Distribution pattern of an expanding Osprey ( Pandion haliaetus) population in a changing environment

We studied the nest site selection and distribution pattern at landscape level of the German Osprey population, and demonstrated how to test the predictions of the ideal free distribution theory and its derivatives on such an expanding population. Information about the location and breeding success of each Osprey nest site between 1995 and 2005 was collected through a long-term monitoring programme. Data of land cover types were acquired from the administrations of each federal state and the CORINE Land Cover database. The results showed that Ospreys preferred landscapes with more water bodies and forests. Such sites were also occupied earlier and had higher local population density. However, in the study period of 11 years, there was a gradual shift from forest-dominated landscapes to agricultural land-dominated landscapes. The breeding success increased over time, with no difference in the breeding success between pairs nesting on trees and poles, whereas there was higher breeding success at nest sites surrounded by more agricultural land and less forest. The more efficient foraging in eutrophic lakes in agricultural landscapes was the most likely cause for the higher breeding success. The distribution pattern of the Ospreys did not match the resource allocation, which deviated from the models tested. We suggested that the proximate cues used for nest site selection mismatched site quality due to anthropogenic environmental changes.     

Hepatitis C virus 3′UTR regulates viral translation through direct interactions with the host translation machinery

The 3′ untranslated region (3′UTR) of hepatitis C virus (HCV) messenger RNA stimulates viral translation by an undetermined mechanism. We identified a high affinity interaction, conserved among different HCV genotypes, between the HCV 3′UTR and the host ribosome. The 3′UTR interacts with 40S ribosomal subunit proteins residing primarily in a localized region on the 40S solvent-accessible surface near the messenger RNA entry and exit sites. This region partially overlaps with the site where the HCV internal ribosome entry site was found to bind, with the internal ribosome entry site-40S subunit interaction being dominant. Despite its ability to bind to 40S subunits independently, the HCV 3′UTR only stimulates translation in cis, without affecting the first round translation rate. These observations support a model in which the HCV 3′UTR retains ribosome complexes during translation termination to facilitate efficient initiation of subsequent rounds of translation.     

Tetramethylpyrazine scavenges superoxide anion and decreases nitric oxide production in human polymorphonuclear leukocytes

Tetramethylpyrazine is one of the active ingredients of the Chinese herb Ligusticum wallichii Franchat. By electron spin resonance spin trapping methods, effects of tetramethylpyrazine on superoxide anion and nitric oxide generated by human polymorphonuclear leukocytes were studied. During the respiratory burst of polymorphonuclear leukocytes induced by N-formylmethionyl-leucyl-phenylalanine, tetramethylpyrazine scavenges superoxide anion dose-dependently, and decreases the production of nitric oxide significantly, but shows no influence on oxygen consumption. These results suggest that the effective protection of tetramethylpyrazine against ischemic brain injury might be due to its scavenging of reactive oxygen species and regulation on nitric oxide production, and consequent prevention of peroxynitrite formation.     

A catalogue of Burmite inclusions

Burmite (Burmese amber) from the Hukawng Valley in northern Myanmar is a remarkable valuable and obviously the most important amber for studying terrestrial diversity in the mid-Cretaceous.The diversity of Burmite inclusions is very high and many new taxa were found,including new order,new family/subfamily,and new genus.Till the end of 2016,14 phyla,21 classes,65 orders,279 families,515 genera and 643 species of organisms are recorded,which are summized and complied in this catalogue.Among them,587 species are arthropods.In addtion,the specimens which can not be identified into species are also listed in the paper.The information on type specimens,other materials,host and deposition of types are provided.     

Asymmetric reduction of ketopantolactone using a strictly (<Emphasis Type="Italic">R</Emphasis>)-stereoselective carbonyl reductase through efficient NADPH regeneration and the substrate constant-feeding strategy

Objectives

To characterize a recombinant carbonyl reductase from Saccharomyces cerevisiae (SceCPR1) and explore its use in asymmetric synthesis of (R)-pantolactone [(R)-PL].

Results

The NADPH-dependent SceCPR1 exhibited strict (R)-enantioselectivity and high activity in the asymmetric reduction of ketopantolactone (KPL) to (R)-PL. Escherichia coli, coexpressing SceCPR1 and glucose dehydrogenase from Exiguobacterium sibiricum (EsGDH), was constructed to fulfill efficient NADPH regeneration. During the whole-cell catalyzed asymmetric reduction of KPL, the spontaneous hydrolysis of KPL significantly affected the yield of (R)-PL, which was effectively alleviated by the employment of the substrate constant-feeding strategy. The established whole-cell bioreduction for 6 h afforded 458 mM (R)-PL with the enantiomeric excess value of >99.9% and the yield of 91.6%.

Conclusions

Escherichia coli coexpressing SceCPR1 and EsGDH efficiently catalyzed the asymmetric synthesis of (R)-PL through the substrate constant-feeding strategy.

     

ADMA induces monocyte adhesion via activation of chemokine receptors in cultured THP-1 cells

Asymmetric dimethylarginine (ADMA), an endogenous NOS inhibitor, is also an important inflammatory factor contributing to the development of atherosclerosis (AS). The present study was to test the effect of ADMA on angiotensin (Ang) II-induced monocytic adhesion. Human monocytoid cells (THP-1) or isolated peripheral blood monocyte cells (PBMCs) were incubated with Ang II (10⁻⁶ M) or exogenous ADMA (30 μM) for 4 or 24 h in the absence or presence of losartan or antioxidant PDTC. In cultured THP-1 cells, Ang II (10⁻⁶ M) for 24 h elevated the level of ADMA in the medium, upregulated the protein expression of protein arginine methyltransferase (PRMT) and decreased the activity of dimethylarginine dimethylaminohydrolase (DDAH). Both of Ang II and ADMA increased monocytic adhesion to human umbilical vein endothelial cells (HUVECs), elevated the levels of monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8 and tumor necrosis factor (TNF)-α and upregulated CCR₂ and CXCR₂ mRNA expression, concomitantly with increase in reactive oxygen species (ROS) generation and activation of nuclear factor (NF)-κB. Pretreatment with losartan (10 μM) or PDTC (10 μM) abolished the effects mediated by Ang II or ADMA. In isolated PBMCs from healthy individuals, ADMA upregulated the expression of CXCR₂ mRNA, which was attenuated by losartan (10 μM), however, ADMA had no effect on surface protein expression of CCR₂. The present results suggest that ADMA may be involved in monocytic adhesion induced by Ang II via activation of chemokine receptors by ROS/NF-κB pathway.