Bioactive Endophytes Warrant Intensified Exploration and Conservation

A key argument in favor of conserving biodiversity is that as yet undiscovered biodiversity will yield products of great use to humans. However, the link between undiscovered biodiversity and useful products is largely conjectural. Here we provide direct evidence from bioassays of endophytes isolated from tropical plants and bioinformatic analyses that novel biology will indeed yield novel chemistry of potential value.We isolated and cultured 135 endophytic fungi and bacteria from plants collected in Peru. nrDNAs were compared to samples deposited in GenBank to ascertain the genetic novelty of cultured specimens. Ten endophytes were found to be as much as 15–30% different than any sequence in GenBank. Phylogenetic trees, using the most similar sequences in GenBank, were constructed for each endophyte to measure phylogenetic distance. Assays were also conducted on each cultured endophyte to record bioactivity, of which 65 were found to be bioactive.The novelty of our contribution is that we have combined bioinformatic analyses that document the diversity found in environmental samples with culturing and bioassays. These results highlight the hidden hyperdiversity of endophytic fungi and the urgent need to explore and conserve hidden microbial diversity. This study also showcases how undergraduate students can obtain data of great scientific significance

Leishmanicidal Metabolites from Cochliobolus sp., an Endophytic Fungus Isolated from Piptadenia adiantoides (Fabaceae)

Protozoan parasites belonging to genera Leishmania and Trypanosoma are the etiological agents of severe neglected tropical diseases (NTDs) that cause enormous social and economic impact in many countries of tropical and sub-tropical areas of the world. In our screening program for new drug leads from natural sources, we found that the crude extract of the endophytic fungus Cochliobolus sp. (UFMGCB-555) could kill 90% of the amastigote-like forms of Leishmania amazonensis and inhibit by 100% Ellman's reagent reduction in the trypanothione reductase (TryR) assay, when tested at 20 µg mL−1. UFMGCB-555 was isolated from the plant Piptadenia adiantoides J.F. Macbr (Fabaceae) and identified based on the sequence of the internally transcribed spacer (ITS) regions of its ribosomal DNA. The chromatographic fractionation of the extract was guided by the TryR assay and resulted in the isolation of cochlioquinone A and isocochlioquinone A. Both compounds were active in the assay with L. amazonensis, disclosing EC50 values (effective concentrations required to kill 50% of the parasite) of 1.7 µM (95% confidence interval = 1.6 to 1.9 µM) and 4.1 µM (95% confidence interval = 3.6 to 4.7 µM), respectively. These compounds were not active against three human cancer cell lines (MCF-7, TK-10, and UACC-62), indicating some degree of selectivity towards the parasites. These results suggest that cochlioquinones are attractive lead compounds that deserve further investigation aiming at developing new drugs to treat leishmaniasis. The findings also reinforce the role of endophytic fungi as an important source of compounds with potential to enter the pipeline for drug development against NTDs

Ultrasound-guided diagnostic breast biopsy methodology: retrospective comparison of the 8-gauge vacuum-assisted biopsy approach versus the spring-loaded 14-gauge core biopsy approach

<p>Abstract</p> <p>Background</p> <p>Ultrasound-guided diagnostic breast biopsy technology represents the current standard of care for the evaluation of indeterminate and suspicious lesions seen on diagnostic breast ultrasound. Yet, there remains much debate as to which particular method of ultrasound-guided diagnostic breast biopsy provides the most accurate and optimal diagnostic information. The aim of the current study was to compare and contrast the 8-gauge vacuum-assisted biopsy approach and the spring-loaded 14-gauge core biopsy approach.</p> <p>Methods</p> <p>A retrospective analysis was done of all ultrasound-guided diagnostic breast biopsy procedures performed by either the 8-gauge vacuum-assisted biopsy approach or the spring-loaded 14-gauge core biopsy approach by a single surgeon from July 2001 through June 2009.</p> <p>Results</p> <p>Among 1443 ultrasound-guided diagnostic breast biopsy procedures performed, 724 (50.2%) were by the 8-gauge vacuum-assisted biopsy technique and 719 (49.8%) were by the spring-loaded 14-gauge core biopsy technique. The total number of false negative cases (i.e., benign findings instead of invasive breast carcinoma) was significantly greater (P = 0.008) in the spring-loaded 14-gauge core biopsy group (8/681, 1.2%) as compared to in the 8-gauge vacuum-assisted biopsy group (0/652, 0%), with an overall false negative rate of 2.1% (8/386) for the spring-loaded 14-gauge core biopsy group as compared to 0% (0/148) for the 8-gauge vacuum-assisted biopsy group. Significantly more (P < 0.001) patients in the spring-loaded 14-gauge core biopsy group (81/719, 11.3%) than in the 8-gauge vacuum-assisted biopsy group (18/724, 2.5%) were recommended for further diagnostic surgical removal of additional tissue from the same anatomical site of the affected breast in an immediate fashion for indeterminate/inconclusive findings seen on the original ultrasound-guided diagnostic breast biopsy procedure. Significantly more (P < 0.001) patients in the spring-loaded 14-gauge core biopsy group (54/719, 7.5%) than in the 8-gauge vacuum-assisted biopsy group (9/724, 1.2%) personally requested further diagnostic surgical removal of additional tissue from the same anatomical site of the affected breast in an immediate fashion for a benign finding seen on the original ultrasound-guided diagnostic breast biopsy procedure.</p> <p>Conclusions</p> <p>In appropriately selected cases, the 8-gauge vacuum-assisted biopsy approach appears to be advantageous to the spring-loaded 14-gauge core biopsy approach for providing the most accurate and optimal diagnostic information.</p

Rotating Stars in Relativity

Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information one could obtain about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on the equilibrium properties and on the nonaxisymmetric instabilities in f-modes and r-modes have been updated and several new sections have been added on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity.Comment: 101 pages, 18 figures. The full online-readable version of this article, including several animations, will be published in Living Reviews in Relativity at http://www.livingreviews.org

What can whiskers tell us about mammalian evolution, behaviour, and ecology?

Most mammals have whiskers; however, nearly everything we know about whiskers derives from just a handful of species, including laboratory rats Rattus norvegicus and mice Mus musculus, as well as some species of pinniped and marsupial. We explore the extent to which the knowledge of the whisker system from a handful of species applies to mammals generally. This will help us understand whisker evolution and function, in order to gain more insights into mammalian behaviour and ecology. This review is structured around Tinbergen’s four questions, since this method is an established, comprehensive, and logical approach to studying behaviour. We ask: how do whiskers work, develop, and evolve? And what are they for? While whiskers are all slender, curved, tapered, keratinised hairs that transmit vibrotactile information, we show that there are marked differences between species with respect to whisker arrangement, numbers, length, musculature, development, and growth cycles. The conservation of form and a common muscle architecture in mammals suggests that early mammals had whiskers. Whiskers may have been functional even in therapsids. However, certain extant mammalian species are equipped with especially long and sensitive whiskers, in particular nocturnal, arboreal species, and aquatic species, which live in complex environments and hunt moving prey. Knowledge of whiskers and whisker use can guide us in developing conservation protocols and designing enriched enclosures for captive mammals. We suggest that further comparative studies, embracing a wider variety of mammalian species, are required before one can make large-scale predictions relating to evolution and function of whiskers. More research is needed to develop robust techniques to enhance the welfare and conservation of mammals

Synthesis and structures of two thiocyanato-lanthanoid cages

The cages [{La2(NCS)5(NCMe)6}2O]·MeCN and [{Eu2(NCS)5(NCMe)5}2O]·MeCN have been prepared by redox transmetallation between the lanthanoid metals and mercuric thiocyanate in acetonitrile. The structure of the former has a core of four La atoms bonded to a central oxygen atom. Two La atoms are nine coordinate being bonded to oxygen, four terminal MeCN ligands and four N-bridged thiocyanato ligands, whereas the other two are eight coordinate being bonded to oxygen, the four bridging thiocyanato ligands, two terminal acetonitrile molecules, and a terminal N-bonded thiocyanate ion. In the Eu complex, there is a similar core of four Ln atoms bound to a central oxygen atom, but all Eu atoms are eight coordinate, and have four N-bridged thiocyanate ligands. Two have three MeCN ligands, whilst the other two have one terminal NCS− and two acetonitrile ligands