39 research outputs found

    Use of fuzzy edge single-photon emission computed tomography analysis in definite Alzheimer's disease - a retrospective study

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    <p>Abstract</p> <p>Background</p> <p>Definite Alzheimer's disease (AD) requires neuropathological confirmation. Single-photon emission computed tomography (SPECT) may enhance diagnostic accuracy, but due to restricted sensitivity and specificity, the role of SPECT is largely limited with regard to this purpose.</p> <p>Methods</p> <p>We propose a new method of SPECT data analysis. The method is based on a combination of parietal lobe selection (as regions-of-interest (ROI)), 3D fuzzy edge detection, and 3D watershed transformation. We applied the algorithm to three-dimensional SPECT images of human brains and compared the number of watershed regions inside the ROI between AD patients and controls. The Student's two-sample t-test was used for testing domain number equity in both groups.</p> <p>Results</p> <p>AD patients had a significantly reduced number of watershed regions compared to controls (<it>p </it>< 0.01). A sensitivity of 94.1% and specificity of 80% was obtained with a threshold value of 57.11 for the watershed domain number. The narrowing of the SPECT analysis to parietal regions leads to a substantial increase in both sensitivity and specificity.</p> <p>Conclusions</p> <p>Our non-invasive, relatively low-cost, and easy method can contribute to a more precise diagnosis of AD.</p

    Gene therapy for carcinoma of the breast: Genetic ablation strategies

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    The gene therapy strategy of mutation compensation is designed to rectify the molecular lesions that are etiologic for neoplastic transformation. For dominant oncogenes, such approaches involve the functional knockout of the dysregulated cellular control pathways provoked by the overexpressed oncoprotein. On this basis, molecular interventions may be targeted to the transcriptional level of expression, via antisense or ribozymes, or post-transcriptionally, via intracellular single chain antibodies (intrabodies). For carcinoma of the breast, these approaches have been applied in the context of the disease linked oncogenes erbB-2 and cyclin D(1), as well as the estrogen receptor. Neoplastic revision accomplished in modal systems has rationalized human trials on this basis

    Global Analysis of Proline-Rich Tandem Repeat Proteins Reveals Broad Phylogenetic Diversity in Plant Secretomes

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    Cell walls, constructed by precisely choreographed changes in the plant secretome, play critical roles in plant cell physiology and development. Along with structural polysaccharides, secreted proline-rich Tandem Repeat Proteins (TRPs) are important for cell wall function, yet the evolutionary diversity of these structural TRPs remains virtually unexplored. Using a systems-level computational approach to analyze taxonomically diverse plant sequence data, we identified 31 distinct Pro-rich TRP classes targeted for secretion. This analysis expands upon the known phylogenetic diversity of extensins, the most widely studied class of wall structural proteins, and demonstrates that extensins evolved before plant vascularization. Our results also show that most Pro-rich TRP classes have unexpectedly restricted evolutionary distributions, revealing considerable differences in plant secretome signatures that define unexplored diversity

    Abrasive, Silica Phytoliths and the Evolution of Thick Molar Enamel in Primates, with Implications for the Diet of Paranthropus boisei

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    Background: Primates—including fossil species of apes and hominins—show variation in their degree of molar enamel thickness, a trait long thought to reflect a diet of hard or tough foods. The early hominins demonstrated molar enamel thickness of moderate to extreme degrees, which suggested to most researchers that they ate hard foods obtained on or near the ground, such as nuts, seeds, tubers, and roots. We propose an alternative hypothesis—that the amount of phytoliths in foods correlates with the evolution of thick molar enamel in primates, although this effect is constrained by a species ’ degree of folivory. Methodology/Principal Findings: From a combination of dietary data and evidence for the levels of phytoliths in plant families in the literature, we calculated the percentage of plant foods rich in phytoliths in the diets of twelve extant primates with wide variation in their molar enamel thickness. Additional dietary data from the literature provided the percentage of each primate’s diet made up of plants and of leaves. A statistical analysis of these variables showed that the amount of abrasive silica phytoliths in the diets of our sample primates correlated positively with the thickness of their molar enamel, constrained by the amount of leaves in their diet (R 2 = 0.875; p,.0006). Conclusions/Significance: The need to resist abrasion from phytoliths appears to be a key selective force behind the evolution of thick molar enamel in primates. The extreme molar enamel thickness of the teeth of the East African homini

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    Neuroimaging in dementia.

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    Dementia is one of the most quickly expanding topics in psychiatric research, while remaining the most frustrating condition to treat. Over the past decade, the genetics and pathophysiology of certain dementias, especially dementia of the Alzheimer type, have been increasingly clarified. However, the treatment of this condition lags far behind its basic research. Although a number of approaches have been explored, from acetylcholinesterase inhibitors to amyloid vaccinations, the results have been disappointing (Broytman and Malter, 2004; Courtney et al., 2004; Ritchie et al., 2004; Robinson et al., 2004). Neuroimaging has been used in basic clinical research, for diagnostic purposes, or using dementia as a paradigm for local brain lesions to examine normal and disturbed cognitive performance and brain function in parallel. This review will try to give a brief summary of each of these approaches. © 2005 Elsevier Inc. All rights reserved

    Unilateral voluntary hand movement and regional cerebral uptake of technetium-99m-exametazime in human control subjects.

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    The study examines the sensitivity of a region of interest approach to detect functional changes in brain metabolism with SPECT and split-dose 99mTc-exametazime by replicating a simple hand movement experiment previously carried out with PET. Regional uptake of 99mTc-exametazime was determined in 12 healthy controls before and during a thumb-digit opposition task. Analysis of regional uptake was carried out blind to the hand used in the opposition task and showed a significant unilateral activation effect in a pericentral region of interest with opposite results in left- and right-handed activation. The maximum contralateral increase in tracer uptake was 16% before and 26% after correction for back diffusion. This is in good agreement with previous results employing absolute cerebral blood flow determination with PET and confirms the usefulness of 99mTc-exametazime SPECT for the examination of functional metabolic changes
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