344 research outputs found
Molecular-dynamics simulations of stacking-fault-induced dislocation annihilation in pre-strained ultrathin single-crystalline copper films
We report results of large-scale molecular-dynamics (MD) simulations of
dynamic deformation under biaxial tensile strain of pre-strained
single-crystalline nanometer-scale-thick face-centered cubic (fcc) copper
films. Our results show that stacking faults, which are abundantly present in
fcc metals, may play a significant role in the dissociation, cross-slip, and
eventual annihilation of dislocations in small-volume structures of fcc metals.
The underlying mechanisms are mediated by interactions within and between
extended dislocations that lead to annihilation of Shockley partial
dislocations or formation of perfect dislocations. Our findings demonstrate
dislocation starvation in small-volume structures with ultra-thin film
geometry, governed by a mechanism other than dislocation escape to free
surfaces, and underline the significant role of geometry in determining the
mechanical response of metallic small-volume structures.Comment: 28 pages, 3 figure
Tissue culture-independent in planta transformation strategy: an Agrobacterium tumefaciens-mediated gene transfer method to overcome recalcitrance in cotton (Gossypium hirsutum L.)
The major constraint in cotton improvement has been the recalcitrance of cotton varieties to tissue culture. Alternate methods that avoid/ minimize tissue culture would be beneficial for the improvement of cotton. In this report, transgenic cotton plants have been produced by a tissue-culture independent Agrobacterium tumefaciens - mediated transformation procedure. Agrobacterium strain LBA4404 harboring the binary vector pKIWI105 that carries the genes for β-glucuronidase (GUS) and neomycin phosphotransferase (npt II) was used for transformation. Apical meristem of the differentiated embryo of the germinating seedling is infected with Agrobacterium. Since the transgene is integrated into the cells of already differentiated tissues, the T0 plants will be chimeric and stable integration can be seen only in the T1 generation. The first proof of transformability in the T0 generation was indicated by the GUS histochemical analysis of the seedlings, five days after co-cultivation and subsequently in the pollen and lint. T1 transformants were identified by PCR analysis and subsequently confirmed by Southern. Three plants (T1) with single copy insertions were selected for continuing into the next generations. Molecular characterization and GUS expression analysis (histochemical and fluorimetric) of the T1, T2 and T3 generation suggested the feasibility of the method to generate transgenic plants in cotton
TRAIL Coated Genetically Engineered Immunotherapeutic Nano-Ghosts Vesicles Target Human Melanoma-Avoiding the Need for High Effective Therapeutic Concentration of TRAIL
Cancer cell therapy using cytotoxic T lymphocytes (CTL) or mesenchymal stem cells (MSC) possesses hurdles due to the cells, susceptibility to host induced changes. Here, versatile inanimate broadly applicable nanovesicles, termed immunotherapeutic-nano-ghosts (iNGs), are armed with inherent surface-associated targeting and therapeutic capabilities in which the promise and benefits of MSC therapy and T cell immunotherapy are combined into one powerful off-the-shelf approach for treating malignant diseases. To mimic the cytotoxic or immunosuppressive functions of T cells, iNG are produced from MSC that were genetically engineered (GE) or metabolically manipulated to express additional membrane-bound proteins, endowing the NGs derived therefrom with additional surface-associated functions such as tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). iNGs from GE-MSCs (GE-iNGs) show superior TRAIL retention and induce apoptosis in different cancer cell lines in vitro. In vivo studies on a human melanoma model demonstrate that a systemic, three-day frequency, administration of GE-iNGs result in tumor inhibition comparable to a six orders of magnitude higher concentration of soluble TRAIL. The iNGs are therefore a promising nanovesicle platform that can affect tumors in a non-immunogenic manner while avoiding the need for a highly effective therapeutic concentration
Cover to Volume 3
The fibroblast mitogen platelet-derived growth factor -BB (PDGF-BB) induces a transient expression of the orphan nuclear receptor NR4A1 (also named Nur77, TR3 or NGFIB). The aim of the present study was to investigate the pathways through which NR4A1 is induced by PDGF-BB and its functional role. We demonstrate that in PDGF-BB stimulated NIH3T3 cells, the MEK1/2 inhibitor CI-1040 strongly represses NR4A1 expression, whereas Erk5 downregulation delays the expression, but does not block it. Moreover, we report that treatment with the NF-κB inhibitor BAY11-7082 suppresses NR4A1 mRNA and protein expression. The majority of NR4A1 in NIH3T3 was found to be localized in the cytoplasm and only a fraction was translocated to the nucleus after continued PDGF-BB treatment. Silencing NR4A1 slightly increased the proliferation rate of NIH3T3 cells; however, it did not affect the chemotactic or survival abilities conferred by PDGF-BB. Moreover, overexpression of NR4A1 promoted anchorage-independent growth of NIH3T3 cells and the glioblastoma cell lines U-105MG and U-251MG. Thus, whereas NR4A1, induced by PDGF-BB, suppresses cell growth on a solid surface, it increases anchorage-independent growth
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The aryl hydrocarbon receptor mediates raloxifene-induced apoptosis in estrogen receptor-negative hepatoma and breast cancer cells
Identification of new molecular targets for the treatment of breast cancer is an important clinical goal, especially for triple-negative breast cancer, which is refractory to existing targeted treatments. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor known primarily as the mediator of dioxin toxicity. However, the AhR can also inhibit cellular proliferation in a ligand-dependent manner and act as a tumor suppressor in mice, and thus may be a potential anticancer target. To investigate the AhR as an anticancer target, we conducted a small molecule screen to discover novel AhR ligands with anticancer properties. We identified raloxifene, a selective estrogen receptor (ER) modulator currently used in the clinic for prevention of ER-positive breast cancer and osteoporosis in post-menopausal women, as an AhR activator. Raloxifene directly bound the AhR and induced apoptosis in ER-negative mouse and human hepatoma cells in an AhR-dependent manner, indicating that the AhR is a molecular target of raloxifene and mediates raloxifene-induced apoptosis in the absence of ER. Raloxifene selectively induced apoptosis of triple-negative MDA-MB-231 breast cancer cells compared with non-transformed mammary epithelial cells via the AhR. Combined with recent data showing that raloxifene inhibits triple-negative breast cancer xenografts in vivo (Int J Oncol. 43(3):785-92, 2013), our results support the possibility of repurposing of raloxifene as an AhR-targeted therapeutic for triple-negative breast cancer patients. To this end, we also evaluated the role of AhR expression on survival of patients diagnosed with breast cancer. We found that higher expression of the AhR is significantly associated with increased overall survival and distant metastasis-free survival in both hormone-dependent (ER-positive) and hormone-independent (ER and progesterone receptor (PR)-negative) breast cancers. Together, our data strongly support the possibility of using the AhR as a molecular target for the treatment of hormone-independent breast cancers.This is the publisher's pdf, which can be found at http://www.nature.com/cddis/index.html. Copyright remains with the authors
Cardiovascular risk assessment in patients with rheumatoid arthritis using carotid ultrasound B-mode imaging
Rheumatoid arthritis (RA) is a systemic chronic inflammatory disease that affects synovial joints and has various extra-articular manifestations, including atherosclerotic cardiovascular disease (CVD). Patients with RA experience a higher risk of CVD, leading to increased morbidity and mortality. Inflammation is a common phenomenon in RA and CVD. The pathophysiological association between these diseases is still not clear, and, thus, the risk assessment and detection of CVD in such patients is of clinical importance. Recently, artificial intelligence (AI) has gained prominence in advancing healthcare and, therefore, may further help to investigate the RA-CVD association. There are three aims of this review: (1) to summarize the three pathophysiological pathways that link RA to CVD; (2) to identify several traditional and carotid ultrasound image-based CVD risk calculators useful for RA patients, and (3) to understand the role of artificial intelligence in CVD risk assessment in RA patients. Our search strategy involves extensively searches in PubMed and Web of Science databases using search terms associated with CVD risk assessment in RA patients. A total of 120 peer-reviewed articles were screened for this review. We conclude that (a) two of the three pathways directly affect the atherosclerotic process, leading to heart injury, (b) carotid ultrasound image-based calculators have shown superior performance compared with conventional calculators, and (c) AI-based technologies in CVD risk assessment in RA patients are aggressively being adapted for routine practice of RA patients
The Anti-Inflammatory Drug Leflunomide Is an Agonist of the Aryl Hydrocarbon Receptor
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxicity and biological activity of dioxins and related chemicals. The AhR influences a variety of processes involved in cellular growth and differentiation, and recent studies have suggested that the AhR is a potential target for immune-mediated diseases.During a screen for molecules that activate the AhR, leflunomide, an immunomodulatory drug presently used in the clinic for the treatment of rheumatoid arthritis, was identified as an AhR agonist. We aimed to determine whether any biological activity of leflunomide could be attributed to a previously unappreciated interaction with the AhR. The currently established mechanism of action of leflunomide involves its metabolism to A771726, possibly by cytochrome P450 enzymes, followed by inhibition of de novo pyrimidine biosynthesis by A771726. Our results demonstrate that leflunomide, but not its metabolite A771726, caused nuclear translocation of AhR into the nucleus and increased expression of AhR-responsive reporter genes and endogenous AhR target genes in an AhR-dependent manner. In silico Molecular Docking studies employing AhR ligand binding domain revealed favorable binding energy for leflunomide, but not for A771726. Further, leflunomide, but not A771726, inhibited in vivo epimorphic regeneration in a zebrafish model of tissue regeneration in an AhR-dependent manner. However, suppression of lymphocyte proliferation by leflunomide or A771726 was not dependent on AhR.These data reveal that leflunomide, an anti-inflammatory drug, is an agonist of the AhR. Our findings link AhR activation by leflunomide to inhibition of fin regeneration in zebrafish. Identification of alternative AhR agonists is a critical step in evaluating the AhR as a therapeutic target for the treatment of immune disorders
Structure of the TPR Domain of AIP: Lack of Client Protein Interaction with the C-Terminal alpha-7 Helix of the TPR Domain of AIP Is Sufficient for Pituitary Adenoma Predisposition
PMCID: PMC3534021This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
The Post-thrombotic Syndrome-Prevention and Treatment: VAS-European Independent Foundation in Angiology/Vascular Medicine Position Paper.
Importance: The post-thrombotic syndrome (PTS) is the most common long-term complication of deep vein thrombosis (DVT), occurring in up to 40-50% of cases. There are limited evidence-based approaches for PTS clinical management. Objective: To provide an expert consensus for PTS diagnosis, prevention, and treatment. Evidence-review: MEDLINE, Cochrane Database review, and GOOGLE SCHOLAR were searched with the terms "post-thrombotic syndrome" and "post-phlebitic syndrome" used in titles and abstracts up to September 2020. Filters were: English, Controlled Clinical Trial / Systematic Review / Meta-Analysis / Guideline. The relevant literature regarding PTS diagnosis, prevention and treatment was reviewed and summarized by the evidence synthesis team. On the basis of this review, a panel of 15 practicing angiology/vascular medicine specialists assessed the appropriateness of several items regarding PTS management on a Likert-9 point scale, according to the RAND/UCLA method, with a two-round modified Delphi method. Findings: The panelists rated the following as appropriate for diagnosis: 1-the Villalta scale; 2- pre-existing venous insufficiency evaluation; 3-assessment 3-6 months after diagnosis of iliofemoral or femoro-popliteal DVT, and afterwards periodically, according to a personalized schedule depending on the presence or absence of clinically relevant PTS. The items rated as appropriate for symptom relief and prevention were: 1- graduated compression stockings (GCS) or elastic bandages for symptomatic relief in acute DVT, either iliofemoral, popliteal or calf; 2-thigh-length GCS (30-40 mmHg at the ankle) after ilio-femoral DVT; 3- knee-length GCS (30-40 mmHg at the ankle) after popliteal DVT; 4-GCS for different length of times according to the severity of periodically assessed PTS; 5-catheter-directed thrombolysis, with or without mechanical thrombectomy, in patients with iliofemoral obstruction, severe symptoms, and low risk of bleeding. The items rated as appropriate for treatment were: 1- thigh-length GCS (30-40 mmHg at the ankle) after iliofemoral DVT; 2-compression therapy for ulcer treatment; 3- exercise training. The role of endovascular treatment (angioplasty and/or stenting) was rated as uncertain, but it could be considered for severe PTS only in case of stenosis or occlusion above the inguinal ligament, followed by oral anticoagulation. Conclusions and relevance: This position paper can help practicing clinicians in PTS management
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