Origin, divergence, and phylogeny of epichloe endophytes of native Argentine grasses

The epichlo? endophytes are systemic, constitutive, and often vertically transmitted fungal symbionts of grass species in subfamily Po?ideae. Prior studies indicate that several asexual epichlo? endophytes (Neotyphodium species) have evolved directly from sexual (Epichlo?) species, whereas others evolved by hybridization between two or more endophyte species. In this paper, we investigate the phylogenies of 27 Neotyphodium spp. isolates from 10 native grass species (in 4 tribes) in 22 populations throughout Argentina. Relationships among these fungi and a worldwide collection of epichlo? endophytes were estimated by phylogenetic analysis of sequences from variable portions (mainly introns) of genes for beta-tubulin (tub2) and translation elongation factor 1-alpha (tef1). Most of the Argentine endophyte isolates were interspecific hybrids of Epichlo? festucae and E. typhina. Only one isolate was a hybrid of a different ancestry, and three isolates were apparently non-hybrid endophytes. These results indicate that interspecific hybridization, which promotes genetic variation, was common during the evolution of the endophytes of Argentine grasses.     

Linking tricyclic antidepressants to ionotropic glutamate receptors

Although tricyclic antidepressants have been in existence since the 1940s when they were discovered upon screening iminodibenzyl derivatives for other potential therapeutic uses, their mechanism of action has remained unclear [A. Goodman Gilman, T.W. Rall, A.S. Nies, P. Taylor, Goodman and Gilman's The Pharmacological Basis of Therapeutics, eighth ed., Pergamon Press, New York, 1990]. In addition to their ability to hinder the reuptake of biogenic amines, there is mounting evidence that the tricyclic antidepressants inhibit glutamate transmission. Here, intrinsic tryptophan fluorescence spectroscopy is used to document the binding of desipramine, a member of the tricyclic antidepressant family, to a well-defined extracellular glutamate binding domain (S1S2) of the GluR2 subunit of the amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor. The binding is distinct from those of other known effectors of the receptor, including the endogenous sulfated neurosteroids pregnenolone sulfate and 3alpha-hydroxy-5beta-pregnan-20-one sulfate, and is consistent with a conformational change upon binding that is allosterically transmitted to the channel region of the receptor.     

Noradrenergic responses of peripheral organs to cyclophosphamide in mice

To determine if the chemotherapeutic drug cyclophosphamide influences the activity of the sympathetic nervous system, the effects of cyclophosphamide on norepinephrine concentration in the heart, adrenal gland, spleen, and thymus gland were evaluated. Male BALB/cByJ mice were administered a single injection of cyclophosphamide (15, 50, or 100 mg/kg, i.p) or saline-vehicle. Organs were collected 72 or 120 h after injection and norepinephrine concentrations were determined by high pressure liquid chromatography with electrochemical detection. Cyclophosphamide reduced spleen, thymus gland, and heart mass while also elevating spleen and thymus gland norepinephrine concentrations (both pmoles/mg tissue and pmoles/mg protein) in a dose- and time-dependent manner. Norepinephrine concentrations in heart and adrenal gland were not altered by cyclophosphamide at any drug dose or time point. Dose- and time-dependent cyclophosphamide-mediated changes in peripheral norepinephrine levels in the spleen and thymus gland are interesting because subjects administered cyclophosphamide may be more susceptible to opportunistic infections, not only because the drug is antineoplastic, but also because the drug alters nervous system-immune system communication and the neurochemical milieu in which surviving cells interact.     

The strange association between achondroplasia and neurofibromatosis type 1: molecular analysis of a new patient and review of the literature

The association between Achondroplasia and Neurofibromatosis type 1 has been described in only three patients. We report the clinical features and molecular characterization of a new patient with de novo ACH and NF1, providing for the first time a detailed clinical and molecular evaluation. Even if this association seems coincidental, some startling, intriguing correlations are discussed at the clinical and molecular level, between ACH, NF, and the existence of a common "mutator" genotype.     

Microsatellite markers help to assess genetic diversity among Opuntia ficus indica cultivated genotypes and their relation with related species

Opuntia spp. belong to the Cactaceae family and are native to Central America. The most economically important species is O. ficus indica, cultivated both for fruits and cladodes. The genus includes other important edible species (from diploid to octoploid) that occur worldwide as either wild or cultivated species in many arid or semiarid areas (e.g., the Mediterranean region). Several accessions are cultivated in different growing regions, but little is known about their ancestries and levels of genetic diversity. The aim of this study was to investigate the level of intraspecific genetic diversity among O. ficus indica cultivated varieties and some related species. Specifically, six highly polymorphic simple sequence repeats (SSR) and two expressed sequence tag (EST)-SSR loci were investigated in 62 wild and cultivated genotypes belonging to 16 Opuntia species. The clusters identified by the distance and model-based analyses clearly separated the wild opuntias from the cultivated ones. However, the O. ficus indica accessions did not cluster separately from other arborescent cactus pear species, such as O. amyclaea, O. megacantha, O. streptacantha, O. fusicaulis, and O. albicarpa, indicating that their current taxonomical classifications do not fit with their genetic variability. In general, the genotypes cultivated in Mexico showed high levels of diversity, whereas most of the spineless accessions collected in other countries had a very narrow genetic base. This study increases our knowledge of the variability among some of the most diffused Opuntia cultivated accessions. This study also points to the inconsistencies of previous taxonomical genotype assignments that were based solely on morphological characteristics.     

Evaluation of nutrient digestibility and fecal characteristics of exotic felids fed horse‐ or beef‐based diets: use of the domestic cat as a model for exotic felids

The objective of this study was to determine the effects of feeding commercially available beef‐ and horse‐based diets on nutrient digestibility and fecal characteristics of large captive exotic felids and domestic cats. Four species of large exotic felids including cheetahs, Malayan tigers, jaguars, and Amur tigers, and domestic cats were utilized in a crossover design. Raw meat diets included a beef‐based diet (57% protein; 28% fat) and a horse‐based diet (51% protein; 30% fat). All cats were acclimated to the diet for 16 days followed by a 4 day collection period, where total feces, including one fresh sample, were collected. All feces were scored on collection. Intake did not differ due to diet, but fecal output was greater when cats consumed the horse‐based diet. Total tract apparent dry matter (DM) digestibility was higher (P<0.05) and organic matter (OM) and crude protein (CP) digestibilities were lower (P<0.05) when cats were fed the beef‐based diet compared with the horse‐based diet. CP digestibility was similar in domestic cats and cheetahs, and greater (P<0.05) than Amur tigers. Fecal scores were lower and fecal DM was greater (P<0.05) when cats consumed the horse‐based diet compared with the beef‐based diet. Domestic cats had lower (P<0.05) fecal ammonia concentrations compared with all other species. Fecal ammonia concentrations were lowest (P<0.05) when cats were fed the horse‐based diet. Fecal total short‐chain fatty acid (SCFA), branched‐chain fatty acid (BCFA), and butyrate concentrations were higher (P<0.05) when cats consumed the beef‐based diet. Our results suggest that the domestic cat serves as an appropriate model for large exotic felid species, but differences among the species exist. Decreased nutrient digestibility by tigers and jaguars should be considered when developing feeding recommendations for these species based on domestic cat data. Zoo Biol 29:432–448, 2010. © 2009 Wiley‐Liss, Inc.     

Deletion of ripA alleviates suppression of the inflammasome and MAPK by Francisella tularensis

Francisella tularensis is a facultative intracellular pathogen and potential biothreat agent. Evasion of the immune response contributes to the extraordinary virulence of this organism although the mechanism is unclear. Whereas wild-type strains induced low levels of cytokines, an F. tularensis ripA deletion mutant (LVSΔripA) provoked significant release of IL-1β, IL-18, and TNF-α by resting macrophages. IL-1β and IL-18 secretion was dependent on inflammasome components pyrin-caspase recruitment domain/apoptotic speck-containing protein with a caspase recruitment domain and caspase-1, and the TLR/IL-1R signaling molecule MyD88 was required for inflammatory cytokine synthesis. Complementation of LVSΔripA with a plasmid encoding ripA restored immune evasion. Similar findings were observed in a human monocytic line. The presence of ripA nearly eliminated activation of MAPKs including ERK1/2, JNK, and p38, and pharmacologic inhibitors of these three MAPKs reduced cytokine induction by LVSΔripA. Animals infected with LVSΔripA mounted a stronger IL-1β and TNF-α response than that of mice infected with wild-type live vaccine strain. This analysis revealed novel immune evasive mechanisms of F. tularensis.     

Proteomic insights into an expanded cellular role for cytoplasmic lipid droplets

Cytoplasmic lipid droplets (CLDs) are cellular structures composed of a neutral lipid core surrounded by a phospholipid monolayer of amphipathic lipids and a variety of proteins. CLDs have classically been regarded as cellular energy storage structures. However, recent proteomic studies reveal that, although many of the proteins found to associate with CLDs are connected to lipid metabolism, storage, and homeostasis, there are also proteins with no obvious connection to the classical function and typically associated with other cellular compartments. Such proteins are termed refugee proteins, and their presence suggests that CLDs may serve an expanded role as a dynamic protein storage site, providing a novel mechanism for the regulation of protein function and transport.     

The in vitro effect of a lyophilized extract of wine obtained from Jacquez grapes on human chondrocytes

The present work was aimed at evaluating the in vitro effects of a lyophilized extract of wine (JW-E) obtained from Jacquez grapes (Vitis aestivalis-cinereaxVitis vinifera grapes) on the production of key molecules released in inflammatory disease utilising interleukin-1beta (IL-1beta) activated chondrocytes. The extract contains large amounts of phenolic components, in particular some flavonoids (flavan-3-ols, also known as catechins) and proanthocyanidins, as hydroxycinnamic acids and anthocyanins, that possess several biological features such as antiinflammatory and antioxidant effects and a "radical scavenger" activity too. In this study, we assayed the effect of JW-E on the production of key molecules released during chronic inflammatory events as nitric oxide (NO), prostaglandins E(2) (PGE(2)) and reactive oxygen species (ROS) in human chondrocytes culture, stimulated with proinflammatory cytokine interleukin-1beta. The JW-E proved to possess good ability against the harmfull effects of IL-1beta. Our data showed the protective effects of JW-E in cartilage alteration, that appears greater than that elicited by indomethacin, a not steroidal antiinflammatory drug (NSAID), commonly employed in joint diseases.