110 research outputs found

    Core and penumbra estimation using deep learning-based AIF in association with clinical measures in computed tomography perfusion (CTP)

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    Objectives To investigate whether utilizing a convolutional neural network (CNN)-based arterial input function (AIF) improves the volumetric estimation of core and penumbra in association with clinical measures in stroke patients. Methods The study included 160 acute ischemic stroke patients (male = 87, female = 73, median age = 73 years) with approval from the institutional review board. The patients had undergone CTP imaging, NIHSS and ASPECTS grading. convolutional neural network (CNN) model was trained to fit a raw AIF curve to a gamma variate function. CNN AIF was utilized to estimate the core and penumbra volumes which were further validated with clinical scores. Results Penumbra estimated by CNN AIF correlated positively with the NIHSS score (r = 0.69; p  20) and lower ASPECT score ( 10 s, Tmax > 10 s volumes were statistically significantly higher (p < .05). Conclusions With inclusion of the CNN AIF in perfusion imaging pipeline, penumbra and core estimations are more reliable as they correlate with scores representing neurological deficits in stroke. Critical relevance statement With CNN AIF perfusion imaging pipeline, penumbra and core estimations are more reliable as they correlate with scores representing neurological deficits in stroke

    Task-Switching Performance Improvements After Tai Chi Chuan Training Are Associated With Greater Prefrontal Activation in Older Adults

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    Studies have shown that Tai Chi Chuan (TCC) training has benefits on task-switching ability. However, the neural correlates underlying the effects of TCC training on task-switching ability remain unclear. Using task-related functional magnetic resonance imaging (fMRI) with a numerical Stroop paradigm, we investigated changes of prefrontal brain activation and behavioral performance during task-switching before and after TCC training and examined the relationships between changes in brain activation and task-switching behavioral performance. Cognitively normal older adults were randomly assigned to either the TCC or control (CON) group. Over a 12-week period, the TCC group received three 60-min sessions of Yang-style TCC training weekly, whereas the CON group only received one telephone consultation biweekly and did not alter their life style. All participants underwent assessments of physical functions and neuropsychological functions of task-switching, and fMRI scans, before and after the intervention. Twenty-six (TCC, N = 16; CON, N = 10) participants completed the entire experimental procedure. We found significant group by time interaction effects on behavioral and brain activation measures. Specifically, the TCC group showed improved physical function, decreased errors on task-switching performance, and increased left superior frontal activation for Switch &gt; Non-switch contrast from pre- to post-intervention, that were not seen in the CON group. Intriguingly, TCC participants with greater prefrontal activation increases in the switch condition from pre- to post-intervention presented greater reductions in task-switching errors. These findings suggest that TCC training could potentially provide benefits to some, although not all, older adults to enhance the function of their prefrontal activations during task-switching

    Clinical experience of infective endocarditis complicated by acute cerebrovascular accidents

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    To evaluate the clinical results of patients with infective endocarditis (IE) complicated by acute cerebrovascular accidents (CVAs). A total of 44 patients with IE complicated by CVA at admission were retrospectively analyzed in a single medical institute from 2005 to 2011. At the time of admission, 18 patients were diagnosed with hemorrhagic stroke, and 26 patients were diagnosed with ischemic stroke. Fifteen patients received surgical intervention during hospitalization. The hospital mortality rate was 38.9% for the hemorrhagic stroke group and 42.3% for the ischemic stroke group (p = 0.821). The mortality rate was 33.3% for the surgical group and 44.8% for the nonsurgical group (p = 0.531). At 30 days of hospitalization, 45.8% of the patients experienced an adverse event (defined as death due to organ failure, restroke, cardiogenic shock, or septic shock during the treatment period), and the attrition rate was 1.5% per day. Surgery performed after the adverse events increased mortality (80.0%) compared with surgery performed on patients with no adverse events (10.0%, p = 0.017). A Cox regression analysis revealed that creatinine > 2 mg/dL, diabetes, and staphylococcal infection were the risk factors of the adverse events. Early surgical intervention for IE with ischemic stroke may prevent adverse events, particularly in patients with impaired renal function, diabetes, or staphylococcal infection. A delay in operation of > 30 days is recommended after hemorrhagic stroke

    Clinical experience of infective endocarditis complicated by acute cerebrovascular accidents

    No full text
    Background/Objective: To evaluate the clinical results of patients with infective endocarditis (IE) complicated by acute cerebrovascular accidents (CVAs). Methods: A total of 44 patients with IE complicated by CVA at admission were retrospectively analyzed in a single medical institute from 2005 to 2011. At the time of admission, 18 patients were diagnosed with hemorrhagic stroke, and 26 patients were diagnosed with ischemic stroke. Fifteen patients received surgical intervention during hospitalization. Results: The hospital mortality rate was 38.9% for the hemorrhagic stroke group and 42.3% for the ischemic stroke group (p = 0.821). The mortality rate was 33.3% for the surgical group and 44.8% for the nonsurgical group (p = 0.531). At 30 days of hospitalization, 45.8% of the patients experienced an adverse event (defined as death due to organ failure, restroke, cardiogenic shock, or septic shock during the treatment period), and the attrition rate was 1.5% per day. Surgery performed after the adverse events increased mortality (80.0%) compared with surgery performed on patients with no adverse events (10.0%; p = 0.017). A Cox regression analysis revealed that creatinine > 2 mg/dL, diabetes, and staphylococcal infection were the risk factors of the adverse events. Conclusion: Early surgical intervention for IE with ischemic stroke may prevent adverse events, particularly in patients with impaired renal function, diabetes, or staphylococcal infection. A delay in operation of > 30 days is recommended after hemorrhagic stroke

    Development of Folic Acid-Conjugated and Methylene Blue-Adsorbed Au@TNA Nanoparticles for Enhanced Photodynamic Therapy of Bladder Cancer Cells

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    Photodynamic therapy (PDT) is a promising treatment for malignancy. However, the low molecular solubility of photosensitizers (PSs) with a low accumulation at borderline malignant potential lesions results in the tardy and ineffective management of recurrent urothelial carcinoma. Herein, we used tannic acid (TNA), a green precursor, to reduce HAuCl4 in order to generate Au@TNA core-shell nanoparticles. The photosensitizer methylene blue (MB) was subsequently adsorbed onto the surface of the Au@TNA nanoparticles, leading to the incorporation of a PS within the organic shell of the Au nanoparticle nanosupport, denoted as Au@TNA@MB nanoparticles (NPs). By modifying the surface of the Au@TNA@MB NPs with the ligand folate acid (FA) using NH2-PEG-NH2 as a linker, we demonstrated that the targeted delivery strategy achieved a high accumulation of PSs in cancer cells. The cell viability of T24 cells decreased to 87.1%, 57.1%, and 26.6% upon treatment with 10 ppm[Au] Au@TNA/MB NPs after 45 min, 2 h, and 4 h of incubation, respectively. We also applied the same targeted PDT treatment to normal urothelial SV-HUC-1 cells and observed minor phototoxicity, indicating that this safe photomedicine shows promise for applications aiming to achieve the local depletion of cancer sites without side effects
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