21 research outputs found

    A new CFD based non-invasive method for functional diagnosis of coronary stenosis

    No full text
    Abstract Background Accurate functional diagnosis of coronary stenosis is vital for decision making in coronary revascularization. With recent advances in computational fluid dynamics (CFD), fractional flow reserve (FFR) can be derived non-invasively from coronary computed tomography angiography images (FFRCT) for functional measurement of stenosis. However, the accuracy of FFRCT is limited due to the approximate modeling approach of maximal hyperemia conditions. To overcome this problem, a new CFD based non-invasive method is proposed. Methods Instead of modeling maximal hyperemia condition, a series of boundary conditions are specified and those simulated results are combined to provide a pressure-flow curve for a stenosis. Then, functional diagnosis of stenosis is assessed based on parameters derived from the obtained pressure-flow curve. Results The proposed method is applied to both idealized and patient-specific models, and validated with invasive FFR in six patients. Results show that additional hemodynamic information about the flow resistances of a stenosis is provided, which cannot be directly obtained from anatomy information. Parameters derived from the simulated pressure-flow curve show a linear and significant correlations with invasive FFR (r > 0.95, P < 0.05). Conclusion The proposed method can assess flow resistances by the pressure-flow curve derived parameters without modeling of maximal hyperemia condition, which is a new promising approach for non-invasive functional assessment of coronary stenosis

    Bub1 and Bub3 regulate metabolic adaptation via macrolipophagy in Drosophila

    No full text
    Summary: Lipophagy, the process of selective catabolism of lipid droplets (LDs) by autophagy, maintains lipid homeostasis and provides cellular energy under metabolic adaptation, yet its underlying mechanism remains largely ambiguous. Here, we show that the Bub1-Bub3 complex, the crucial regulator involved in the whole process of chromosome alignment and separation during mitosis, controls the fasting-induced lipid catabolism in the fat body (FB) of Drosophila. Bidirectional deviations of the Bub1 or Bub3 level affect the consumption of triacylglycerol (TAG) of fat bodies and the survival rate of adult flies under starving. Moreover, Bub1 and Bub3 work together to attenuate lipid degradation via macrolipophagy upon fasting. Thus, we uncover physiological roles of the Bub1-Bub3 complex on metabolic adaptation and lipid metabolism beyond their canonical mitotic functions, providing insights into the in vivo functions and molecular mechanisms of macrolipophagy during nutrient deprivation

    Cognitive impairment after sleep deprivation: The role of precuneus related connectivity on the intra-individual variability changes

    No full text
    Objective: Intra-individual variability (IIV) in cognitive performance is thought to reflect the efficiency with which attentional resources are allocated in different circumstances requiring cognitive control. IIV in cognitive performance is associated with the strength of the negative correlation between task-positive network and default mode network (DMN) activity. In this study, we investigated the impact of sleep deprivation (SD) on functional connectivity (FC) between the DMN and psychomotor vigilance task-related network (PVT-RN), and its relationship with IIV in cognitive performance. Methods: Two analyses, network-level independent component analysis (NL-ICA) and region-level (RL)-ICA, were employed to compare the coefficient of variation (CV) of the PVT between normal sleep and SD conditions across 67 healthy participants. Results: After SD, in NL-ICA, the FC between the PVT-RN and DMN was positively correlated with the CV of the PVT, as well as the changes therein, compared with normal sleep. Using a mask derived from the DMN and PVT-RN, the RL-ICA revealed that 12 edges/connections between DMN and PVT independent components were associated with the CV of the PVT, with nine of these connections involving the precuneus. Conclusions: These findings suggest that the precuneus may play a crucial role in the interactions of various brain functions during the PVT, with the connections between the precuneus and frontoparietal and somatosensory networks being significantly altered after SD. Moreover, following SD, weakened negative FC between the precuneus and bilateral inferior parietal lobule may disrupt the balance between cognitive and executive control functions, leading to a decline in cognitive performance

    DIRECT CORONARY COUPLING APPROACH FOR COMPUTING FFR CT

    No full text

    Dynamic Contrast-Enhanced MR Imaging in a Phase &#8545; Study on Neoadjuvant Chemotherapy Combining Rh-Endostatin with Docetaxel and Epirubicin for Locally Advanced Breast Cancer

    No full text
    <p><b>Background:</b> Anti-angiogenesis is a promising therapeutic strategy for locally advanced breast cancer. We performed this phase II trial to evaluate the anti-angiogenesis and anti-tumor effect of rh-endostatin combined with docetaxel and epirubicin in patients with locally advanced breast cancer by dynamic contrast-enhanced magnetic resonance imaging in 70 previously untreated locally advanced breast cancer patients.</p><p><b>Methods: </b>The study population was randomly assigned to neoadjuvant chemotherapy with docetaxel and epirubicin (neoadjuvant chemotherapy group) or neoadjuvant chemotherapy combining rh-endostatin with docetaxel and epirubicin (neoadjuvant chemotherapy+rh-endostatin group). The anti-angiogenic and anti-tumor effects of both regimens were evaluated by serial dynamic contrast-enhanced magnetic resonance imaging and microvessel density measurements after final surgery.</p><p><b>Results:</b> The results suggested a higher clinical objective response (90.9% vs. 67.7%, P = 0.021) and greater reductions in tumor size (67.2% vs. 55.9%, P = 0.000), Ki-67 proliferation index (32.79% vs. 12.47%, P = 0.000), tumor signal enhanced ratio (64% vs. 48%, P = 0.018), and K<sup>trans</sup> (67% vs. 39%, P = 0.026) in neoadjuvant chemotherapy+rh-endostatin group than those in neoadjuvant chemotherapy group. In addition, the microvessel density value in the neoadjuvant chemotherapy+rh-endostatin group was significantly lower than in the neoadjuvant chemotherapy group (18.67 &#177; 6.53 vs. 36.05 &#177; 9.64, P = 0.000). Moreover, the microvessel density value was significantly correlated with K<sup>trans</sup> after neoadjuvant chemotherapy+rh-endostatin treatment (r=0.88, P = 0.00).</p><p><b>Conclusions: </b>The neoadjuvant chemotherapy+rh-endostatin treatment significantly repressed angiogenesis in locally advanced breast cancer and synergistically enhanced the anti-tumor effect of neoadjuvant chemotherapy. Serial dynamic contrast-enhanced magnetic resonance imaging data including reductions in tumor size and K<sup>trans</sup>, could provide non-invasive evaluation for chemotherapeutic efficacy and, consequently, optimization of individual chemotherapy for locally advanced breast cancer patients.</p

    Seminal vesicle metastasis after partial hepatectomy for hepatocellular carcinoma

    No full text
    Abstract Background Metastasis to the seminal vesicle is extremely rare for hepatocellular carcinoma (HCC). To our knowledge, it has been not reported in literature. The purpose of the present paper was to report a case of metastasis to the seminal vesicle after HCC resection, along with its histological features and immunohistochemical characteristics. Case Presentation A 46-year-old Chinese man was admitted to our hospital due to abdominal distension. He had a history of HCC related to hepatitis B virus infection. Moreover, left partial hepatectomy was performed in another hospital 28 months ago, and right partial hepatectomy for HCC recurrence in our hospital 4 months ago. After resection, radiofrequency ablation therapy had been performed. About 27 months after the initial operation, contrast-enhanced computed tomography (CT) of the pelvic cavity revealed a mass with homogeneous enhancement in the seminal vesicle. Transrectal needle biopsy revealed a poorly differentiated adenocarcinoma. Therefore, seminal vesiculectomy was resected. The histological diagnosis of the removed tumor was compatible with the original HCC. Immunohistochemical examination demonstrated that the tumor cells were positive for glypican-3 (GPC3), alpha-fetoprotein (AFP), hepatocyte paraffin-1 (Hep Par 1), cytokeratin 18 (CK 18), and hepatocyte antigen, which confirmed that the seminal vesicle tumor was a metastatic tumor of HCC. However, CT subsequently revealed multiple metastatic foci in the abdominal and pelvic cavities in May 2009 and August 2009, respectively. Conclusion The seminal vesicle is an extremely rare metastatic site for HCC, and the prognosis is very poor. A combination of clinical and pathological features is necessary for a correct diagnosis, and primary tumor should be excluded before diagnosing metastatic foci.</p

    Choroidal Thickness in the Subtypes of Angle Closure: An EDI-OCT Study

    No full text
    PURPOSE. To evaluate choroidal thickness (CT) in the subtypes of angle-closure (AC) disease compared with CT in a healthy control. METHODS. A total of 297 subjects (eyes) were enrolled in the study: 87 were nonglaucoma controls and 210 were AC subtype eyes (primary AC suspect [PACS] Enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT) was used to measure the macular CT in the subtypes of AC disease and in healthy control subjects. The average CT was compared among the five groups. RESULTS. Thinner CT was associated with older age and longer axial length (AL) (all P &lt; 0.001). All AC groups had thicker subfoveal CT (SFCT) compared with the control eyes (all P &lt; 0.05), even after controlling for age and the AL factor. Acute primary angle-closure eyes had the thickest SFCT and were 61.9-lm thicker than healthy eyes, while PACS, PAC, and PACG eyes were 32.9-, 30.9-, and 25.4-lm thicker than healthy eyes, respectively. No significant difference was observed among the PACS, PAC, and PACG groups. CONCLUSIONS. Increased CT might be another anatomic characteristic of AC eyes. These findings may support the hypotheses that choroidal expansion is a contributing factor to the development of AC disease
    corecore