Portable optical blood scattering sensor

Modern non-invasive medical sensors can continuously provide vital information such as blood oxygenation, hemoglobin and glucose, based on substance-specific spectral or electrochemical properties. Cells and other geometrical formations are difficult to observe non-invasively due to the absence of a distinctive substantial signature. Optical scattering angle measurements could provide geometrical information but multiple scattering results in diffusion profiles, limiting their direct applicability. Mie scattering correlation to blood cell size has been demonstrated in the lab and various biomedical optical techniques are under intense investigation towards decoupling direct from indirect scattering, requiring specialized equipment. In this paper, a portable sensor is introduced for in-vitro and potentially in-vivo study of light scattering from blood. A microcontroller-based prototype has been designed and fabricated, with a 650 nm laser source, a 128 × 1 photodiode array and a custom dual-core real-time data acquisition algorithm. The prototype has been evaluated using latex sphere solutions calibrated to emulated red blood cells, white blood cells and platelets. Distinct scattering signatures are demonstrated for the three blood cell sizes. Reproducibility and repeatability tests analyzing data from multiple independent experiments demonstrate the reliability of the demonstration. This device platform provides a flexible and simple means for evaluating optical processing methods towards non-invasive continuous counting of blood cells

Mesenchymal Stem Cells in a Transgenic Mouse Model of Multiple System Atrophy: Immunomodulation and Neuroprotection

Mesenchymal stem cells (MSC) are currently strong candidates for cell-based therapies. They are well known for their differentiation potential and immunoregulatory properties and have been proven to be potentially effective in the treatment of a large variety of diseases, including neurodegenerative disorders. Currently there is no treatment that provides consistent long-term benefits for patients with multiple system atrophy (MSA), a fatal late onset α-synucleinopathy. Principally neuroprotective or regenerative strategies, including cell-based therapies, represent a powerful approach for treating MSA. In this study we investigated the efficacy of intravenously applied MSCs in terms of behavioural improvement, neuroprotection and modulation of neuroinflammation in the (PLP)-αsynuclein (αSYN) MSA model.MSCs were intravenously applied in aged (PLP)-αSYN transgenic mice. Behavioural analyses, defining fine motor coordination and balance capabilities as well as stride length analysis, were performed to measure behavioural outcome. Neuroprotection was assessed by quantifying TH neurons in the substantia nigra pars compacta (SNc). MSC treatment on neuroinflammation was analysed by cytokine measurements (IL-1α, IL-2, IL-4, IL-5, IL-6, IL-10, IL-17, GM-CSF, INFγ, MCP-1, TGF-β1, TNF-α) in brain lysates together with immunohistochemistry for T-cells and microglia. Four weeks post MSC treatment we observed neuroprotection in the SNc, as well as downregulation of cytokines involved in neuroinflammation. However, there was no behavioural improvement after MSC application.To our knowledge this is the first experimental approach of MSC treatment in a transgenic MSA mouse model. Our data suggest that intravenously infused MSCs have a potent effect on immunomodulation and neuroprotection. Our data warrant further studies to elucidate the efficacy of systemically administered MSCs in transgenic MSA models

Design of an embedded sensor system for measuring laser scattering on blood cells

In this paper, a sensor system architecture for laboratory and in-vivo light scattering studies on blood cells is presented. It aims at correlating Mie scattering to compositional and physiological information of blood cells towards a non-invasive blood-cell counting sensor. An overview of previously reported experimental techniques on light scattering from blood cells is presented. State-of-the-art methods such as differential pulse measurements, vessel pressure optimization identified as promising for enhancing the scattering signal in such measurements. Indicative simulations of Mie scattering by blood cells are presented, illustrating the potential for distinguishing among cells and identifying size distribution. A prototype sensor system based on a 640-660 nm laser light source and a photo diode array is implemented and programmed to obtain mean amplitude and scattering angle measurements

Electrochemical Single-Molecule Detection in Aqueous Solution Using Self-Aligned Nanogap Transducers

Electrochemical detection of individual molecular tags in nanochannels may enable cost-effective, massively parallel analysis and diagnostics platforms. Here we demonstrate single-molecule detection of prototypical analytes in aqueous solution based on redox cycling in 40 nm nanogap transducers. These nanofluidic devices are fabricated using standard microfabrication techniques combined with a self-aligned approach that minimizes gap size and dead volume. We demonstrate the detection of three common redox mediators at physiological salt concentrations

Health-related quality of life in multiple system atrophy

Although multiple system atrophy (MSA) is a neurodegenerative disorder leading to progressive disability and decreased life expectancy, little is known about patients' own evaluation of their illness and factors associated with poor health-related quality of life (Hr-QoL). We, therefore, assessed Hr-QoL and its determinants in MSA. The following scales were applied to 115 patients in the European MSA-Study Group (EMSA-SG) Natural History Study: Medical Outcome Study Short Form (SF-36), EQ-513, Beck Depression Inventory (BDI), Mini-Mental state examination (MMSE), Unified MSA Rating Scale (UMSARS), Hoehn & Yahr (H&Y) Parkinson's disease staging scale, Composite Autonomic Symptom Scale (COMPASS), and Parkinson's Disease Sleep Scale (PDSS). Forty-six percent of patients had moderate to severe depression (BDI >= 17); Hr-QoL scores on the SF-36 and EQ-5D were significantly impaired. Pain, the only domain with similar scores in MSA and published PD patients, was reported more frequently in patients with MSA-P (predominantly parkinsonian motor subtype) than MSA-C (predominantly cerebellar motor subtype; 76% vs. 50%; P = 0.005). Hr-QoL scores correlated most strongly with UMSARS motor, COMPASS, and BDI scores but not with MMSE scores, age at onset, or disease duration. The COMPASS and UMSARS activities of daily living scores were moderate-to-strong predictors for the SF-36 physical summary score and the BDI and UMSARS motor scores for the SF-36 mental summary score. This report is the first study to show that Hr-QoL is significantly impaired in MSA. Although not all possible factors related to impaired Hr-QoL in MSA could be assessed, autonomic dysfunction, motor impairment, and depression were most closely associated with poor Hr-QoL, and therapeutic management, therefore, should concentrate upon these aspects of the disease. (c) 2006 Movement Disorder Society