Publications by authors named "Styren S"

Background: Schwannomatosis (SWN) is a rare tumor suppressor syndrome that predisposes affected individuals to develop multiple schwannomas and, less often, meningiomas. The most common symptom is chronic, severe pain. No medications are broadly effective in treating SWN-associated pain.

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Introduction: Multiple intravenous doses of ponezumab, an anti-amyloid antibody, were evaluated in subjects with mild-to-moderate Alzheimer's disease (AD).

Methods: In part A, 77 subjects were randomized to ponezumab 0.1, 0.

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Background: Immunotherapy with monoclonal antibodies that target amyloid beta has been under investigation as a treatment for patients with Alzheimer's disease (AD). The 3000 and 3001 phase 3 clinical studies of intravenous bapineuzumab assessed safety and efficacy in patients with mild to moderate AD recruited in over 26 countries. This article describes the long-term safety and tolerability of bapineuzumab in the extension studies for these two protocols.

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Background: Bapineuzumab, an anti-amyloid monoclonal antibody, was evaluated as a candidate for immunotherapy in mild-to-moderate Alzheimer's disease (AD) patients.

Objective: To assess the treatment effect of bapineuzumab therapy on disease-relevant biomarkers in patients with mild-to-moderate AD, using exposure-response modeling.

Methods: Biomarker data from two Phase III studies were combined to model the impact of bapineuzumab exposure on week-71 change from baseline in brain amyloid burden by 11C-labeled Pittsburgh compound B (PiB) PET imaging (global cortical average of the Standardized Uptake Value ratio values), cerebrospinal fluid (CSF) phosphorylated (p)-tau concentrations, and brain volumetrics (brain boundary shift integral) by magnetic resonance imaging.

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Introduction: The objective of this study was to estimate longitudinal changes in disease progression (measured by Alzheimer's disease assessment scale-cognitive 11-item [ADAS-cog/11] scale) after bapineuzumab treatment and to identify covariates (demographics or baseline characteristics) contributing to the variability in disease progression rate and baseline disease status.

Methods: A population-based disease progression model was developed using pooled placebo and bapineuzumab data from two phase-3 studies in ε4 noncarrier and carrier Alzheimer's disease (AD) patients.

Results: A beta regression model with the Richard's function as the structural component best described ADAS-cog/11 disease progression for mild-to-moderate AD population.

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Article Synopsis
  • The study integrated data from two phase-3 trials of bapineuzumab to model disease progression in Alzheimer’s patients, focusing on disability assessments related to dementia.
  • A beta regression model was found to best describe changes in disability, showing no significant treatment effect from bapineuzumab, aligning with earlier findings of limited clinical efficacy.
  • Factors such as baseline disease status, age, and medication use significantly influenced baseline DAD scores and disease progression rates, suggesting that the impact of bapineuzumab might be more notable in patients with mild Alzheimer’s disease.
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Objective: Ponezumab (PF-04360365) is a humanized anti-amyloid beta (Aβ) monoclonal antibody designed for treatment of Alzheimer disease (AD). A single 2-hour intravenous infusion of 0.1 to 10 mg/kg was previously shown to be safe and well tolerated in subjects with mild to moderate AD, with measurable effects on plasma and cerebrospinal fluid Aβ.

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Background: The status of nerve growth factor (NGF) levels during the prodromal phase of Alzheimer disease (AD), characterized by mild cognitive impairment (MCI), remains unknown.

Objective: To investigate whether cortical and/or hippocampal NGF levels are altered in subjects with MCI or different levels of AD severity.

Design And Main Outcome Measures: An NGF enzyme-linked immunosorbent assay determined protein levels in the hippocampus and 5 cortical areas in people clinically diagnosed as having no cognitive impairment, MCI, mild AD, or severe AD.

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Interleukin-1 (IL-1) is induced immediately after insults to the brain, and elevated levels of IL-1 have been strongly implicated in the neurodegeneration that accompanies stroke, Alzheimer's disease, and multiple sclerosis. In animal models, antagonizing IL-1 has been shown to reduce cell death; however, the basis for this protection has not been elucidated. Here we analyzed the response to penetrating brain injury in mice lacking the type 1 IL-1 receptor (IL-1R1) to determine which cellular and molecular mediators of tissue damage require IL-1 signaling.

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In Alzheimer's disease (AD), loss of cortical and hippocampal choline acetyltransferase (ChAT) activity has been correlated with dementia severity and disease duration, and it forms the basis for current therapies. However, the extent to which reductions in ChAT activity are associated with early cognitive decline has not been well established. We quantified ChAT activity in the hippocampus and four cortical regions (superior frontal, inferior parietal, superior temporal, and anterior cingulate) of 58 individuals diagnosed with no cognitive impairment (NCI; n = 26; mean age 81.

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Transgenic Caenorhabditis elegans animals can be engineered to express high levels of the human beta amyloid peptide (Abeta). Histochemistry of fixed tissue from these animals reveals deposits reactive with the amyloid-specific dyes Congo Red and thioflavin S (Fay et al., J.

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Casein kinase Iepsilon (CKIepsilon), a central component of the circadian clock, interacts with and phosphorylates human period protein 1 (hPER1) [Keesler, G.A. et al.

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X-34, a lipophilic, highly fluorescent derivative of Congo red, was examined as a histochemical stain for pathological changes in Alzheimer's disease (AD). X-34 intensely stained neuritic and diffuse plaques, neurofibrillary tangles (NFTs), neuropil threads, and cerebrovascular amyloid. Comparison to standard methods of demonstrating AD pathology showed that X-34 correlated well with Bielschowsky and thioflavin-S staining.

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Type 2 5'-deiodinase (5'-D2), which converts thyroxine to the more active thyroid hormone 3,5,3'-triiodothyronine (T3), is believed to be an important source of intracellular T3 in the brain. The activity of this enzyme is increased in hypothyroidism and decreased in hyperthyroidism, and as such, it serves an important role to protect the brain from wide fluctuations in T3 during changes in thyroidal state. Although it has been hypothesized that T3 may facilitate neuronal regeneration after CNS injury, the 5'-D2 response to brain injury is unknown.

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A variety of factors and processes have been implicated in the development and progression of the pathology of Alzheimer's Disease (AD), including amyloid fragment deposition, reactive gliosis, alpha-1-antichymotrypsin (ACT), and apolipoprotein E (APOE). Carriers of the APOE 4 allele have been shown to have an enhanced risk of developing AD, and the ACT signal peptide A/A genotype may modify the APOEepsilon4 risk. The protein products of these genes have been shown to enhance conversion of diffuse beta amyloid (Abeta) fibrils, which are found in diffuse plaques, to the fibrillar form found in neuritic plaques.

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Previous studies from our group have demonstrated an upregulation in nerve growth factor (NGF) RNA and protein in the cortex 24 h following traumatic brain injury (TBI) in a rat model. This increase in NGF is suppressed if rats are subjected to 4 h of whole-body hypothermia following TBI. In the present study we used in situ hybridization to extend our initial RNA gel-blot (Northern) hybridization findings by demonstrating that NGF RNA is increased in the cortex following TBI and that hypothermia diminishes this response.

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We have previously reported that epidermal growth factor receptor (EGFR) was expressed on vascular endothelial cells from postmortem specimens of demented but not cognitively normal subjects. In the present study, we examined skin biopsies from 35 living patients who were either normal or had a clinical diagnosis of probable Alzheimer's disease. In this living cohort, there was no correlation between the presence of vascular EGFR expression and clinically determined cognitive status.

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The Fetal ALZ-50 Reactive Clone 1 (FAC1) gene is expressed at high levels during brain development and is re-expressed in some neurodegenerative diseases. It is hypothesized that FAC1 functions during neuronal differentiation and may play an active role in neuritic re-organization following brain injury. We have previously employed the entorhinal cortex lesion model to examine reactive synaptogenesis and plasticity in the hippocampal dentate molecular layer following denervating lesion.

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In a number of centers throughout the world, fetal nigral transplantation is being performed for the treatment of Parkinson's disease (PD). Clinical results have been inconsistent. One parameter that differs among transplant studies is the degree and manner by which patients are immunosuppressed following transplantation.

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Dementia results from a combination of structural and neurochemical pathologies. The most reliable index of cognition in both postmortem and biopsied AD brain is synapse loss.

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Although the dorsal midbrain has been implicated in cognitive processes in animals, its role in humans is unclear. We report the neuropsychological and postmortem neuropathological findings of a 52-yr-old university professor who developed a profound dementia in association with a focal dorsal midbrain lesion. The patient's disorder appeared to result from a tuberculous granuloma based on the clinical course and autopsy results.

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Traumatic brain injury (TBI) induces astrocytic and microglial activation and proliferation and augmented production of the cytokine interleukin-1 beta (IL-1 beta) and nerve growth factor (NGF). The increase in NGF temporally follows the increase in IL-1 beta, suggesting that the IL-1 beta up-regulation after trauma directly induces the increase in NGF. We examined the effect of IL-1 receptor antagonist protein (IL-1ra) on microglial proliferation and NGF production in rat cortex, following two different models of TBI.

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Controlled cortical impact (CCI) is a contemporary model of experimental cerebral contusion. We examined the cerebrovascular and neuropathologic effects of a severe CCI in rats. The utility of magnetic resonance imaging (MRI) for the assessment of contusion volume after severe CCI was also established.

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Significant morbidity and mortality associated with traumatic brain injury (TBI) are allied with secondary posttrauma inflammatory complications. Hypothermia has been suggested as a possible treatment to lessen or suppress these inflammatory reactions. We report here that interleukin 1 beta, a cytokine responsible for initiating inflammatory cascades, is elevated in rat cortex within 6 h of TBI in the rat.

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In the CNS the cell adhesion molecule L1 plays a role in axonal growth and fasciculation. Since its roles in synapse formation and CNS regeneration are unknown, we followed the staining of L1 through the sequence of degeneration and reactive axon sprouting in the denervated outer molecular layer (ML) of the hippocampal dentate gyrus following ipsilateral entorhinal cortex (ERC) lesion. We compared immunohistological and ultrastructural localization of L1 and employed image analysis to evaluate lamina-specific changes over time.

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