29 research outputs found

    A Dynamic-Image Computational Approach for Modeling the Spine

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    We propose a dynamic-image driven computational approach for the modeling and simulation of the spine. We use static and dynamic medical images, computational methods and anatomic knowledge to accurately model and measure the subject-specific dynamic behavior of structures in the spine. The resulting models have applications in biomechanical simulations, computer animation, and orthopaedic surgery. We first develop a semi-automated motion reconstruction method for measuring 3D motion with sub-millimeter accuracy. The automation of the method enables the study of subject-specific spine kinematics over large groups of population. The accuracy of the method enables the modeling and analysis of small anatomical features that are difficult to capture in-vivo using existing imaging techniques. We then develop a set of computational tools to model spine soft-tissue structures. We build dynamic-motion driven geometric models that combine the complementary strengths of the accurate but static models used in orthopaedics and the dynamic but low level-of-detail multibody simulations used in humanoid computer animation. Leveraging dynamic images and reconstructed motion, this approach allows the modeling and analysis anatomical features that are too small to be imaged in-vivo and of their dynamic behavior. Finally, we generate predictive, subject-specific models of healthy and symptomatic spines. The predictive models help to identify, understand and validate hypotheses about spine disorders

    Molecular Profiling of Hepatocellular Carcinoma Using Circulating Cell-Free DNA.

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    PurposeMolecular profiling has been used to select patients for targeted therapy and determine prognosis. Noninvasive strategies are critical to hepatocellular carcinoma (HCC) given the challenge of obtaining liver tissue biopsies.Experimental designWe analyzed blood samples from 206 patients with HCC using comprehensive genomic testing (Guardant Health) of circulating tumor DNA (ctDNA).ResultsA total of 153/206 (74.3%) were men; median age, 62 years (range, 18-91 years). A total of 181/206 patients had ≥1 alteration. The total number of alterations was 680 (nonunique); median number of alterations/patient was three (range, 1-13); median mutant allele frequency (% cfDNA), 0.49% (range, 0.06%-55.03%). TP53 was the common altered gene [>120 alterations (non-unique)] followed by EGFR, MET, ARID1A, MYC, NF1, BRAF, and ERBB2 [20-38 alterations (nonunique)/gene]. Of the patients with alterations, 56.9% (103/181) had ≥1 actionable alterations, most commonly in MYC, EGFR, ERBB2, BRAF, CCNE1, MET, PIK3CA, ARID1A, CDK6, and KRAS. In these genes, amplifications occurred more frequently than mutations. Hepatitis B (HBV)-positive patients were more likely to have ERBB2 alterations, 35.7% (5/14) versus 8.8% HBV-negative (P = 0.04).ConclusionsThis study represents the first large-scale analysis of blood-derived ctDNA in HCC in United States. The genomic distinction based on HCC risk factors and the high percentage of potentially actionable genomic alterations suggests potential clinical utility for this technology

    Dose-response relationship between arsenic exposure and the serum enzymes for liver function tests in the individuals exposed to arsenic: a cross sectional study in Bangladesh

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    <p>Abstract</p> <p>Background</p> <p>Chronic arsenic exposure has been shown to cause liver damage. However, serum hepatic enzyme activity as recognized on liver function tests (LFTs) showing a dose-response relationship with arsenic exposure has not yet been clearly documented. The aim of our study was to investigate the dose-response relationship between arsenic exposure and major serum enzyme marker activity associated with LFTs in the population living in arsenic-endemic areas in Bangladesh.</p> <p>Methods</p> <p>A total of 200 residents living in arsenic-endemic areas in Bangladesh were selected as study subjects. Arsenic concentrations in the drinking water, hair and nails were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The study subjects were stratified into quartile groups as follows, based on concentrations of arsenic in the drinking water, as well as in subjects' hair and nails: lowest, low, medium and high. The serum hepatic enzyme activities of alkaline phosphatase (ALP), aspartate transaminase (AST) and alanine transaminase (ALT) were then assayed.</p> <p>Results</p> <p>Arsenic concentrations in the subjects' hair and nails were positively correlated with arsenic levels in the drinking water. As regards the exposure-response relationship with arsenic in the drinking water, the respective activities of ALP, AST and ALT were found to be significantly increased in the high-exposure groups compared to the lowest-exposure groups before and after adjustments were made for different covariates. With internal exposure markers (arsenic in hair and nails), the ALP, AST and ALT activity profiles assumed a similar shape of dose-response relationship, with very few differences seen in the higher groups compared to the lowest group, most likely due to the temporalities of exposure metrics.</p> <p>Conclusions</p> <p>The present study demonstrated that arsenic concentrations in the drinking water were strongly correlated with arsenic concentrations in the subjects' hair and nails. Further, this study revealed a novel exposure- and dose- response relationship between arsenic exposure metrics and serum hepatic enzyme activity. Elevated serum hepatic enzyme activities in the higher exposure gradients provided new insights into arsenic-induced liver toxicity that might be helpful for the early prognosis of arsenic-induced liver diseases.</p

    \u3cem\u3eIn Vitro\u3c/em\u3e and \u3cem\u3eIn Vivo\u3c/em\u3e Synergistic Antitumor Activity of the Combination of BKM120 and Erlotinib in Head and Neck Cancer: Mechanism of Apoptosis and Resistance

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    We previously reported that the EGFR-targeted inhibitor erlotinib induces G1 arrest of squamous cell carcinoma of the head and neck (SCCHN) cell lines without inducing significant apoptosis. Large-scale genomic studies suggest that \u3e50% of SCCHN cases have activation of PI3K pathways. This study investigated whether cotargeting of EGFR and PI3K has synergistic antitumor effects and apoptosis induction. We examined growth suppression, apoptosis, and signaling pathway modulation resulting from single and combined targeting of EGFR and PI3K with erlotinib and BKM120, respectively, in a panel of SCCHN cell lines and a xenograft model of SCCHN. In a panel of 12 cell lines, single targeting of EGFR with erlotinib or PI3K with BKM120 suppressed cellular growth without inducing significant apoptosis. Cotargeting of EGFR and PI3K synergistically inhibited SCCHN cell line and xenograft tumor growth, but induced variable apoptosis; some lines were highly sensitive, others were resistant. Mechanistic studies revealed that the combination inhibited both axes of the mTORC1 (S6 and 4EBP1) pathway in apoptosis sensitive cell lines along with translational inhibition of Bcl-2, Bcl-xL, and Mcl-1, but failed to inhibit p-4EBP1, Bcl-2, Bcl-xL, and Mcl-1 in an apoptosis-resistant cell line. siRNA-mediated knockdown of eIF4E inhibited Bcl-2 and Mcl-1 and sensitized this cell line to apoptosis. Our results strongly suggest that cotargeting of EGFR and PI3K is synergistic and induces apoptosis of SCCHN cell lines by inhibiting both axes of the AKT–mTOR pathway and translational regulation of antiapoptotic Bcl-2 proteins. These findings may guide the development of clinical trials using this combination of agents

    Curcumin induces p73-dependent apoptosis.

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    <p>(A) Tu212 (left) and H1299 (right) cells were treated with curcumin and expression of p73 and p73β were measured by Western blotting. (B-C) p73 was inactivated in H1299 (B) and 041 (C) cells by dominant negative p73 and apoptosis was measured by annexin V-PE staining. (D) H1299 cells expressing empty vector or dominant negative p73 were treated with curcumin. Whole cell lysates were immunoblotted with PARP and caspase 3 antibodies. For B and C, average results from three independent experiments were plotted with standard deviation as error bars. p values were determined by student t-test. p<0.05 was considered statistically significant.</p

    Curcumin Induces Apoptosis of Upper Aerodigestive Tract Cancer Cells by Targeting Multiple Pathways

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    <div><p>Curcumin, a natural compound isolated from the Indian spice "Haldi" or "curry powder", has been used for centuries as a traditional remedy for many ailments. Recently, the potential use of curcumin in cancer prevention and therapy urges studies to uncover the molecular mechanisms associated with its anti-tumor effects. In the current manuscript, we investigated the mechanism of curcumin-induced apoptosis in upper aerodigestive tract cancer cell lines and showed that curcumin-induced apoptosis is mediated by the modulation of multiple pathways such as induction of p73, and inhibition of p-AKT and Bcl-2. Treatment of cells with curcumin induced both p53 and the related protein p73 in head and neck and lung cancer cell lines. Inactivation of p73 by dominant negative p73 significantly protected cells from curcumin-induced apoptosis, whereas ablation of p53 by shRNA had no effect. Curcumin treatment also strongly inhibited p-AKT and Bcl-2 and overexpression of constitutively active AKT or Bcl-2 significantly inhibited curcumin-induced apoptosis. Taken together, our findings suggest that curcumin-induced apoptosis is mediated via activating tumor suppressor p73 and inhibiting p-AKT and Bcl-2.</p></div
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