2,380 research outputs found

    Novel Therapeutic Strategies for Alzheimer’s Disease: Prostaglandin D2 Signaling and Its Human Polymorphisms as Well as a Polypharmacological Approach

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    Alzheimer’s disease (AD) is an age related neurodegenerative disease with pathology that includes amyloid plaques, neurofibrillary tangles and non-resolving neuroinflammation. Non-resolving neuroinflammation lasts the entire course of the disease and has deleterious effects and is often thought to accelerate AD pathology. Non-Steroidal Anti-inflammatory Drugs (NSAIDs) have commonly been used as therapeutics to treat pain, inflammation and vascular. NSAIDs work by altering the cyclooxygenase (COX) mediated biosynthesis of prostaglandins which are lipid mediators that have many physiological functions, for example nociception, inflammation and vasodilation. Epidemiological studies support the notion that NSAIDs could be used to treat AD. Yet, clinical trials using NSAIDs have failed repeatedly. Therefore, the effectiveness of NSAIDs is likely counterproductive by blocking the production of neuroprotective as well as neurotoxic prostaglandins. Many people are also intolerant to extended NSAID use shown to increase the risk of other diseases. A more specific approach is necessary to reduce side effects and optimize effectiveness. One such approach that I investigated in the studies reported here, is to target downstream of the COX enzymes, specifically prostaglandin signaling including their receptors. Prostaglandin D2 (PGD2) is particularly of interest because PGD2 is the most abundant prostaglandin in the brain and increases the most under pathological conditions. PGD2 signals through prostaglandin D2 receptor 1 (DP1) and receptor 2 (DP2). Interestingly, PGD2 signaling is well established to be one of the main drivers of inflammation in diseases of airway inflammation. As an alternative to PGD2 signaling to treat AD, I explored a combination drug treatment strategy. AD is a multifactorial disease for which therapeutic efficacy should benefit from a multi-target approach. Thus, I tested a combination treatment with diazoxide (DZ) and dibenzoylmethane (DIB). DZ is a potassium channel activator. DIB restores eIF2B activity, thus reversing stress-induced translational depression. Previous studies examined each drug’s individual therapeutic benefits on attenuating neurodegeneration and apoptosis in other animal model systems. However, their combined treatment potential was not addressed. The overall goal of my studies was to investigate novel therapeutic strategies to treat AD. Thus, I examined novel options to treat AD (1) by targeting PGD2 signaling with timapiprant (TIMA), an antagonist of its DP2 receptor, and (2) by using a co-treatment therapy with DZ and DIB, to investigate a polypharmacology strategy. My hypothesis is that manipulating PGD2 signaling or using a combination DZ/DIB drug treatment will effectively slow down the progression of AD pathology. To test my hypothesis, I used the transgenic TG-AD Fisher 344 rat model of AD (Tg-AD). Tg-AD rats develop multiple hallmarks of AD including plaques, tangles, neuronal loss, neuroinflammation and cognitive deficits in an age-dependent progressive manner that is comparable to human AD. Most of my studies included 11-month old rats, because at this age the Tg-AD rats exhibit most (moderate) of the full AD-pathology (goal 1). Some of my studies (goal 3) also used rats at 4 months of age to be able to compare this pre-pathology stage with the moderate-pathology at 11-month old rats

    Solid-state metathesis reactions under pressure: A rapid route to crystalline gallium nitride

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    High pressure chemistry has traditionally involved applying pressure and increasing temperature until conditions become thermodynamically favorable for phase transitions or reactions to occur. Here, high pressure alone is used as a starting point for carrying out rapid, self-propagating metathesis reactions. By initiating chemical reactions under pressure, crystalline phases, such as gallium nitride, can be synthesized which are inaccessible when initiated from ambient conditions. The single-phase gallium nitride made by metathesis reactions under pressure displays significant photoluminescence intensity in the blue/ultraviolet region. The absence of size or surface-state effects in the photoluminescence spectra show that the crystallites are of micron dimensions. The narrow lines of the x-ray diffraction patterns and scanning electron microscopy confirm this conclusion. Brightly luminescent thin films can be readily grown using pulsed laser deposition

    High plasma leptin levels confer increased risk of atherosclerosis in women with systemic lupus erythematosus, and are associated with inflammatory oxidised lipids.

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    BackgroundPatients with systemic lupus erythematosus (SLE) are at increased risk of atherosclerosis, even after accounting for traditional risk factors. High levels of leptin and low levels of adiponectin are associated with both atherosclerosis and immunomodulatory functions in the general population.ObjectiveTo examine the association between these adipokines and subclinical atherosclerosis in SLE, and also with other known inflammatory biomarkers of atherosclerosis.MethodsCarotid ultrasonography was performed in 250 women with SLE and 122 controls. Plasma leptin and adiponectin levels were measured. Lipoprotein a (Lp(a)), oxidised phospholipids on apoB100 (OxPL/apoB100), paraoxonase, apoA-1 and inflammatory high-density lipoprotein (HDL) function were also assessed.ResultsLeptin levels were significantly higher in patients with SLE than in controls (23.7±28.0 vs 13.3±12.9 ng/ml, p<0.001). Leptin was also higher in the 43 patients with SLE with plaque than without plaque (36.4±32.3 vs 20.9±26.4 ng/ml, p=0.002). After multivariate analysis, the only significant factors associated with plaque in SLE were leptin levels in the highest quartile (≥29.5 ng/ml) (OR=2.8, p=0.03), proinflammatory HDL (piHDL) (OR=12.8, p<0.001), age (OR=1.1, p<0.001), tobacco use (OR=7.7, p=0.03) and hypertension (OR=3.0, p=0.01). Adiponectin levels were not significantly associated with plaque in our cohort. A significant correlation between leptin and piHDL function (p<0.001), Lp(a) (p=0.01) and OxPL/apoB100 (p=0.02) was also present.ConclusionsHigh leptin levels greatly increase the risk of subclinical atherosclerosis in SLE, and are also associated with an increase in inflammatory biomarkers of atherosclerosis such as piHDL, Lp(a) and OxPL/apoB100. High leptin levels may help to identify patients with SLE at risk of atherosclerosis

    1938: Abilene Christian College Bible Lectures - Full Text

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    Delivered in the Auditorium of Abilene Christian College, February, 1938 Abilene, Texas. Published October, 1939 PRICE, $1.00 FIRM FOUNDATION PUBLISHING HOUSE Austin, Texas

    Mitochondrial and nuclear genes suggest that stony corals are monophyletic but most families of stony corals are not (Order Scleractinia, Class Anthozoa, Phylum Cnidaria)

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    Modern hard corals (Class Hexacorallia; Order Scleractinia) are widely studied because of their fundamental role in reef building and their superb fossil record extending back to the Triassic. Nevertheless, interpretations of their evolutionary relationships have been in flux for over a decade. Recent analyses undermine the legitimacy of traditional suborders, families and genera, and suggest that a non-skeletal sister clade (Order Corallimorpharia) might be imbedded within the stony corals. However, these studies either sampled a relatively limited array of taxa or assembled trees from heterogeneous data sets. Here we provide a more comprehensive analysis of Scleractinia (127 species, 75 genera, 17 families) and various outgroups, based on two mitochondrial genes (cytochrome oxidase I, cytochrome b), with analyses of nuclear genes (ßtubulin, ribosomal DNA) of a subset of taxa to test unexpected relationships. Eleven of 16 families were found to be polyphyletic. Strikingly, over one third of all families as conventionally defined contain representatives from the highly divergent "robust" and "complex" clades. However, the recent suggestion that corallimorpharians are true corals that have lost their skeletons was not upheld. Relationships were supported not only by mitochondrial and nuclear genes, but also often by morphological characters which had been ignored or never noted previously. The concordance of molecular characters and more carefully examined morphological characters suggests a future of greater taxonomic stability, as well as the potential to trace the evolutionary history of this ecologically important group using fossils

    Recent Studies in Andean Prehistory and Protohistory: Papers from the Second Annual Northeast Conference on Andean Archaeology and Ethnohistory

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    The contributions in this volume represent nine of the twenty-three papers presented at the Second Annual Northeast Conference on Andean Archaeology and Ethnohistory (NCAAE) held at the American Museum of Natural History on November 19-20, 1983. Papers include The Preceramic and Formative Period Occupations in the Cordillera Negra: Preliminary Report by Michael A. Malpass, The Early Horizon--Early Intermediate Period Transition: A View from the Nepena and Viru Valleys by Richard E. Daggett, Paracas in Chincha and Pisco: A Reappraisal of the Ocucaje Sequence by Dwight T. Wallace, Impressions in Metal: Reconstructing Burial Context at Loma Negra, Peru by Anne-Louise Schaeffer, The Moche Moon by Elizabeth P. Benson, Archaeological Investigation in the Andean Piedmont and High Llanos of Western Venezuela: A Preliminary Report by Charles S. Spencer and Elsa M. Redmond, Pachacamac--An Andean Oracle Under Inca Rule by Thomas C. Patterson, The Spanish League and Inca Sites: A Reassessment of the Itinerary of Juan de Matienzo through N.W. Argentina by Gordon C. Pollard, and Written Sources on Andean Cosmogony by George Kubler.https://digitalcommons.library.umaine.edu/andean_past_special/1001/thumbnail.jp

    1951: Abilene Christian College Bible Lectures - Full Text

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    Delivered in the Auditorium of Abilene Christian College Abilene, Texas February 18-22, 1951 Price, $3.00 FIRM FOUNDATION PUBLISHING HOUSE Austin, Texa

    Were Fertile Crescent crop progenitors higher yielding than other wild species that were never domesticated?

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    During the origin of agriculture in the Fertile Crescent, the broad spectrum of wild plant species exploited by hunter-gatherers narrowed dramatically. The mechanisms responsible for this specialization and the associated domestication of plants are intensely debated. We investigated why some species were domesticated rather than others, and which traits they shared. We tested whether the progenitors of cereal and pulse crops, grown individually, produced a higher yield and less chaff than other wild grasses and legumes, thereby maximizing the return per seed planted and minimizing processing time. We compared harvest traits of species originating from the Fertile Crescent, including those for which there is archaeological evidence of deliberate collection. Unexpectedly, wild crop progenitors in both families had neither higher grain yield nor, in grasses, less chaff, although they did have larger seeds. Moreover, small-seeded grasses actually returned a higher yield relative to the mass of seeds sown. However, cereal progenitors had threefold fewer seeds per plant, representing a major difference in how seeds are packaged on plants. These data suggest that there was no intrinsic yield advantage to adopting large-seeded progenitor species as crops. Explaining why Neolithic agriculture was founded on these species, therefore, remains an important unresolved challenge
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