22 research outputs found

    Theta and gamma rhythmic coding through two spike output modes in the hippocampus during spatial navigation

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    Hippocampal CA1 neurons generate single spikes and stereotyped bursts of spikes. However, it is unclear how individual neurons dynamically switch between these output modes and whether these two spiking outputs relay distinct information. We performed extracellular recordings in spatially navigating rats and cellular voltage imaging and optogenetics in awake mice. We found that spike bursts are preferentially linked to cellular and network theta rhythms (3–12 Hz) and encode an animal's position via theta phase precession, particularly as animals are entering a place field. In contrast, single spikes exhibit additional coupling to gamma rhythms (30–100 Hz), particularly as animals leave a place field. Biophysical modeling suggests that intracellular properties alone are sufficient to explain the observed input frequency-dependent spike coding. Thus, hippocampal neurons regulate the generation of bursts and single spikes according to frequency-specific network and intracellular dynamics, suggesting that these spiking modes perform distinct computations to support spatial behavior.Fil: Lowet, Eric. Boston University; Estados UnidosFil: Sheehan, Daniel J.. Boston University; Estados UnidosFil: Chialva, Ulises. Universidad Nacional del Sur. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; ArgentinaFil: De Oliveira Pena, Rodrigo. New Jersey Institute of Technology; Estados UnidosFil: Mount, Rebecca A.. Boston University; Estados UnidosFil: Xiao, Sheng. Boston University; Estados UnidosFil: Zhou, Samuel L.. Boston University; Estados UnidosFil: Tseng, Hua-an. Boston University; Estados UnidosFil: Gritton, Howard. University of Illinois. Urbana - Champaign; Estados UnidosFil: Shroff, Sanaya. Boston University; Estados UnidosFil: Kondabolu, Krishnakanth. Boston University; Estados UnidosFil: Cheung, Cyrus. Boston University; Estados UnidosFil: Wang, Yangyang. Boston University; Estados UnidosFil: Piatkevich, Kiryl D.. Westlake University; ChinaFil: Boyden, Edward S.. McGovern Institute for Brain Research; Estados Unidos. Massachusetts Institute of Technology; Estados UnidosFil: Mertz, Jerome. Boston University; Estados UnidosFil: Hasselmo, Michael E.. Boston University; Estados UnidosFil: Rotstein, Horacio. New Jersey Institute of Technology; Estados UnidosFil: Han, Xue. Boston University; Estados Unido

    Efficacy and Safety of Alemtuzumab Through 9 Years of Follow-up in Patients with Highly Active Disease: Post Hoc Analysis of CARE-MS I and II Patients in the TOPAZ Extension Study

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    Background: Alemtuzumab efficacy versus subcutaneous interferon-β-1a (SC IFNB-1a) was demonstrated over 2 years in patients with relapsing-remitting multiple sclerosis, with continued efficacy over 7 additional years. Alemtuzumab is included as a recommended treatment for patients with highly active disease (HAD) by the American Academy of Neurology Practice Guidelines, and the label indication in Europe was recently restricted to the treatment of HAD patients. There is currently no consensus definition for HAD, and alemtuzumab efficacy across various HAD definitions has not been explored previously. Objectives: In this post hoc analysis, we assess the efficacy and safety of alemtuzumab in Comparison of Alemtuzumab and Rebif® Efficacy in Multiple Sclerosis (CARE-MS) trial patients who met criteria for at least one of four separate definitions of HAD (one primary and three alternatives). Over 2 years, alemtuzumab-treated HAD patients were compared with SC IFNB-1a-treated HAD patients, with additional 7-year follow-up in patients from the alemtuzumab arm. Methods: Patients in the CARE-MS studies received either alemtuzumab (baseline: 5 days; 12 months later: 3 days) or SC IFNB-1a (3 times weekly). Alemtuzumab-treated patients who enrolled in the extensions could receive additional courses ≥ 12 months apart. Four definitions of HAD were applied to assess alemtuzumab efficacy: the pre-specified primary definition (two or more relapses in the year prior to baseline and at least one gadolinium [Gd]-enhancing lesion at baseline) and three alternative definitions that focused on relapse, magnetic resonance imaging (MRI), or prior treatment response criteria. Efficacy outcomes were annualized relapse rate, change in Expanded Disability Status Scale score, 6-month confirmed disability worsening, 6-month confirmed disability improvement, MRI disease activity, and brain volume change. Adverse events were summarized for HAD patients meeting the primary definition. Results: In the pooled CARE-MS population, 208 alemtuzumab-treated patients met the primary HAD definition. Annualized relapse rate was 0.27 in years 0–2 and 0.16 in years 3–9. Over 9 years, 62% of patients were free of 6-month confirmed disability worsening, 50% had 6-month confirmed disability improvement, and median cumulative change in brain volume was − 2.15%. During year 9, 62% had no evidence of disease activity, and 69% were free of MRI disease activity. Similar efficacy outcomes were observed using an alternative relapse-driven HAD definition. For patients meeting alternative HAD definitions focused on either higher MRI lesion counts or disease activity while on prior therapy, reduced efficacy for some endpoints was seen. Safety was consistent with the overall CARE-MS population through year 9. Conclusions: Over 9 years, alemtuzumab efficacy was maintained in CARE-MS HAD patients based on four HAD definitions. These results support intervention with alemtuzumab in patients with early indicators of HAD, including frequent relapse without high MRI activity. No safety signals were observed over 9 years that were unique to the HAD populations. ClinicalTrials.gov Identifiers: NCT00530348; NCT00548405; NCT00930553; NCT02255656

    Australian super-model Megan Gale walks along the catwalk wearing an outfit by Australian fashion designer Jayson Brunsdon during the David Jones Autumn-Winter 2007 Collection launch at Sydney Town Hall, New South Wales, 13th February 2007 [picture] /

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    Title devised by cataloguer based on information provided by vendor.; Acquired in digital format; access copy available online.; Part of the collection: David Jones Autumn-Winter 2007 Collection launch, Sydney Town Hall, New South Wales, 13th February 2007.; Mode of access: Internet via World Wide Web

    Plasma Thymidine Kinase Activity as a Novel Biomarker in Metastatic Melanoma Patients Treated with Immune Checkpoint Inhibitors

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    Background. Immune checkpoint inhibitors (ICI) are effective in fractions of patients with disseminated melanoma. This study is the first to analyze the plasma activity of thymidine kinase (TK), an enzyme involved in DNA synthesis and repair, as a biomarker in melanoma patients. Methods. Plasma samples were collected prior to treatment start in patients with unresectable metastatic cutaneous melanoma, treated with ICI (anti-CTLA-4 and/or anti-PD-1). Plasma TK activity (TKa) levels were determined using the DiviTum TKa ELISA assay. TKa levels were correlated with patients’ baseline characteristics, response rate (RR), progression-free survival (PFS), and overall survival (OS). Results. In the 90 study patients, the median TKa level was 42 Du/L (range p = 0.003), M1c-d disease (p = 0.015), and elevated lactate dehydrogenase levels (p p = 0.022). The median PFS was 19.9 and 12.6 months in patients with low or high TKa, respectively (hazard ratio (HR) 1.83 (95% CI, 1.08–3.08), p = 0.024). The median OS was >60 months and 18.5 months in patients with low or high TKa, respectively (HR: 2.25 (95% CI, 1.25–4.05), p = 0.011. Conclusions. High pretreatment plasma TKa levels were significantly associated with worse baseline characteristics and poor response and survival in ICI-treated melanoma patients. TKa is hence a novel and interesting plasma biomarker in melanoma and should be further studied to define its role as a prognostic and predictive marker in this disease

    Impact of the first tumor response at eight weeks on overall survival in metastatic breast cancer patients treated with first-line combination chemotherapy

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    The aim of this was to determine whether the change of size observed at the first response evaluation after initiation of first-line combination chemotherapy correlates with overall survival (OS) in patients with metastatic breast cancer (MBC). The change in size of tumors derived from measurements according to Response Evaluation Criteria In Solid Tumors (RECIST) at the first evaluation on computed tomography (CT) was obtained from a multicenter, randomized phase III trial ("TEX trial," n = 287) comparing treatment with a combination of epirubicin and paclitaxel alone or with capecitabine (TEX). Cox regression and Kaplan-Meier analyses were performed to evaluate the correlations between the first change in tumor size, response according to RECIST and OS. Data from CT evaluations of 233 patients were available. Appearance of new lesions or progression of non-target lesions (new/non-target) indicated short OS by univariable regression analysis (HR 3.76, 95 % CI 1.90-7.42, p 30 % at this early time point was prognostic favorable (HR 0.69, 95 % CI 0.49-0.98, p = 0.04) and not significantly less than the best overall response according to RECIST. After adjustment for previous adjuvant treatment and the treatment given within the frame of the randomized trial, OS was still significantly shorter in patients with new/non-target lesions after a median 8 weeks of treatment (HR 4.41, 95 % CI 2.74-7.11, p < 0.001). Disease progression at the first evaluation correlates with OS in patients with MBC treated with first-line combination chemotherapy. The main reason for early disease progression was the appearance of new lesions or progression of non-target lesions. These patients had poor OS even though more lines of treatment were available. Thus, these factors should be focused on in the response evaluations besides tumor size changes
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