langerhans cells are positive for S100 and are thought to represent antigen-presenting cells. These cells were most frequent in buccal mucosa, a result that is in accordance with the predisposition of oral lichen planus

    Predicting Maximum and Cumulative Response of A Base-isolated Building Using Pushover Analysis

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    The evaluation of the maximum and cumulative response is an important issue for the seismic design of new base-isolated buildings. This study predicts the maximum and cumulative response of a 14-story reinforced concrete base-isolated building using a set of pushover analyses. In the proposed pushover analysis method, the maximum and cumulative responses of the first and higher modes are evaluated from the nonlinear analysis of equivalent single-degree-of-freedom (SDOF) models. Then, the maximum local responses are predicted by enveloping the two pushover analysis results by referring to the contribution of the first and higher modal responses, while the cumulative strain energies of the lead-rubber bearings and steel dampers are predicted from the cumulative response of the first mode. The results reveal that the responses predicted by the proposed set of pushover analyses have satisfactory accuracy

    Catalytic Combustion of Pre-Vaporized Liquid Fuel

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