Norepinephrine, but not epinephrine, enhances platelet reactivity and coagulation after exercise in humans

The effects of exercise and catecholamineson platelet reactivity or coagulation and fibrinolysis appear to beinconsistent. This may be partly due to the methods employed inprevious studies. In the present study, we investigated the effects ofacute aerobic exercise and catecholamines on the thrombotic status by anovel in vitro method, shear-induced hemostatic plug formation(hemostatometry), using nonanticoagulated (native) blood. Aerobicexercise (60% maximal O₂consumption) was performed by healthy male volunteers for 20 min, andthe effect on platelet reactivity and coagulation was assessed byperforming hemostatometry before and immediately after exercise.Exercise significantly increased shear-induced platelet reactivity,coagulation, and catecholamine levels. The effect of catecholamines onplatelet reactivity and coagulation was assessed in vitro by addingcatecholamines to blood collected in the resting state. The mainfindings of the present study are that elevation of circulatingnorepinephrine at levels that are attained during exercise causesplatelet hyperreactivity and a platelet-mediated enhanced coagulation.This may be a mechanism of an association of aerobic exercise withthrombotic risk.

     

UV-B light induces an adaptive response to UV-C exposure via photoreactivation activity in Euglena gracilis.

Phytoplankton such as Euglena are constantly exposed to solar light which is used for photosynthesis. Although the solar ultraviolet (UV) induces DNA damage such as cyclobutane-pyrimidine dimers (CPDs), many kinds of living organisms can repair CPDs by photoreactivation (PR) utilizing the near-UV/blue light component in sunlight. Euglena cells are known to possess such PR activity. In the present paper, the formation of CPDs induced by UV-C exposure and the photoreactivation PR repair of these CPDs by UV-A are demonstrated. To clarify the adaptive responses prior UV-B irradiation on PR activity, cells were cultured in the dark or under UV-B light. When the cells were cultured in the dark for 3 d prior to UV-C exposure, PR activity decreased. When the cells were cultured under UV-B light, however, PR activity increased. These results suggest that exposing the cells to UV-B prior to exposure to UV-C induced an adaptive response towards DNA damage caused by UV-C exposure, and this UV-C induced damage was repaired through PR activity.     

Phylogenetics of family Enterobacteriaceae and proposal to reclassify Escherichia hermannii and Salmonella subterranea as Atlantibacter hermannii and Atlantibacter subterranea gen. nov., comb. nov.

Multilocus sequence analysis based on hypervariable housekeeping proteins was utilized to differentiate closely related species in the family Enterobacteriaceae. Of 150 housekeeping proteins, the top 10 hypervariable proteins were selected and concatenated to obtain distance data. Distances between concatenated proteins within the family were 0.9–41.2%, whereas the 16S rRNA and atpD‐gyrB‐infB‐rpoB concatenated sequence (4MLSA) distances were 0.8–6.0% and 0.9–22.1%, respectively. These data indicate that phylogenetic analysis by concatenation of hypervariable proteins is a powerful tool for discriminating species in the family Enterobacteriaceae. To confirm the discriminatory power of the 10 chosen concatenated hypervariable proteins (C10HKP), phylogenetic trees based on C10HKP, 4MLSA, and the 16S rRNA gene were constructed. Comparison of average bootstrap values among C10HKP, 4MLSA and 16S rRNA genes indicated that the C10HKP tree was the most reliable. Location via the C10HKP tree was consistent with existing assignments for almost all species in the family Enterobacteriaceae. However, the C10HKP tree suggested that several species (including Enterobacter massiliensis, Escherichia vulneris, Escherichia hermannii, and Salmonella subterranea) should be reassigned to different clusters than those defined in previous analyses. Furthermore, E. hermannii and S. subterranea appeared to fall onto a branch independent from those occupied by the other Enterobacteriaceae. Therefore, we propose Atlantibacter gen. nov., such that E. hermannii and S. subterranea would be transferred to genus Atlantibacter as Atlantibacter hermannii, comb. nov. and Atlantibacter subterranea. comb. nov., respectively.     

Strong between‐site variation in New Caledonian crows’ use of hook‐tool‐making materials

Functional tool use requires the selection of appropriate raw materials. New Caledonian crows Corvus moneduloides are known for their extraordinary tool‐making behaviour, including the crafting of hooked stick tools from branched vegetation. We describe a surprisingly strong between‐site difference in the plant materials used by wild crows to manufacture these tools: crows at one study site use branches of the non‐native shrub Desmanthus virgatus, whereas only approximately 7 km away, birds apparently ignore this material in favour of the terminal twigs of an as‐yet‐unidentified tree species. Although it is likely that differences in local plant communities drive this striking pattern, it remains to be determined how and why crows develop such strong site‐specific preferences for certain raw materials.     

Alendronate suppresses tumor angiogenesis by inhibiting Rho activation of endothelial cells

We previously reported that alendronate inhibits intraperitoneal dissemination in an in vivo ovarian cancer model. Recently, nitrogen-containing bisphosphonates have been reported to have antiangiogenic activities. In this study, alendronate inhibited human umbilical vein endothelial cell (HUVEC) migration and capillary-like structure formation in vitro. These inhibitory effects were associated with reduced Rho activation and suppression of the formation of actin stress fibers and focal adhesions in HUVECs. Furthermore, the inhibition by alendronate was reversed by geranylgeraniol, which abrogated the inhibition of Rho geranylgeranylation. Next, we examined the effect of alendronate on angiogenesis in disseminated ovarian tumors of athymic immunodeficient mice. Alendronate treatment reduced the intra-tumor neoangiogenesis compared with that in the non-treated mice, although tumor-derived VEGF expression was not altered. In conclusion, the in vivo anti-tumor effect of alendronate might be derived, at least in part, from its direct antiangiogenic effects on intra-tumor endothelial cells by inhibiting Rho geranylgeranylation.     

Drosophila beta 1,4-N-acetylgalactosaminyltransferase-A synthesizes the LacdiNAc structures on several glycoproteins and glycosphingolipids

The GalNAcbeta1,4GlcNAc (LacdiNAc or LDN) structure is a more common structural feature in invertebrate glycoconjugates when compared with the Galbeta1,4GlcNAc structure. Recently, beta1,4-N-acetylgalactosaminyltransferase (beta4GalNAcT) was identified in some invertebrates including Drosophila. However, the LDN structure has not been reported in Drosophila, and the biological function of LDN remains to be determined. In this study, we examined acceptor substrate specificity of Drosophila beta4GalNAcTA by using some N- and O-glycans on glycoproteins and neutral glycosphingolipids (GSLs). GalNAc was efficiently transferred toward N-glycans, O-glycans, and the arthro-series GSLs. Moreover, we showed that dbeta4GalNAcTA contributed to the synthesis of the LDN structure in vivo. The dbeta4GalNAcTA mRNA was highly expressed in the developmental and adult neuronal tissues. Thus, these results suggest that dbeta4GalNAcTA acts on the terminal GlcNAc residue of some glycans for the synthesis of LDN, and the LDN structure may play a role in the physiological or neuronal development of Drosophila.     

Mate-searching behavior of the black chafer <Emphasis Type="Italic">Holotrichia kiotonensis</Emphasis> (Coleoptera: Scarabaeidae): identification of a sex pheromone,and male orientation behavior controlled by olfactory and visual cues

In the black chafer Holotrichia kiotonensis Brenske (Coleoptera: Scarabaeidae), mating behavior was observed between 1940 and 2010 hours at < 0.1 lx in both the laboratory and the field. In the laboratory, an ether extract of female abdominal glands induced a series of pre-mating behaviors such as short-distance orientation and abdominal bending. When the extract was fractionated by silica gel column chromatography, the active fraction was eluted with 50% ether in hexane and 100% ether. Gas chromatography–mass spectrometry analysis revealed that both active fractions contained anthranilic acid (2-amino-benzoic acid) as a major compound. The amount of this compound was determined to be ca. 600 ng/female by high performance liquid chromatography analysis with a fluorescence detector. In the field, male chafers were observed to land on cotton balls impregnated with 10 mg of authentic anthranilic acid. When a white ball treated with anthranilic acid was placed 2–10 cm away from an untreated black ball, males were observed to land significantly more frequently on the latter. These results suggest that males could recognize white balls below 0.1 lx and landed on black balls. When a treated black ball was placed beside an untreated black ball, more males landed on the former. The difference was significant when the distance between the two lures was 5 or 10 cm, but not significant when it was 2 cm. These observations demonstrated that anthranilic acid was the sex-attractant pheromone for the black chafer H. kiotonensis and that the males located and landed on a pheromone source by using olfaction in conjunction with visual orientation. The importance of visual orientation in this nocturnal species is discussed in comparison with the congeneric diurnal species Holotrichia loochooana loochooana.     

Glycans define the stemness of naïve and primed pluripotent stem cells

Cell surface glycans are tissue-specific and developmentally regulated. They function as essential modulators in cell-cell interactions, cell-extracellular matrix interactions, and ligand-receptor interactions, binding to various ligands, including Wnt, fibroblast growth factors, and bone morphogenetic proteins. Embryonic stem (ES) cells, originally derived from the inner cell mass of blastocysts, have the essential characteristics of pluripotency and self-renewal. Recently, it has been proposed that mouse and human conventional ES cells are present in different developmental stages, namely pre-implantation blastocyst and post-implantation blastocyst stages, also called the naïve state and the primed state, respectively. They therefore require different extrinsic signals for the maintenance of self-renewal and pluripotency, and also appear to require different surface glycans. Understanding of molecular mechanisms involving glycans in self-renewal and pluripotency of ES cells is increasingly important for potential clinical applications, as well as for basic research. This review focuses on the roles of glycans in the two different states of pluripotent stem cells, namely the naïve state and the primed state, and the transition between these two states.     

Diversity of laccase among Cryptococcus neoformans serotypes

The pathogenic yeast C. neoformans is classified into three varieties with five serotypes; var. grubii (serotype A), var. neoformans (serotype D), var. gattii (serotypes B and C), and serotype AD. Melanin is a virulence factor in the species, and its biosynthesis is catalyzed by laccase, encoded by the LAC1 gene. In order to estimate the natural variability of the LAC1 gene among Cryptococcus serotypes, the laccase protein sequence from 55 strains was determined and the phylogenetic relationships between cryptococcal and related fungal laccases revealed. The deduced laccase proteins consisted of 624 amino acid residues in serotypes A, D and AD, and 613 to 615 residues in serotypes B and C. Intra-serotype amino acid variation was marginal within serotypes A and D, and none was found within serotypes AD and C. Maximum amino acid replacement occurred in two serotype B strains. The similarity in the deduced sequence ranged from 80 to 96% between serotypes. The sequence in the copper-binding regions was strongly conserved in the five serotypes. The laccases of the five serotypes were grouped together in the same clade of the phylogenetic tree reconstructed from different fungal laccases, suggesting a monophyletic clade.     

Pseudohalide-bridged five-coordinate Ni(II) or Co(II) complexes with bulky bidentate ligands: Magneto-structural correlationship

Bidentate ligands 2,2′-biquinoline (biq) and 6,6′-dimethyl-2,2′-bipyridine (dmbpy) with steric hindrance substituents cis to the nitrogen atoms have been used in the synthesis of transition metal complexes. Six new doubly end-on azido-bridged binuclear complexes [M₂(biq)₂(μ_1,1-N₃)₂(N₃)₂] (M = Ni (1), M = Co (2)), [M₂(biq)₂(μ_1,1-N₃)₂Cl₂] (M = Ni (3), M = Co (4)), [M₂(dmbpy)₂(μ_1,1-N₃)₂(N₃)₂] (M = Ni (5), M = Co (6)) and one end-to-end thiocyanato-bridged polymeric [Ni(dmbpy)(μ_1,3-SCN)(NCS)]_n (7) have been synthesized and characterized by single crystal X-ray diffraction analysis and magnetic studies. Complexes 1-6 comprise five-coordinate M(II) ions bridged by two end-on azide ligands. The bridging M-N-M bond angles are in the small range 104.1-105.2°. Complex 7 consists of a singly thiocyanate-bridged Ni(II) chain in which Ni(II) ions are five-coordinate. This research suggests that the bulky ligands play a key role in the formation of five-coordinate coordination structure. All complexes display intramolecular intermetallic ferromagnetic coupling with J_NiNi and J_CoCo of ca. 23 or 13 cm⁻¹ based on the Hamiltonian (S₁ = S₂ = 1 for Ni₂, or 3/2 for Co₂). The singly SCN⁻-bridged chainlike complex 7 shows intrachain ferromagnetic interaction with J = 3.96(2) cm⁻¹ and D = −4.55(8) cm⁻¹ (. Magneto-structural correlationship has been investigated.