183 research outputs found
IGF-I influences everolimus activity in medullary thyroid carcinoma
Context: Medullary thyroid carcinoma (MTC) is a rare tumor originating from thyroid parafollicular C cells. It has been previously demonstrated that insulin-like growth factor I (IGF-I) protects MTC from the effects of antiproliferative drugs. Everolimus, an mTOR inhibitor, has shown potent antiproliferative effects in a human MTC cell line, TT, and in two human MTC primary cultures.
Objective: To verify whether IGF-I may influence the effects of everolimus in a group of human MTC primary cultures.
Design: We collected 18 MTCs that were dispersed in primary cultures, treated without or with 10 nM-1 mu M everolimus and/or 50 nM IGF-I. Cell viability was evaluated after 48 h, and calcitonin (CT) secretion was assessed after a 6 h incubation. IGF-I receptor downstream signaling protein expression profile was also investigated.
Results: Everolimus significantly reduced cell viability in eight MTC [by similar to 20%; P < 0.01 vs. control; everolimus-responders (E-R) MTCs], while cell viability did not change in 10 MTCs [everolimus-non-responders (E-NR) MTCs]. In E-R MTCs, IGF-I blocked the antiproliferative effects of everolimus that did not affect CT secretion, but blocked the stimulatory effects of IGF-I on this parameter. IGF-I receptor downstream signaling proteins were expressed at higher levels in E-NR MTC as compared to E-R MTCs.
Conclusion: IGF-I protects a subset of MTC primary cultures from the antiproliferative effects of everolimus and stimulates CT secretion by an mTOR mediated pathway that, in turn, may represent a therapeutic target in the treatment of aggressive MTCs
Cadmium- and lead-induced apoptosis in mallard erythrocytes (Anas platyrhynchos)
©2008 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the Published version of a Published Work that appeared in final form in Ecotoxicology and Environmental Safety. To access the final edited and published work see https://doi.org/10.1016/j.ecoenv.2008.05.004Cadmium, lead and cadmium–lead (1:10) induced apoptosis were studied using mallard blood cells. The allowable range in concentrations were: 0.01–0.5, 0.1–5.0, and 0.01:0.10–0.50:5.00 mM, for cadmium, lead and cadmium–lead, respectively. The lowest EC50 achieved was for cadmium (0.2270.04 mM). Two doses from each treatment group were chosen to study apoptosis and the presence of metals in cells. The percentage of apoptotic cells increased as the concentration of metals increased. The percentage of cells with intracellular metals was high for both exposure levels and the quantity of intracellular metal was greater for exposure to high concentrations. Morphological alterations for all types of exposure were related to the diverse range of effects that these metals have on membranes. We suggest that the decrease in the number of erythrocytes observed in specimens suffering from lead and cadmium poisoning is related to the induction of apoptosis
MTOR, p70S6K, AKT, and ERK1/2 levels predict sensitivity to mTOR and PI3K/mTOR inhibitors in human bronchial carcinoids
Bronchial carcinoids (BCs) are rare neuroendocrine tumors that are still orphans of medical treatment. Human BC primary cultures may display resistance to everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), in terms of cell viability reduction. Our aim was to assess whether the novel dual phosphatidylinositol 3-kinase (PI3K)/mTOR inhibitor NVP-BEZ235 is effective in everolimus-resistant human BC tissues and cell lines. In addition, we searched for possible markers of the efficacy of mTOR inhibitors that may help in identifying the patients who may benefit from treatment with mTOR inhibitors, sparing them from ineffective therapy. We found that NVP-BEZ235 is twice as potent as everolimus in reducing cell viability and activating apoptosis in human BC tissues that display sensitivity to mTOR inhibitors, but is not effective in everolimus-resistant BC tissues and cell lines that bypass cyclin D1 downregulation and escape G0/G1 blockade. Rebound AKT activation was not observed in response to treatment with either mTOR inhibitor in the 'resistant' BC cells. In addition to total mTOR levels, putative markers of the sensitivity of BCs to mTOR inhibitors are represented by AKT, p70S6K (RPS6KB2), and ERK1/2 (MAPK3/1) protein levels. Finally, we validated these markers in an independent BC group. These data indicate that the dual PI3K/mTOR inhibitor NVP-BEZ235 is more potent than everolimus in reducing the proliferation of human BC cells. 'Resistant' cells display lower levels of mTOR, p70S6K, AKT, and ERK1/2, indicating that these proteins may be useful as predictive markers of resistance to mTOR and PI3K/mTOR inhibitors in human BCs. \ua9 2013 Society for Endocrinology
A critical review of adverse effects to the kidney: mechanisms, data sources and in silico tools to assist prediction
Introduction: The kidney is a major target for toxicity elicited by pharmaceuticals and environmental pollutants. Standard testing which often does not investigate underlying mechanisms has proven not to be an adequate hazard assessment approach. As such, there is an opportunity for the application of computational approaches that utilise multi-scale data based on the Adverse Outcome Pathway (AOP) paradigm, coupled with an understanding of the chemistry underpinning the molecular initiating event (MIE) to provide a deep understanding of how structural fragments of molecules relate to specific mechanisms of nephrotoxicity.
The aim of this investigation was to review the current scientific landscape related to computational methods, including mechanistic data, AOPs, publicly available knowledge bases and current in silico models, for the assessment of pharmaceuticals and other chemicals with regard to their potential to elicit nephrotoxicity. A list of over 250 nephrotoxicants enriched with, where possible, mechanistic and AOP-derived understanding was compiled.
Expert opinion: Whilst little mechanistic evidence has been translated into AOPs, this review identified a number of data sources of in vitro, in vivo and human data that may assist in the development of in silico models which in turn may shed light on the inter-relationships between nephrotoxicity mechanisms
Targeting protein kinase C by Enzastaurin restrains proliferation and secretion in human pancreatic endocrine tumors
Dysregulation of the protein kinase C (PKC) signaling pathway has been implicated in tumor progression. In this study, we investigate the effects of a PKC inhibitor, Enzastaurin, in human pancreatic neuroendocrine neoplasms (PNN) primary cultures and in the human pancreatic endocrine cancer cell line, BON1. To this aim six human PNN dispersed in primary cultures and BON1 cells were treated without or with 1–10 μM Enzastaurin and/or 100 nM IGF1 in the presence or absence of serum. Cell viability and apoptosis were evaluated after 48–72 h; Chromogranin A (CgA) and/or insulin secretion was assessed after 6 h of incubation. PKC expression was investigated by immunofluorescence and western blot. We found that Enzastaurin significantly reduced human PNN primary culture cell viability, as well as CgA and insulin secretion. Moreover, in the BON1 cell line Enzastaurin inhibited cell proliferation at 5 and 10 μM by inducing caspase-mediated apoptosis, and reduced phosphorylation of glycogen synthetase kinase 3β (GSK3β) and of Akt, both downstream targets of PKC pathway and pharmacodynamic markers for Enzastaurin. In addition, Enzastaurin blocked the stimulatory effect of IGF1 on cell proliferation, and reduced CgA expression and secretion in BON1 cells. Two different PKC isoforms are expressed at different levels and have partially different subcellular localization in BON1 cells. In conclusion, Enzastaurin reduces cell proliferation by inducing apoptosis, with a mechanism likely involving GSK3β signaling, and inhibits secretory activity in PNNin vitromodels, suggesting that Enzastaurin might represent a possible medical treatment of human PNN
A Critical Review of Adverse Effects to the Kidney: Mechanisms, Data Sources and In Silico Tools to Assist Prediction
Introduction: The kidney is a major target for toxicity elicited by pharmaceuticals and environmental pollutants. Standard testing which often does not investigate underlying mechanisms has proven not to be an adequate hazard assessment approach. As such, there is an opportunity for the application of computational approaches that utilise multi-scale data based on the Adverse Outcome Pathway (AOP) paradigm, coupled with an understanding of the chemistry underpinning the molecular initiating event (MIE) to provide a deep understanding of how structural fragments of molecules relate to specific mechanisms of nephrotoxicity.
Aims covered: The aim of this investigation was to review the current scientific landscape related to computational methods, including mechanistic data, AOPs, publicly available knowledge bases and current in silico models, for the assessment of pharmaceuticals and other chemicals with regard to their potential to elicit nephrotoxicity. A list of over 250 nephrotoxicants enriched with, where possible, mechanistic and AOP-derived understanding was compiled.
Expert opinion: Whilst little mechanistic evidence has been translated into AOPs, this review identified a number of data sources of in vitro, in vivo and human data that may assist in the development of in silico models which in turn may shed light on the inter-relationships between nephrotoxicity mechanisms
Proceedings of the Third Annual Deep Brain Stimulation Think Tank: A Review of Emerging Issues and Technologies
The proceedings of the 3rd Annual Deep Brain Stimulation Think Tank summarize the most contemporary clinical, electrophysiological, imaging, and computational work on DBS for the treatment of neurological and neuropsychiatric disease. Significant innovations of the past year are emphasized. The Think Tank\u27s contributors represent a unique multidisciplinary ensemble of expert neurologists, neurosurgeons, neuropsychologists, psychiatrists, scientists, engineers, and members of industry. Presentations and discussions covered a broad range of topics, including policy and advocacy considerations for the future of DBS, connectomic approaches to DBS targeting, developments in electrophysiology and related strides toward responsive DBS systems, and recent developments in sensor and device technologies
Management of Preschool Wheezing: Guideline from the Emilia-Romagna Asthma (ERA) Study Group
Preschool wheezing should be considered an umbrella term for distinctive diseases with different observable and measurable phenotypes. Despite many efforts, there is a large gap in knowledge regarding management of preschool wheezing. In order to fill this lack of knowledge, the aim of these guidelines was to define management of wheezing disorders in preschool children (aged up to 5 years). A multidisciplinary panel of experts of the Emilia-Romagna Region, Italy, addressed twelve different key questions regarding the management of preschool wheezing. Clinical questions have been formulated by the expert panel using the PICO format (Patients, Intervention, Comparison, Outcomes) and systematic reviews have been conducted on PubMed to answer these specific questions, with the aim of formulating recommendations. The GRADE approach has been used for each selected paper, to assess the quality of the evidence and the degree of recommendations. These guidelines represent, in our opinion, the most complete and up-to-date collection of recommendations on preschool wheezing to guide pediatricians in the management of their patients, standardizing approaches. Undoubtedly, more research is needed to find objective biomarkers and understand underlying mechanisms to assess phenotype and endotype and to personalize targeted treatment
Optical Coherence Tomography in Parkinsonian Syndromes
BACKGROUND/OBJECTIVE: Parkinson's disease (PD) and the atypical parkinsonian syndromes multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) are movement disorders associated with degeneration of the central nervous system. Degeneration of the retina has not been systematically compared in these diseases. METHODS: This cross-sectional study used spectral-domain optical coherence tomography with manual segmentation to measure the peripapillar nerve fiber layer, the macular thickness, and the thickness of all retinal layers in foveal scans of 40 patients with PD, 19 with MSA, 10 with CBS, 15 with PSP, and 35 age- and sex-matched controls. RESULTS: The mean paramacular thickness and volume were reduced in PSP while the mean RNFL did not differ significantly between groups. In PSP patients, the complex of retinal ganglion cell- and inner plexiform layer and the outer nuclear layer was reduced. In PD, the inner nuclear layer was thicker than in controls, MSA and PSP. Using the ratio between the outer nuclear layer and the outer plexiform layer with a cut-off at 3.1 and the additional constraint that the inner nuclear layer be under 46 µm, we were able to differentiate PSP from PD in our patient sample with a sensitivity of 96% and a specificity of 70%. CONCLUSION: Different parkinsonian syndromes are associated with distinct changes in retinal morphology. These findings may serve to facilitate the differential diagnosis of parkinsonian syndromes and give insight into the degenerative processes of patients with atypical parkinsonian syndromes
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