Brugada syndrome is an inherited channelopathy associated with an increased risk of syncope and sudden cardiac death. In rare cases it can be manifested with electrical storm. We report two cases of Brugada syndrome that presented with electrical storm and were treated successfully with oral quinidine, an "endangered species" drug. 相似文献
Control charts, the most popular tool of statistical process control, appeared in the literature to ensure that an industrial process is operating only with natural variability, i.e., under statistical control. In the last decades, control charts have been also widely used to assess the quality of non-industrial processes, such as medicine and public health. Mainly in the last two decades, a modification of standard and advanced control charts appeared in the bibliography to improve the monitoring mainly of medical processes. This is the risk-adjusted control charts which take into consideration the varying health conditions of the patients. These charts are used to monitor certain medical processes such as surgeries, mortality, and doctors’ experience. In this paper, we have tried to present all the risk-adjusted control charts presented in the literature appropriately categorized. The risk-adjusted charts have been grouped into three categories: control charts for continuous variables, control charts for attributes (non-continuous variables), time-weighted control charts. The application of risk-adjusted control charts in practical medical processes is also discussed. This review paper highlights the value of the risk-adjusted control charts.
Brain biomechanics has been investigated for more than 30 years. In particular, finite element analyses and other powerful
computational methods have long been used to provide quantitative results in the investigation of dynamic processes such as
head trauma. Nevertheless, the potential of these methods to simulate and predict the outcome of quasi-static processes such
as neurosurgical procedures and neuropathological processes has only recently been explored. Some inherent difficulties in
modeling brain tissues, which have impeded progress, are discussed in this work. The behavior of viscoelastic and poroelastic
constitutive models is compared in simple 1-D simulations using the ABAQUS finite element platform. In addition, the behaviors
of quasi-static brain constitutive models that have recently been proposed are compared. We conclude that a compressible viscoelastic
solid model may be the most appropriate for modeling neurosurgical procedures.
Received: 19 March 2002 / Accepted: 6 June 2002
Work is supported by a generous grant from the Whitaker Foundation. We would like to also thank Dr. Christos Davatzikos (Johns
Hopkins School of Medicine, Baltimore, Maryland) for his help. 相似文献
Visual cortex is retinotopically organized so that neighboring populations of cells map to neighboring parts of the visual field. Functional magnetic resonance imaging allows us to estimate voxel-based population receptive fields (pRF), i.e., the part of the visual field that activates the cells within each voxel. Prior, direct, pRF estimation methods1 suffer from certain limitations: 1) the pRF model is chosen a-priori and may not fully capture the actual pRF shape, and 2) pRF centers are prone to mislocalization near the border of the stimulus space. Here a new topographical pRF estimation method2 is proposed that largely circumvents these limitations. A linear model is used to predict the Blood Oxygen Level-Dependent (BOLD) signal by convolving the linear response of the pRF to the visual stimulus with the canonical hemodynamic response function. PRF topography is represented as a weight vector whose components represent the strength of the aggregate response of voxel neurons to stimuli presented at different visual field locations. The resulting linear equations can be solved for the pRF weight vector using ridge regression3, yielding the pRF topography. A pRF model that is matched to the estimated topography can then be chosen post-hoc, thereby improving the estimates of pRF parameters such as pRF-center location, pRF orientation, size, etc. Having the pRF topography available also allows the visual verification of pRF parameter estimates allowing the extraction of various pRF properties without having to make a-priori assumptions about the pRF structure. This approach promises to be particularly useful for investigating the pRF organization of patients with disorders of the visual system. 相似文献
The objective of the present experiment was to determine the implications of prenatal undernutrition on the behaviour of juvenile lambs. Dams of one group (C) were fed 100% of the recommended requirements throughout pregnancy, while those of two other groups were fed 50% of the control nutrient allowance during the first 30 days of pregnancy (R1) or 50% of the control nutrient allowance from days 31–100 of pregnancy (R2). Between 2 and 5 months old, behaviour of lambs was tested by the implementation of 2 types of test: isolation and novelty. There were no statistical differences between lamb treatments in escape behaviour and heart rates during isolation test, or the latency to approach a novel or a familiar object in the novelty test in tests conducted at 2, 3, 4 and 5 months of age.Male lambs showed a tendency of turning to the right-hand side of the test pen, irrespective of treatment group, between the age of 2 and 5 months old. A greater proportion of C compared to R1 males turned right at the age of 2 and 5 months old (P < 0.05). Significant differences concerning laterality were found also between C and R1 female lambs at the age of 2 and 4 months old (P < 0.001), between C and R2 male lambs at the age of 2 months old (P < 0.05), between C and R2 female lambs at the age of 4 and 5 months old (P < 0.01), between R1 and R2 male lambs at the age of 2 and 5 months old (P < 0.05) and between R1 and R2 female lambs at the age of 2 months old (P < 0.001).It is concluded that prenatal undernutrition during different periods of pregnancy had no effect on fear-related behaviour, but effect on laterality at the early stages of lamb age between 2 and 5 months old. 相似文献
Human rhinoviruses (RV), the most common triggers of acute asthma exacerbations, are considered not cytotoxic to the bronchial epithelium. Recent observations, however, have questioned this knowledge. The aim of this study was to evaluate the ability of RV to induce epithelial cytotoxicity and affect epithelial repair in-vitro.
Methods
Monolayers of BEAS-2B bronchial epithelial cells, seeded at different densities were exposed to RV serotypes 1b, 5, 7, 9, 14, 16. Cytotoxicity was assessed chromatometrically. Epithelial monolayers were mechanically wounded, exposed or not to RV and the repopulation of the damaged area was assessed by image analysis. Finally epithelial cell proliferation was assessed by quantitation of proliferating cell nuclear antigen (PCNA) by flow cytometry.
Results
RV1b, RV5, RV7, RV14 and RV16 were able to induce considerable epithelial cytotoxicity, more pronounced in less dense cultures, in a cell-density and dose-dependent manner. RV9 was not cytotoxic. Furthermore, RV infection diminished the self-repair capacity of bronchial epithelial cells and reduced cell proliferation.
Conclusion
RV-induced epithelial cytotoxicity may become considerable in already compromised epithelium, such as in the case of asthma. The RV-induced impairment on epithelial proliferation and self-repair capacity may contribute to the development of airway remodeling. 相似文献