7,551 research outputs found
A three dimensional infinite wedge shaped solid block sliding into water along an inclined beach
The three dimensional (3D) problem of a solid block sliding into water along an inclined beach is investigated. The main part of the block is an infinite wedge cylinder and the front of the body is part of an elliptical cone. Incompressible velocity potential theory is used together with fully nonlinear boundary conditions. When gravity is ignored, it is found that self-similar solution is possible. The boundary element method is used to solve the problem. The free surface shape is updated together with the potential on the free surface until the flow has become self-similar. Convergence studies are taken with respect to marching step and element size. Simulations are made for different bodies and different beach angles. Extensive results are provided for the pressure as well as the free surface shape, and their implications in physics are discussed
Local flow at plate edge during water entry
The local flow near the edge of a horizontal plate impacting a flat liquid surface is investigated through velocity potential flow theory. The inner solution is matched with the outer solution. The far field of the inner solution is assumed to be far away from the other edge of the plate, and thus, its effect can be neglected. The effects of surface tension, viscous friction, and gravity are accounted for in the fully nonlinear dynamic boundary condition on the free surface. When one of these effects is dominant and the other two can be ignored, it is then possible to use self-similar variables to describe the local flow if the entry speed varies with time in a corresponding manner. Detailed results for various self-similar solutions are provided, and the relative importance of the Weber number, Reynolds number, and Froude number is investigated. Simulations are also undertaken for general non-similar flow, and the comparison with the experimental data is also made
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Enhanced Delivery of Rituximab Into Brain and Lymph Nodes Using Timed-Release Nanocapsules in Non-Human Primates.
Tumor metastasis into the central nervous system (CNS) and lymph nodes (LNs) is a major obstacle for effective therapies. Therapeutic monoclonal antibodies (mAb) have revolutionized tumor treatment; however, their efficacy for treating metastatic tumors-particularly, CNS and LN metastases-is poor due to inefficient penetration into the CNS and LNs following intravenous injection. We recently reported an effective delivery of mAb to the CNS by encapsulating the anti-CD20 mAb rituximab (RTX) within a thin shell of polymer that contains the analogs of choline and acetylcholine receptors. This encapsulated RTX, denoted as n-RTX, eliminated lymphoma cells systemically in a xenografted humanized mouse model using an immunodeficient mouse as a recipient of human hematopoietic stem/progenitor cells and fetal thymus more effectively than native RTX; importantly, n-RTX showed notable anti-tumor effect on CNS metastases which is unable to show by native RTX. As an important step toward future clinical translation of this technology, we further analyzed the properties of n-RTX in immunocompetent animals, rats, and non-human primates (NHPs). Our results show that a single intravenous injection of n-RTX resulted in 10-fold greater levels in the CNS and 2-3-fold greater levels in the LNs of RTX, respectively, than the injection of native RTX in both rats and NHPs. In addition, we demonstrate the enhanced delivery and efficient B-cell depletion in lymphoid organs of NHPs with n-RTX. Moreover, detailed hematological analysis and liver enzyme activity tests indicate n-RTX treatment is safe in NHPs. As this nanocapsule platform can be universally applied to other therapeutic mAbs, it holds great promise for extending mAb therapy to poorly accessible body compartments
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Sustained delivery and molecular targeting of a therapeutic monoclonal antibody to metastases in the central nervous system of mice.
Approximately 15-40% of all cancers develop metastases in the central nervous system (CNS), yet few therapeutic options exist to treat them. Cancer therapies based on monoclonal antibodies are widely successful, yet have limited efficacy against CNS metastases, owing to the low levels of the drug reaching the tumour site. Here, we show that the encapsulation of rituximab within a crosslinked zwitterionic polymer layer leads to the sustained release of rituximab as the crosslinkers are gradually hydrolysed, enhancing the CNS levels of the antibody by approximately tenfold with respect to the administration of naked rituximab. When the nanocapsules were functionalized with CXCL13-the ligand for the chemokine receptor CXCR5, which is frequently found on B-cell lymphoma-a single dose led to improved control of CXCR5-expressing metastases in a murine xenograft model of non-Hodgkin lymphoma, and eliminated lymphoma in a xenografted humanized bone marrow-liver-thymus mouse model. Encapsulation and molecular targeting of therapeutic antibodies could become an option for the treatment of cancers with CNS metastases
Development of a Broad-Spectrum Antiviral Agent with Activity Against Herpesvirus Replication and Gene Expression
Purpose: To evaluate the broad-spectrum antiviral activity of peptide H9 (H9) in vitro in order to gain insight into its underlying molecular mechanisms.Method: Antiviral activity against Herpes simplex virus type 1 (HSV-1) was determined using thiazolyl blue (MTT) assay. Polymerase Chain Reaction (PCR) was employed to assay H9 antiviral activity against human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV). The inhibitory effect of H9 on the replication of these viral genes including early genes was assayed by real time-Ppolymerase chain reaction (RT-PCR) and Western blot.Results: H9 possessed significant inhibitory effect on the four different herpesviruses with 50 % inhibitory concentration (IC50) of 1.21 ng/mL (HSV-1). AD169 infection was strongly inhibited with an EC50 value of 0.46 ng/ml. The anti-herpesviral activity of H9 was dose-dependent. The peptide acted primarily during the early stage of infection by detection of the early genes.Conclusion: The results demonstrate that H9 can inhibit the infection of HSV-1, EBV and HCMV. Furthermore, H9 has a broad-spectrum anti-herpesviral effect in vitro based on targeted killing of infected cells expressing genes.Keywords: Antagonist, Trapping receptor/ligand, Broad-spectrum, Anti-herpesvirus, H9 peptide, Gene expressio
Trinitrophenol Reactive T-Cell Hybridomas Recognize Antigens That Require Antigen Processing
Protein antigens must be taken up, processed, and displayed on the surface of antigen-presenting cells in association with major histocompatibility complex molecules before they can be recognized by T cells. Whether recognition of the haptens used to study allergic contact hypersensitivity in murine models similarly requires processing has not been determined. We analyzed whether presentation of trinitrophenol to trinitrophenol reactive T-cell hybridomas requires antigen processing by studying the effects of inhibitors of antigen processing and presentation on tile ability of a syngeneic B-cell tumor (A20) to present trinitrophenol to a series of interleukin-2 producing, trinitrophenol specific, major histocompatibility complex class II-restricted T-cell hybridomas.The ability of trinitrophenol modified A20 cells to stimulate the hybridomas was completely inhibited by rnonoclonal, anti-trinitrophenol, or anti-Ia antibodies and was significantly reduced by paraformaldehyde fixation immediately after trinitrophenol modification. Trinitrophenol-modified A20 cultured at 37°C for 2h prior to fixation was significantly more effective at stimulating the hybridomas than trinitrophenol-modified A20 to present trinitrophenol was inhibited by chloroquine. Paraformaldehyde fixation and chloroquine treatment had similar effects on the ability of trinitrophenol modified lymph node dendritic cells to stimulate the trinitrophenol specific hybridomas. Paraformaldehyde fixation and chloroquine treatment had similar effects on the ability of A20 cells to present ovalbumin to ovalbumin-specific hybridomas as they had on the ability of trinitrophenol modified A20 cells to present trinitrophenol to the trinitrophenol specific hybridomas. One of seven T-cell hybridomas responded to trinitrophenol modified ovalbumin but not other trinitrophenol modified proteins. These results suggest that, at least in part, T cells in the contact hypersensitivity response to trinitrophenol recognize antigens that require processing and that trinitrophenol modified proteins can be recognized
The Combination of RAD001 and NVP-BEZ235 Exerts Synergistic Anticancer Activity against Non-Small Cell Lung Cancer In Vitro and In Vivo
The phosphoinositide 3-kinase (PI3K)-mammalian target of rapamycin (mTOR) signaling axis has emerged as a novel target for cancer therapy. Agents that inhibit PI3K, mTOR or both are currently under development. The mTOR allosteric inhibitor, RAD001, and the PI3K/mTOR dual kinase inhibitor, BEZ235, are examples of these agents. We were interested in developing strategies to enhance mTOR-targeted caner therapy. In this study, we found that BEZ235 alone effectively inhibited the growth of rapamycin-resistant cancer cells. Interestingly, the combination of sub-optimal concentrations of RAD001 and BEZ235 exerted synergistic inhibition of the growth of human lung cancer cells along with induction of apoptosis and G1 arrest. Furthermore, the combination was also more effective than either agent alone in inhibiting the growth of lung cancer xenografts in mice. The combination showed enhanced effects on inhibiting mTOR signaling and reducing the expression of c-Myc and cyclin D1. Taken together, our results suggest that the combination of RAD001 and BEZ235 is a novel strategy for cancer therapy
Novel lung imaging biomarkers and skin gene expression subsetting in dasatinib treatment of systemic sclerosis-associated interstitial lung disease.
BackgroundThere are no effective treatments or validated clinical response markers in systemic sclerosis (SSc). We assessed imaging biomarkers and performed gene expression profiling in a single-arm open-label clinical trial of tyrosine kinase inhibitor dasatinib in patients with SSc-associated interstitial lung disease (SSc-ILD).MethodsPrimary objectives were safety and pharmacokinetics. Secondary outcomes included clinical assessments, quantitative high-resolution computed tomography (HRCT) of the chest, serum biomarker assays and skin biopsy-based gene expression subset assignments. Clinical response was defined as decrease of >5 or >20% from baseline in the modified Rodnan Skin Score (MRSS). Pulmonary function was assessed at baseline and day 169.ResultsDasatinib was well-tolerated in 31 patients receiving drug for a median of nine months. No significant changes in clinical assessments or serum biomarkers were seen at six months. By quantitative HRCT, 65% of patients showed no progression of lung fibrosis, and 39% showed no progression of total ILD. Among 12 subjects with available baseline and post-treatment skin biopsies, three were improvers and nine were non-improvers. Improvers mapped to the fibroproliferative or normal-like subsets, while seven out of nine non-improvers were in the inflammatory subset (p = 0.0455). Improvers showed stability in forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO), while both measures showed a decline in non-improvers (p = 0.1289 and p = 0.0195, respectively). Inflammatory gene expression subset was associated with higher baseline HRCT score (p = 0.0556). Non-improvers showed significant increase in lung fibrosis (p = 0.0313).ConclusionsIn patients with SSc-ILD dasatinib treatment was associated with acceptable safety profile but no significant clinical efficacy. Patients in the inflammatory gene expression subset showed increase in skin fibrosis, decreasing pulmonary function and worsening lung fibrosis during the study. These findings suggest that target tissue-specific gene expression analyses can help match patients and therapeutic interventions in heterogeneous diseases such as SSc, and quantitative HRCT is useful for assessing clinical outcomes.Trial registrationClinicaltrials.gov NCT00764309
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