100 research outputs found
Pharmacokinetic analysis of two different docetaxel dose levels in patients with non-small cell lung cancer treated with docetaxel as monotherapy or with concurrent radiotherapy
<p>Abstract</p> <p>Background</p> <p>Previous pharmacokinetic studies with docetaxel have mostly used 3-weekly (75 mg/m<sup>2 </sup>and 100 mg/m<sup>2</sup>) or weekly regimens (35–40 mg/m<sup>2</sup>). The pharmacokinetics and radiosensitizing efficacy of weekly 20 mg/m<sup>2 </sup>docetaxel, has however not been well characterized. We examined the pharmacokinetics of weekly docetaxel when administered with concurrent radiotherapy and compared the results with a 3-weekly 100 mg/m<sup>2 </sup>regimen.</p> <p>Methods</p> <p>Thirty-four patients with non small cell lung cancer (NSCLC) were included in this study, 19 receiving 100 mg/m<sup>2 </sup>docetaxel 3-weekly as single therapy, and 15 receiving 20 mg/m<sup>2 </sup>docetaxel weekly with concurrent radiotherapy. A newly developed HPLC method was used for measuring docetaxel levels, capable of quantifying docetaxel in plasma down to the nanomolar level.</p> <p>Results</p> <p>The HPLC method showed detectable concentrations of docetaxel in plasma even after 72 hours. In the present study we have demonstrated that median docetaxel plasma levels of 3 nM can be obtained 72 hours after a dose of 20 mg/m<sup>2</sup>.</p> <p>Conclusion</p> <p>The pharmacokinetics of docetaxel is characterized by great inter-individual variability and at some time points plasma concentrations for 20 mg/m<sup>2 </sup>and 100 mg/m<sup>2 </sup>docetaxel were overlapping. Extrapolation of these results indicates that radio sensitizing docetaxel concentrations may be present for as long as 1 week, thus supporting the use of 20 mg/m<sup>2 </sup>weekly docetaxel.</p
Expression of Actin-interacting Protein 1 Suppresses Impaired Chemotaxis of Dictyostelium Cells Lacking the Na+-H+ Exchanger NHE1
Dictyostelium cells lacking the intracellular pH regulator NHE1 have defective chemotaxis. A modifier screen and reconstitution studies show expression of recombinant actin interacting protein 1 (Aip1) suppresses the Ddnhe1-phenotype. Aip1 promotes cofilin-dependent actin remodeling, which is likely a major determinant in pH-dependent chemotaxis
The Actin-Binding Protein Capulet Genetically Interacts with the Microtubule Motor Kinesin to Maintain Neuronal Dendrite Homeostasis
BACKGROUND: Neurons require precise cytoskeletal regulation within neurites, containing microtubule tracks for cargo transport in axons and dendrites or within synapses containing organized actin. Due to the unique architecture and specialized function of neurons, neurons are particularly susceptible to perturbation of the cytoskeleton. Numerous actin-binding proteins help maintain proper cytoskeletal regulation. METHODOLOGY/PRINCIPAL FINDINGS: From a Drosophila forward genetic screen, we identified a mutation in capulet--encoding a conserved actin-binding protein--that causes abnormal aggregates of actin within dendrites. Through interaction studies, we demonstrate that simultaneous genetic inactivation of capulet and kinesin heavy chain, a microtubule motor protein, produces elongate cofilin-actin rods within dendrites but not axons. These rods resemble actin-rich structures induced in both mammalian neurodegenerative and Drosophila Alzheimer's models, but have not previously been identified by loss of function mutations in vivo. We further demonstrate that mitochondria, which are transported by Kinesin, have impaired distribution along dendrites in a capulet mutant. While Capulet and Cofilin may biochemically cooperate in certain circumstances, in neuronal dendrites they genetically antagonize each other. CONCLUSIONS/SIGNIFICANCE: The present study is the first molecularly defined loss of function demonstration of actin-cofilin rods in vivo. This study suggests that simultaneous, seemingly minor perturbations in neuronal dendrites can synergize producing severe abnormalities affecting actin, microtubules and mitochondria/energy availability in dendrites. Additionally, as >90% of Alzheimer's and Parkinson's cases are sporadic this study suggests mechanisms by which multiple mutations together may contribute to neurodegeneration instead of reliance on single mutations to produce disease
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Artificial intelligence extension of the OSCAR-IB criteria
Artificial intelligence (AI)-based diagnostic algorithms have achieved ambitious aims through automated image pattern recognition. For neurological disorders, this includes neurodegeneration and inflammation. Scalable imaging technology for big data in neurology is optical coherence tomography (OCT). We highlight that OCT changes observed in the retina, as a window to the brain, are small, requiring rigorous quality control pipelines. There are existing tools for this purpose. Firstly, there are human-led validated consensus quality control criteria (OSCAR-IB) for OCT. Secondly, these criteria are embedded into OCT reporting guidelines (APOSTEL). The use of the described annotation of failed OCT scans advances machine learning. This is illustrated through the present review of the advantages and disadvantages of AI-based applications to OCT data. The neurological conditions reviewed here for the use of big data include Alzheimer disease, stroke, multiple sclerosis (MS), Parkinson disease, and epilepsy. It is noted that while big data is relevant for AI, ownership is complex. For this reason, we also reached out to involve representatives from patient organizations and the public domain in addition to clinical and research centers. The evidence reviewed can be grouped in a five-point expansion of the OSCAR-IB criteria to embrace AI (OSCAR-AI). The review concludes by specific recommendations on how this can be achieved practically and in compliance with existing guidelines
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