Food For Thought: Short-Term Fasting Upregulates Glucose Transporters in Neurons and Endothelial Cells,But Not in Astrocytes

Neurochemical Research - Our group previously reported that 6-h fasting increased both insulin II mRNA expression and insulin level in rat hypothalamus. Given that insulin effects on central...     

Effects of climate change and horticultural use on the spread of naturalized alien garden plants in Europe

Climate warming is supposed to enlarge the area climatically suitable to the naturalization of alien garden plants in temperate regions. However, the effects of a changing climate on the spread of naturalized ornamentals have not been evaluated by spatially and temporarily explicit range modelling at larger scales so far. Here, we assess how climate change and the frequency of cultivation interactively determine the spread of 15 ornamental plants over the 21st century in Europe. We coupled species distribution modelling with simulations of demography and dispersal to predict range dynamics of these species in annual steps across a 250 × 250 m raster of the study area. Models were run under four scenarios of climate warming and six levels of cultivation intensity. Cultivation frequency was implemented as size of the area used for planting a species. Although the area climatically suitable to the 15 species increases, on average, the area predicted to be occupied by them in 2090 shrinks under two of the three climate change scenarios. This contradiction obviously arises from dispersal limitations that were pronounced although we assumed that cultivation is spatially adapting to the changing climate. Cultivation frequency had a much stronger effect on species spread than climate change, and this effect was non‐linear. The area occupied increased sharply from low to moderate levels of cultivation intensity, but levelled off afterwards. Our simulations suggest that climate warming will not necessarily foster the spread of alien garden plants in Europe over the next decades. However, climatically suitable areas do increase and hence an invasion debt is likely accumulating. Restricting cultivation of species can be effective in preventing species spread, irrespective of how the climate develops. However, for being successful, they depend on high levels of compliance to keep propagule pressure at a low level.     

Co-localization of beta1,6-branched oligosaccharides and coarse melanin in macrophage-melanoma fusion hybrids and human melanoma cells in vitro

Fusion hybrids between normal macrophages and Cloudman S91 melanoma cells were shown earlier to have increased metastatic potential, along with high expression of beta1,6-N-acetylglucosaminyltransferase V and beta1,6-branched oligosaccharides. Curiously, hybrids, but not parental melanoma cells, also produced 'coarse melanin'- autophagic vesicles with multiple melanosomes. As beta1,6-branched oligosaccharides were known to be associated with metastasis, and coarse melanin had been described in invasive human melanomas, we looked for potential relationships between the two. Using lectin- and immunohistochemistry, we analyzed cell lines producing coarse melanin for beta1,6-branched oligosaccharides: gp100/pmel-17 (a melanosomal structural component) and CD63 (a late endosome/lysosome component associated with melanoma and certain other human cancers). Cell lines used in this study were (i) hybrid 94-H48, a highly metastatic, macrophage-melanoma experimental fusion hybrid; (ii) 6(neo) mouse melanoma cells, the weakly metastatic, parental fusion partner; and (iii) SKmel-23, a human melanoma cell line derived from a metastasis. Coarse melanin granules were prominent both in hybrids and in SKmel-23 cells, and co-localized with stains for beta1,6-branched oligosaccharides, gp100/pmel 17, and CD63. This is the first report of this phenotype being expressed in vitro, although co-expression of beta1,6-branched oligosaccharides and coarse melanin was recently shown to be a common and pervasive characteristic in archival specimens of human melanomas, and was most prominent in metastases. The results suggest that pathways of melanogenesis in melanoma may differ significantly from those in normal melanocytes. In vitro expression of this phenotype provides new biological systems for more detailed analyses of its genesis and regulation at the molecular genetic level.     

Skin waste, vertex angle, and scar length in excisional biopsies: comparing five excision patterns--fusiform ellipse, fusiform circle, rhomboid, mosque, and S-shaped

The common excision skin pattern is either a fusiform ellipse or another pattern with dissimilar length and width. The purpose of this study was to define the most advantageous skin pattern regarding skin waste, vertex angle, and scar length. Five skin excision patterns used traditionally for closure of round lesions were analyzed: fusiform ellipse, fusiform circle, rhomboid, mosque, and S-shaped. In the analysis, the pattern characteristics were formulated by geometric principles, from which the results were compared. The smallest skin waste was found in rhomboid and mosque patterns, whereas the largest skin waste was found in the fusiform circle and ellipse. The vertex angle was found to decrease monotonously with the excision length-to-width ratio for all patterns except the mosque shape, which is zero per definition. The paradigm stating that a vertex angle of 30 degrees or less is maintained for length-to-width ratios below 4 in the surgical ellipse was found incorrect. It holds only for rhomboid and S-shaped excisions. The scar length was found almost independent of the pattern, with a variance of 3 percent. The authors conclude that the most advantageous surgical skin patterns are the rhomboid and mosque excisions.     

Thyroid receptor ligands. Part 2: Thyromimetics with improved selectivity for the thyroid hormone receptor beta

A set of thyromimetics having improved selectivity for TR-beta1 were prepared by replacing the 3'-isopropyl group of 2 and 3 with substituents having increased steric bulk. From this limited SAR study, the most potent and selective compounds identified were derived from 2 and contained a 3'-phenyl moiety bearing small hydrophobic groups meta to the biphenyl link. X-ray crystal data of 15c complexed with TR-beta1 LBD shows methionine 442 to be displaced by the bulky R3' phenyl ethyl amide side chain. Movement of this amino acid side chain provides an expanded pocket for the bulky side chain while the ligand-receptor complex retains full agonist activity.     

The EMBL Nucleotide Sequence Database: major new developments

The EMBL Nucleotide Sequence Database (http://www.ebi.ac.uk/embl/) incorporates, organizes and distributes nucleotide sequences from all available public sources. The database is located and maintained at the European Bioinformatics Institute (EBI) near Cambridge, UK. In an international collaboration with DDBJ (Japan) and GenBank (USA), data are exchanged amongst the collaborating databases on a daily basis to achieve optimal synchronization. Webin is the preferred web-based submission system for individual submitters, while automatic procedures allow incorporation of sequence data from large-scale genome sequencing centres and from the European Patent Office (EPO). Database releases are produced quarterly. Network services allow free access to the most up-to-date data collection via FTP, Email and World Wide Web interfaces. EBI's Sequence Retrieval System (SRS) integrates and links the main nucleotide and protein databases plus many other specialized molecular biology databases. For sequence similarity searching, a variety of tools (e.g. Fasta, BLAST) are available which allow external users to compare their own sequences against the latest data in the EMBL Nucleotide Sequence Database and SWISS-PROT. All resources can be accessed via the EBI home page at http://www.ebi.ac.uk.     

Molecular cloning,expression and characterization of three distinctive genes encoding methionine aminopeptidases in cyanobacterium<Emphasis Type="Italic"> Synechocystis</Emphasis> sp. strain PCC6803

Methionine aminopeptidase, known to be encoded by single genes in prokaryotes, is a cobalt-dependent enzyme that catalyzes the removal of N-terminal methionine residues from nascent polypeptides. Three ORFs encoding putative methionine aminopeptidases from the genome of cyanobacterium Synechocystis sp. strain PCC6803, designated as slr0786 (map-1), slr0918 (map-2) and sll0555 (map-3) were cloned and expressed in Escherichia coli. The purified recombinant proteins encoded by map-1 and map-3 had much higher methionine aminopeptidase activity than the recombinant protein encoded by map-2. Comparative analysis revealed that the three recombinant enzymes differed in their substrate specificity, divalent ion requirement, pH, and temperature optima. The broad activities of the iso-enzymes are discussed in light of the structural similarities with other peptidase families and their levels of specificity in the cell. Potential application of cyanobacterial MetAPs in the production of recombinant proteins used in medicine is proposed. This is the first report of a prokaryote harboring multiple methionine aminopeptidases.Abbreviations map Gene encoding methionine aminopeptidase - MetAP Methionine aminopeptidase - eMetAP-Ia Escherichia coli methionine aminopeptidase type Ia - yMetAP-Ib Yeast methionine aminopeptidase type Ib - yMetAP-IIa Yeast methionine aminopeptidase type IIa - hMetAP-IIb Human methionine aminopeptidase type IIb - pfMetAP–IIa Pyrococcus furiosis methionine aminopeptidase type Ia - bst MetAP-Ia Bacillus stearothermophilus methionine aminopeptidase type Ia - c1MetAP-Ia Cyanobacterial methionine aminopeptidase type Ia encoded by map-1 - c2MetAP-Ia Cyanobacterial methionine aminopeptidase type Ia encoded by map-2 - c3MetAP-Ib Cyanobacterial methionine aminopeptidase type Ib, ncoded by map-3     

Melatonin and activity rhythm responses to light pulses in mice with the Clock mutation

Melatonin and wheel-running rhythmicity and the effects of acute and chronic light pulses on these rhythms were studied in Clock(Delta19) mutant mice selectively bred to synthesize melatonin. Homozygous melatonin-proficient Clock(Delta19) mutant mice (Clock(Delta19/Delta19)-MEL) produced melatonin rhythmically, with peak production 2 h later than the wild-type controls (i.e., just before lights on). By contrast, the time of onset of wheel-running activity occurred within a 20-min period around lights off, irrespective of the genotype. Melatonin production in the mutants spontaneously decreased within 1 h of the expected time of lights on. On placement of the mice in continuous darkness, the melatonin rhythm persisted, and the peak occurred 2 h later in each cycle over the first two cycles, consistent with the endogenous period of the mutant. This contrasted with the onset of wheel-running activity, which did not shift for several days in constant darkness. A light pulse around the time of expected lights on followed by constant darkness reduced the expected 2-h delay of the melatonin peak of the mutants to approximately 1 h and advanced the time of the melatonin peak in the wild-type mice. When the Clock(Delta19/Delta19)-MEL mice were maintained in a skeleton photoperiod of daily 15-min light pulses, a higher proportion entrained to the schedule (57%) than melatonin-deficient mutants (9%). These results provide compelling evidence that mice with the Clock(Delta19) mutation express essentially normal rhythmicity, albeit with an underlying endogenous period of 26-27 h, and they can be entrained by brief exposure to light. They also raise important questions about the role of Clock in rhythmicity and the usefulness of monitoring behavioral rhythms compared with hormonal rhythms.