617 research outputs found

    Lonchiphyllum aplospermum gen. et sp. nov.: An Anatomically Preserved Glossopterid Megasporophyll from the Upper Permian of Skaar Ridge, Transantarctic Mountains, Antarctica

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    A new anatomically preserved megasporophyll, Lonchiphyllum aplospermum, is described from permineralized peat collected on Skaar Ridge in the central Transantarctic Mountains. This new genus contains vascular features similar to those of the leaf genus Glossopteris schopfii, which is the exclusive leaf genus in the specimens in which the sporophylls were found. The vasculature of the sporophyll consists of a central vascular region with bordered pitting and anastomosing lateral bundles with helical-scalariform thickenings. Ovules are attached oppositely to suboppositely to lateral veins on the adaxial surface of the sporophyll. There is an abundance of bisaccate pollen of the Protohaploxypinus type at the base of the ovules. The ovules of Lonchiphyllum are small (1.1 mm × 0.97 mm) and ovate and have an unornamented integument. Comparison with anatomically known ovules from Skaar Ridge, i.e., Plectilospermum elliotii, Choanostoma verruculosum, and Lakkosia kerasata and Homevaleia gouldii from the Bowen Basin of Australia, supports the classification of Lonchiphyllum as a glossopterid. The differences in the sarcotesta and sclerotesta of all the Skaar Ridge ovules may indicate specialization for pollination or dispersal

    The First Permineralized Microsporophyll of the Glossopteridales: Eretmonia macloughlinii sp. nov.

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    This is the publisher's version, which has been made available with permission of the publisher. The original version may be found at the following link: http://dx.doi.org/10.1086/666667Eretmonia du Toit is a microsporophyll genus attributed to the Permian Glossopteridales. Microsporophylls are scale leaves (smaller leaves with morphology similar to that of Glossopteris leaves) that bear clusters of sporangia at the end of stalks attached to the petiole of the sporophyll. Late Permian permineralized specimens of Eretmonia from the central Transantarctic Mountains in Antarctica reveal the first anatomical information of the genus. Numerous veins run the length of the petiole and alternate with large canals/air spaces; the veins and canals are separated by increasing amounts of parenchyma. The ground tissue of the leaves is composed of isodiametric parenchyma of varying diameters. Beneath the epidermis is a hypodermis two to three layers thick. Pollen sac walls are a single layer thick with a tapered apex and bulbous base. The simplicity of the bisaccate pollen grains does not suggest a specialized form of pollination but rather that the glossopterids were wind pollinated

    Evolution of the Toxins Muscarine and Psilocybin in a Family of Mushroom-Forming Fungi

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    Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography–tandem mass spectrometry (LC–MS/MS) to determine whether muscarine was present in 30 new samples of Inocybaceae, the majority of which have not been previously assayed or that originated from either the tropics or temperate regions of the southern hemisphere. Our main objective is to test the hypothesis that the presence of muscarine is a shared ancestral feature of the Inocybaceae. In addition, we also test whether species of Inocyabceae that produce psilocybin are monophyletic. Our findings suggest otherwise. Muscarine has evolved independently on several occasions, together with several losses. We also detect at least two independent transitions of muscarine-free lineages to psilocybin-producing states. Although not ancestral for the family as a whole, muscarine is a shared derived trait for an inclusive clade containing three of the seven major lineages of Inocybaceae (the Inocybe, Nothocybe, and Pseudosperma clades), the common ancestor of which may have evolved ca. 60 million years ago. Thus, muscarine represents a conserved trait followed by several recent losses. Transitions to psilocybin from muscarine-producing ancestors occurred more recently between 10–20 million years ago after muscarine loss in two separate lineages. Statistical analyses firmly reject a single origin of muscarine-producing taxa. DOI: 10.1371/journal.pone.006464

    Evolution of the Toxins Muscarine and Psilocybin in a Family of Mushroom-Forming Fungi

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    Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography–tandem mass spectrometry (LC–MS/MS) to determine whether muscarine was present in 30 new samples of Inocybaceae, the majority of which have not been previously assayed or that originated from either the tropics or temperate regions of the southern hemisphere. Our main objective is to test the hypothesis that the presence of muscarine is a shared ancestral feature of the Inocybaceae. In addition, we also test whether species of Inocyabceae that produce psilocybin are monophyletic. Our findings suggest otherwise. Muscarine has evolved independently on several occasions, together with several losses. We also detect at least two independent transitions of muscarine-free lineages to psilocybin-producing states. Although not ancestral for the family as a whole, muscarine is a shared derived trait for an inclusive clade containing three of the seven major lineages of Inocybaceae (the Inocybe, Nothocybe, and Pseudosperma clades), the common ancestor of which may have evolved ca. 60 million years ago. Thus, muscarine represents a conserved trait followed by several recent losses. Transitions to psilocybin from muscarine-producing ancestors occurred more recently between 10–20 million years ago after muscarine loss in two separate lineages. Statistical analyses firmly reject a single origin of muscarine-producing taxa. DOI: 10.1371/journal.pone.006464

    l-α-Lysophosphatidylinositol (LPI) aggravates myocardial ischemia/reperfusion injury via a GPR55/ROCK-dependent pathway

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    The phospholipid l-α-lysophosphatidylinositol (LPI), an endogenous ligand for GPR55, is elevated in patients with acute coronary syndrome, and a GPR55 antagonist cannabidiol (CBD) reduces experimental ischemia/reperfusion (I/R) injury. While LPI activates multiple signaling pathways, little is known about which ones are important in cardiomyocytes. In this study we explored whether activation of the Rho kinase/ROCK/p38 MAPK pathway is responsible for LPI-induced extension of I/R injury. Using a high-throughput screening method (dynamic mass redistribution; DMR), mouse- and human-induced pluripotent stem cell (iPSC) cardiomyocytes exposed to LPI were shown to exhibit a rapid, sustained, and concentration‐dependent (1 nmol L−1‐30 μmol L−1) cellular response. Y‐27632 (ROCK inhibitor; 10 & 50 μmol L−1) and CBD (1 μmol L−1) both abolished the DMR response to LPI (10 μmol L−1). In murine iPSC cardiomyocytes, LPI-induced ROCK and p38 MAPK phosphorylation, both of which were prevented by Y-27632 and CBD, but did not induce JNK activation or cleavage of caspase-3. In hearts isolated from wild type (WT) mice subjected to 30 minutes global I/R, LPI (10 μmol L−1) administered via the coronary circulation increased infarct size when applied prior to ischemia onset, but not when given at the time of reperfusion. The exacerbation of tissue injury by LPI was not seen in hearts from GPR55−/− mice or in the presence of Y-27632, confirming that injury is mediated via the GPR55/ROCK/p38 MAPK pathway. These findings suggest that raised levels of LPI in the vicinity of a developing infarct may worsen the outcome of AMI

    Allele diversity of the H-ras-1 variable number of tandem repeats in Norwegian lung cancer patients

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    We have examined restriction fragment length polymorphisms of the H-ras-1 gene in germ-line DNA from 214 lung cancer patients and 309 unaffected controls. When DNA samples were digested with MspI/HpaII, Southern blot analysis revealed at least 22 different alleles, grouped according to their frequencies as common, intermediate, and rare. The frequency of rare alleles in lung cancer patients (16/428) is significantly different (p = 0.002) from that in the control group (5/618). Individuals with rare alleles were found to be at 4.7-fold greater risk of lung cancer than those with no rare alleles.publishedVersio

    Detection of signal recognition particle (SRP) RNAs in the nuclear ribosomal internal transcribed spacer 1 (ITS1) of three lineages of ectomycorrhizal fungi (Agaricomycetes, Basidiomycota)

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    During a routine scan for Signal Recognition Particle (SRP) RNAs in eukaryotic sequences, we surprisingly found in silico evidence in GenBank for a 265-base long SRP RNA sequence in the ITS1 region of a total of 11 fully identified species in three ectomycorrhizal genera of the Basidiomycota (Fungi): Astraeus, Russula, and Lactarius. To rule out sequence artifacts, one specimen from a species indicated to have the SRP RNA-containing ITS region in each of these genera was ordered and re-sequenced. Sequences identical to the corresponding GenBank entries were recovered, or in the case of a non-original but conspecific specimen differed by three bases, showing that these species indeed have an SRP RNA sequence incorporated into their ITS1 region. Other than the ribosomal genes, this is the first known case of non-coding RNAs in the eukaryotic ITS region, and it may assist in the examination of other types of insertions in fungal genomes.RHN acknowledges financial support from FORMAS (215-2011- 498) and from Stiftelsen Olle Engkvist Byggmästare. MPM was partially supported by Plan Nacional I+D+i project CGL2012-35559. CW acknowledges a Marie Skłodowska-Curie post doc grant (660122, CRYPTRANS)Peer reviewe

    Pharmacological profiling of the hemodynamic effects of cannabinoid ligands: a combined in vitro and in vivo approach.

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    The receptors mediating the hemodynamic responses to cannabinoids are not clearly defined due to the multifarious pharmacology of many commonly used cannabinoid ligands. While both CB1 and TRPV1 receptors are implicated, G protein-coupled receptor 55 (GPR55) may also mediate some of the hemodynamic effects of several atypical cannabinoid ligands. The present studies attempted to unravel the pharmacology underlying the in vivo hemodynamic responses to ACEA (CB1 agonist), O-1602 (GPR55 agonist), AM251 (CB1 antagonist), and cannabidiol (CBD; GPR55 antagonist). Agonist and antagonist profiles of each ligand were determined by ligand-induced GTPcS binding in membrane preparations expressing rat and mouse CB1 and GPR55 receptors. Blood pressure responses to ACEA and O-1602 were recorded in anesthetized and conscious mice (wild type, CB1 / and GPR55 / ) and rats in the absence and presence of AM251 and CBD. ACEA demonstrated GTPcS activation at both receptors, while O-1602 only activated GPR55. AM251 exhibited antagonist activity at CB1 and agonist activity at GPR55, while CBD demonstrated selective antagonist activity at GPR55. The depressor response to ACEA was blocked by AM251 and attenuated by CBD, while O-1602 did not induce a depressor response. AM251 caused a depressor response that was absent in GPR55 / mice but enhanced by CBD, while CBD caused a small vasodepressor response that persisted in GPR55 / mice. Our findings show that assessment of the pharmacological profile of receptor activation by cannabinoid ligands in in vitro studies alongside in vivo functional studies is essential to understand the role of cannabinoids in hemodynamic control

    Topical and Systemic Cannabidiol Improves Trinitrobenzene Sulfonic Acid Colitis in Mice

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    Background/Aims: Compounds of Cannabis sativa are known to exert anti-inflammatory properties, some of them without inducing psychotropic side effects. Cannabidiol (CBD) is such a side effect-free phytocannabinoid that improves chemically induced colitis in rodents when given intraperitoneally. Here, we tested the possibility whether rectal and oral application of CBD would also ameliorate colonic inflammation, as these routes of application may represent a more appropriate way for delivering drugs in human colitis. Methods: Colitis was induced in CD1 mice by trinitrobenzene sulfonic acid. Individual groups were either treated with CBD intraperitoneally (10 mg/kg), orally (20 mg/kg) or intrarectally (20 mg/kg). Colitis was evaluated by macroscopic scoring, histopathology and the myeloperoxidase (MPO) assay. Results: Intraperitoneal treatment of mice with CBD led to improvement of colonic inflammation. Intrarectal treatment with CBD also led to a significant improvement of disease parameters and to a decrease in MPO activity while oral treatment, using the same dose as per rectum, had no ameliorating effect on colitis. Conclusion: The data of this study indicate that in addition to intraperitoneal application, intrarectal delivery of cannabinoids may represent a useful therapeutic administration route for the treatment of colonic inflammation. Copyright (C) 2012 S. Karger AG, Base
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