Antibacterial activity of lactoferrin and a pepsin-derived lactoferrin peptide fragment

Although the antimicrobial activity of lactoferrin has been well described, its mechanism of action has been poorly characterized. Recent work has indicated that in addition to binding iron, human lactoferrin damages the outer membrane of gram-negative bacteria. In this study, we determined whether bovine lactoferrin and a pepsin-derived bovine lactoferrin peptide (lactoferricin) fragment have similar activities. We found that both 20 microM bovine lactoferrin and 20 microM lactoferricin release intrinsically labeled [3H]lipopolysaccharide ([3H]LPS) from three bacterial strains, Escherichia coli CL99 1-2, Salmonella typhimurium SL696, and Salmonella montevideo SL5222. Under most conditions, more LPS is released by the peptide fragment than by whole bovine lactoferrin. In the presence of either lactoferrin or lactoferricin there is increased killing of E. coli CL99 1-2 by lysozyme. Like human lactoferrin, bovine lactoferrin and lactoferricin have the ability to bind to free intrinsically labeled [3H]LPS molecules. In addition to these effects, whereas bovine lactoferrin was at most bacteriostatic, lactoferricin demonstrated consistent bactericidal activity against gram-negative bacteria. This bactericidal effect is modulated by the cations Ca2+, Mg2+, and Fe3+ but is independent of the osmolarity of the medium. Transmission electron microscopy of bacterial cells exposed to lactoferricin show the immediate development of electron-dense membrane blisters. These experiments offer evidence that bovine lactoferrin and lactoferricin damage the outer membrane of gram-negative bacteria. Moreover, the peptide fragment lactoferricin has direct bactericidal activity. As lactoferrin is exposed to proteolytic factors in vivo which could cleave the lactoferricin fragment, the effects of this peptide are of both mechanistic and physiologic relevance

How stratospheric are deep stratospheric intrusions?

Preliminary attempts of quantifying the stratospheric ozone contribution in the observations at the Zugspitze summit (2962 m a.s.l.) next to Garmisch-Partenkirchen in the German Alps had yielded an approximate doubling of the stratospheric fraction of the Zugspitze ozone during the time period 1978 to 2004. These investigations had been based on data filtering by using low relative humidity (RH) and elevated 7Be as the criteria for selecting half-hour intervals of ozone data representative of stratospheric intrusion air. To quantify the residual stratospheric component in stratospherically influenced air masses, however, the mixing of tropospheric air into the stratospheric intrusion layers must be taken into account. In fact, the dewpoint mirror instrument at the Zugspitze summit station rarely registers RH values lower than 10% in stratospheric air intrusions. Since 2007 a programme of routine lidar sounding of ozone, water vapour and aerosol has been conducted in the Garmisch-Partenkirchen area. The lidar results demonstrate that the intrusion layers are drier by roughly one order of magnitude than indicated in the in situ measurements. Even in thin layers RH values clearly below 1% have frequently been observed. These thin, undiluted layers present an important challenge for atmospheric modelling. Although the ozone values never reach values typical of the lower-stratosphere it becomes, thus, obvious that, without strong wind shear or convective processes, mixing of stratospheric and tropospheric air must be very slow in most of the free troposphere. As a consequence, the analysis the Zugspitze data can be assumed to be more reliable than anticipated. Finally, the concentrations of Zugspitze carbon monoxide rarely drop inside intrusion layers and normally stay clearly above full stratospheric values. This indicates that most of the CO, and thus the intrusion air mass, originates in the shallow "mixing layer" around the thermal tropopause. The CO mixing ratio in these descending layers between 1990 and 2004 exhibits a slightly positive trend indicating some Asian influence on the lowermost stratosphere in the high-latitude source region of most intrusions reaching the station

Optical And Physical Properties Of Er3+-yb3+ Co-doped Tellurite Fibers

In this work we present results of physical and optical properties of Er3+-Yb3+ co-doped tellurite glasses and fibers. The Double Clad Tellurite Fibers (DCTFs) are based on glasses with the composition: TeO2-WO3-Nb2O5-Na 2O-Al2O3-Er2O3-Yb 2O3. The DCTFs were fabricated by using the rod-in-tube technique and a Heathway drawing tower. The optical absorption spectra (ranging from 350 to 1750 nm) of these fibers were measured using an Optical Spectrum Analyzer (OSA). The emission spectra, around 1550 nm band, of these fibers (lengths varying from 1 to 60 cm) were obtained by using a 980nm diode laser pump. The optimal Amplified Spontaneous Emission (ASE) spectra were observed for fiber lengths ranging from 2 to 6 cm. The Er 3+/Yb3+ co-doped DCTFs show an efficient up-conversion process in comparison with the Er3+-doped DCTF. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).8120The Society of Photo-Optical Instrumentation Engineers (SPIE)Murugan, G.S., Suzuki, T., Ohishi, Y., Raman characteristics and nonlinear optical properties of tellurite and phosphotellurite glasses containing heavy metal oxides with ultrabroad Raman bands (2006) J. of Appl. Phys., 100, p. 023107Nandi, P., Jose, G., Ytterbium-doped P2O5-TeO2 glass for laser applications (2006) IEEE J. of Quat. Electron., 42, pp. 1115-1121Man, S.Q., Pun, E.Y.B., Chung, P.S., Tellurite glasses for 1.3 mm optical amplifiers" (1999) Opt. Comm., 168, pp. 369-373Wang, J.S., Vogel, E.M., Snitzer, E., Tellurite Glass: A New Candidate for Fiber Devices" (1994) Opt. Mat., 3, pp. 187-203Xu, S., Sun, H., Dai, S., Zhang, J., Jiang, Z., Upconversion luminescence of Tm3+/Yb3+-codoped oxyhalide tellurite glasses" (2005) Sol. St. Comm., 133, pp. 89-92Bookey, H.T., Lousteau, J., Jha, A., Gayraud, N., Thomson, R.R., Psaila, N.D., Li, H., Kar, A.K., Multiple rare earth emissions in a multicore tellurite fiber with a single pump wavelength" (2007) Opt. Express, 15, pp. 17554-17561Qin, G., Mori, A., Ohishi, Y., Brillouin lasing in a single-mode tellurite fiber" (2007) Opt. Lett., 32, pp. 2179-2181Zweig, A.D., Frenz, M., Romano, V., Weber, H.P., A comparative study of laser tissue interaction at 2.94 μm and 10.6 μm" (1988) Appl. Phys. B, 47, pp. 259-265Zhang, J., Dai, S., Wang, G., Sun, H., Zhang, L., Hu, L., Fabrication and emission properties of Er3+/Yb3+ codoped tellurite glass fiber for broadband optical amplification (2005) J. of Lum., 115, pp. 45-52Shixun, D., Tiefeng, X., Qiuhua, N., Xiang, S., Xunsi, W., Fabrication and gain performance of Er3+/Yb3+-codoped tellurite glass fiber (2008) J. of Rare Earths, 26, pp. 915-918Jakutis, J., Gomes, L., Amancio, C.T., Kassab, L.R.P., Martinelli, J.R., Wetter, N.U., Increased Er3+ upconversion in tellurite fibers and glasses by co-doping with Yb3+ (2010) Opt. Mat., 33, pp. 107-111Hruby, A., Evaluation of glass-forming tendency by means of DTA (1972) Czech J. Phys B, 22, pp. 1187-119

Epithelial-mesenchymal transitions: the importance of changing cell state in development and disease

The events that convert adherent epithelial cells into individual migratory cells that can invade the extracellular matrix are known collectively as epithelial-mesenchymal transition (EMT). Throughout evolution, the capacity of cells to switch between these two cellular states has been fundamental in the generation of complex body patterns. Here, we review the EMT events that build the embryo and further discuss two prototypical processes governed by EMT in amniotes: gastrulation and neural crest formation. Cells undergo EMT to migrate and colonize distant territories. Not surprisingly, this is also the mechanism used by cancer cells to disperse throughout the body

Four-dimensional distribution of the 2010 Eyjafjallajökull volcanic cloud over Europe observed by EARLINET

© Author(s) 2013. This work is distributed under the Creative Commons Attribution 3.0 License.The eruption of the Icelandic volcano Eyjafjallaj ökull in April-May 2010 represents a "natural experiment" to study the impact of volcanic emissions on a continental scale. For the first time, quantitative data about the presence, altitude, and layering of the volcanic cloud, in conjunction with optical information, are available for most parts of Europe derived from the observations by the European Aerosol Research Lidar NETwork (EARLINET). Based on multi-wavelength Raman lidar systems, EARLINET is the only instrument worldwide that is able to provide dense time series of high-quality optical data to be used for aerosol typing and for the retrieval of particle microphysical properties as a function of altitude. In this work we show the four-dimensional (4-D) distribution of the Eyjafjallajökull volcanic cloud in the troposphere over Europe as observed by EARLINET during the entire volcanic event (15 April-26 May 2010). All optical properties directly measured (backscatter, extinction, and particle linear depolarization ratio) are stored in the EARLINET database available at www.earlinet.org. A specific relational database providing the volcanic mask over Europe, realized ad hoc for this specific event, has been developed and is available on request at www.earlinet.org. During the first days after the eruption, volcanic particles were detected over Central Europe within a wide range of altitudes, from the upper troposphere down to the local planetary boundary layer (PBL). After 19 April 2010, volcanic particles were detected over southern and south-eastern Europe. During the first half of May (5-15 May), material emitted by the Eyjafjallajökull volcano was detected over Spain and Portugal and then over the Mediterranean and the Balkans. The last observations of the event were recorded until 25 May in Central Europe and in the Eastern Mediterranean area. The 4-D distribution of volcanic aerosol layering and optical properties on European scale reported here provides an unprecedented data set for evaluating satellite data and aerosol dispersion models for this kind of volcanic events.Peer reviewe

Signal Transduction in the Footsteps of Goethe and Schiller

The historical town of Weimar in Thuringia, the "green heart of Germany" was the sphere of Goethe and Schiller, the two most famous representatives of German literature's classic era. Not yet entirely as influential as those two cultural icons, the Signal Transduction Society (STS) has nevertheless in the last decade established within the walls of Weimar an annual interdisciplinary Meeting on "Signal Transduction – Receptors, Mediators and Genes", which is well recognized as a most attractive opportunity to exchange results and ideas in the field

ITPK1 is an InsP6/ADP phosphotransferase that controls phosphate signaling in Arabidopsis

In plants, phosphate (Pi) homeostasis is regulated by the interaction of PHR transcription factors with stand-alone SPX proteins, which act as sensors for inositol pyrophosphates. Here, we combined different methods to obtain a comprehensive picture of how inositol (pyro)phosphate metabolism is regulated by Pi and dependent on the inositol phosphate kinase ITPK1. We found that inositol pyrophosphates are more responsive to Pi than lower inositol phosphates, a response conserved across kingdoms. With CE-ESI-MS we could separate different InsP7 isomers in Arabidopsis and rice, and identify 4/6-InsP7 and a PP-InsP4 isomer hitherto not reported in plants. We found that the inositol pyrophosphates 1/3-InsP7, 5-InsP7 and InsP8 increase severalfold in shoots after Pi resupply and that tissue-specific accumulation of inositol pyrophosphates relies on ITPK1 activities and MRP5-dependent InsP6 compartmentalization. Notably, ITPK1 is critical for Pi-dependent 5-InsP7 and InsP8 synthesis in planta and its activity regulates Pi starvation responses in a PHR-dependent manner. Furthermore, we demonstrate that ITPK1-mediated conversion of InsP6 to 5-InsP7 requires high ATP concentrations and that Arabidopsis ITPK1 has an ADP phosphotransferase activity to dephosphorylate specifically 5-InsP7 under low ATP. Collectively, our study provides deeper insights into Pi-dependent changes in nutritional and energetic states with the synthesis of regulatory inositol pyrophosphates

Hereditary palmoplantar keratoderma - phenotypes and mutations in 64 patients

Background Hereditary palmoplantar keratodermas (PPK) represent a heterogeneous group of rare skin disorders with epidermal hyperkeratosis of the palms and soles, with occasional additional manifestations in other tissues. Mutations in at least 69 genes have been implicated in PPK, but further novel candidate genes and mutations are still to be found. Objectives To identify mutations underlying PPK in a cohort of 64 patients. Methods DNA of 48 patients was analysed on a custom-designed in-house panel for 35 PPK genes, and 16 patients were investigated by a diagnostic genetic laboratory either by whole-exome sequencing, gene panels or targeted single-gene sequencing. Results Of the 64 PPK patients, 32 had diffuse (50%), 19 focal (30%) and 13 punctate (20%) PPK. None had striate PPK. Pathogenic mutations in altogether five genes were identified in 31 of 64 (48%) patients, the majority (22/31) with diffuse PPK. Of them, 11 had a mutation in AQP5, five in SERPINB7, four in KRT9 and two in SLURP1. AAGAB mutations were found in nine punctate PPK patients. New mutations were identified in KRT9 and AAGAB. No pathogenic mutations were detected in focal PPK. Variants of uncertain significance (VUS) in PPK-associated and other genes were observed in 21 patients that might explain their PPK. No suggestive pathogenic variants were found for 12 patients. Conclusions Diffuse PPK was the most common (50%) and striate PPK was not observed. We identified pathogenic mutations in 48% of our PPK patients, mainly in five genes: AQP5, AAGAB, KRT9, SERPINB7 and SLURP1.Peer reviewe

Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient

We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide

Manejo da fertilidade do solo e adubação do milho na Região Centro Oeste.

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