50 research outputs found

    Discovery of os cordis in the cardiac skeleton of chimpanzees (Pan troglodytes)

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    Cardiovascular diseases, especially idiopathic myocardial fibrosis, is one of the most significant causes of morbidity and mortality in captive great apes. This study compared the structure and morphology of 16 hearts from chimpanzees (Pan troglodytes) which were either healthy or affected by myocardial fibrosis using X-ray microtomography. In four hearts, a single, hyperdense structure was detected within the right fibrous trigone of the cardiac skeleton. High resolution scans and histopathology revealed trabecular bones in two cases, hyaline cartilage in another case and a focus of mineralised fibro-cartilaginous metaplasia with endochondral ossification in the last case. Four other animals presented with multiple foci of ectopic calcification within the walls of the great vessels. All hearts affected by marked myocardial fibrosis presented with bone or cartilage formation, and increased collagen levels in tissues adjacent to the bone/cartilage, while unaffected hearts did not present with os cordis or cartilago cordis. The presence of an os cordis has been described in some ruminants, camelids, and otters, but never in great apes. This novel research indicates that an os cordis and cartilago cordis is present in some chimpanzees, particularly those affected by myocardial fibrosis, and could influence the risk of cardiac arrhythmias and sudden death

    Calcific aortic valve stenosis:hard disease in the heart: A biomolecular approach towards diagnosis and treatment

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    Calcific aortic valve stenosis (CAVS) is common in the ageing population and set to become an increasing economic and health burden. Once present, it inevitably progresses and has a poor prognosis in symptomatic patients. No medical therapies are proven to be effective in holding or reducing disease progression. Therefore, aortic valve replacement remains the only available treatment option. Improved knowledge of the mechanisms underlying disease progression has provided us with insights that CAVS is not a passive disease. Rather, CAVS is regulated by numerous mechanisms with a key role for calcification. Aortic valve calcification (AVC) is actively regulated involving cellular and humoral factors that may offer targets for diagnosis and intervention. The discovery that the vitamin K-dependent proteins are involved in the inhibition of AVC has boosted our mechanistic understanding of this process and has opened up novel avenues in disease exploration. This review discusses processes involved in CAVS progression, with an emphasis on recent insights into calcification, methods for imaging calcification activity, and potential therapeutic options

    Estructura poblacional de Teline monspessulana (L.) K. Koch en fragmentos de bosque maulino en Chile central

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    In this note we examine the population structure of Teline monspessulana, an exotic plant that is invading fragments of theMaulino Forest. We evaluate density T. monspessulana, sizes, proportion of reproductive individuals and his relation withthe size of the patches in 8 forest fragments. Our results indicate a high proportion of individuals growing inside fragments.Moreover, the fragment size is not correlated with T. monspessulana density.In this note we examine the population structure of Teline monspessulana, an exotic plant that is invading fragments of theMaulino Forest. We evaluate density T. monspessulana, sizes, proportion of reproductive individuals and his relation withthe size of the patches in 8 forest fragments. Our results indicate a high proportion of individuals growing inside fragments.Moreover, the fragment size is not correlated with T. monspessulana density

    Estructura poblacional de Pinus radiata D.Don en fragmentos de Bosque Maulino en Chile central

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    Gomez, P (reprint author), Univ Talca, Jardin Bot, Casilla 747, Talca, Chile.Gomez, P (Gomez, Persy); Bustamante, R (Bustamante, Ramiro); San Martin, J (San Martin, Jose); Hahn, S (Hahn, Steffen)In this note we examine the population structure of Pinus radiata, exotic plant that is invading fragments of the Maulino Forest. We evaluate pine density, age, proportion of reproductive individuals across 8 forest fragments. Our results indicate a high proportion of young individuals and reproductive individuals growing inside fragments. Moreover, the fragment size is negatively correlated with pine density but, the proportion of reproductive individuals are not correlated with this landscape attribute. Our result indicate the existence of a pine population that is actively invading forest fragments, a fact that needs to be considered in conservation plans of this native forest

    Photoreactions of 3-Diazo-3H-benzofuran-2-one; Dimerization and Hydrolysis of Its Primary Photoproduct, A Quinonoid Cumulenone: A Study by Time-Resolved Optical and Infrared Spectroscopy

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    Light-induced deazotization of 3-diazo-3H-benzofuran-2-one (1) in solution is accompanied by facile (CO)-O bond cleavage yielding 6-(oxoethenylidene)-2,4-cyclohexadien-1-one (3), which appears with a rise time of 28 ps. The expected Wolff-rearrangement product, 7-oxabicyclo[4.2.0]octa-1,3,5-trien-8-ylidenemethanone (4), is not formed. The efficient light-induced formation of the quinonoid cumulenone 3 opens the way to determine the reactivity of a cumulenone in solution. The reaction kinetics of 3 were monitored by nanosecond flash photolysis with optical (λ max ≈ 460 nm) as well as Raman (1526 cm -1) and IR detection (2050 cm -1). Remarkably, the reactivity of 3 is that expected from its valence isomer, the cyclic carbene 3H-benzofuran-2-one-3-ylidene, 2. In aqueous solution, acid-catalyzed addition of water forms the lactone 3-hydroxy-3H-benzofuran-2-one (5). The reaction is initiated by protonation of the cumulenone on its β-carbon atom. In hexane, cumulenone 3 dimerizes to isoxindigo ((E)-[3,3′ ]bibenzofuranylidene-2,2′-dione, 7), coumestan (6H-benzofuro[3,2-c][1]benzopyran-6-one, 8), and a small amount of dibenzonaphthyrone ([1]benzopyrano[4,3-][1]benzopyran-5,11-dione, 9) at a nearly diffusion-controlled rate. Ab initio calculations (G3) are consistent with the observed data. Carbene 2 is predicted to have a singlet ground state, which undergoes very facile, strongly exothermic (irreversible) ring opening to the cumulenone 3. The calculated barrier to formation of 4 (Wolff-rearrangement) is prohibitive. DFT calculations indicate that protonation of 3 on the β-carbon is accompanied by cyclization to the protonated carbene 2H +, and that dimerization of 3 to 7 and 9 takes place in a single step with negligible activation energy.link_to_subscribed_fulltex
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