bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of an Ex vivo Femoral Head Model Assessed by Markers of Bone and Cartilage Turnover
Authors: Madsen Suzi Hoegh , Goettrup Anne Sofie , Thomsen Gedske , Christensen Søren Tvorup , Schultz Nikolaj , Henriksen Kim , Bay-Jensen Anne-Christine , Karsdal Morten Asser
Published: October 2010

Objective:

The pathophysiology of osteoarthritis involves the whole joint and is characterized by cartilage degradation and altered subchondral bone turnover. At present, there is a need for biological models that allow investigation of the interactions between the key cellular players in bone/cartilage: osteoblasts, osteoclasts, and chondrocytes.

Methods:

Femoral heads from 3-, 6-, 9-, and 12-week-old female mice were isolated and cultured for 10 days in serum-free media in the absence or presence of IGF-I (100 nM) (anabolic stimulation) or OSM (10 ng/mL) + TNF-α (20 ng/mL) (catabolic stimulation). Histology on femoral heads before and after culture was performed, and the growth plate size was examined to evaluate the effects on cell metabolism. The conditioned medium was examined for biochemical markers of bone and cartilage degradation/formation.

Results:

Each age group represented a unique system regarding the interest of bone or cartilage metabolism. Stimulation over 10 days with OSM + TNF-α resulted in depletion of proteoglycans from the cartilage surface in all ages. Furthermore, OSM + TNF-α decreased growth plate size, whereas IGF-I increased the size. Measurements from the conditioned media showed that OSM + TNF-α increased the number of osteoclasts by approximately 80% and induced bone and cartilage degradation by approximately 1200% and approximately 2600%, respectively. Stimulation with IGF-I decreased the osteoclast number and increased cartilage formation by approximately 30%.

Conclusion:

Biochemical markers and histology together showed that the catabolic stimulation induced degradation and the anabolic stimulation induced formation in the femoral heads. We propose that we have established an explant whole-tissue model for investigating cell-cell interactions, reflecting parts of the processes in the pathogenesis of joint degenerative diseases.
Primary and secondary phases in copper-cobalt smelting slags from the Copperbelt Province, Zambia
Authors: Vítková M. , Ettler V. , Johan Z. , Kříbek B. , Šebek O. , Mihaljevič M.
Published: October 2010

Pyrometallurgical slags from three Cu-Co smelters (Nkana, Mufulira, Chambishi) in the Copperbelt Province, Zambia, were studied from mineralogical and chemical points of view. The slags were enriched in metals and metalloids, mainly Cu (up to 35 wt.%), Co (up to 2.4 wt.%) and As (up to 3650 ppm). The following primary phases were observed in slags: Ca-Fe silicates (clinopyroxene, olivine) and leucite, oxides (spinel-series phases), ubiquitous silicate glass and sulphide/metallic droplets of various sizes. The presence of glass and skeletal/dendritic crystal shapes indicated rapid cooling of the slag melt. Copper and cobalt were found in low concentrations in the majority of silicates (olivine, clinopyroxene) and oxides, substituting for Fe in their structures (up to 7.15 wt.% CoO in olivine, 4.11 wt.% CuO in spinel). Similarly, up to 0.91 wt.% CoO and 6.90 wt.% CuO were observed in the interstitial glass. Nevertheless, the main carriers of these metals in the slags studied were Cu sulphides (digenite, chalcocite, bornite, chalcopyrite), Co-Fe sulphides (cobaltpentlandite), Co-bearing intermetallic phases ((Fe,Co)2As) and alloys. Weathering features corresponding to the presence of secondary metal-bearing phases, such as malachite (Cu2(CO3)(OH)2), brochantite (Cu4SO4(OH)6) and sphaerocobaltite (CoCO3), were observed on the slag surfaces. They indicate that the slags studied are reactive on contact with water/atmosphere and that their environmental stability and release of potentially harmful metals and metalloids must be evaluated further.
The Mull Palaeogene dyke swarm: insights into the evolution of the Mull igneous centre and dyke-emplacement mechanisms
Authors: MacDonald R. , Bagiński B. , Upton B. G. J. , Pinkerton H. , MacInnes D. A. , MacGillivray J. C.
Published: October 2010

Geochemical data are presented for five large Palaeogene dykes, members of the Mull swarm in southern Scotland and northern England (the Moneyacres, Hawick-Acklington, Barrmill, Muirkirk- Hartfell and Dalraith-Linburn dykes). The rock types range from basalt through andesite to dacite, although the range in individual intrusions is more restricted. The dykes are divisible into two groups; those where the compositional variation was generated by fractional crystallization of basaltic magmas, and those where it resulted from variable degrees of mixing of basaltic and silicic magmas. Several dykes are composite; the marginal facies can be more or less evolved than the central facies. The dyke magmas are thought to have originated from stratified magma chambers beneath the Mull centre and models are presented to show how the different components were derived from the chambers. Some dykes appear to have been terminated at or near the Southern Upland Fault, perhaps as a result of the chilling of early magma pulses by water in the fault. The Palaeogene dyke swarm is considerably more complex than previously recognized and has a significant input to models of the evolution of the Mull magmatic system.
Carlhintzeite, Ca2AlF7·H2O, from the Gigante granitic pegmatite, Córdoba province, Argentina: description and crystal structure
Authors: Kampf A. R. , Colombo F. , González del Tánago J.
Published: October 2010

Carlhintzeite, Ca2AlF7·H2O, has been found at the Gigante pegmatite, Punilla Department, Córdoba Province, Argentina. It occurs as colourless prismatic crystals up to 0.8 mm long, ubiquitously twinned on {001}. Electron microprobe analyses provided the empirical formula Ca1.98Al1.02F6.24(OH)0.76·H1.62O. A crystal fragment used for the collection of structure data provided the triclinic, C1̄ cell: a = 9.4227(4), b = 6.9670(5), c = 9.2671(7) Å, α = 90.974(6), β = 104.802(5), γ = 90.026(6)°, V = 558.08(7) Å3 and Z = 4. The crystal structure, solved by direct methods and refined to R1 = 0.0322 for 723 Fo > 4σF reflections, is made up of linkages of AlF6 octahedra, CaF8 polyhedra and CaF6(H2O)2 polyhedra. The AlF6 octahedra are isolated from one another, but share polyhedral elements with Ca polyhedra. Most notably, the Al1 octahedron shares trans faces with two CaF8 polyhedra and the Al2 octahedron shares trans edges with two CaF6(H2O)2 polyhedra. The linkage of the Ca polyhedra alone can be described as a framework in which edge-sharing chains along b are cross-linked by edge-sharing. Edge-sharing chains of Ca polyhedra along b in the carlhintzeite structure are similar to those along c in the structures of gearksutite, CaAlF4(OH)·(H2O), and prosopite, CaAl2F4(OH)4.
The experimental replacement of ilmenite by rutile in HCl solutions
Authors: Janssen A. , Putnis A. , Geisler T. , Putnis C. V.
Published: October 2010

To determine the mechanism of acid-leaching of ilmenite to ultimately forming rutile, we have carried out an experimental study of ilmenite alteration in autoclaves at 150ºC in HCl solutions. The resulting products were studied by X-ray diffraction, scanning electron microscopy, electron microprobe and Raman spectroscopy. In some experiments the solution was initially enriched in 18O and the distribution of the isotope in the alteration products mapped from the frequency shift of cation oxygen stretching bands in the Raman spectra. The alteration begins at the original ilmenite crystal surface and has also taken place along an intricate branching network of fractures in the ilmenite, generated by the reaction. Element-distribution maps and chemical analyses of the reaction product within the fractures show marked depletion in Fe and Mn and a relative enrichment of Ti. Chemical analyses however, do not correspond to any stoichiometric composition, and may represent mixtures of TiO2 and Fe2O3. The fracturing is possibly driven by volume changes associated with dissolution of ilmenite and simultaneous reprecipitation of the product phases (including rutile) from an interfacial solution along an inward moving dissolution-reprecipitation front. Raman spectroscopy shows that the 18O is incorporated in the rutile structure during the recrystallization. Throughout the alteration process, the original morphology of the ilmenite is preserved although the product is highly porous. The rutile inherits crystallographic information from the parent ilmenite, resulting in a triply-twinned rutile microstructure. The results indicate that the ilmenite is replaced directly by rutile without the formation of any intermediate reaction products. The reaction is described in terms of an interface-coupled dissolution-precipitation mechanism.
Major- and trace-element composition of REE-rich turkestanite from peralkaline granites of the Morro Redondo Complex, Graciosa Province, south Brazil
Authors: Vilalva F. C. J. , Vlach S. R. F.
Published: October 2010

Turkestanite, a rare Th- and REE-bearing cyclosilicate in the ekanite–steacyite group was found in evolved peralkaline granitesfrom the Morro Redondo Complex, south Brazil. It occurswith quartz, alkali feldspar and an unnamed Y-bearing silicate. Electron microprobe analysis indicates relatively homogeneous compositions with maximum ThO2, Na2O and K2O contentsof 22.4%, 2.93% and 3.15 wt.%, respectively, and significant REE2O3 abundances(5.21 to 11.04 wt.%). The REE patterns show enrichment of LREE over HREE, a strong negative Eu anomaly and positive Ce anomaly, the latter in the most transformed crystals. Laser ablation inductively coupled plasma mass spectrometry trace element patterns display considerable depletions in Nb, Zr, Hf, Ti and Li relative to whole-rock sample compositions. Observed compositional variations suggest the influence of coupled substitution mechanisms involving steacyite, a Na-dominant analogue of turkestanite, iraqite, a REE-bearing end-member in the ekanite–steacyite group, ekanite and some theoretical end-members. Turkestanite crystals were interpreted as having precipitated during post-magmatic stages in the presence of residual HFSE-rich fluidscarrying Ca, the circulation of which wasenhanced by deformational events.
Fluid-mineral interactions and constraints on monazite alteration during metamorphism
Authors: Budzyń B. , Hetherington C. J. , Williams M. L. , Jercinovic M. J. , Michalik M.
Published: October 2010

Clasts of metamorphosed Cadomian granites from the ∼50—60 Ma Carpathian flysch in Gródek near the Rożnowskie Lake (Silesian Unit, SE Poland) are studied. They are considered to represent the Silesian Ridge, one of the hypothetical, currently unexposed source areas that supplied Carpathian sedimentary basins with clastic material. The gneisses preserve several examples of corona textures that include cores of primary monazite surrounded by polygonal grains of secondary apatite with thorianite inclusions, with intermediate zones of lamellar grains of secondary monazite and outermost rims of clay minerals, or various combinations thereof. Preservation of the complete textures is rare with polygonal apatite with thorianite inclusions, lamellar grains of monazite and clay minerals being particularly prevalent. Locally, polygonal apatite with thorianite inclusions surrounded by allanite and REE-epidote corona with a bastnasite-synchysite phase occurs also. The textures observed developed during primary monazite breakdown and replacement by secondary minerals. The variation in reaction products indicates that alteration was strictly dependent on the local chemical system.
Lead hydrogen citrate monohydrate, Pb(C6H6O7)·H2O, formation during specimen cleaning: a cautionary mineralogical tale
Authors: Kampf A. R. , Mills S. J.
Published: October 2010

Crystal-structure analysis was used to identify crystals of Pb(C6H6O7)·H2O on a specimen of hematite pseudomorphous after magnetite from the Payύn Matrύ volcanic field, Mendoza Province, Argentina. The compound is triclinic,P, a = 6.3434(2),b= 6.4566(2), c = 12.0640(9) Å, α = 99.233(7), β = 102.810(7), γ = 101.562(7)° andZ=2.The crystal structure, refined toR1= 0.0169 for 2021 reflections[Fo>4σ(F)],consists of a zig-zag chain of 9-coordinated Pb2+atoms alongb. Chains are linked together by citrate molecules to form thick irregular layers in theabplane. The layers are linked together only by H bonds. The citrate molecule exhibits normal bond lengths and angles. The Pb2+atom exhibits markedly lopsided coordination due to the 6s2lone-electron-pair effect. The lone electron pairs on alternating sets of adjacent Pb2+atoms in the chain point towards one another.

The formation of the Pb(C6H6O7)·H2O crystals was the result of specimen cleaning in citric acid. The cleaning solution was apparently contaminated through the dissolution of minor associated Pb-bearing species by the citric acid. It is important to be aware of the possibility that micro-crystals may be inadvertently grown on mineral specimens during chemical cleaning, to carefully and critically inspect paragenetic relationships especially when studying mineral specimens that may have been cleaned in chemical agents, and to be particularly aware of health risks when treating Pb-bearing minerals in aqueous citric acid solutions.
Rare earth element geochemistry of columbite-group minerals: LA-ICP-MS data
Authors: Graupner T. , Melcher F. , Gäbler H.-E. , Sitnikova M. , Brätz H. , Bahr A.
Published: October 2010

New data on rare earth element (REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented. The REE geochemistry was studied by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Five major types of chondrite-normalized REE distribution patterns are defined for columbite-group minerals (CGM) from lithium-caesium-tantalum (LCT) pegmatites and rare-metal granites. Features to discriminate between the types include (1) the shape of the pattern (e.g. flat or concave), (2) calculated ratios between groups of the REE (e.g. heavy REEN/middle REEN), and (3) the presence and intensity of anomalies (e.g. Ce*, Eu*). Four pegmatites in central and southern Africa are used as case studies to discuss application of the types of REE patterns in individual deposits. The REE fractionation during progressive evolution of the melt in a pegmatite body (either Nb → Ta or Fe → Mn fractionation lines, or both) results in smaller heavy REEN/middle REEN ratios whereas replacement of primary CGM by secondary CGM produces modifications in the light REEN patterns and the heavy REEN/middle REEN ratios also. Critical features of REE patterns such as highly variable heavy REEN/middle REEN ratios or striking differences in the appearance of Eu anomalies are discussed considering structural data of the host minerals and the differentiation behaviour of the pegmatitic melt. In general, CGM from each individual Ta-ore province are characterized by a predominance of one type of REE distribution pattern. Consequently, these patterns are suitable for tracing the origin of tantalum ore concentrates (e.g. as a forensic tool).
Hidden story of tapiolite
Authors: Ercit T. S.
Published: October 2010

The crystal chemistry of tapiolite is more complicated than previously recognized. Perusal and synthesis of relatively recent publications reveals a ‘hidden’ story about tapiolite, one that: (1) permits quantification of the effects of Mn, Fe3+, Ti (and Sn) upon the unit-cell parameters of maximally ordered tapiolite; (2) shows that the effect of Nb = Ta substitution upon unit-cell parameters is insignificant; (3) casts doubt on the usefulness of heating experiments for accurately evaluating cation order in tapiolite; (4) suggests that rutile exsolves from tapiolite upon heating in air at lower temperatures than previously established; (5) shows that the maximum solubility of TiO2 in FeTa2O6 tapiolite during the later stages of crystallization of granitic pegmatites is ∼1 mol.%; (6) shows that the heating paths for at least some natural tapiolite samples are not necessarily linear, consisting of two sequential steps; (7) sheds doubt on the usefulness of unit-cell parameters as quantitative measures of long-range cation order, Q, in tapiolite; but (8) does show that the intensity ratio I011/I110 can provide an accurate and reasonably precise measure of cation order in tapiolite.
Minerals of the ammonioalunite—ammoniojarosite series formed on a burning coal dump at Czerwionka, Upper Silesian Coal Basin, Poland
Authors: Parafiniuk J. , Kruszewski Ł.
Published: October 2010

Ammonioalunite, ammoniojarosite and their solid-solution series found on a burning coal dump at Czerwionka, Upper Silesian Coal Basin, Poland, were examined using powder X-ray diffraction, electron probe microanalysis, inductively coupled plasma mass spectrometry, infrared spectroscopy and thermal analysis methods. The minerals occur as yellow, fine-grained crusts and botryoidal masses in the outer part of a sulphate crust found ∼1 m below the surface. The crust is composed mainly of godovikovite and tschermigite that formed by interaction of sour fire gases or solutions and waste materials beneath the surface of the burning coal dump at temperatures of at least 80—100°C. The crystals often reveal oscillatory zoning due to different Al and Fe contents in thin bands, from near end-members to extensive solid solutions. Our analyses suggest the existence in nature of a complete solid solution between ammonioalunite and ammoniojarosite. They also carry essential amounts of chlorine.
Thermal behaviour of ‘metamorphic vermiculite’ in Ca-rich ancient ceramic sherds and experimental ceramics
Authors: Rathossi C. , Tsolis-Katagas P. , Katagas C.
Published: October 2010

A ‘metamorphic vermiculite’-like phase was identified in Ca-rich ancient ceramic sherds from excavations in NW Peloponnese, Greece. Archaeometric investigations have shown that the raw materials used in the production of ancient ceramics were derived from local Plio-Pleistocene sediments. Analysis by X-ray diffraction and scanning electron microscopy-energy dispersive spectroscopy showed that ‘metamorphic vermiculite’ is a common constituent phase of these sediments occurring in three texturally different types: as interstratified white mica-chlorite and chlorite-vermiculite, and white mica-(white mica-chlorite) stacks. In an attempt to elucidate the thermal transformation of ‘metamorphic vermiculite’ present in the calcareous raw materials, we produced experimental ceramics made from these local raw materials and fired them at 700, 750, 850, 950 and 1050°C in a static air furnace. The mixed-layered chlorite-vermiculite was transformed completely at ∼800°C contributing to the formation of new high-T minerals. The two other types of ‘metamorphic vermiculite’ retain their original lath-like shape up to 1050°C and only a few crystals show that they have undergone complete transformation at this temperature. In the latter crystals, numerous nanocrystals were formed sub-parallel to the former cleavages of ‘metamorphic vermiculite’ pseudomorphs, suggesting their contribution to the nucleation of high-T minerals (i.e. ferrian aluminian diopside, spinel, Fe oxides) by reactions with the available CaO. It is suggested that the firing conditions (i.e. maximum reaction temperature of 1050°C, reaction time of 1 h, oxygen atmosphere) which promote disequilibrium reactions, and the greater contribution of the white mica constituent against chlorite in some of the initial structures of ‘metamorphic vermiculite’ may be responsible for the delay of its thermal decomposition at 1050°C.
Zoned Ca-amphibole as a new marker of the Alpine metamorphic evolution of phyllites from the Jubrique unit, Alpujárride Complex, Betic Cordillera, Spain
Authors: Ruiz Cruz M. D.
Published: October 2010

Zoned Ca-amphibole from metaclastic rocks and synfolial quartz-rich veins of the Jubrique area (Alpujárride complex, Betic Cordillera, Spain), and their significance in the Alpine metamorphic evolution are described here for the first time. Typical Al-rich metapelites from this area show assemblages with white mica and chlorite, with sporadic kyanite and chloritoid. Nevertheless, some Ca-richer phyllites, fine-grained quartzites and quartz veins, show assemblages consisting of Ca-amphibole, plagioclase, epidote, titanite, chlorite and quartz. Ca-amphibole, appearing in large radial grains as well as in smaller subhedral crystals, displays a zonation with actinolite cores, overgrown by magnesiohomblende (and edenite) and minor tschermakite (and pargasite or hastingsite). The zoning suggests growth during prograde metamorphism. Retrogressive rims are variably developed in the several lithotypes. General zonation is well described in terms of the tschermakite, the edenite and the Fe3+Al-1, the MgFe2+-1, the NaK-1 and the OHCl-1 exchanges. Chemical parameters (IVAl, A(Na+K), BNa) indicate an evolution from low- to medium-grade temperature and pressure. The Al-in-amphibole thermobarometer provides a range of prograde temperatures between ∼300°C (for cores) and ∼600°C (for rims), for pressures from ∼1 to ∼6 kbar, respectively. Despite the uncertainty resulting from the fact that the thermobarometer used was calibrated for metabasites, amphibole defines a prograde pressure-temperature path typical of Barrovian-type metamorphism.
Homoharringtonine reduced Mcl-1 expression and induced apoptosis in chronic lymphocytic leukemia
Authors: Chen Rong , Guo Lei , Chen Yuling , Jiang Yingjun , Wierda William G. , Plunkett William
Published: October 2010

Homoharringtonine (HHT) is a plant alkaloid that inhibits the elongation phase of translation that is currently in clinical trials. Because the intrinsically short-lived antiapoptotic protein myeloid cell leukemia-1 (Mcl-1) has been reported to support the survival of chronic lymphocytic leukemia (CLL) cells, we hypothesized that inhibition of protein synthesis by HHT would decrease Mcl-1 expression and induce apoptosis in CLL. In primary CLL cells, HHT induced significant apoptosis independent of the prognostic characteristics of the patients. This was associated with inhibition of translation and decreased Mcl-1 levels in CLL cells. Mcl-1 reduction was evident as early as 2 hours and continued to decrease in the next 6-8 hours, whereas cell death started in 2 hours and continued to increase for 24 hours. Reduction of the Mcl-1 level was due to translation inhibition and proteasome degradation rather than to transcription inhibition or caspase cleavage. HHT and the transcription inhibitor SNS-032 induced synergistic cell killing. Although stromal cells induced Mcl-1 expression and protected CLL cells from the toxicity of fludarabine, this induction was reversed by HHT, which overcame stromal cell–mediated protection. Thus, these results provide a rationale for clinical development of HHT in CLL as single agent or in combinations.
A novel role for IL-22R1 as a driver of inflammation
Authors: Savan Ram , McFarland Adelle P. , Reynolds Della A. , Feigenbaum Lionel , Ramakrishnan Karthika , Karwan Megan , Shirota Hidekazu , Klinman Dennis M. , Dunleavy Kieron , Pittaluga Stefania , Anderson Stephen K. , Donnelly Raymond P. , Wilson Wyndham H. , Young Howard A.
Published: October 2010

The interleukin (IL)–22R1 chain of the heterodimeric IL-22 receptor is not expressed on normal leukocytes, but this receptor is expressed on T cells from anaplastic lymphoma kinase–positive (ALK+) anaplastic large cell lymphoma (ALCL) patients. To investigate the consequences of aberrant expression of this receptor on lymphocytes, we generated transgenic mice that express IL-22R1 on lymphocytes. The health of these animals progressively deteriorated at 8 to 12 weeks of age, as they displayed respiratory distress, rough coat and sluggish movement, and subsequent lethality due to multiorgan inflammation. The IL-22R1 transgenic animals developed neutrophilia that correlated with increased levels of circulating IL-17 and granulocyte colony-stimulating factor. In addition, these mice had increased serum IL-22 levels, suggesting that T cells expressing IL-22R1 generate IL-22 in a positive autoregulatory loop. As a result of the mouse model findings, we analyzed circulating cytokine levels in ALK+ALCL patients and detected elevated levels of IL-22, IL-17, and IL-8 in untreated patient samples. Importantly, IL-22 and IL-17 were undetectable in all patients who were in complete remission after chemotherapy. This study documents a previously unknown role of IL-22R1 in inflammation and identifies the involvement of IL-22R1/IL-22 in ALK+ALCL.
Notch2 signaling is required for proper mast cell distribution and mucosal immunity in the intestine
Authors: Sakata-Yanagimoto Mamiko , Sakai Toru , Miyake Yasuyuki , Saito Toshiki I. , Maruyama Haruhiko , Morishita Yasuyuki , Nakagami-Yamaguchi Etsuko , Kumano Keiki , Yagita Hideo , Fukayama Masashi , Ogawa Seishi , Kurokawa Mineo , Yasutomo Koji , Chiba Shigeru
Published: October 2010

Notch receptor-mediated signaling is involved in the developmental process and functional modulation of lymphocytes, as well as in mast cell differentiation. Here, we investigated whether Notch signaling is required for antipathogen host defense regulated by mast cells. Mast cells were rarely found in the small intestine of wild-type C57BL/6 mice but accumulated abnormally in the lamina propria of the small-intestinal mucosa of the Notch2-conditional knockout mice in naive status. When transplanted into mast cell–deficient Wsh/Wsh mice, Notch2-null bone marrow-derived mast cells were rarely found within the epithelial layer but abnormally localized to the lamina propria, whereas control bone marrow-derived mast cells were mainly found within the epithelial layer. After the infection of Notch2 knockout and control mice with L3 larvae of Strongyloides venezuelensis, the abundant number of mast cells was rapidly mobilized to the epithelial layer in the control mice. In contrast, mast cells were massively accumulated in the lamina propria of the small intestinal mucosa in Notch2-conditional knockout mice, accompanied by impaired eradication of Strongyloides venezuelensis. These findings indicate that cell-autonomous Notch2 signaling in mast cells is required for proper localization of intestinal mast cells and further imply a critical role of Notch signaling in the host-pathogen interface in the small intestine.
Immune modulation by Fas ligand reverse signaling: lymphocyte proliferation is attenuated by the intracellular Fas ligand domain
Authors: Lückerath Katharina , Kirkin Vladimir , Melzer Inga Maria , Thalheimer Frederic B. , Siele Dagmar , Milani Wiebke , Adler Thure , Aguilar-Pimentel Antonio , Horsch Marion , Michel Geert , Beckers Johannes , Busch Dirk H. , Ollert Markus , Gailus-Durner Valerie , Fuchs Helmut , Hrabĕ de Angelis Martin , Staal Frank J. T. , Rajalingam Krishnaraj , Hueber Anne-Odile , Strobl Lothar J. , Zimber-Strobl Ursula , Zörnig Martin
Published: October 2010

Fas ligand (FasL) not only induces apoptosis in Fas receptor-bearing target cells, it is also able to transmit signals into the FasL-expressing cell via its intracellular domain (ICD). Recently, we described a Notch-like proteolytic processing of FasL that leads to the release of the FasL ICD into the cytoplasm and subsequent translocation into the nucleus where it may influence gene transcription. To study the molecular mechanism underlying such reverse FasL signaling in detail and to analyze its physiological importance in vivo, we established a knockout/knockin mouse model, in which wild-type FasL was replaced with a deletion mutant lacking the ICD. Our results demonstrate that FasL ICD signaling impairs activation-induced proliferation in B and T cells by diminishing phosphorylation of phospholipase C γ, protein kinase C, and extracellular signal-regulated kinase 1/2. We also demonstrate that the FasL ICD interacts with the transcription factor lymphoid-enhancer binding factor-1 and inhibits lymphoid-enhancer binding factor-1–dependent transcription. In vivo, plasma cell numbers, generation of germinal center B cells, and, consequently, production of antigen-specific immunoglobulin M antibodies in response to immunization with T cell–dependent or T cell–independent antigen are negatively affected in presence of the FasL ICD, suggesting that FasL reverse signaling participates in negative fine-tuning of certain immune responses.
Patient-derived C-terminal mutation of FANCI causes protein mislocalization and reveals putative EDGE motif function in DNA repair
Authors: Colnaghi Luca , Jones Mathew J. K. , Cotto-Rios Xiomaris M. , Schindler Detlev , Hanenberg Helmut , Huang Tony T.
Published: October 2010

Fanconi anemia (FA) is a rare familial genome instability syndrome caused by mutations in FA genes that results in defective DNA crosslink repair. Activation of the FA pathway requires the FA core ubiquitin ligase complex-dependent monoubiquitination of 2 interacting FA proteins, FANCI and FANCD2. Although loss of either FANCI or FANCD2 is known to prevent monoubiquitination of its respective partner, it is unclear whether FANCI has any additional domains that may be important in promoting DNA repair, independent of its monoubiquitination. Here, we focus on an FA-I patient-derived FANCI mutant protein, R1299X (deletion of 30 residues from its C-terminus), to characterize important structural region(s) in FANCI that is required to activate the FA pathway. We show that, within this short 30 amino acid stretch contains 2 separable functional signatures, a nuclear localization signal and a putative EDGE motif, that is critical for the ability of FANCI to properly monoubiquitinate FANCD2 and promote DNA crosslink resistance. Our study enable us to conclude that, although proper nuclear localization of FANCI is crucial for robust FANCD2 monoubiquitination, the putative FANCI EDGE motif is important for DNA crosslink repair.
The kinetics of αIIbβ3 activation determines the size and stability of thrombi in mice: implications for antiplatelet therapy
Authors: Stolla Moritz , Stefanini Lucia , Roden R. Claire , Chavez Massiel , Hirsch Jessica , Greene Teshell , Ouellette Timothy D. , Maloney Sean F. , Diamond Scott L. , Poncz Mortimer , Woulfe Donna S. , Bergmeier Wolfgang
Published: October 2010

Two major pathways contribute to Ras-proximate-1–mediated integrin activation in stimulated platelets. Calcium and diacyglycerol-regulated guanine nucleotide exchange factor I (CalDAG-GEFI, RasGRP2) mediates the rapid but reversible activation of integrin αIIbβ3, while the adenosine diphosphate receptor P2Y12, the target for antiplatelet drugs like clopidogrel, facilitates delayed but sustained integrin activation. To establish CalDAG-GEFI as a target for antiplatelet therapy, we compared how each pathway contributes to thrombosis and hemostasis in mice. Ex vivo, thrombus formation at arterial or venous shear rates was markedly reduced in CalDAG-GEFI−/− blood, even in the presence of exogenous adenosine diphosphate and thromboxane A2. In vivo, thrombosis was virtually abolished in arterioles and arteries of CalDAG-GEFI−/− mice, while small, hemostatically active thrombi formed in venules. Specific deletion of the C1-like domain of CalDAG-GEFI in circulating platelets also led to protection from thrombus formation at arterial flow conditions, while it only marginally increased blood loss in mice. In comparison, thrombi in the micro- and macrovasculature of clopidogrel-treated wild-type mice grew rapidly and frequently embolized but were hemostatically inactive. Together, these data suggest that inhibition of the catalytic or the C1 regulatory domain in CalDAG-GEFI will provide strong protection from athero-thrombotic complications while maintaining a better safety profile than P2Y12 inhibitors like clopidogrel.
Identification of a novel A4GALT exon reveals the genetic basis of the P1/P2 histo-blood groups
Authors: Thuresson Britt , Westman Julia S. , Olsson Martin L.
Published: October 2010

The A4GALT locus encodes a glycosyltransferase that synthesizes the terminal Galα1-4Gal of the Pk (Gb3/CD77) glycosphingolipid, important in transfusion medicine, obstetrics, and pathogen susceptibility. Critical nucleotide changes in A4GALT not only abolish Pk formation but also another Galα1-4Gal–defined antigen, P1, which belongs to the only blood group system for which the responsible locus remains undefined. Since known A4GALT polymorphisms do not explain the P1−Pk+ phenotype, P2, we set out to elucidate the genetic basis of P1/P2. Despite marked differences (P1 > P2) in A4GALT transcript levels in blood, luciferase experiments showed no difference between P1/P2-related promoter sequences. Investigation of A4GALT mRNA in cultured human bone marrow cells revealed novel transcripts containing only the noncoding exon 1 and a sequence (here termed exon 2a) from intron 1. These 5′-capped transcripts include poly-A tails and 3 polymorphic sites, one of which was P1/P2-specific among > 200 donors and opens a short reading frame in P2 alleles. We exploited these data to devise the first genotyping assays to predict P1 status. P1/P2 genotypes correlated with both transcript levels and P1/Pk expression on red cells. Thus, P1 zygosity partially explains the well-known interindividual variation in P1 strength. Future investigations need to focus on regulatory mechanisms underlying P1 synthesis.
Histidine-rich glycoprotein: the Swiss Army knife of mammalian plasma
Authors: Poon Ivan K. H. , Patel Kruti K. , Davis David S. , Parish Christopher R. , Hulett Mark D.
Published: October 2010

Histidine-rich glycoprotein (HRG), also known as histidine-proline-rich glyco-protein, is an abundant and well-characterized protein of vertebrate plasma. HRG has a multidomain structure that allows the molecule to interact with many ligands, including heparin, phospholipids, plasminogen, fibrinogen, immunoglobulin G, C1q, heme, and Zn2+. The ability of HRG to interact with various ligands simultaneously has suggested that HRG can function as an adaptor molecule and regulate numerous important biologic processes, such as immune complex/necrotic cell/pathogen clearance, cell adhesion, angiogenesis, coagulation, and fibrinolysis. The present review covers the proposed multifunctional roles of HRG with a focus on recent findings that have led to its emergence as a key regulator of immunity and vascular biology. Also included is a discussion of the striking functional similarities between HRG and other important multifunctional proteins found in plasma, such as C-reactive protein, C1q, β2 glycoprotein I, and thrombospondin-1.
Talin-dependent integrin activation is required for fibrin clot retraction by platelets
Authors: Haling Jacob R. , Monkley Susan J. , Critchley David R. , Petrich Brian G.
Published: October 2010

Talin functions both as a regulator of integrin affinity and as an important mechanical link between integrins and the cytoskeleton. Using genetic deletion of talin, we show for the first time that the capacity of talin to activate integrins is required for fibrin clot retraction by platelets. To further dissect which talin functions are required for this process, we tested clot retraction in platelets expressing a talin1(L325R) mutant that binds to integrins, but exhibits impaired integrin activation ascribable to disruption of the interaction between talin and the membrane-proximal region (MPR) in the β-integrin cytoplasmic domain. Talin-deficient and talin1(L325R) platelets were defective in retracting fibrin clots. However, the defect in clot retraction in talin1(L325R) platelets, but not talin-deficient platelets, was rescued by extrinsically activating integrins with manganese, thereby proving that integrin activation is required and showing that talin1(L325R) can form functional links to the actin cytoskeleton.
The complete mitochondrial genome of the citrus red mite Panonychus citri (Acari: Tetranychidae): high genome rearrangement and extremely truncated tRNAs
Authors: Yuan Ming-Long , Wei Dan-Dan , Wang Bao-Jun , Dou Wei , Wang Jin-Jun
Published: October 2010

Background

The family Tetranychidae (Chelicerata: Acari) includes ~1200 species, many of which are of agronomic importance. To date, mitochondrial genomes of only two Tetranychidae species have been sequenced, and it has been found that these two mitochondrial genomes are characterized by many unusual features in genome organization and structure such as gene order and nucleotide frequency. The scarcity of available sequence data has greatly impeded evolutionary studies in Acari (mites and ticks). Information on Tetranychidae mitochondrial genomes is quite important for phylogenetic evaluation and population genetics, as well as the molecular evolution of functional genes such as acaricide-resistance genes. In this study, we sequenced the complete mitochondrial genome ofPanonychus citri(Family Tetranychidae), a worldwide citrus pest, and provide a comparison to other Acari.

Results

The mitochondrial genome ofP. citriis a typical circular molecule of 13,077 bp, and contains the complete set of 37 genes that are usually found in metazoans. This is the smallest mitochondrial genome within all sequenced Acari and other Chelicerata, primarily due to the significant size reduction of protein coding genes (PCGs), a large rRNA gene, and the A + T-rich region. The mitochondrial gene order forP. citriis the same as those forP. ulmiandTetranychus urticae, but distinctly different from other Acari by a series of gene translocations and/or inversions. The majority of theP. citrimitochondrial genome has a high A + T content (85.28%), which is also reflected by AT-rich codons being used more frequently, but exhibits a positive GC-skew (0.03). The Acari mitochondrialnad1exhibits a faster amino acid substitution rate than other genes, and the variation of nucleotide substitution patterns of PCGs is significantly correlated with the G + C content. Most tRNA genes ofP. citriare extremely truncated and atypical (44-65, 54.1 ± 4.1 bp), lacking either the T- or D-arm, as found inP. ulmi,T. urticae, and other Acariform mites.

Conclusions

TheP. citrimitochondrial gene order is markedly different from those of other chelicerates, but is conserved within the family Tetranychidae indicating that high rearrangements have occurred after Tetranychidae diverged from other Acari. Comparative analyses suggest that the genome size, gene order, gene content, codon usage, and base composition are strongly variable among Acari mitochondrial genomes. While extremely small and unusual tRNA genes seem to be common for Acariform mites, further experimental evidence is needed.
Explaining the impact of a women's group led community mobilisation intervention on maternal and newborn health outcomes: the Ekjut trial process evaluation
Authors: Rath Suchitra , Nair Nirmala , Tripathy Prasanta K , Barnett Sarah , Rath Shibanand , Mahapatra Rajendra , Gope Rajkumar , Bajpai Aparna , Sinha Rajesh , Costello Anthony , Prost Audrey
Published: October 2010

Background

Few large and rigorous evaluations of participatory interventions systematically describe their context and implementation, or attempt to explain the mechanisms behind their impact. This study reports process evaluation data from the Ekjut cluster-randomised controlled trial of a participatory learning and action cycle with women's groups to improve maternal and newborn health outcomes in Jharkhand and Orissa, eastern India (2005-2008). The study demonstrated a 45% reduction in neonatal mortality in the last two years of the intervention, largely driven by improvements in safe practices for home deliveries.

Methods

A participatory learning and action cycle with 244 women's groups was implemented in 18 intervention clusters covering an estimated population of 114 141. We describe the context, content, and implementation of this intervention, identify potential mechanisms behind its impact, and report challenges experienced in the field. Methods included a review of intervention documents, qualitative structured discussions with group members and non-group members, meeting observations, as well as descriptive statistical analysis of data on meeting attendance, activities, and characteristics of group attendees.

Results

Six broad, interrelated factors influenced the intervention's impact: (1) acceptability; (2) a participatory approach to the development of knowledge, skills and 'critical consciousness'; (3) community involvement beyond the groups; (4) a focus on marginalized communities; (5) the active recruitment of newly pregnant women into groups; (6) high population coverage. We hypothesize that these factors were responsible for the increase in safe delivery and care practices that led to the reduction in neonatal mortality demonstrated in the Ekjut trial.

Conclusions

Participatory interventions with community groups can influence maternal and child health outcomes if key intervention characteristics are preserved and tailored to local contexts. Scaling-up such interventions requires (1) a detailed understanding of the way in which context affects the acceptability and delivery of the intervention; (2) planned but flexible replication of key content and implementation features; (3) strong support for participatory methods from implementing agencies.
EGFR inhibitor C225 increases the radiosensitivity of human lung squamous cancer cells
Authors: Zhang Yingdong , Wang Junjie , Liu Feng , You Zhenyu , Yang Ruijie , Zhao Yong
Published: October 2010

Background

The purpose of the present study is to investigate the direct biological effects of the epidermal growth factor receptor (EGFR) inhibitor C225 on the radiosensitivity of human lung squamous cancer cell-H520. H520 cells were treated with different dosage of60Co γ ray irradiation (1.953 Gy/min) in the presence or absence of C225. The cellular proliferation, colony forming capacity, apoptosis, the cell cycle distribution as well as caspase-3 were analyzed in vitro.

Results

We found that C225 treatment significantly increased radiosensitivity of H-520 cells to irradiation, and led to cell cycle arrest in G1phase, whereas60Co γ ray irradiation mainly caused G2phase arrest. H-520 cells thus displayed both the G1and G2phase arrest upon treatment with C225 in combination with60Co γ ray irradiation. Moreover, C225 treatment significantly increased the apoptosis percentage of H-520 cells (13.91% ± 1.88%) compared with the control group (5.75% ± 0.64%, P < 0.05).

Conclusion

In this regard, C225 treatment may make H-520 cells more sensitive to irradiation through the enhancement of caspase-3 mediated tumor cell apoptosis and cell cycle arrest.
Results of a sector-wide quality improvement initiative for substance-abuse care: an uncontrolled before-after study in Catalonia, Spain
Authors: Hilarion Pilar , Groene Oliver , Colom Joan , Lopez Rosa M , Suñol Rosa
Published: October 2010

Background

The Health Department of the Regional Government of Catalonia, Spain, issued a quality plan for substance abuse centers. The objective of this paper is to evaluate the impact of a multidimensional quality improvement initiative in the field of substance abuse care and to discuss potentials and limitations for further quality improvement.

Methods

The study uses an uncontrolled, sector-wide pre-post design. All centers providing services for persons with substance abuse issues in the Autonomous Community of Catalonia participated in this assessment. Measures of compliance were developed based on indicators reported in the literature and by broad stakeholder involvement. We compared pre-post differences in dimension-specific and overall compliance-scores using one-way ANOVA for repeated measures and the Friedman statistic. We described the spread of the data using the inter-quartile range and the Fligner-Killen statistic. Finally, we adjusted compliance scores for location and size using linear and logistic regression models.

Results

We performed a baseline and follow up assessment in 22 centers for substance abuse care and observed substantial and statistically significant improvements for overall compliance (pre: 60.9%; post: 79.1%) and for compliance in the dimensions 'care pathway' (pre: 66.5%; post: 83.5%) and 'organization and management' (pre: 50.5%; post: 77.2%). We observed improvements in the dimension 'environment and infrastructure' (pre: 81.8%; post: 95.5%) and in the dimension 'relations and user rights' (pre: 66.5%; post: 72.5%); however, these were not statistically significant. The regression analysis suggests that improvements in compliance are positively influenced by being located in the Barcelona region in case of the dimension 'relations and user rights'.

Conclusion

The positive results of this quality improvement initiative are possibly associated with the successful involvement of stakeholders, the consciously constructed feedback reports on individual and sector-wide performance and the support of evidence-based guidance wherever possible. Further research should address how contextual issues shape the uptake and effectiveness of quality improvement actions and how such quality improvements can be sustained.
Store-operated Ca2+ signaling in dendritic cells occurs independently of STIM1
Authors: Bandyopadhyay Bidhan C , Pingle Sandeep C , Ahern Gerard P
Published: October 2010

SOCE via CRAC channels is a critical signaling event in immune cells. Recent studies have identified key proteins underlying this process; STIM is an ER Ca2+ sensor that interacts with Orai, an intrinsic, pore-forming protein of the CRAC channel. In heterologous expression systems, STIM1 regulates SOCE by interacting with Orai1, -2, and -3. In native tissues, however, the precise roles of STIM and Orai proteins are not well defined. Here, we have investigated the molecular components of SOCE signaling in mouse DCs. We show that DCs predominantly express STIM2 and only very low levels of STIM1 compared with T lymphocytes. Upon store depletion with Tg, STIM2 aggregates and interacts selectively with Orai2. In contrast, Tg fails to aggregate STIM1 or enhance STIM1-mediated interactions with Orai proteins. Consistent with this biochemical characterization, stimulation of DCs with the adhesion molecule ICAM-1 selectively recruits STIM2 and Orai2 to the IS. Together, these data demonstrate a novel, STIM2-dependent SOCE signaling pathway in DCs.
Persistence of seed-based activity following segmentation of a microRNA guide strand
Authors: Chorn Guillaume , Zhao Lihong , Sachs Alan B. , Flanagan W. Michael , Lim Lee P.
Published: October 2010

microRNAs are ∼22 nucleotide regulatory RNAs that are processed into duplexes from hairpin structures and incorporated into Argonaute proteins. Here, we show that a nick in the middle of the guide strand of an miRNA sequence allows for seed-based targeting characteristic of miRNA activity. Insertion of an inverted abasic, a dye, or a small gap between the two segments still permits target knockdown. While activity from the seed region of the segmented miRNA is apparent, activity from the 3′ half of the guide strand is impaired, suggesting that an intact guide backbone is required for contribution from the 3′ half. miRNA activity was also observed following nicking of a miRNA precursor. These results illustrate a structural flexibility in miRNA duplexes and may have applications in the design of miRNA mimetics.