159 research outputs found

    Low-interference sensing electronics for high-resolution error-correcting biomechanical ground reaction sensor cluster

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    Journal ArticleAbstract- This paper presents a low-interference and low -power sensing electronics design for a high-resolution errorcorrecting biomechanical ground reaction sensor cluster (GRSC) developed for improving inertial measurement unit (IMU) positioning resolution and accuracy. The GRSC is composed of 13 x 13 sensing nodes, which can measure dynamic ground forces, shear strains, and sole deformation associated with a ground locomotion gait. The integrated sensing electronics consist of a front-end multiplexer that can sequentially connect individual sensing nodes in a GRSC to a capacitance-to-voltage converter followed by an ADC, digital control unit, and driving circuitry to interrogate the GRSC. The sensing electronics are designed in a 0.15 μm CMOS process and occupy an area of approximately 3 mm2 with an expected resolution of 10-bits and 14-bits for the z-axis pressure sensing and the x and y-axes shear strain sensing, respectively, while dissipating a DC power less than 2 mW from a 3V supply

    Detailed immunohistochemical characterization of temporal and spatial progression of Alzheimer's disease-related pathologies in male triple-transgenic mice

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    <p>Abstract</p> <p>Background</p> <p>Several transgenic animal models genetically predisposed to develop Alzheimer's disease (AD)-like pathology have been engineered to facilitate the study of disease pathophysiology and the vetting of potential disease-modifying therapeutics. The triple transgenic mouse model of AD (3xTg-AD) harbors three AD-related genetic loci: human PS1<sup>M146V</sup>, human APP<sup>swe</sup>, and human tau<sup>P301L</sup>. These mice develop both amyloid plaques and neurofibrillary tangle-like pathology in a progressive and age-dependent manner, while these pathological hallmarks are predominantly restricted to the hippocampus, amygdala, and the cerebral cortex the main foci of AD neuropathology in humans. This model represents, at present, one of the most advanced preclinical tools available and is being employed ever increasingly in the study of mechanisms underlying AD, yet a detailed regional and temporal assessment of the subtleties of disease-related pathologies has not been reported.</p> <p>Methods and results</p> <p>In this study, we immunohistochemically documented the evolution of AD-related transgene expression, amyloid deposition, tau phosphorylation, astrogliosis, and microglial activation throughout the hippocampus, entorhinal cortex, primary motor cortex, and amygdala over a 26-month period in male 3xTg-AD mice. Intracellular amyloid-beta accumulation is detectable the earliest of AD-related pathologies, followed temporally by phospho-tau, extracellular amyloid-beta, and finally paired helical filament pathology. Pathology appears to be most severe in medial and caudal hippocampus. While astrocytic staining remains relatively constant at all ages and regions assessed, microglial activation appears to progressively increase temporally, especially within the hippocampal formation.</p> <p>Conclusion</p> <p>These data fulfill an unmet need in the ever-widening community of investigators studying 3xTg-AD mice and provide a foundation upon which to design future experiments that seek to examine stage-specific disease mechanisms and/or novel therapeutic interventions for AD.</p

    Altered drainage patterns in patients with melanoma and previous axillary dissection.

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    The incidence of melanoma is increasing rapidly in the United States. Sentinel lymph node biopsy is an important diagnostic tool in the treatment and staging of melanoma. However, many patients with melanoma will have had lymph node surgery for previous melanoma or breast cancer. We set out to examine alterations in drainage patterns in patients with previous axillary dissection for breast cancer. We reviewed four patients with truncal and/or extremity melanomas and examined their lymphoscintigraphy and drainage patterns. Three patients with truncal melanoma mapped to cervical lymph nodes and a fourth patient with an arm melanoma mapped to her previously dissected axilla. Sentinel lymph node mapping is still an important adjunct in patients with melanoma despite previous axillary dissection

    Lymph node ratio is an important and independent prognostic factor for patients with stage III melanoma

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    INTRODUCTION: The incidence of melanoma is dramatically increasing worldwide. We hypothesized that the ratio of metastatic to examined lymph node ratio (LNR) would be the most important prognostic factor for stage III patients. METHODS: We retrospectively reviewed our institutional database of melanoma patients and identified 168 patients who underwent lymph node dissection (LND) for stage III disease between 1993 and 2007. Patients were divided into three groups based on LNR (≤10%, n = 93; 10-≤25%, n = 45; and \u3e25%, n = 30). Univariate and multivariate analysis was performed using Cox proportional hazards model. RESULTS: The median survival time of the entire group of patients was 34 months. The median number of positive nodes was 2 (range = 1, 55), and the median number of examined nodes was 22 (range = 5-123). Tumor characteristics of the primary melanoma (such as thickness, ulceration, and primary site) were not significant predictors of survival in this analysis. By univariate analysis, LNR was an important prognostic factor. Patients with LNR 10-25% and \u3e25% had decreased survival compared to those patients with LNR ≤10% (HR = hazard ratio = 2.0 and 3.1, respectively; P ≤ 0.005). The number of positive lymph nodes also impacted on survival (P = 0.001). In multivariate analysis, LNR of 10-25% and \u3e25% predicted survival (HR = 2.5 and 4.0, respectively). CONCLUSION: LNR is an important prognostic factor in patients undergoing LND for stage III melanoma. It can be used to stratify patients being considered for adjuvant therapy trials and should be evaluated using a larger prospective database

    In vitro migration of cytotoxic T lymphocyte derived from a colon carcinoma patient is dependent on CCL2 and CCR2

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    BACKGROUND: Infiltration of colorectal carcinomas (CRC) with T-cells has been associated with good prognosis. There are some indications that chemokines could be involved in T-cell infiltration of tumors. Selective modulation of chemokine activity at the tumor site could attract immune cells resulting in tumor growth inhibition. In mouse tumor model systems, gene therapy with chemokines or administration of antibody (Ab)-chemokine fusion proteins have provided potent immune mediated tumor rejection which was mediated by infiltrating T cells at the tumor site. To develop such immunotherapeutic strategies for cancer patients, one must identify chemokines and their receptors involved in T-cell migration toward tumor cells. METHODS: To identify chemokine and chemokine receptors involved in T-cell migration toward CRC cells, we have used our previously published three-dimensional organotypic CRC culture system. Organotypic culture was initiated with a layer of fetal fibroblast cells mixed with collagen matrix in a 24 well tissue culture plate. A layer of CRC cells was placed on top of the fibroblast-collagen layer which was followed by a separating layer of fibroblasts in collagen matrix. Anti-CRC specific cytotoxic T lymphocytes (CTLs) mixed with fibroblasts in collagen matrix were placed on top of the separating layer. Excess chemokine ligand (CCL) or Abs to chemokine or chemokine receptor (CCR) were used in migration inhibition assays to identify the chemokine and the receptor involved in CTL migration. RESULTS: Inclusion of excess CCL2 in T-cell layer or Ab to CCL2 in separating layer of collagen fibroblasts blocked the migration of CTLs toward tumor cells and in turn significantly inhibited tumor cell apoptosis. Also, Ab to CCR2 in the separating layer of collagen and fibroblasts blocked the migration of CTLs toward tumor cells and subsequently inhibited tumor cell apoptosis. Expression of CCR2 in four additional CRC patients\u27 lymphocytes isolated from infiltrating tumor tissues suggests their role in migration in other CRC patients. CONCLUSIONS: Our data suggest that CCL2 secreted by tumor cells and CCR2 receptors on CTLs are involved in migration of CTLs towards tumor. Gene therapy of tumor cells with CCL2 or CCL2/anti-tumor Ab fusion proteins may attract CTLs that potentially could inhibit tumor growth

    Personal Navigation via High-Resolution Gait-Corrected Inertial Measurement Units

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    In this paper, a personal micronavigation system that uses high-resolution gait-corrected inertial measurement units is presented. The goal of this paper is to develop a navigation system that uses secondary inertial variables, such as velocity, to enable long-term precise navigation in the absence of Global Positioning System (GPS) and beacon signals. In this scheme, measured zerovelocity duration from the ground reaction sensors is used to reset the accumulated integration errors from accelerometers and gyroscopes in position calculation. With the described system, an average position error of 4 m is achieved at the end of half-hour walks

    Personal Navigation via High-Resolution Gait-Corrected Inertial Measurement Units

    Get PDF
    In this paper, a personal micronavigation system that uses high-resolution gait-corrected inertial measurement units is presented. The goal of this paper is to develop a navigation system that uses secondary inertial variables, such as velocity, to enable long-term precise navigation in the absence of Global Positioning System (GPS) and beacon signals. In this scheme, measured zerovelocity duration from the ground reaction sensors is used to reset the accumulated integration errors from accelerometers and gyroscopes in position calculation. With the described system, an average position error of 4 m is achieved at the end of half-hour walks

    Phase I Study of Ipilimumab Combined with Whole Brain Radiation Therapy or Radiosurgery for Melanoma Patients with Brain Metastases

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    Purpose: We performed a phase I study to determine the maximum tolerable dose (MTD) and safety of ipilimumab with stereotactic radiosurgery (SRS) or whole brain radiotherapy (WBRT) in patients with brain metastases (BM) from melanoma. Methods: Based on intracranial (IC) disease burden, patients were treated with WBRT (Arm A) or SRS (Arm B). Ipilimumab starting dose was 3 mg/kg (every 3 weeks, starting on day 3 of WBRT or 2 days after SRS). Ipilimumab was escalated to 10 mg/kg using a two-stage, 3+3 design. The primary endpoint was to determine the MTD of ipilimumab combined with radiotherapy. Secondary endpoints were overall survival (OS), IC and extracranial (EC) control, progression free survival (PFS), and toxicity. This trial is regis- tered with ClinicalTrials.gov, number NCT01703507. Results: Characteristics of the 16 patients enrolled between 2011 and 2014 were: mean age, 60; median BM, 2 (1 to \u3e10); number with EC disease, 13 (81%). Treatment included WBRT (n=5), SRS (n=11), ipilimumab 3mg/kg (n=7), 10 mg/kg (n=9). Median follow-up was 8 months (Arm A) and 10.5 months (Arm B). There were 21 grade 1-2 neuro- toxic effects with no dose-limiting toxicities (DLTs). One patient experienced grade 3 neurotoxicity prior to ipilimumab administration. Ten additional grade 3 toxicities were reported with gastrointestinal (n=5, 31%) as the most common. There were no grade 4/5 toxicities. Median PFS and OS, respectively, in Arm A were 2.5 months and 8 months, and in Arm B were 2.1 months and not reached. Conclusion: Concurrent ipilimumab 10 mg/kg with SRS is safe. The WBRT arm was closed early due to slow accrual, but demonstrated safety with ipilimumab 3 mg/kg. No patient experienced DLT. Larger studies with ipilimumab 10 mg/kg and SRS are warranted
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