391 research outputs found

    Aging into Perceptual Control: A Dynamic Causal Modeling for fMRI Study of Bistable Perception

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    Aging is accompanied by stereotyped changes in functional brain activations, for example a cortical shift in activity patterns from posterior to anterior regions is one hallmark revealed by functional magnetic resonance imaging (fMRI) of aging cognition. Whether these neuronal effects of aging could potentially contribute to an amelioration of or resistance to the cognitive symptoms associated with psychopathology remains to be explored. We used a visual illusion paradigm to address whether aging affects the cortical control of perceptual beliefs and biases. Our aim was to understand the effective connectivity associated with volitional control of ambiguous visual stimuli and to test whether greater top-down control of early visual networks emerged with advancing age. Using a bias training paradigm for ambiguous images we found that older participants (n = 16) resisted experimenter-induced visual bias compared to a younger cohort (n = 14) and that this resistance was associated with greater activity in prefrontal and temporal cortices. By applying Dynamic Causal Models for fMRI we uncovered a selective recruitment of top-down connections from the middle temporal to lingual gyrus by the older cohort during the perceptual switch decision following bias training. In contrast, our younger cohort did not exhibit any consistent connectivity effects but instead showed a loss of driving inputs to orbitofrontal sources following training. These findings suggest that perceptual beliefs are more readily controlled by top-down strategies in older adults and introduce age-dependent neural mechanisms that may be important for understanding aberrant belief states associated with psychopathology

    Tyrosine kinase inhibitors for the therapy of anaplastic thyroid cancer

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    Anaplastic thyroid cancer (ATC) is often incurable so new therapeutic approaches are needed. Tyrosine kinases inhibitors (such as imanitib, sunitinib or sorafenib) are under evaluation for the treatment of ATC. Other vascular disrupting agents, such as combretastatin A4 phosphate, and antiangiogenic agents, such as aplidin, PTK787/ZK222584 and human VEGF monoclonal antibodies (bevacizumab, cetuximab), have been evaluated. Small-molecule adenosine triphosphate competitive inhibitors directed intracellularly at EGFRs tyrosine kinase, such as erlotinib or gefitinib, are also studied. Furthermore, new molecules have been shown to be active against ATC, such as CLM94 and CLM3. However, more research is needed to finally identify therapies able to control and to cure this disease

    Phase I Safety, Pharmacokinetics, and Clinical Activity Study of Lapatinib (GW572016), a Reversible Dual Inhibitor of Epidermal Growth Factor Receptor Tyrosine Kinases, in Heavily Pretreated Patients With Metastatic Carcinomas

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    PURPOSE: This study (EGF10004) assessed the safety/tolerability, pharmacokinetics, and clinical activity of daily oral dosing with lapatinib (GW572016) in patients with ErbB1-expressing and/or ErbB2-overexpressing advanced-stage refractory solid tumors. PATIENTS AND METHODS: Heavily pretreated patients with ErbB1-expressing and/or ErbB2-overexpressing metastatic cancers were randomly assigned to one of five dose cohorts of lapatinib administered once daily. Pharmacokinetic samples were obtained on days 1 and 20. Clinical response was assessed every 8 weeks. RESULTS: Sixty-seven patients with metastatic solid tumors were treated with lapatinib. The most frequently reported drug-related adverse events were diarrhea (42%) and rash (31%). No grade 4 drug-related adverse events were reported. Five grade 3 drug-related toxicities (gastrointestinal events and rash) were experienced by four patients. Drug-related interstitial pneumonitis or cardiac dysfunction associated with other ErbB-targeted therapies was not reported. Four patients with trastuzumab-resistant metastatic breast cancer-two of whom were classified as having inflammatory breast cancer-had partial responses (PRs). Twenty-four patients with various other carcinomas experienced stable disease, of whom 10 received lapatinib for > or = 6 months. The relationships between lapatinib dose or serum concentration and clinical response could not be adequately characterized due to the limited response data. The incidence of diarrhea increased with increasing dose, whereas the incidence of rash was not related to dose. CONCLUSION: Lapatinib was well tolerated at doses ranging from 500 to 1,600 mg once daily. Clinical activity was observed in heavily pretreated patients with ErbB1-expressing and/or ErbB2-overexpressing metastatic cancers, including four PRs in patients with trastuzumab-resistant breast cancers and prolonged stable disease in 10 patients

    Vascular disrupting agent for neovascular age related macular degeneration: a pilot study of the safety and efficacy of intravenous combretastatin A-4 phosphate

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    BACKGROUND: This study was designed to assess the safety, tolerability, and efficacy of intravenous infusion of CA4P in patients with neovascular age-related macular degeneration (AMD). METHODS: Prospective, interventional, dose-escalation clinical trial. Eight patients with neovascular AMD refractory to at least 2 sessions of photodynamic therapy received CA4P at a dose of 27 or 36 mg/m2 as weekly intravenous infusion for 4 consecutive weeks. Safety was monitored by vital signs, ocular and physical examinations, electrocardiogram, routine laboratory tests, and collection of adverse events. Efficacy was assessed using retinal fluorescein angiography, optical coherence tomography, and best corrected visual acuity (BCVA). RESULTS: The most common adverse events were elevated blood pressure (46.7%), QTc prolongation (23.3%), elevated temperature (13.3%), and headache (10%), followed by nausea and eye injection (6.7%). There were no adverse events that were considered severe in intensity and none resulted in discontinuation of treatment. There was reduction of the excess foveal thickness by 24.15% at end of treatment period and by 43.75% at end of the two-month follow-up (p = 0.674 and 0.161, respectively). BCVA remained stable throughout the treatment and follow-up periods. CONCLUSIONS: The safety profile of intravenous CA4P was consistent with that reported in oncology trials of CA4P and with the class effects of vascular disruptive agents; however, the frequency of adverse events was different. There are evidences to suggest potential efficacy of CA4P in neovascular AMD. However, the level of systemic safety and efficacy indicates that systemic CA4P may not be suitable as an alternative monotherapy to current standard-of-care therapy

    Co-transducing B7H3 CAR-NK cells with the DNR preserves their cytolytic function against GBM in the presence of exogenous TGF-β

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    Cord blood (CB)-derived natural killer (NK) cells that are genetically engineered to express a chimeric antigen receptor (CAR) are an attractive off-the-shelf therapy for the treatment of cancer, demonstrating a robust safety profile in vivo. For poor prognosis brain tumors such as glioblastoma multiforme (GBM), novel therapies are urgently needed. Although CAR-T cells demonstrate efficacy in preclinical GBM models, an off-the-shelf product may exhibit unwanted side effects like graft-versus-host disease. Hence, we developed an off-the-shelf CAR-NK cell approach using a B7H3 CAR and showed that CAR-transduced NK cells have robust cytolytic activity against GBM cells in vitro. However, transforming growth factor (TGF)-β within the tumor microenvironment has devastating effects on the cytolytic activity of both unmodified and CAR-transduced NK cells. To overcome this potent immune suppression, we demonstrated that co-transducing NK cells with a B7H3 CAR and a TGF-β dominant negative receptor (DNR) preserves cytolytic function in the presence of exogenous TGF-β. This study demonstrates that a novel DNR and CAR co-expression strategy may be a promising therapeutic for recalcitrant CNS tumors like GBM

    Interleukin-6 gene (IL-6): a possible role in brain morphology in the healthy adult brain

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    Background: Cytokines such as interleukin 6 (IL-6) have been implicated in dual functions in neuropsychiatric disorders. Little is known about the genetic predisposition to neurodegenerative and neuroproliferative properties of cytokine genes. In this study the potential dual role of several IL-6 polymorphisms in brain morphology is investigated. Methodology: In a large sample of healthy individuals (N = 303), associations between genetic variants of IL-6 (rs1800795; rs1800796, rs2069833, rs2069840) and brain volume (gray matter volume) were analyzed using voxel-based morphometry (VBM). Selection of single nucleotide polymorphisms (SNPs) followed a tagging SNP approach (e.g., Stampa algorigthm), yielding a capture 97.08% of the variation in the IL-6 gene using four tagging SNPs. Principal findings/results: In a whole-brain analysis, the polymorphism rs1800795 (−174 C/G) showed a strong main effect of genotype (43 CC vs. 150 CG vs. 100 GG; x = 24, y = −10, z = −15; F(2,286) = 8.54, puncorrected = 0.0002; pAlphaSim-corrected = 0.002; cluster size k = 577) within the right hippocampus head. Homozygous carriers of the G-allele had significantly larger hippocampus gray matter volumes compared to heterozygous subjects. None of the other investigated SNPs showed a significant association with grey matter volume in whole-brain analyses. Conclusions/significance: These findings suggest a possible neuroprotective role of the G-allele of the SNP rs1800795 on hippocampal volumes. Studies on the role of this SNP in psychiatric populations and especially in those with an affected hippocampus (e.g., by maltreatment, stress) are warranted.Bernhard T Baune, Carsten Konrad, Dominik Grotegerd, Thomas Suslow, Eva Birosova, Patricia Ohrmann, Jochen Bauer, Volker Arolt, Walter Heindel, Katharina Domschke, Sonja Schöning, Astrid V Rauch, Christina Uhlmann, Harald Kugel and Udo Dannlowsk

    Angiogenesis inhibitors in clinical development; where are we now and where are we going?

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    Angiogenesis is crucial for tumour growth and the formation of metastases. Various classes of angiogenesis inhibitors that are each able to inhibit one of the various steps of this complex process can be distinguished. Results from clinical studies with these agents are summarised. In general, it has been shown that most angiogenesis inhibitors can be safely administered, but that tumour regressions are rare. Combining angiogenesis inhibitors with cytotoxic chemotherapy can enhance anticancer activity. Recently, some promising data with regard to clinical efficacy have been presented. While performing clinical studies with angiogenesis inhibitors, defining biological activity is crucial, but thus far no validated techniques are available. It is conceivable that in the near future various classes of angiogenesis inhibitors will be combined in an attempt to further improve antiangiogenic and anticancer activity

    Interaction between gemcitabine and topotecan in human non-small-cell lung cancer cells: effects on cell survival, cell cycle and pharmacogenetic profile

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    The pyrimidine analogue gemcitabine is an established effective agent in the treatment of non-small-cell lung cancer (NSCLC). The present study investigates whether gemcitabine would be synergistic with the topoisomerase I inhibitor topotecan against the NSCLC A549 and Calu-6 cells. Cells were treated with gemcitabine and topotecan for 1 h and the type of drug interaction was assessed using the combination index (CI). Cell cycle alterations were analysed by flow cytometry, while apoptosis was examined by the occurrence of DNA internucleosomal fragmentation, nuclear condensation and caspase-3 activation. Moreover, the possible involvement of the PI3K-Akt signalling pathway was investigated by the measurement of Akt phosphorylation. Finally, quantitative, real-time PCR (QRT-PCR) was used to study modulation of the gemcitabine-activating enzyme deoxycytidine kinase (dCK) and the cellular target enzyme ribonucleotide reductase (RR). In results, it was found that simultaneous and sequential topotecan → gemcitabine treatments were synergistic, while the reverse sequence was antagonistic in both cell lines. DNA fragmentation, nuclear condensation and enhanced caspase-3 activity demonstrated that the drug combination markedly increased apoptosis in comparison with either single agent, while cell cycle analysis showed that topotecan increased cells in S phase. Furthermore, topotecan treatment significantly decreased the amount of the activated form of Akt, and enhanced the expression of dCK (+155.0 and +115.3% in A549 and Calu-6 cells, respectively), potentially facilitating gemcitabine activity. In conclusion, these results indicate that the combination of gemcitabine and topotecan displays schedule-dependent activity in vitro against NSCLC cells. The gemcitabine → topotecan sequence is antagonistic while drug synergism is obtained with the simultaneous and the sequential topotecan → gemcitabine combinations, which are associated with induction of decreased Akt phosphorylation and increased dCK expression

    Interleukin-6 promoter polymorphism interacts with pain and life stress influencing depression phenotypes

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    Interleukin-6 (IL-6) has emerged as a potent biomarker for depression as its elevated plasma levels in patients with clinical depression have been confirmed by meta-analyses. Increased plasma IL-6 concentration was associated with various psychological stress factors and physical disorders accompanied by pain. Another modulator of the IL-6 level is rs1800795, a promoter polymorphism in the IL-6 gene which is able to influence its expression rate. Therefore, we examined in a Hungarian population sample of 1053 volunteers with European origins if rs1800795 polymorphism can affect depression symptoms measured by Zung Self-rating Depression Scale (ZSDS), and Brief Symptom Inventory (BSI). We also investigated the interactions of the polymorphism with reported painful physical conditions and Recent Negative Life Events (RLE) measured by the List of Life Threatening Experiences. Rs1800795 significantly interacted with both RLE and painful condition on depressive symptoms measured by ZSDS and BSI using different heritability models, while no main effects of the polymorphism were identified. After correction for multiple testing only the rs1800795 x RLE interaction effect (recessive model) remained significant on the BSI score, while both RLE and painful conditions significantly interacted on the ZSDS. In conclusion, the functional IL-6 rs1800795 polymorphism in interaction with various stress factors increases the risk of depression and has a greater impact on symptoms measured by the ZSDS. Thus, IL-6 and other cytokines may be more relevant in the development of somatic symptoms compared to affective signs of depression, delineating a specific genotype-phenotype relationship in this heterogeneous disorder
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