bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence that a significant number of naive T cells enter non‐lymphoid organs as part of a normal migratory pathway
Authors: Cose Stephen , Brammer Clair , Khanna Kamal M. , Masopust David , Lefrançois Leo
Published: May 2006

Only activated and effector memory T cells are thought to access non‐lymphoid tissues. In contrast, naive T cells are thought to circulate only between the blood, lymph and secondary lymphoid organs. We examined the phenotype of endogenous T cells in various non‐lymphoid organs and showed that a subset of cells exhibited an apparently naive phenotype and were functionally inactive. FTY720 treatment selectively depleted this population from the non‐lymphoid tissues. In addition, RAG‐deficient TCR transgenic CD4 and CD8 T cells were present in non‐lymphoid tissues in bone marrow chimeric mice and in situ imaging analysis revealed their location in the parenchymal tissues. Moreover, migration of TCR transgenic T cells to non‐lymphoid tissues after adoptive transfer was pertussis‐toxin resistant. Overall, the results suggest that naive T cells may circulate through non‐lymphoid tissues as part of their normal migratory pathway.
Alloiococcus otitidis is a ligand for collectins and Toll‐like receptor 2, and its phagocytosis is enhanced by collectins
Authors: Konishi Masanori , Nishitani Chiaki , Mitsuzawa Hiroaki , Shimizu Takeyuki , Sano Hitomi , Harimaya Atsushi , Fujii Nobuhiro , Himi Tetsuo , Kuroki Yoshio
Published: May 2006

Alloiococcus otitidis has been found to be associated with otitis media with effusion. In this study we investigated whether TLR2 and collectins, surfactant protein A (SP‐A) and mannose‐binding lectin (MBL), interacted with A. otitidis. Both SP‐A and MBL bound to A. otitidis in a Ca2+‐dependent manner. A. otitidis induced IL‐8 secretion from U937 cells and NF‐κB activation in TLR2‐transfected HEK293 cells. However, the cells transfected with the mutant TLR2P681H did not respond to A. otitidis. In addition, A. otitidis co‐sedimented a recombinant soluble form of the extracellular TLR2 domain, indicating direct binding of the bacterium to TLR2. SP‐A and MBL augmented the phagocytosis of A. otitidis by J774A.1 cells. The collectin‐stimulated phagocytosis of A. otitidis was significantly attenuated when fucoidan and polyinosinic acid were co‐incubated. Immunoblotting analysis revealed that MBL was present in the middle ear effusion from patients with otitis media. These results demonstrate that A. otitidis is a ligand for the collectins and TLR2, and that the collectins enhance the phagocytosis of A. otitidis by macrophages, suggesting important roles of the collectins and TLR2 in the innate immunity of the middle ear against A. otitidis infection.
Functional impairment of cytotoxic T cells in the lung airways following respiratory virus infections
Authors: Vallbracht Simone , Unsöld Heike , Ehl Stephan
Published: May 2006

We investigated the differentiation phenotype and function of virus‐specific and non‐specific CTL that were recruited to the lung parenchyma and the bronchoalveolar space after respiratory virus infections. Soon after virus elimination, we observed functional impairment of CTL isolated from the airways in their ability to produce IFN‐γ and TNF‐α and to lyse target cells. Impaired cytotoxicity was due to a reduced content of granzyme B and a reduced ability to mobilize lytic granules. This impairment in effector functions (a) was largely restricted to CTL in the lung airways, (b) affected both CTL specific for the infecting virus as well as those that were recruited non‐specifically to the inflamed lung, (c) was independent of contact between CTL and their specific viral antigen, (d) was not restricted to terminally differentiated CTL but also affected resting memory CTL and (e) could be elicited by both respiratory syncytial virus and influenza virus and thus seemed to be largely independent of the infecting virus. These observations suggest that functional impairment of antiviral T cells in the lung is not the consequence of a viral escape strategy. It may rather result from the particular milieu in the bronchoalveolar space and reflect a host mechanism to prevent excessive pulmonary inflammation.
BLIMP‐1 is a target of cellular stress and downstream of the unfolded protein response
Authors: Doody Gina M. , Stephenson Sophie , Tooze Reuben M.
Published: May 2006

B lymphocyte‐induced maturation protein‐1 (BLIMP‐1) acts during differentiation of B cells and monocytes, but was originally identified as a repressor of the IFN‐β promoter induced during viral infection. A central regulator of the intracellular response to viral infection is the interferon‐inducible double‐stranded RNA activated protein kinase (PKR). PKR belongs to a family of kinases that phosphorylate the eukaryotic translation initiation factor 2‐alpha (eIF2α) and activate common downstream signaling pathways. PERK, the endoplasmic reticulum resident PKR‐homologue, is activated during the unfolded protein response (UPR), a stress response involved in both macrophage activation and terminal B‐cell differentiation. This suggested that BLIMP‐1 might be a target of stress responses involving PERK. We demonstrate that BLIMP‐1 is rapidly up‐regulated during the UPR in human myeloid and B‐cell lines. This response is conserved in murine B‐cells and murine macrophages, in which mimics of physiological stress and classical activation stimuli also induce Blimp‐1. During the UPR, BLIMP‐1 mRNA is induced at the level of transcription. This response is dependent on an intact PERK signaling pathway, independent of new protein synthesis and blocked by an inhibitor of NF‐κB. Our data provide evidence for a novel pathway linking cellular stress to BLIMP‐1, a regulator of differentiation in macrophages and B cells.
Colitogenic and non‐colitogenic commensal bacteria differentially trigger DC maturation and Th cell polarization: An important role for IL‐6
Authors: Frick Julia S. , Zahir Naima , Müller Martina , Kahl Frauke , Bechtold Oliver , Lutz Manfred B. , Kirschning Carsten J. , Reimann Jörg , Jilge Burghard , Bohn Erwin , Autenrieth Ingo B.
Published: May 2006

We investigated whether commensal bacteria modulate activation and maturation of bone marrow‐derived DC and their ability to prime CD4+ T cells. We used Escherichia coli mpk, which induces colitis in gnotobiotic IL‐2‐deficient (IL‐2–/–) mice, and Bacteroides vulgatus mpk, which prevents E. coli‐induced colitis. Stimulation of DC with E. coli induced TNF‐α, IL‐12 and IL‐6 secretion and expression of activation markers. Moreover, stimulation of DC with E. coli increased T cell activation and led to Th1 polarization. Stimulation with B. vulgatus led only to secretion of IL‐6, and DC were driven into a semi‐mature state with low expression of activation markers and did not promote Th1 responses. B. vulgatus‐induced semi‐mature DC were non‐responsive to stimulation by E. coli in terms of maturation, T cell priming and TNF‐α but not IL‐6 production. The non‐responsiveness of B. vulgatus‐stimulated DC was abrogated by addition of anti‐IL‐6 mAb or mimicked with rIL‐6. These data suggest that B. vulgatus‐induced IL‐6 drives DC into a semi‐mature state in which they are non‐responsive to proinflammatory activation by E. coli. This in vitro mechanism might contribute to the prevention of E. coli‐triggered colitis development by B. vulgatus in vivo; high IL‐6 mRNA expression was consistently found in B. vulgatus‐colonized or B. vulgatus/E. coli co‐colonized IL‐2–/– mice and was associated with absence of colitis.
Persistent antigenic stimulation alters the transcription program in T cells, resulting in antigen‐specific tolerance
Authors: Anderson Per O. , Manzo Barbara A. , Sundstedt Anette , Minaee Sophie , Symonds Alistair , Khalid Sabah , Rodriguez‐Cabezas Maria E. , Nicolson Kirsty , Li Suling , Wraith David C. , Wang Ping
Published: May 2006

Repetitive antigen stimulation induces peripheral T cell tolerance in vivo. It is not known, however, whether multiple stimulations merely suppress T cell activation or, alternatively, change the transcriptional program to a distinct, tolerant state. In this study, we have discovered that STAT3 and STAT5 were activated in response to antigen stimulation in vivo, in marked contrast to the suppression of AP‐1, NF‐κB and NFAT. In addition, a number of transcription factors were induced in tolerant T cells following antigen challenge in vivo, including T‐bet, Irf‐1 and Egr‐2. The altered transcription program in tolerant cells associates closely with the suppression of cell cycle progression and IL‐2 production, as well as with the induction of IL‐10. Studies of T‐bet and Egr‐2 show that the function of T‐bet in peptide treatment‐induced regulatory T cells is not associated with Th1 differentiation, but correlates with the suppression of IL‐2, whereas expression of Egr‐2 led to an up‐regulation of the cell cycle inhibitors p21cip1 and p27kip. Our results demonstrate a balanced transcription program regulated by different transcription factors for T cell activation and/or tolerance during antigen‐induced T cell responses. Persistent antigen stimulation can induce T cell tolerance by changing the balance of transcription factors.

See accompanying commentary http://www.dx.doi.org/10.1002/eji.200636171
The hidden truth about gene expression in Tregs: Is it what you don't see that counts?
Authors: Cobbold Stephen P.
Published: May 2006

A population of IL‐10 secreting regulatory T cells (PI‐Tregs) can be induced in a mouse TCR transgenic model of experimental autoimmune encephalomyelitis (EAE) by intranasal administration of the N‐terminal peptide of myelin basic protein. A paper in this issue of the European Journal of Immunology identifies patterns of gene expression that distinguish PI‐Treg from naïve T cells after activation in vivo. PI‐Tregs are anergic and the expression of egr2 may be involved in regulation of the cell cycle. The surprising expression of the Th1 determining gene T‐bet in PI‐Tregs may be functionally relevant as transfection of T‐bet into a hybridoma induced some genes associated with regulatory T cells, such as tlr2 and gzmb. In this commentary, PI‐Tregs are considered in comparison to other Tregs, such as the natural CD4+CD25+ and Tr1 cells, and there seems to be considerable overlap in gene expression between all three Treg populations, but also with both Th1 and Th2 cells. It is suggested that regulatory activity may be a common feature of all activated T cells and that a defining principle of a Treg is the lack of effector functions due to a partial or incomplete differentiation to either Th1 or Th2.

See accompanying article http://dx.doi.org/10.1002/eji.200635883
Synthesis, Structure, and Magnetic Properties of Hydroxo‐Bridged Vanadium Oxalate V2O2(OH)2(C2O4)(H2O)2
Authors: Yang Sihai , Li Guobao , Tian Shujian , Liao Fuhui , Lin Jianhua
Published: May 2006

The reaction of V2O5 with H2C2O4·2H2O in the presence of H3BO3 under hydrothermal conditions has afforded V2O2(OH)2(C2O4)(H2O)2 (1), which crystallizes in the triclinic system, space group P$\bar {1}$ with a = 5.2405(10) Å, b = 5.7340(11) Å, c = 7.1778(14) Å, α = 76.44(3)°, β = 69.37(3)°, γ = 75.37(3)°. The vanadium atoms in 1 form dimers by sharing edges consisting of μ‐OH groups, and these dimers are connected further by oxalate ligands to form chains. The magnetic susceptibility data of 1 fit excellently with the Heisenberg dimer model in the temperature interval 2–300 K. Compound 1 is antiferromagnetic with a J value of –29.6 cm–1. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Semicarbazide‐Functionalized Silicate Nanoparticles for Peptide Ligation
Authors: Doussineau Tristan , Durand Jean‐Olivier , El‐Mahdi Ouafâa , Maillet Céline , Melnyk Oleg , Olivier Christophe , Smaïhi Monique
Published: May 2006

Monodisperse silicate nanoparticles have been used for the development of a site‐specific ligation method that enables the control of the biomolecule orientation at the solid–liquid interface. Two types of zeolite nanoparticles were studied: zeolite β, which possesses a Si/Al ratio of 25, and silicalite‐1, which is a fully silicic material. Zeolite‐type materials are microporous silicate with pores of a well‐defined size ranging from 2 to 20 Å. Semicarbazide‐functionalized silicate colloids have been prepared for the site‐specific ligation of COCHO‐modified polypeptides. The obtained colloidal suspensions have been characterized by complementary techniques providing information on the size distribution, morphology, and porosity of the particles and chemical nature of the grafting. The specificity of the particles’ surface for the semicarbazide group has been studied by fluorescence spectroscopy with two peptides labeled with rhodamine. A first peptide bares a COCHO functionality, which should bind covalently with the semicarbazide surface. The second peptide bares an amine end‐group, which should interact by nonspecific adsorption with the surface. The results demonstrated that the peptide/colloids’ reactivity is dramatically influenced by the chemical composition of the particles’ surface. Indeed, while zeolite β (aluminosilicate) particles react indifferently with the two peptides, silicalite particles (pure silicate) anchor exclusively the peptide bearing the COCHO functionality. This particular physisorption phenomenon of zeolite β is attributed to the aluminum atoms present at the particles’ surface, which have a specific affinity for peptides. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Design of Cyano‐Bridged Coordination Polymers Based on Tetrahedral Rhenium Cluster Cyanide Complexes and 3d Transition Metals
Authors: Efremova Olga A. , Mironov Yuri V. , Fedorov Vladimir E.
Published: May 2006

This microreview surveys some novel possibilities in the design of coordination polymers using the tetrahedral rhenium cluster chalcocyanide complexes [Re4Q4(CN)12]4– (Q = S, Se, Te) and 3d transition metals. The large number of cyano groups in the cluster complexes [Re4Q4(CN)12]4–, their ambidentate character and their strong ability to form cyano‐bridged structures lead to the formation of a wide variety of coordination polymers with different architectures that depend on the reaction conditions. The diversity of the coordination environment of the transition metals has been used as one of the most important factors to control the dimensionality of the crystal structures of the target compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
First Example of Dendrons as Topological Amplifiers
Authors: Turrin Cédric‐Olivier , Maraval Alexandrine , Magro Germinal , Maraval Valérie , Caminade Anne‐Marie , Majoral Jean‐Pierre
Published: May 2006

A phosphorus‐containing dendron was synthesized and grafted to a tetraphosphorus macrocycle. The presence of such bulky substituents allowed for the first time the amplification of topological differences in the macrocycle. These differences become detectable by 31P NMR spectroscopy, with the appearance of several signals for the phosphorus atoms included in the macrocycle. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Reactions of Aminobis(phenolate)‐Supported Dioxidotungsten(VI) and Dioxidomolybdenum(VI) Complexes
Authors: Lehtonen Ari , Sillanpää Reijo
Published: May 2006

The dioxidotungsten(VI) and ‐molybdenum(VI) complexes [WO2(O2NOMe)] (1), [MoO2(O2NOMe)] (2) and [{MoO2(O2NMe)}2] (3) [O2NOMe methoxyethylamino‐N,N‐bis(2‐methylene‐4,6‐dimethylphenolate) dianion, O2NMe = methylamino‐N,N‐bis(2‐methylene‐4,6‐dimethylphenolate) dianion] can react with chloride sources (Me3SiCl, SOCl2) to form resultant monooxido dichloro compounds [WOCl2(O2NOMe)] (4), [MoOCl2(O2NOMe)] (5) and [MoOCl2(O2NMe)] (6), respectively. The reaction of tungsten complex yields of the mixture of cis‐4 and trans‐4, which can be separated and characterized. The reactions of analogous molybdenum complexes with Me3SiCl yield trans isomers of 5 and 6 as individual products. Reaction of dioxidotungsten complex 1 with isopropyl isocyanate was found to produce a tungsten(VI) complex [W(O2NOMe)(N‐iPr)(L)] (7) (L = N,N′‐diisopropylureate) with a terminal imido group and a bidentate ureate ligand. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis and Reactivity of β‐Bromo‐β‐Substituted Dehydroalanines
Authors: Ferreira Paula M. T. , Monteiro Luís S.
Published: May 2006

The methyl ester of N‐tert‐butoxycarbonyl‐(Z)‐β‐bromo‐β‐(1,2,4‐triazol‐1‐yl)dehydroalanine was prepared by treatment of the methyl ester of N‐tert‐butoxycarbonyl‐(E)‐β‐(1,2,4‐triazol‐1‐yl)dehydroalanine with N‐bromosuccinimide (NBS), followed by Et3N. The reactivities of this compound and of our previously synthesized methyl ester of N‐tert‐butoxycarbonyl‐β,β‐dibromodehydroalanine towards several nucleophiles were studied, and it was found that these compounds react with oxygen nucleophiles to give the corresponding α‐alkoxy‐β,β‐disubstituted alanines. Addition to the α‐carbon atom also occurred when the β,β‐dibromodehydroalanine derivative was treated with primary amines, giving α‐amino‐β,β‐dibromoalanines. Treatment of the β‐bromo‐β‐(1,2,4‐triazol‐1‐yl)dehydroalanine derivative with amines gave α‐(alkylamino)‐β‐(alkylimino)alanines in high yields. These iminoalanines afforded α‐aminoglycines when treated with silica in dichloromethane. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
An Efficient and Diastereoselective Intramolecular 1,3‐Dipolar Cycloaddition of Cyclic Azomethine Ylides and Nitrones
Authors: Pedrosa Rafael , Andrés Celia , Nieto Javier , Pérez‐Cuadrado Cristóbal , San Francisco Iván
Published: May 2006

Nitrones and azomethine ylides formed by condensation of chiral 2‐formyl‐perhydro benzoxazines and N‐substituted hydroxylamines or cyclic α‐amino acids cyclize intramolecularly yielding polycyclic isoxazolidine or pyrrolidine derivatives, respectively, with total diastereoselectivity. On the contrary, stabilized azomethine ylides derived from methyl prolinate undergo the cyclization products in very low yields.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis of N‐(3‐Phenylpropyl)‐Substituted Tricyclic ABE Ring Analogues of the Alkaloid Methyllycaconitine
Authors: Lehmann Anna , Brocke Constanze , Barker David , Brimble Margaret A.
Published: May 2006

The synthesis of several ABE tricyclic analogues 5, 31 and 32 of the alkaloid methyllycaconitine (1) is reported. The analogues contain two key pharmacophores: a tertiary N‐(3‐phenylpropyl) substituent attached to a 3‐azabicyclo[3.3.1]nonane ring system and a 2‐(3‐methyl‐2,5‐dioxopyrrolidin‐1‐yl)benzoate ester. Double Mannich reaction of the cyclic β‐keto esters 6 and 17 with the bis(aminol) ether 7 using methyltrichlorosilane as an activating agent provided an efficient method for the construction of the 3‐azabicyclo[3.3.1]nonanes 8 and 18. Ring‐closing metathesis of the derived dienes 11, 19, and 20 afforded the tricyclic ethers 12, 21, and 22, respectively, the C‐8 ester of which was reduced to a hydroxymethyl group to form the ABE tricyclic analogues 13, 23, and 24. Conversion of the alcohol 13 to the anthranilate ester 14 using N‐(trifluoroacetyl)anthranilic acid followed by fusion with methylsuccinic anhydride afforded the analogue 5 containing the key N‐(methylsuccinimido)anthranilate pharmacophore. In the case of the alcohols 23 and 24 the 2‐(3‐methyl‐2,5‐dioxopyrrolidin‐1‐yl)benzoate ester pharmacophore was appended by direct esterification with unsaturated acid 28 followed by hydrogenation to the ABE tricyclic compounds 33 and 34. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Pyriporphyrin – A Porphyrin Homologue Containing A Built‐in Pyridine Moiety
Authors: Myśliborski Radomir , Latos‐Grażyński Lechosław , Szterenberg Ludmiła
Published: May 2006

Pyriporphyrin 1 (6,11,16,21‐tetraaryl‐22‐aza‐m‐benziporphyrin), the simplest homologue of 5,10,15,20‐tetraarylporphyrin can be constructed by replacement of one of the pyrrole rings of 5,10,15,20‐tetraarylporphyrin with a pyridine moiety, linked to the macrocycle through α,α′‐carbon atoms. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Retracted:It's all in the timing: measuring emotional reactions to stereotype threat before and after taking a test
Authors: Marx David M. , Stapel Diederik A.
Published: May 2006

Stereotype threat is often described as resulting from increased anxiety over confirming a negative stereotype about one's group (Steele, 1997). However, variations in the type of emotional reactions targets experience as a function of stereotype threat has never been examined systematically before and after taking a test, thus it is unclear whether targets experience different emotions at different points in the testing session. The present study investigated this issue of emotional specificity. Results demonstrate that targets of a negative stereotype, but not non‐targets, experienced heightened anxiety prior to taking a test under stereotype threat conditions and heightened frustration once the test was concluded. No effects were found in the non‐stereotype threat conditions. These findings, therefore, highlight the specific affective states that targets and non‐targets experience in threat and non‐threat conditions, as well as how these affective states can be assessed using self‐report measures. Copyright © 2006 John Wiley & Sons, Ltd.
A comparison of SRTM and high‐resolution digital elevation models and their use in catchment geomorphology and hydrology: Australian examples
Authors: Hancock G. R. , Martinez C. , Evans K. G. , Moliere D. R.
Published: May 2006

The recently released Shuttle Radar Topography Mission (SRTM) 3‐arc second digital elevation data set provides a complete global coverage of the Earth's land surface. In this paper we examine the SRTM data for three catchments in Australia over a range of climates, geology and resultant geomorphology. To test this new data set the SRTM data are compared with high resolution digital elevation models. We use basic hydrological and geomorphological statistics and descriptors such as the area–slope relationship, cumulative area distribution and hypsometric curve, along with Strahler and networking statistics. The above measures describe the surface morphology of a catchment, therefore integrating catchment geology, climate and vegetation. The SRTM data were also assessed as input into the SIBERIA landscape evolution and soil erosion model as were runoff properties, using a wetness index. The results demonstrate that the 90 m SRTM data provide a poor catchment representation. Hillslopes appear as a linked set of facets and display little of the complex curvature that is observed in high resolution data. While catchment area–slope and area–elevation (hypsometry) properties are largely correct, catchment area, relief and shape (as measured by the width function) are poorly captured by the SRTM data. Catchment networking statistics are also variable. The large grid size of the SRTM data also results in incorrect drainage network patterns and different runoff properties. Consequently, care must be used for quantitative assessment of catchment hydrology and geomorphology, as in all cases SRTM‐derived catchment area is incorrect and smaller digital elevation grid sizes are required for accurate catchment‐wide assessment. While only a limited number of catchments have been examined, we believe our findings are applicable to other areas. © Crown Copyright 2006. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd.
Flame‐retardant action of red phosphorus/magnesium oxide and red phosphorus/iron oxide compositions in recycled PET
Authors: Laoutid F. , Ferry L. , Lopez‐Cuesta J. M. , Crespy A.
Published: May 2006

Red phosphorus was combined with metallic oxides Fe2O3 and MgO to improve the fire properties of recycled PET. Both Fe2O3 and MgO act as co‐synergist agents at a total loading of 5 wt%. The analysis by diffraction X of the char formed during combustion shows that transformation of Fe2O3 to Fe3O4 occurs. Fe2O3 favours the oxidation and improves the effectiveness of red phosphorus. It is suggested that MgO interacts with acidic end groups of PET and forms a thermal stable residue. The thermal decomposition of recycled PET containing red phosphorus combined with Fe and Mg oxides was studied by thermal analysis and leads to an increase in char formation. While the incorporation of Fe2O3 in this ternary blend maintains the mechanical properties of PET, the reactivity of MgO leads to a brittle material. The use of reinforcements (talc and glass fibres) to mechanically stabilize the char formed during combustion of ternary blend with Fe2O3 entails a further decrease in heat release rate, nevertheless impact resistance of the material decreases dramatically. Copyright © 2005 John Wiley & Sons, Ltd.
The identity of Paeonia corsica Sieber ex Tausch (Paeoniaceae), with special reference to its relationship with P. mascula (L.) Mill.
Authors: De‐Yuan Hong , Xiao‐Quan Wang
Published: May 2006

The taxonomy of the genus Paeonia in central Mediterranean islands has been controversial, with number of recognized taxa changing greatly from one species without infraspecific division to three species or five infraspecific taxa in one species, and with the number of synonyms as great as 30. In the present work, the taxonomic history is thoroughly reviewed and a taxonomic revision is made based on extensive field work, chromosome observation, population sampling, examination of a large amount of herbarium specimens, and subsequent statistic analysis. As a result of the studies P. corsica Sieber ex Tausch, an ignored specific name, is restored at specific rank, and the species is found distinct from all the three subspecies of P. mascula in this region in having mostly nine (vs ≥ 10) leaflets/segments, shorter hairs (1.5 mm vs 3 mm long) on carpels, rather densely holosericeous (vs glabrous or very sparsely hirsute) on the lower surface of leaves. It is a diploid, confined to Corsica France), Sardinia (Italy), Ionian Islands and Akarnania Province of Greece, whereas P. mascula is a tetraploid, widely distributed from Spain to Turkey and Iraq, but not in Corsica, Sardinia and W Greece. In addition, type specimens of four taxa are designated, and 29 botanic names are listed as synonyms of P. corsica in this paper. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Studien über oligozäne Populus ‐Arten aus der Weißelstersenke südlich von Leipzig, Sachsen (Deutschland)
Authors: Reuschel Ch. , Walther H.
Published: May 2006

Aus dem höheren Paläogen der Weißelstersenke (Weißelsterbecken) südlich von Leipzig (Sachsen, Deutschland) werden von mehreren Fundorten zwei fossile Populus ‐Arten [P. germanica (Menzel) Walther und P. zaddachii Heer] nach Merkmalskomplexen der Blattmorphologie und Epidermisstruktur an mehr als 500 Belegen aus paläogenen (Unteroligozän bis Oligo‐/Miozän) Sedimenten unterschiedlicher Fazies untersucht. Eingehende Vergleiche mit rezenten Populus ‐Arten der Sektionen Leucoides Spach, Leuce Duby und Tacamahaca Spach ergeben bestimmte Analogien zur fossilen Formart Populus zaddachii. Vor allem mit den heute in China (1300–3500 m Höhe) verbreiteten P. lasiocarpa Oliv. und P. wilsonii Schneider bestehen sowohl in der Blattmorphologie als auch in der Epidermisstruktur große Übereinstimmungen. Die in der Blattmorphologie äußerst variable Morphospezies Populus germanica ist eine sehr ursprüngliche Pappel‐Art, deren Blätter als archaisches Merkmal eine Subpeltation aufweisen können. Zu P. germanica konnte bisher keine analoge rezente Pappel‐Art gefunden werden.

Populus germanica ist als dominantes Florenelement der azonalen Waldvegetationen (flussbegleitende Auenwälder) aus dem tiefen Unteroligozän, Oberoligozän und Oligo/Miozän von Mitteldeutschland bekannt.

Populus zaddachii kommt im Oligozän Mitteleuropas (z. B. Sachsen) und im Umfeld von Kaliningrad (Russland) in den alttertiären „Baltischen Floren“ vor. In den meeresnahen Oligozän‐Floren (z. B. Florenkomplex Thierbach) kann diese Art prädominant gemeinsam mit P. germanica als Auenwaldelement auftreten. In den tief unteroligozänen vulkanischen Floren des Böhmischen Mittelgebirges (Tschechische Republik) und der Südlausitz (Deutschland) ist sie nur ein akzessorisches Element des Mixed Mesophytic Forest (Kundratice, Bechlejovice/Tschechische Republik; Seifhennersdorf, Südostoberlausitz /Deutschland). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bomarea edulis (Tussac) Herb. a nearly forgotten pre‐Columbian cultivated plant and its closest relatives (Alstroemeriaceae)
Authors: Hofreiter A.
Published: May 2006

The morphological variability, distribution, tuber anatomy, use and taxonomy of Bomarea edulis are discussed. Bomarea edulis is distributed from Mexico to Argentina. Its wide distribution may be caused by the fact that the root tubers have been used as food. A well developed plant can bear more than 20 root tubers with 5 cm in diameter. The tubers are named with a number of local names, best known as “white Jerusalem artichoke” or in German as “Bomarie”, respectively. Bomarea edulis is morphologically variable, this and the wide distribution have caused 23 synonyms, the very similar and also edible B. ovata has seven synonyms. Bomarea edulis is compared to its closest similar species and a key is given to determine them. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Species diversity and species composition of epiphytic bryophytes and lichens – a comparison of managed and unmanaged beech forests in NE Germany
Authors: Friedel A. , v.Oheimb G. , Dengler J. , Härdtle W.
Published: May 2006

The impact of forest management on the species diversity and species composition of epiphytic bryophytes and lichens in beech forests (Fagus sylvatica) of NE Germany was analysed. The investigations were carried out in one unmanaged and in one managed forest, with 45 sample plots of 400 m2each. In the sample plots, the presence of the epiphytes on 2–4 randomly chosen trees (100 trees per forest) and seven environmental variables were recorded. The total number of species and the mean lichen density per mantle area was higher in the unmanaged forest than in the managed forest. Regression analyses and DCA revealed the diameter at breast height (dbh) as the most important factor affecting the species diversity and species composition in both forest types. The dbh was positively correlated with the number of growth anomalies and with the bark roughness of the phorophytes and thus a good indicator for the habitat quality. Moreover, the light conditions had a significant impact on the species composition in both forests types and on the species diversity in the managed forest. In particular, epiphytes demanding shady conditions and a consistent humidity may suffer from the abrupt exposition to radiation and the lower humidity after logging. Species typical for the unmanaged forest and most rare species must be considered as stenoecious as they demand the shady and humid conditions of the forest interior and grow on old, large trees. With the aim of sustaining the diversity of epiphytic bryophytes and lichens, forest management should ensure the continuous occurrence of big trees above the target diameter. In addition, a single tree selection felling method should be applied to minimise strong changes in the microclimate. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variability of male cones in Chamaecyparis as an example for Cupressaceae male cones
Authors: Schulz C. , Stützel Th.
Published: May 2006

In contrast to flowers of other seed plants, male cones in Cupressaceae show a high intraspecific variability regarding the number of scales per cone and the number of pollen sacs per scale. This is the first time a qualitative and quantitative analysis of this variability is given. The variability is shown in distinct patterns. A typical pattern or diagram can be gathered from the analyses of 30 cones, which illustrate the “normal” situation and the most frequent variability (average cone diagram). However, the overlapping intersections in the cone diagrams between the species do however not allow identifications based on single male cones. A detailed study of all five species of Chamaecyparis shows that all of them can be distinguished on the basis of their average male cone diagram. A principal component analysis shows that these five Chamaecyparis species form distinct clusters. Sample cones from different positions of the tree reveal no effect within the variability of the cone diagrams. In contrast, comparison between the species and its cultivars reveals a higher variability in cultivars. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Are population sizes of Campanula glomerata on the decline following the abandonment of traditional land‐use practices?
Authors: Bachmann U. , Hensen I.
Published: May 2006

In Central Germany, many species are known to decline due to the abandonment of traditional land use practices, among them Campanula glomerata . Within the scope of a population viability analysis for this species we monitored the development of several population size parameters such as total number of stems, number of flowering stems, population density and the area occupied by a population, all in landscapes defined by traditional land use practices as well as in landscapes where land use has been halted. However, over a time span of three years we did not detect any constant tendency for decreasing sizes of populations of C. glomerata on disused land compared to those on traditionally used land. Populations in used and abandoned landscapes were characterized by a high variability and fluctuation of size, and did not differ in any of the size parameters we determined. Further studies should include the monitoring of the age state structure of populations as important to facilitate a meaningful comparison of C. glomerata populations in abandoned and traditionally used landscapes. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Taxonomic studies of the species of Turbinaria (Fucales, Phaeophyta) from South India
Authors: Sophiammal Nettar P. , Panikkar M. V. N.
Published: May 2006

The taxonomic studies of seven taxa of Turbinaria , collected from different parts of South India are presented. The taxa include three species [T. conoides (J. Agardh) Kützing, T. decurrens Bory, and T. ornata (Turner) J.Agardh] and four forms [T. conoides f. laticuspidata W.R.Taylor, T. ornata f. evesiculosa (Barton) W.R.Taylor, T. ornata f. hainanensis W.R.Taylor and T. ornata f. krishnamurthii f. nova Sophiammal & Panikkar]. Out of these seven taxa, T. ornata (Turner) J.Agardh f. hainanensis W.R.Taylor is a new report to India and T. ornata (Turner) J.Agardh f. krishnamurthii is a new addition to Indian marine flora. All the collected taxa were screened for their morphological characters and the identification was based on the general shape, branching pattern, shape, size and arrangement of the laterals (‘leaves’), size of the vesicles and the occurrence and orientation of the spines. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Four new species in Aspidistra Ker‐Gawl. (Ruscaceae) from China, Vietnam and Japan
Authors: Tillich H.‐J.
Published: May 2006

Four species of Aspidistra new to science are described, i.e. two species from China, Prov. Sichuan (A. nanchuanensis H.‐J.Tillich sp. nova and A. lobata H.‐J.Tillich sp. nova), one species from northern Vietnam (A. tubiflora H.‐J.Tillich sp. nova), and one species from southern Japan, Ohsumi Islands (A. insularis H.‐J.Tillich sp. nova). Including the four new species, the genus recently encompasses 80 species. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pollen morphology of African Celtis (Celtidaceae)
Authors: Sattarian A. , van den Berg R. G. , van der Maesen L. J. G.
Published: May 2006

Pollen morphology of all African Celtis species was examined and compared with that of some Asian species, using light and scanning electron microscopy. The pollen grains are triporate and more or less spheroidal. Two pollen types could be distinguished based on a feature of the apertures and the density of the surface ornamentation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
EnumeratioAlbucarum(Hyacinthaceae) Austro‐Africanarum adhuc cognitarum
Authors: Müller‐Doblies Ute
Published: May 2006

In continuation of a series of papers on the Southern African species ofAlbucathe following taxonomic additions to the subgeneraFalconeraandAlbucaare presented: (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Epidermal growth factor receptor expression regulates proliferation in the postnatal rat retina
Authors: Close Jennie L. , Liu Janice , Gumuscu Burak , Reh Thomas A.
Published: May 2006

Epidermal growth factor (EGF) is known to promote proliferation of both retinal progenitors and Muller glia in vitro, but several questions remain concerning an in vivo role for this factor. In this study, we investigated whether the EGF receptor (EGFR) is necessary for the maintenance of normal levels of progenitor and Muller glial proliferation in vivo. Here, we show that (1) mice with homozygous deletion of the Egfr gene have reduced proliferation in late stages of retinal histogenesis, (2) EGF is mitogenic for Müller glia in vivo during the first two postnatal weeks in the rodent retina, (3) the effectiveness of EGF as a Müller glial mitogen declines in parallel with the decline in EGFR expression as the retina matures, and (4) following damage to the retina from continuous light exposure, EGFR expression is up‐regulated in Müller glia to levels close to those in the neonatal retina, resulting in a renewed mitotic response to EGF. Together with previous results from other studies, these data indicate that the downregulation of a growth factor receptor is one mechanism by which glial cells maintain mitotic quiescence in the mature nervous system. © 2006 Wiley‐Liss, Inc.
Three‐dimensional reconstruction of the nose epidermal cells in the microbial feeding nematode, Acrobeles complexus (Nematoda: Rhabditida)
Authors: Bumbarger Daniel J. , Crum John , Ellisman Mark H. , Baldwin James G.
Published: May 2006

The epidermis of the anterior end (nose) plays an important role in the evolution, development, and functional feeding morphology in nematodes, but information on this complex organ system is limited. Here, we produce a 3D model of 13 of the cells making up this organ system reconstructed from serial transmission electron micrographs of the microbial feeding nematode, Acrobeles complexus. Nose epidermal cells were found to be broadly similar to those of the distantly related model organism Caenorhabditis elegans in the number and arrangement of nuclei in these largely syncytial cells; this similarity demonstrates striking evolutionary conservation that allows for robust statements of homology between the taxa. Examining details of cell shape, however, revealed surprisingly complex subcellular specialization, which differed markedly from C. elegans in the number and arrangement of cell processes. Anterior toroid processes of the anterior arcade, posterior arcade, and HypB syncytia form a nested complex at the base of the labial probolae. Anterior toroid processes of HypC and the inner labial socket cells are associated with the base of the cephalic probolae and radial ridge processes. Extracellular filaments (tendon organs) and radiating cytoskeletal filaments of the posterior arcade syncytium form a connection between the body wall muscle cells and the pharynx. An epidermal cell with no known homolog in other nematodes is identified. Findings provide a basis to propose hypotheses related to the development and evolutionary origin of specialized feeding appendages (probolae) in the Cephalobinae (including Acrobeles), and hypotheses of homology are revised for epidermal cells in the nose of the closely related and primarily plant parasitic group, Tylenchida. J. Morphol. © 2006 Wiley‐Liss, Inc.
Chronic systemic D‐galactose exposure induces memory loss, neurodegeneration, and oxidative damage in mice: Protective effects of R‐α‐lipoic acid
Authors: Cui Xu , Zuo Pingping , Zhang Qing , Li Xuekun , Hu Yazhuo , Long Jiangang , Packer Lester , Liu Jiankang
Published: May 2006

Chronic systemic exposure of mice, rats, and Drosophila to D‐galactose causes the acceleration of senescence and has been used as an aging model. The underlying mechanism is yet unclear. To investigate the mechanisms of neurodegeneration in this model, we studied cognitive function, hippocampal neuronal apoptosis and neurogenesis, and peripheral oxidative stress biomarkers, and also the protective effects of the antioxidant R‐alpha‐lipoic acid. Chronic systemic exposure of D‐galactose (100 mg/kg, s.c., 7 weeks) to mice induced a spatial memory deficit, an increase in cell karyopyknosis, apoptosis and caspase‐3 protein levels in hippocampal neurons, a decrease in the number of new neurons in the subgranular zone in the dentate gyrus, a reduction of migration of neural progenitor cells, and an increase in death of newly formed neurons in granular cell layer. The D‐galactose exposure also induced an increase in peripheral oxidative stress, including an increase in malondialdehyde, a decrease in total anti‐oxidative capabilities (T‐AOC), total superoxide dismutase (T‐SOD), and glutathione peroxidase (GSH‐Px) activities. A concomitant treatment with lipoic acid ameliorated cognitive dysfunction and neurodegeneration in the hippocampus, and also reduced peripheral oxidative damage by decreasing malondialdehyde and increasing T‐AOC and T‐SOD, without an effect on GSH‐Px. These findings suggest that chronic D‐galactose exposure induces neurodegeneration by enhancing caspase‐mediated apoptosis and inhibiting neurogenesis and neuron migration, as well as increasing oxidative damage. In addition, D‐galactose‐induced toxicity in mice is a useful model for studying the mechanisms of neurodegeneration and neuroprotective drugs and agents. © 2006 Wiley‐Liss, Inc.
Antioxidant effect of rosemary, borage, green tea, pu‐erh tea and ascorbic acid on fresh pork sausages packaged in a modified atmosphere: influence of the presence of sodium chloride
Authors: Martínez Luis , Cilla Irene , Beltrán José A , Roncalés Pedro
Published: May 2006

Fresh pork sausages formulated with and without salt, and with antioxidant mixtures containing either rosemary extract, green tea powder, pu‐erh tea infusion or borage meal and their mixtures with ascorbic acid, were packaged in an atmosphere containing four parts O2 with one part CO2 (v/v) and stored in the dark for 20 days. In a series of three experiments, the following parameters were measured at 4‐day intervals: instrumental colour (CIE L* and a*), thiobarbituric acid reactive substances (TBARS), aerobic psychrotroph counts and sensory off‐odour and discolouration. NaCl caused a decrease of the L* value and promoted lipid oxidation, but it protected sausages from discolouration. Green tea powder, pu‐erh tea infusion and borage meal caused a strong inhibition of lipid oxidation, dependent on the concentration used, but they failed to protect sausages from colour loss, even in the presence of ascorbic acid. Rosemary extract plus ascorbic acid strongly inhibited lipid oxidation and therefore off‐odour formation, delayed sausage discolouration and inhibited microbial growth, extending the shelf‐life of salted fresh pork sausages by at least 4 days. Copyright © 2006 Society of Chemical Industry
Viscoelastic properties of caseinmacropeptide isolated from cow, ewe and goat cheese whey
Authors: Martín‐Diana AB , Gomez‐Guillén MC , Montero P , Fontecha J
Published: May 2006

Caseinmacropeptide (CMP) is a C‐terminal glycopeptide released from κ‐casein by the action of chymosin during cheese‐making. It is recognised as a bioactive peptide and is thought to be an ingredient with a potential use in functional foods. CMP occurs in sweet cheese whey and whey protein concentrate (WPC). Its composition is variable and depends on the particular whey source and the fractionation technology employed in the isolation. There were no significant (P < 0.05) differences in the relative apparent viscosities between species of CMPs (cow, ewe and goat). Analyses at different pH (2, 4, 7, 10), ionic strength (0, 0.2, 0.4 and 0.7 as NaCl molarity) and protein concentration (50, 100 and 200 g kg−1) at temperatures from 10 to 90 °C carried out found pH 7 and high protein concentration (200 g kg−1) conditions to be the best for CMP solutions to keep low and constant relative viscosity values with increasing temperature up to 75 °C. The viscoelastic properties–storage modulus, loss modulus and phase angle–of the different CMPs and WPC solutions were determined. Heat‐induced rheological changes in CMP solutions occurred at moderate temperatures (40–50 °C) with no appreciable differences in viscosity. Gelation took place significantly (P < 0.05) earlier in goat CMP (41 °C), followed by cow CMP (44 °C), ewe CMP (47 °C) and WPC (56 °C). Heating at 90 °C showed that WPC required significantly (P < 0.05) longer times to form gels (>5 min) than the CMPs (<5 min). WPC gels had higher (>20°) phase angle than CMP (<20°), which could be associated with untidy structures, limiting elastic properties of the gel. Copyright © 2006 Society of Chemical Industry
Changes in cell wall pectin and pectinase activity in apple and tomato fruits during Penicillium expansum infection
Authors: Miedes Eva , Lorences Ester P
Published: May 2006

Cell wall pectin degradation in apple and tomato fruit during infection by Penicillium expansum was investigated. In infected apple fruit, a significant decrease in the average molecular mass was observed in pectins extracted with CDTA and also in pectins extracted with Na2CO3. In tomato fruits, depolymerisation was also observed in both pectic fractions during infection, the major change being in the pectins extracted with Na2CO3. This pectin depolymerisation associated with P. expansum infection can be attributed to the action of pectinases; in apple fruit, a significant increase in polygalacturonase and pectin methylesterase was observed in infected fruits, although in tomato fruit the only increase in enzymatic activity significantly related to the infection was in polygalacturonase. These differences between apple and tomato fruit during fungus infection could be related to differences in cell wall structure and composition and also to the specificity of P. expansum's infection spectrum in each case. In both cases, pectin depolymerisation might increase the porosity of the wall and allow increased access of fungus colonisation and facilitate the progress of the fungal infection. Copyright © 2006 Society of Chemical Industry
Xylitol bioproduction from wheat straw: hemicellulose hydrolysis and hydrolyzate fermentation
Authors: Canilha Larissa , Carvalho Walter , Batista João , Silva Almeida e
Published: May 2006

A 22 central composite design with five center points was performed to estimate the effects of temperature (120, 130 and 140 °C) and acid loading (100, 150 and 200 mg g−1) on the yield of monomeric xylose recovery from wheat straw hemicellulose (YS/RM). Under the best hydrolysis condition (140 °C and 200 mg g−1), a YS/RM of 0.26 g g−1 was achieved. After vacuum concentration and detoxification by pH alteration and active charcoal adsorption, the hydrolyzate was used as source of xylose for xylitol bioproduction in a stirred tank reactor. A xylitol production of 30.8 g L−1 was achieved after 54 h−1 of fermentation, resulting in a productivity (QP) of 0.57 g L−1 h−1 and bioconversion yield (YP/S) of 0.88 g g−1. The maximum specific rates of xylose consumption and xylitol production were 0.19 and 0.15 g g−1 h−1, respectively. Copyright © 2006 Society of Chemical Industry