A new species of Galearis (Orchidinae: Orchidaceae) from Sichuan,China

A new species, Galearis huanglongensis Q.W.Meng & Y.B.Luo, is described and illustrated. It is similar to Galearis cyclochila (Franch. & Sav.) Soó and Galearis diantha (Schltr.) P.F.Hunt, but differs in having a short spur, two elliptical lateral stigma lobes and distinctly separated bursicles. This new species is known only from the type locality, the Huanglong Valley, Songpan County, western Sichuan, China, growing amongst mosses under alpine shrubs at an elevation of about 3000 m. Based on two years of observations of its population size, the species was categorized as critically endangered CR (B1a, B2a) according to the World Conservation Union (IUCN) Red List Categories and Criteria, Version 3.1. The micromorphology of pollinia and seeds was observed by scanning electron microscopy and compared with that of G. cyclochila and G. diantha. The results supported G. huanglongensis Q.W.Meng & Y.B.Luo as a new species. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 689–695.     

Spatial and temporal factors associated with nest survival of Gray Flycatchers in managed ponderosa pine forests

Gray Flycatchers (Empidonax wrightii) breed in a variety of habitats in the arid and semi‐arid regions of the western United States, but little is known about their breeding biology, especially in the northern portion of their range where they nest in ponderosa pine (Pinus ponderosa) forests. From May to July 2014 and 2015, we conducted surveys for singing male Gray Flycatchers along the eastern slope of the Cascade Range in Washington, U.S.A, monitored flycatcher nests, and quantified nest‐site vegetation. We used a logistic‐exposure model fit within a Bayesian framework to model the daily survival probability of flycatcher nests. During the 2 yr of our study, we monitored 141 nests, with 93% in ponderosa pines. Mean clutch size was 3.6 eggs and the mean number of young fledged per nest was 3.2. Predation accounted for 90% of failed nests. We found a positive association between daily nest survival and both nest height and distance of nest substrates from the nearest tree. Flycatchers that locate their nests higher above the ground and further from adjacent trees may be choosing the safest alternative because higher nests may be less exposed to terrestrial predators and nests in trees that are farther from other trees may be less exposed to arboreal predators such as jays (Corvidae) that may forage in patches with connected canopies. Nests in trees farther from other trees may also allow earlier detection of approaching predators and thus aid in nest defense.     

The enzyme that cleaves apolipoprotein A-II upon in vitro incubation of human plasma high-density lipoprotein-3 with blood polymorphonuclear cells is an elastase

The proteolytic activity directed against apolipoprotein A-II (apo-A-II) which is released from human blood polymorphonuclear cells (PMN) when they are incubated with human plasma high-density lipoprotein-3 (HDL3) was studied to assess the properties and site specificity of the enzyme. When 125I-apo-A-II-labeled HDL3 was incubated with the PMN protease at 37 degrees C, a complete cleavage of apo-A-II was observed which paralleled the formation of bands of approximately 11,000 and 7,000 daltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The 7,000-dalton component had the following N-terminal sequence: NH2-Thr-Asp-Tyr-Gly-Lys-Asp-Leu-Met-Glu-Lys. This corresponds to residues 19 through 28 of the intact apo-A-II monomer. Methoxysuccinyl (MeO-Suc)-Ala-Ala-Pro-Val-chloromethylketone-(CH2Cl) caused a 90% inhibition of apo-A-II hydrolysis at the highest concentration tested (6 X 10(-4)M). Besides apo-A-II, the PMN enzyme also hydrolyzed a synthetic substrate, MeO-Suc-Ala-Ala-Pro-Val-4-nitroanilide and its 4-methylcoumaryl-7-amide analogue. The protease appeared to have a mass of 28,000 daltons as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the [3H]diisopropylfluorophosphate-labeled PMN enzyme. That the PMN enzyme which cleaves apo-A-II is an elastase was derived from the following criteria: 1) cleavage at the Val-X bond in apo-A-II and in the two synthetic substrates studied; 2) prevention of the cleavage by MeO-Suc-Ala-Ala-Pro-Val-CH2Cl, a known specific elastase inhibitor; and 3) a mass comparable to that reported for a pure PMN elastase. These studies establish that apolipoproteins can be suitable substrates for enzymes of the elastase family.     

The metalloproteinase ADAM‐12 regulates bronchial epithelial cell proliferation and apoptosis

Abstract. Objectives: The ADAMs (a disintegrin and metalloproteinase) enzymes compose a family of membrane‐bound proteins characterized by their multi‐domain structure and ADAM‐12 expression is elevated in human non‐small cell lung cancers. The aim of this study was to investigate the roles played by ADAM‐12 in critical steps of bronchial cell transformation during carcinogenesis. Materials and methods: To assess the role of ADAM‐12 in tumorigenicity, BEAS‐2B cells were transfected with a plasmid encoding human full‐length ADAM‐12 cDNA, and then the effects of ADAM‐12 overexpression on cell behaviour were explored. Treatment of clones with heparin‐binding epidermal growth factor (EGF)‐like growth factor (HB‐EGF) neutralizing antibodies as well as an EGFR inhibitor allowed the dissection of mechanisms regulating cell proliferation and apoptosis. Results: Overexpression of ADAM‐12 in BEAS‐2B cells promoted cell proliferation. ADAM‐12 overexpressing clones produced higher quantities of HB‐EGF in their culture medium which may rely on membrane‐bound HB‐EGF shedding by ADAM‐12. Targeting HB‐EGF activity with a neutralizing antibody abrogated enhanced cell proliferation in the ADAM‐12 overexpressing clones. In sharp contrast, targeting of amphiregulin, EGF or transforming growth factor‐α failed to influence cell proliferation; moreover, ADAM‐12 transfectants were resistant to etoposide‐induced apoptosis and the use of a neutralizing antibody against HB‐EGF activity restored rates of apoptosis to be similar to controls.Conclusions: ADAM‐12 contributes to enhancing HB‐EGF shedding from plasma membranes leading to increased cell proliferation and reduced apoptosis in this bronchial epithelial cell line.