bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution's Pedagogy: An Adaptationist Model of Pretense and Entertainment
Authors: Steen Francis , Owens Stephanie
Published: July 2002

The portrayal of the actions of fictive characters for purposes of entertainment is a familiar phenomenon. Theories that seek to explain why we are attracted to such fictions and whether we learn from them have produced no consensus and no adequate overall account. In this paper, we present the hypothesis that entertainment relies on cognitive adaptations for pretend play. As a simplified model system, we draw on our field study of children's chase play, which is characterized by an elementary form of pretense. The children pretend, at first without consciously representing their pretense, to be chased by predators. The details of this behavior, widespread among mammals, indicate that the biological function of the game may be to train predator-evasion strategies. Chase play, we suggest, evolved in early mammals because it enabled cheap and plentiful resources to be used to train strategies for events that are rare, dangerous, and expensive. More generally, we argue that pretense is used to access spaces of possible actions in order to locate and practice new strategies. It relies on the creation of a simulated scenario and requires sophisticated source monitoring. The simulation is experienced as intrinsically rewarding; boredom is a design feature to motivate the construction of a more appropriate pedagogical situation, while the thrill of play signals optimal learning conditions. The conscious narrative elaboration of chase games involves an elementary form of role play, where we propose a virtual agent is created that tracks and acts on the memories required for coherent action within the simulation. These complex if familiar design features, we suggest, provide a minimalist functional and adaptationist account of the central features of entertainment: that it is fun, that it involves us imaginatively and emotionally, and that it has a tacit pedagogical effect. The model provides a principled and testable account of fiction-based entertainment grounded in evolutionary and cognitive processes.
ON THE HIGHER CLASSIFICATION OF LAKE BAIKAL AMPHIPODS
Authors: Kamaltynov Ravil Masalimovich
Published: July 2002

A new system of higher taxa of Baikalian amphipods is proposed. This fauna forms a monophyletic part of the superfamily Gammaroidea Leach, 1814 (sensu Bousfield, 1977) and now comprises: Acanthogammaridae Garjajeff, 1901 (with the subfamilies: Acanthogammarinae Garjajeff, 1901, Abyssogammarinae n. subfam., Eulimnogammarinae n. subfam., Hyalellopsinae n. subfam., Odontogammarinae n. subfam., Plesiogammarinae n. subfam., Parapallaseinae n. subfam., and Poekilogammarinae n. subfam.), Macrohectopidae Sowinsky, 1915, Micruropidae n. fam., and Pachyschesidae n. fam. The amphipod fauna of Lake Baikal consists of 50 genera, 261 species, and 73 subspecies. One genus, 4 species, and 8 subspecies of Baikalian origin are endemic to the Angara River and one species is endemic to the Yenisey River delta. The total number of taxa of Baikalian amphipods is now 4 families, 8 subfamilies, 51 genera, 265 species, and 81 subspecies. Un nouveau systeme de taxa superieurs est propose pour les amphipodes du lac Baikal. Cette faune constitue une partie monophyletique de la super-famille Gammaroidea Leach, 1814 (sensu Bousfield, 1977) et comprend maintenant: Acanthogammaridae Garjajeff, 1901 (avec les sousfamilles: Acanthogammarinae Garjajeff, 1901, Abyssogammarinae n. sous-fam., Eulimnogammarinae n. sous-fam., Hyalellopsinae n. sous-fam., Odontogammarinae n. sous-fam., Plesiogammarinae n. sous-fam., Parapallaseinae n. sous-fam., Poekilogammarinae n. sous-fam.), Macrohectopidae Sowinsky, 1915, Micruropidae n. fam. et Pachyschesidae n. fam. La faune d'amphipodes du lac Baikal comprend 50 genres, 261 especes et 73 sous-especes. Un genre, 4 especes et 8 sous-especes d'origine baikalienne sont endemiques du fleuve Angara et une espece est endemique du delta du fleuve Yenisey. Le nombre total des taxa d'amphipodes du Baikal est maintenant de 4 familles, 8 sous-familles, 51 genres, 265 especes et 81 sous-especes.
Requirements for branched chain amino acids and their interactions in the nematode Caenorhabditis elegans
Authors: Perelman Dalia , Lu Nancy
Published: July 2002

Branched chain amino acid (BCAA) requirements and their interactions were studied in the nematode Caenorhabditis elegans. Optimal, deficiency and toxic levels affecting nematode population growth were determined for each of the three BCAAs. The optimal range for leucine was 0.72-2.8; for isoleucine, 0.86-1.7; and for valine, 0.51-4.1 mg ml-1. Leucine at high concentrations was toxic. When isoleucine and valine were both added at high concentrations, they also exerted a marked toxic effect. The interactions of the branched chain amino acids found among vertebrate animals were not observed in C. elegans. Les besoins relatifs aux amino-acides en chaîne ramifiée et leurs interactions chez le nématode Caenorhabditis elegans - Les besoins relatifs aux amino-acides en chaîne ramifiée (BCAA) et leurs interactions ont été étudiés chez le nématode Caenorhabditis elegans. Les niveaux optimal, de déficience et toxique affectant la croissance de la population du nématode ont été déterminés pour chacune des BCAA. L'optimum est, pour la leucine de 0,72 à 2,8, pour l'isoleucine de 0,86 à 1,7 et pour la valine de 0,51 à 4,1 mg ml-1. A forte concentration la leucine est toxique. Si l'isoleucine et la valine sont ajoutées à forte concentration elles exercent également une action toxique prononcée. Les interactions entre BCAA observées chez les vertébrés ne l'ont pas été chez les C. elegans.
Steinernema loci sp. n. and Steinernema thanhi sp. n. (Rhabditida: Steinernematidae) from Vietnam
Authors: Moens Maurice , Nguyen Ngoc Chau , Phan Ke Long
Published: July 2002

Two new species of Steinernema (Rhabditida), Steinernema loci sp. n. and S. thanhi sp. n., were isolated from beach soil in Thanhhoa and Hatinh provinces in the northern part of Vietnam. A combination of morphological, morphometric and rDNA-RFLP features indicated the distinctness of both species from other Steinernema spp. Diagnostic characters of Steinernema loci sp. n. include: total body length (896-1072 μm), distance from anterior end to excretory pore (EP = 71-86 μm), tail length (66-83 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end of the third stage infective juvenile; first generation males were characterised by body width, spicule length and the ratio spicule length : anal body width (SW). Diagnostic characters of Steinernema thanhi sp. n. third stage infective juveniles include: total body length (720-960 μm), EP (68-84 μm), tail length (52-72 μm), lateral field in mid-body with eight ridges (nine distinct lines) and rounded, broad and smooth anterior end. Spicule length, ratio SW and arrangement of genital papillae characterised the first generation males.
THE SO-CALLED COPTIC OINTMENT PRAYER OF DIDACHE 10,8 ONCE MORE
Authors: Ysebaert Joseph
Published: July 2002

In the so-called Coptic ointment prayer of Didache 10,8 the Coptic equivalent stinoufi does not mean 'ointment' but 'good smell'. It corresponds to Greek ευωδια which in 2Cor 2,15 is used for the good smell of Jesus that Christians are to God. This gives a good sense in the context of Did 10,8. Moreover, the expression ευχαριστεω ϑεω υπερ means 'to give thanks to God for' something. In Did 10,8 this is wrongly understood as 'to bless' or 'to consecrate'. In this meaning ευχαριστεω has an accusative object and is only used for the consecrating of the Eucharistic bread and wine.
The aggregation of methylene blue in montmorillonite dispersions
Authors: Bujdák J. , Iyi N. , Fujita T.
Published: July 2002

Theories concerning the optical properties of cationic dyes adsorbed on clay surfaces are analysed in detail. An investigation of the aggregation of methylene blue (MB) in montmorillonite dispersions is conducted using visible (VIS) spectroscopy. The effects of the dye/ clay ratio and of the swelling properties of the montmorillonite substrate on dye aggregation are compared in terms of the effect of clay layer charge. The observed influence on dye aggregation was almost negligible for both swelling and dye loading. The layer charge of the silicate determines the extent and the type of dye aggregation in freshly prepared MB/montmorillonite dispersions. Observed spectral changes with time indicate a rearrangement and redistribution of dye H-aggregates (band close to 570 nm) to monomers (660 nm), dimers (605 nm) and J-aggregates (760 nm). Dye aggregates are probably already formed during dye cation migration in the vicinity of clay colloid particles. The extent and the type of initially formed species are probably affected by the electric double layer of clay layers. After reaching the clay surface, dye cation assemblies are rearranged and decompose as described above. Reaching chemical equilibrium, dye cations adjust the distribution of the layer charge, in order that each cation could balance the charge due to one unequivalent substitution.
A hydrogeological model for palygorskite formation in the Danian continental facies of the Provence Basin (France)
Authors: Colson J. , Cojan I. , Thiry M.
Published: July 2002

The Danian of the Provence basin (SE France) is characterized by a strong subatmospheric alteration processes throughout the basin. A wide range of facies, depositional and weathering, were recognized in an interval of 5 Myr and include floodplain fine-grained alluvium, palustrine limestones, playa dolostones, mottled palaeosols, vadose and phreatic calcretes, and phreatic dolocretes. Palygorskite was invariably found in laminar, massive and honeycomb vadose calcretes and phreatic dolocretes, as well as in playa dolostones, and only exceptionally in floodplain siltstones, nodular calcretes and palustrine limestones. Regardless of the facies, palygorskite is associated with smectites. An authigenic origin, based on the morphology of the fibres and the vertical distribution of clay minerals, is proposed for palygorskites in all of the facies. The simultaneous occurrence of palygorskite in these environments is interpreted as a sign of a stable seasonal semi-arid climate and low detrital input during a period of low lake level (-0.5 Myr). The occurrence of authigenic palygorskite in siltstones around the lake was attributed to the rising of the water table, retention of the already saturated water in the pore spaces of the sediment, and its subsequent evaporation in a confined environment. A hydrogeological model is proposed for the distribution of palygorskite. The elongated shape of the Provence basin enhanced the influence of lateral inflow of freshwater during the low lake period which explains the distribution of palygorskite in different environments of the Provence basin as well as spatial distribution of phreatic calcretes and dolocretes. During the high lake level, palygorskite formed in the few remaining ephemeral ponds and on the floodplain along the lake margin.
Removal of organic matter by disodium peroxodisulphate: effects on mineral structure, chemical composition and physicochemical properties of some clay minerals
Authors: Menegatti A. P. , Früh-Green G. L. , Stille P.
Published: July 2002

The use of disodium peroxodisulphate combined with a neutral buffer is a new method for the efficient removal of organic matter from clay-bearing sediments. The effects of this oxidation procedure on mineral structure were investigated by treatment of different standard clay minerals (kaolinite ‘china clay’, illite ‘Le Puy’, montmorillonite SWy-1). The materials were characterized by means of XRD, FTIR, SEM and TEM before and after leaching with disodium peroxodisulphate. Systematic experiments were conducted to determine the effects of leaching on the chemical and isotopic composition of oxygen, hydrogen and K-Ar in these samples. Effects on the physicochemical properties of the clays such as BET external surface area, cation exchange capacity (CEC) and expandability with ethylene glycol were also investigated. The results show that structure, chemical composition, oxygen and hydrogen isotope ratios, as well as the K-Ar system remain unaffected by leaching with disodium peroxodisulphate. The CEC and expandability remain unchanged, whereas changes in BET area can be attributed to mechanical dispersion by ultrasonic treatment.
Hydrothermal reactivity of K-smectite at 300°C and 100 bar: dissolution-crystallization process and non-expandable dehydrated smectite formation
Authors: Mosser-Ruck R. , Cathelineau M. , Baronnet A. , Trouiller A.
Published: July 2002

The hydrothermal reactivity of a smectite saturated with K was studied experimentally at 300°C and 100 bar in (Na,K) chloride solutions (Na/K = 0, 50 and 100, liquid/solid ratio = 10/1). X-ray diffraction, TEM and microprobe results show: (1) a partial to total dissolution of the initial smectite layers; and (2) the crystallization of newly-formed euhedral I-S. Random I-S is formed after 7 days, but an ordered mixed-layer I-S containing <30% expandable layers formed in the longest runs (112 days). The I-S is characterized by non-expandable layers of two distinct types: dehydrated smectite and illite. The Si content is lower in the I-S than in the initial smectite, thus creating a charge deficit, mostly compensated by the introduction of Na to the interlayer space, and yielding a silica release to the solution and subsequent crystallization of quartz and cristobalite.
The steam condensate alteration mineralogy of Ruatapu cave, Orakei Korako geothermal field, Taupo Volcanic Zone, New Zealand
Authors: Rodgers K. A. , Hamlin K. A. , Browne P. R. L. , Campbell K. A. , Martin R.
Published: July 2002

Ruatapu cave has developed beneath a block of hydrothermally altered Quaternary vitric tuff in the active Orakei Korako geothermal field. The cave extends ∼45 m, with a vertical drop of 23 m, to a shallow pool of clear, sulfate-rich (∼.450 µg/g), warm (T = 43–48°C), acid (pH = 3.0) water. Steam, accompanied by H2S, rises from the pool surface, from a second pool nearby, and from fumaroles and joints in the ignimbrite, to condense on surfaces within the cave. Oxidation of the H2S to H2SO4 produces acid sulfate fluids which react with the surficial rocks to generate three principal and distinct assemblages of secondary minerals. Kaolinite ± opal-A ± cristobalite ± alunite ± alunogen dominate the assemblage at the cave mouth; the essential Al, K and Si are derived from the tuffs and Na, Ca, Fe and Mg removed. In the main body of the cave the highly limited throughflow of water results in the more soluble of the leached constituents, notably Na and K, being retained in surface moisture and becoming available to form tamarugite and potash alum as efflorescences, in part at the expense of kaolin, along with lesser amounts of alunogen, meta-alunogen, mirabilite, halotrichite, kalinite, gypsum and, possibly, tschermigite; the particular species being determined by the prevailing physico-chemical conditions. Heat and moisture assist in moving Fe out of the rock to the air-water interface but, unlike typical surficial acid alteration systems elsewhere in the TVZ, there is an insufficient flow of water, of appropriate Eh-pH, to continue to move Fe out of the cave system. Much becomes locally immobilized as Fe oxides and oxyhydroxides that mottle the sides and roof of the cave. Jarosite crusts have developed where acid sulfate pool waters have had protracted contact with ignimbrite wallrock coated with once-living microbial mats. Subsequent lowering of the waters has caused the porous jarositic crusts to alter to potash alum ± akaganéite or schwertmannite. Meteoric water, with chloride concentrations of up to 10,000 µg/g, seeping through the roof produces a white, semi-thixotropic slurry which when dried yields 5.7 wt.% chloride and consisted of tamarugite plus halite. Some of this chloride (and sulfate) eventually enters the pool waters which have Cl− concentrations of 200 µg/g. This implies that the pools are not necessarily fed by a neutral pH alkali chloride fluid ascending from the geothermal reservoir, but are perched waters heated by ascending steam and fed largely by steam condensate.
A revised phase diagram for the bornite-digenite join from in situ neutron diffraction and DSC experiments
Authors: Grguric B. A. , Harrison R. J. , Putnis A.
Published: July 2002

Phase relations along the join bornite (Cu5FeS4)-digenite (Cu8.52Fe0.12S4.88) have been redefined using a combination of in situ high-resolution neutron diffraction and differential scanning calorimetry (DSC). Time-of-flight neutron diffraction patterns were collected on a synthetic sample of bn90 at 16 temperatures between 35 and 350°C. This data is compared with data from a natural end-member bornite sample obtained in an earlier study under identical conditions. Phase relations along the bornite-digenite join are inferred from the temperature evolution of the lattice parameters and the intensity of subcell and supercell reflections of coexisting phases.

The DSC scans over the temperature range 50–300°C were performed on a natural digenite sample and samples synthesized at 5 mol.% intervals along the join Cu5FeS4-Cu9S5. The thermal anomalies are correlated with structural phase transitions in componen phases and the solvus temperature for each bulk composition. A phase diagram topology is defined, which was consistent with both diffraction and calorimetric data, but in marked contrast to previous diagrams, shows a consolute point at X = Cu5FeS4 and T = 265°C. This temperature corresponds to that of the tricritical intermediate-high transition in bornite. Isothermal annealing experiments carried out on synthetic starting materials for up to 7 months showed coarsening behaviour consistent with the revised phase diagram topology.
Petrogenetic implications from biotite compositional variations in the Cornubian granite batholith
Authors: Stone M.
Published: July 2002

Lithium oxide contents of biotites in some Cornubian granites which have been studied by electron microprobe are estimated from their SiO2 and F contents using samples formerly analysed by XRF and wet chemistry. Better formulae which include Li show that most of these biotites are lithian siderophyllites/ lithian Al-annites although some Dartmoor samples, especially those in the basic microgranite (ME) enclaves, are closer to Al-annites. Dartmoor samples are slightly more basic and poorer in Alvi than those from the Isles of Scilly and Carnmenellis granites agreeing with the broad differences in the host rocks. Biotites in volcanic clasts from the New Red Sandstone are significantly different in having much higher Si, Ti, Mg, F and ΣY and lower Alvi contents than those of the granite biotites: these are lithian Fe-Mg biotites. These clasts are believed to be the volcanic equivalents of an evolving Dartmoor magma (Awad et al., 1996). If so, their biotites reflect the composition of the granite biotites at the time of magma emplacement. They subsequently evolved as they equilibrated with the cooling granite to give the present biotite compositions of the Dartmoor granites.
Analcime reactions at 25–90°C in hyperalkaline fluids
Authors: Savage D. , Rochelle C. , Moore Y. , Milodowski A. , Bateman K. , Bailey D. , Mihara M.
Published: July 2002

Extensive use of cement and concrete is envisaged in the construction of geological disposal facilities for radioactive wastes. The hyperalkaline porefluids typical of groundwaters that have reacted with these materials have the potential to react chemically with other engineered barrier components such as bentonite, potentially degrading their performance. Analcime, NaAlSi2O6.H2O, has been identified from previous modelling and experimental studies as a potential alteration product of bentonite.

Laboratory experiments to investigate the stability of analcime under hyperalkaline porefluid conditions have been performed. Experiments used both batch and fluidized bed equipment at 25, 50, 70 and 90°C in K-based pH buffer solutions, both under- and over-saturated with respect to analcime. Results from dissolution experiments demonstrate that release of Na was greatly enhanced (by up to a factor of thirty) over that for Si and Al, particularly at pH 10 and 11. However, enhanced release of both Na and Al occurred in the batch experiments at pH 12–13. Near stoichiometric dissolution was observed in fluidized bed experiments under steady-state conditions at 70°C. Sodium was removed from the analcime structure by ion exchange for K, without involving dissolution and re-precipitation of the analcime framework. Scanning electron microscopy of reacted analcime grains showed that some grains had pronounced cracks parallel to original cleavage traces. These cracks were a result of volume decrease due to the substitution of K for Na ions and water molecules in the analcime structure to form leucite, KAlSi2O6.

Synthesis of the dissolution data shows that the rate of dissolution increased with increasing temperature in the range 25–70°C and with pH at each temperature. Absolute rates of dissolution ranged from 10−10 mol m−2 s−1 at pH 9.5 at 25°C to 10−7 mol m−2 s−1 a pH 12 at 70 and 90°C. The rate of dissolution at any temperature was pH-dependent, such that the rate could be described by k (aH+)n, where k is the rate constant and n is −0.3 at 25°C, −0.4 at 50°C, −0.6 at 70°C and −0.7 at 90°C. Attempts to measure the growth rate of analcime in supersaturated solutions at 70 and 90°C were unsuccessful, although a limiting rate at 70°C, pH 10 was calculated to be 4 × 10−11 mol m−2 s−1, roughly 100× less than the rate of dissolution under the same conditions.

These results imply that any trace amounts of analcime in bentonite will be converted to leucite by reaction with cement fluids with a high K/Na ratio. In some instances, leucite may thus incorporate K+ in preference to other phases (e.g. illite, K-feldspar) during alteration of bentonite by cement porefluids.
A reexamination of the turquoise group: the mineral aheylite, planerite (redefined), turquoise and coeruleolactite
Authors: Foord Eugene E. , Taggart Joseph E.
Published: July 2002

The turquoise group has the general formula:A0–1B6(PO4)4−x(PO3OH)x(OH)8.4H2O, wherex= 0–2, and consists of six members: planerite, turquoise, faustite, aheylite, chalcosiderite and an unnamed Fe2+-Fe3+analogue. The existence of ‘coeruleolactite’ is doubtful. Planerite is revalidated as a species and is characterized by a dominantA-site vacancy. Aheylite is established as a new member of the group, and is characterized by having Fe2+dominant in theA-site.

Chemical analyses of 15 pure samples of microcrystalline planerite, turquoise, and aheylite show that a maximum of two of the (PO4) groups are protonated (PO3OH) in planerite. Complete solid solution exists between planerite and turquoise. Other members of the group show variableA-site vacancy as well. Most samples of ‘turquoise’ are cation-deficient or are planerite. Direct determination of water indicates that there are 4 molecules of water.

Planerite, ideally ☐Al6(PO4)2(PO3OH)2(OH)8.4H2O, is white, pale blue or pale green, and occurs as mamillary, botryoidal crusts as much as several mm thick; may also be massive; microcrystalline, crystals typically 2–4 micrometres, luster chalky to earthy, H. 5, somewhat brittle, no cleavage observed, splintery fracture, Dm2.68(2), Dc2.71, not magnetic, not fluorescent, mean RI about 1.60.a7.505(2),b9.723(3),c7.814(2) Å, α 111.43°, β 115.56°, γ 68.69°, V 464.2(1) Å3, Z = 1.

Aheylite, ideally Fe2+Al6(PO4)4(OH)8.4H2O, is pale blue or green, and occurs as isolated and aggregate clumps of hemispherical or spherical, radiating to interlocked masses of crystals that average 3 micrometres in maximum dimension; porcelaneous-subvitreous luster, moderate to brittle tenacity, no cleavage observed, hackly to splintery fracture, not magnetic, not fluorescent, biax. (+), mean RI is about 1.63, Dm2.84(2), Dc2.90.a7.400(1),b9.896(1),c7.627(1) Å, α 110.87°, β 115.00°, γ 69.96°, V 460.62(9) Å3, Z = 1.
Manganese valency and the colour of the Mn2AsO4(OH) polymorphs eveite and sarkinite
Authors: Hålenius Ulf , Westlund Erika
Published: July 2002

Polarized optical absorption spectra of single crystals of the two dimorphic Mn2AsO4(OH)-minerals eveite and sarkinite show that minor concentrations of Mn3+ at the octahedral site determine the colour and cause the distinct pleochroism in green and yellow of eveite. In the sarkinite spectra only absorption bands due to spin-forbidden d-d transitions in Mn2+ at six- and five-coordinated sites are observed, which produce a weak flesh-red mineral colour and a very faint pleochroism.
Molecular processes on oxide surfaces studied by first-principles calculations
Authors: Gillan M. J. , Lindan P. J. D. , Kantorovich L. N. , Bates S. P.
Published: July 2002

First-principles quantum techniques based on density functional theory (DFT) have made important contributions to the understanding of oxide surfaces over the last four years. Important features of these calculations include: the use of periodic boundary conditions, which avoid the edge effects associated with the cluster approach; plane-wave basis sets, which make the calculation of ionic forces straightforward, so that both static relaxation and dynamical simulation can be done; and the approximate inclusion of electron correlation. A short introduction to DFT techniques is given, and recent work on the structure and energetics of a variety of oxide surfaces is presented. It is shown how the techniques can be used to study molecular and dissociative adsorption of molecules on oxide surfaces, with the emphasis on water and simple organic molecules. The growing importance of dynamical first-principles simulation in the study of surface chemical reactions is illustrated.
Increased expression of the INK4a/ARF locus in polycythemia vera
Authors: Dai Chunhua , Krantz Sanford B.
Published: July 2002

The retinoblastoma (Rb), cyclin-dependent kinase (CDK), and CDK inhibitor genes regulate cell generation, and deregulation can produce increased cell growth and tumorigenesis. Polycythemia vera (PV) is a clonal myeloproliferative disease where the mechanism producing increased hematopoiesis is still unknown. To investigate possible defects in cell-cycle regulation in PV, the expression of Rb and CDK inhibitor gene messenger RNAs (mRNAs) in highly purified human erythroid colony-forming cells (ECFCs) was screened using an RNase protection assay (RPA) and 11 gene probes. It was found that RNA representing exon 2 of p16INK4a and p14ARF was enhanced by 2.8- to 15.9-fold in 11 patients with PV. No increase of exon 2 mRNA was evident in the T cells of patients with PV, or in the ECFCs and T cells from patients with secondary polycythemia. p27 also had elevated mRNA expression in PV ECFCs, but to a lesser degree. Because the INK4a/ARF locus encodes 2 tumor suppressors, p16INK4a and p14ARF with the same exon 2 sequence, the increased mRNA fragment could represent either one. To clarify this, mRNA representing the unique first exons of INK4a and ARF were analyzed by semiquantitative reverse transcription–polymerase chain reaction. This demonstrated that mRNAs from the first exons of both genes were increased in erythroid and granulocyte-macrophage cells and Western blot analysis showed that the INK4a protein (p16INK4a) was increased in PV ECFCs. Sequencing revealed no mutations of INK4a or ARF in 10 patients with PV. p16INK4a is an important negative cell-cycle regulator, but in contrast with a wide range of malignancies where inactivation of theINK4a gene is one of the most common carcinogenetic events, in PV p16 INK4a expression was dramatically increased without a significant change in ECFC cell cycle compared with normal ECFCs. It is quite likely that p16INK4a and p14ARF are not the pathogenetic cause of PV, but instead represent a cellular response to an abnormality of a downstream regulator of proliferation such as cyclin D, CDK4/CDK6, Rb, or E2F. Further work to delineate the function of these genes in PV is in progress.
Allogeneic bone marrow cells that facilitate complete chimerism and eliminate tumor cells express both CD8 and T-cell antigen receptor–αβ
Authors: Lan Fengshuo , Zeng Defu , Huie Philip , Higgins John P. , Strober Samuel
Published: July 2002

Nonmyeloablative host conditioning regimens have been used in clinical allogeneic bone marrow and hematopoietic progenitor transplantation to effectively treat lymphohematopoietic tumors and reduce early toxicity. However, severe graft-versus-host disease (GVHD) remains a major problem. The goal of the current study was to determine whether specific subsets of cells in allogeneic bone marrow transplants can effectively treat the BCL1 B-cell lymphoma in nonmyeloablated BALB/c mouse hosts given a single dose of sublethal (450 cGy) total body irradiation, without inducing severe GVHD. The experimental results show that high doses of whole bone marrow cells from major histocompatiblity complex (MHC)-mismatched donors eliminate both normal and malignant host-type lymphohematopoietic cells without causing injury to nonlymphohematopoietic host tissues. The CD8+T-cell antigen receptor–αβ+(TCRαβ+) T cells within the marrow transplants mediated the killing of the tumor cells via both perforin- and FasL-dependent pathways. Cells present in marrow transplants from either CD8−/− or TCRα−/− donors failed to eliminate malignant and normal host lymphohematopoietic cells. Addition of small numbers of blood mononuclear cells to the marrow inoculum caused lethal GVHD. Thus, the resident allogeneic bone marrow CD8+ TCRαβ+ T cells had the unique capacity to eliminate the host lymphohematopoietic cells without nonlymphohematopoietic tissue injury.
Circulating autoantibodies to oxidized cardiolipin correlate with isoprostane F2α-VI levels and the extent of atherosclerosis in ApoE-deficient mice: modulation by vitamin E
Authors: Praticò Domenico , Tangirala Rajendra K. , Hörkkö Sohvi , Witztum Joseph L. , Palinski Wulf , FitzGerald Garret A.
Published: July 2002

Lipid peroxidation plays an important role in atherogenesis. Previous studies suggested that autoantibodies against epitopes of oxidized low-density lipoprotein may indicate the extent or rate of progression of atherosclerosis. The aim of this study was to investigate whether autoantibodies to oxidized phospholipids, such as oxidized cardiolipin (OxCL), correlate with levels of isoprostane F2α-VI, a sensitive marker of in vivo lipid peroxidation, as well as with the extent of atherosclerosis. Two groups of apolipoprotein E-deficient mice were fed chow with or without vitamin E (2000 IU/kg diet) for 16 weeks. In untreated animals, autoantibodies against OxCL and urinary, plasma, and aortic isoprostane F2α-VI levels increased significantly. Vitamin E treatment significantly reduced antibody titers, isoprostane levels, and atherosclerosis at the end of the study, compared with untreated mice. Autoantibodies to OxCL correlated with aortic isoprostane F2α-VI levels (r2 = 0.42,P = .001 for IgG andr2 = 0.63, P < .001 for IgM). Both aortic isoprostane F2α-VI levels (r2 = 0.59, P < .001) and titers of OxCL antibodies (r2 = 0.70, P < .001 for IgG and r2 = 0.68,P < .001 for IgM) correlated with the extent of aortic atherosclerosis. The fact that the levels of autoantibodies to OxCL correlated with a sensitive direct measure of lipid peroxidation in vivo and that both autoantibodies and aortic isoprostane F2α-VI levels correlated with the extent of atherosclerosis suggests that antibodies to OxCL are a sensitive indicator of in vivo lipid peroxidation and atherosclerosis.
Investigating the platelet-sparing mechanism of paclitaxel/carboplatin combination chemotherapy
Authors: Pertusini Esther , Ratajczak Janina , Majka Marcin , Vaughn David , Ratajczak Mariusz Z. , Gewirtz Alan M.
Published: July 2002

Paclitaxel and carboplatin chemotherapy is reported to be a platelet-sparing drug combination. This study investigated potential mechanisms for this observation by studying the effects of paclitaxel and carboplatin on (1) normal donor and chemotherapy patient-derived erythroid (burst-forming units-erythroid [BFU-E]), myeloid (colony-forming units-granulocyte/macrophage [CFU-GM]), and megakaryocyte (CFU-Meg) progenitor cell growth; (2) P-glycoprotein (P-gp) protein and glutathione S-transferase (GST) messenger RNA (mRNA) expression; (3) serum thrombopoietin (Tpo), stem cell factor (SCF), interleukin-6 (IL-6), IL-11, IL-1β, IL-8, and tumor necrosis factor-α levels in patients treated with paclitaxel and carboplatin; and (4) stromal cell production of Tpo and SCF after paclitaxel and carboplatin exposure. CFU-Meg were more resistant to paclitaxel alone, or in combination with carboplatin, than CFU-GM and BFU-E. Although all progenitors expressed P-gp protein and GST mRNA, verapamil treatment significantly, and selectively, increased the toxicity of paclitaxel and carboplatin to CFU-Meg, suggesting an important role for P-gp in megakaryocyte drug resistance. Compared to normal controls, serum Tpo levels in patients receiving paclitaxel and carboplatin were significantly elevated 5 hours after infusion and remained elevated at day 7 (287% ± 63% increase,P < .001). Marrow stroma was shown to be the likely source of this Tpo. It is concluded here that P-gp–mediated efflux of paclitaxel, and perhaps GST-mediated detoxification of carboplatin, results in relative sparing of CFU-Meg, which may then respond to locally high levels of stromal cell–derived Tpo. The confluence of these events might lead to the platelet-sparing phenomenon observed in patients treated with paclitaxel and carboplatin chemotherapy.
Evidence that Hodgkin and Reed-Sternberg cells in Hodgkin disease do not represent cell fusions
Authors: Küppers Ralf , Bräuninger Andreas , Müschen Markus , Distler Verena , Hansmann Martin-Leo , Rajewsky Klaus
Published: July 2002

In most cases, Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin disease (HD) carry rearranged immunoglobulin (Ig) genes and thus derive from B cells. In rare cases, HRS cells originate from T cells. However, based on the unusual immunophenotype of HRS cells, often showing coexpression of markers typical for different hematopoetic lineages, and the regular detection of numerical chromosomal abnormalities, it has been speculated that HRS cells might represent cell fusions. Five cases of HD with 2 rearranged IgH alleles were analyzed for the presence of additional IgH alleles in germline configuration as a potential footprint of a cell fusion between a B and a non-B cell. Similarly, one case of T-cell–derived HD with biallelic T-cell receptor β (TCRβ) rearrangements was studied for the presence of unrearranged TCRβ alleles. In none of the 6 cases was evidence for additional IgH (or TCRβ) alleles obtained, strongly arguing against a role of cell fusion in HRS cell generation.
Enhanced immune activity of cytotoxic T-lymphocyte epitope analogs derived from positional scanning synthetic combinatorial libraries
Authors: Rosa Corinna La , Krishnan Radhika , Markel Susan , Schneck Jonathan P. , Houghten Richard , Pinilla Clemencia , Diamond Don J.
Published: July 2002

The pp65495-503 cytotoxic T-lymphocyte (CTL) epitope from cytomegalovirus (CMV) is universally recognized among CMV+ individuals who express an allele of the human leukocyte antigen A (HLA-A*0201). The relative binding affinity of the epitope to HLA-A*0201 is moderate, and its increased activity might prove beneficial in its use as a CTL epitope vaccine. A new approach to enhance the activity of T-cell epitopes is the use of positional scanning synthetic combinatorial libraries (PS-SCLs). Using a nonamer PS-SCL, the pp65495-503 epitope was modified after screening a CMV-specific T-cell clone (TCC) (3-3F4) from which the native peptide sequence was derived. Two peptides with amino acid substitutions at P1, P3, P7, and P8 are between 103 and 104 more active than the native epitope. Although the native CTL epitope terminates as a free acid, both tetrasubstituted peptides only function as CTL epitopes when the carboxyl terminus is amidated. Selective substitution of the native sequence based on PS-SCL screening results identified 3 amidated monosubstituted and disubstituted peptides that are better recognized than the native epitope by TCCs from a cohort expressing HLA-A*0201. In vitro stimulation of peripheral blood mononuclear cells with each of the peptide epitope analogs stimulated memory CTLs, which recognized CMV-infected targets among a high percentage of CMV+ individuals. Binding studies of peptide analogs with HLA-Ig (immunoglobulin) dimers and 2 different TCCs correlated with in vitro lysis results. These data suggest that increasing the activity of CTL epitopes while maintaining broad recognition is possible, which holds promise for vaccine development in infectious disease and cancer.
Down-regulation of CD8+ T-cell expansions in patients with human immunodeficiency virus infection receiving highly active combination therapy
Authors: Gorochov Guy , Neumann Avidan U. , Parizot Christophe , Li Taisheng , Katlama Christine , Debré Patrice
Published: July 2002

Analysis of T-cell receptor (TCR) repertoire usage made by peripheral T lymphocytes during the chronic phase of HIV-1 infection has revealed the presence of clonal expansions of CD8 T cells that are also shown to be largely HIV-specific. Yet, it remains unclear whether the global repertoire perturbation observed during the chronic phase of the infection is also HIV-related and reversible in the long term with the application of highly active antiretroviral therapy. Furthermore, the diversity and the stability of repertoire usage after a relapse of viral replication were never examined. Eight patients were observed longitudinally up to 31 months under triple-association therapy. When viral replication was steadily suppressed, CD8 repertoires were significantly stabilized. Conversely, in situations of incomplete or only transient viral suppression, persistence or rebound in repertoire perturbation was observed. Finally, a T-cell response remarkably different from baseline, as reflected by a repertoire switch, was generated after the discontinuation of highly active therapy. In conclusion, a sustained control of HIV replication correlated with profound modifications of the CD8 repertoire usage. These data also suggested that autovaccination by the withdrawal of antiviral drugs would result in the selection and expansion of T-cell clones that were not necessarily dominant before the onset of treatment.
Postgrafting administration of granulocyte colony-stimulating factor impairs functional immune recovery in recipients of human leukocyte antigen haplotype–mismatched hematopoietic transplants
Authors: Volpi Isabella , Perruccio Katia , Tosti Antonella , Capanni Marusca , Ruggeri Loredana , Posati Sabrina , Aversa Franco , Tabilio Antonio , Romani Luigina , Martelli Massimo F. , Velardi Andrea
Published: July 2002

In human leukocyte antigen haplotype–mismatched transplantation, extensive T-cell depletion prevents graft-versus-host disease (GVHD) but delays immune recovery. Granulocyte colony-stimulating factor (G-CSF) is given to donors to mobilize stem cells and to recipients to ensure engraftment. Studies have shown that G-CSF promotes T-helper (Th)-2 immune deviation which, unlike Th1 responses, does not protect against intracellular pathogens and fungi. The effect of administration of G-CSF to recipients of mismatched hematopoietic transplants with respect to transplantation outcome and functional immune recovery was investigated. In 43 patients with acute leukemia who received G-CSF after transplantation, the engraftment rate was 95%. However, the patients had a long-lasting type 2 immune reactivity, ie, Th2-inducing dendritic cells not producing interleukin 12 (IL-12) and high frequencies of IL-4– and IL-10–producing CD4+ cells not expressing the IL-12 receptor β2 chain. Similar immune reactivity patterns were observed on exposure of donor cells to G-CSF. Elimination of postgrafting administration of G-CSF in a subsequent series of 36 patients with acute leukemia, while not adversely affecting engraftment rate (93%), resulted in the anticipated appearance of IL-12–producing dendritic cells (1-3 months after transplantation versus > 12 months in transplant recipients given G-CSF), of CD4+ cells of a mixed Th0/Th1 phenotype, and of antifungal T-cell reactivity in vitro. Moreover, CD4+ cell counts increased in significantly less time. Finally, elimination of G-CSF–mediated immune suppression did not significantly increase the incidence of GVHD (< 15%). Thus, this study found that administration of G-CSF to recipients of T-cell–depleted hematopoietic transplants was associated with abnormal antigen-presenting cell functions and T-cell reactivity. Elimination of postgrafting administration of G-CSF prevented immune dysregulation and accelerated functional immune recovery.
A novel myeloid-restricted zebrafish CCAAT/enhancer-binding protein with a potent transcriptional activation domain
Authors: Lyons Susan E. , Shue Bixiong C. , Oates Andrew C. , Zon Leonard I. , Liu P. Paul
Published: July 2002

The CCAAT/enhancer-binding protein (C/EBP) family consists of transcription factors essential for hematopoiesis. The defining feature of the C/EBPs is a highly conserved carboxy-terminal bZIP domain that is necessary and sufficient for dimerization and DNA binding, whereas their amino-terminal domains are unique. This study reports a novelc/ebp gene (c/ebp1) from zebrafish that encodes a protein homologous to mammalian C/EBPs within the bZIP domain, but with an amino terminus lacking homology to any C/EBP or to any known sequence. In zebrafish embryos, c/ebp1 expression was initially observed in cells within the yolk sac circulation valley at approximately the 16-to 18-somite stage, and at 24 hours postfertilization (hpf), also in circulating cells. Mostc/ebp1+cells also expressed a known early macrophage marker, leukocyte-specific plastin (l-plastin). Expression of both markers was lost in cloche, a mutant affecting hematopoiesis at the level of the hemangioblast. Expression of both markers was retained in m683 andspadetail, mutants affecting erythropoiesis, but not myelopoiesis. Further, c/ebp1 expression was lost in a mutant with defective myelopoiesis, but intact erythropoiesis. These data suggest that c/ebp1 is expressed exclusively in myeloid cells. In electrophoretic mobility shift assays, c/ebp1 was able to bind a C/EBP consensus DNA site. Further, a chimeric protein containing the amino-terminal domain of c/ebp1 fused to the DNA-binding domain of GAL4 induced a GAL4 reporter 4000-fold in NIH3T3 cells. These results suggest that c/ebp1 is a novel member of the C/EBP family that may function as a potent transcriptional activator in myeloid cells.
Phagocytic dendritic cells from myelomas activate tumor-specific T cells at a single cell level
Authors: Dembic Zlatko , Røttingen John-Arne , Dellacasagrande Jérôme , Schenck Karl , Bogen Bjarne
Published: July 2002

Antigen-presenting cells (APCs) from subcutaneous mouse MOPC315 plasmacytoma phagocytosed immunoglobulin G–coated magnetic beads, enabling efficient isolation within 2 hours by magnetic separation (APC-MB). Cell morphology was heterogeneous, with some of the cells having dendrites. The surface phenotype of purified tumor APCs-MB was CD11b+, CD11c+, CD40+, CD80+, CD86+, and MHC class II+. Tumor APCs-MB expressed messenger RNA for fractalkine and ABCD-1 chemokines, and for CC-type chemokine receptors CCR5 and CCR7, indicating the presence of mature dendritic cells (DCs). Visualized at a single cell level within 4 hours after disruption of the tumor, APCs-MB induced rapid Ca++ mobilization in MHC class II–restricted tumor idiotype (Id)–specific cloned CD4+ T cells. In long-term assays, tumor APCs-MB induced proliferation of naive T cells from Id-specific T-cell receptor transgenic mice. The results suggest that tumor APCs-MB represent a heterogeneous cell population that includes myeloid-derived DCs of various stages of maturation. A considerable fraction (≥ 15%) of DCs is spontaneously primed with tumor-specific antigen.
Role of p21Cip1/Waf1 in cell-cycle exit of endomitotic megakaryocytes
Authors: Baccini Véronique , Roy Lydia , Vitrat Natacha , Chagraoui Hédia , Sabri Siham , Couedic Jean-Pierre Le , Debili Najet , Wendling Françoise , Vainchenker William
Published: July 2002

The cyclin-dependent kinase inhibitor p21Waf-1/Cip-1 is expressed at high level during megakaryocyte differentiation, but its precise function remains unknown. In this study, it is confirmed that p21 was expressed at a high level in hypoploid (2N and 4N) and polyploid (at least 8N) human megakaryocytes derived from CD34+ cells. A high expression of p27Kip1, p16, cyclin E, and cyclin D3 was also found in both populations associated with a hypophosphorylated form of retinoblastoma protein, suggesting that the majority of hypoploid and polyploid megakaryocytes are G1-arrested cells. As human megakaryocytes grown in vitro present a defect in their polyploidization, the study switched to the murine model. The modal ploidy of megakaryocytes derived from lineage-negative cells was 32N, and an elevated expression of p21 was found in high-ploidy megakaryocytes. In addition, p21 and p27 were coexpressed in the majority of mature polyploid megakaryocytes. The p21 was detected by immunofluorescence in megakaryocytes derived from p53−/− mice, demonstrating a p53-independent regulation during megakaryocyte differentiation. Megakaryocytopoiesis of p21−/− mice was subsequently studied. No marked abnormality in the ploidy of primary or cultured megakaryocytes was detected. Overexpression of p21 in p21−/− or normal murine megakaryocytes and in human megakaryocytes showed in all these cases a marked inhibition in megakaryocyte polyploidization. In conclusion, while a reciprocal relation is observed between p21 levels in megakaryocytes and the cycling state of the cells, p21 is not essential for the determination of the ploidy profile in normal megakaryocytes in vivo. However, high levels of its expression in cultured megakaryocytes arrest the endomitotic cell cycle.
Selective T-cell subset ablation demonstrates a role for T1 and T2 cells in ongoing acute graft-versus-host disease: a model system for the reversal of disease
Authors: Liu Jinli , Anderson Britt E. , Robert Marie E. , McNiff Jennifer M. , Emerson Stephen G. , Shlomchik Warren D. , Shlomchik Mark J.
Published: July 2002

Graft-versus-host disease (GVHD) is a major cause of morbidity and mortality of allogeneic stem cell transplantation. Strategies to control GVHD while maintaining graft versus leukemia (GVL) include herpes simplex virus thymidine kinase (HSV-tk) gene transduction of donor T cells followed by treatment with ganciclovir (GCV). Alternatively, GVHD and GVL may be mediated by distinct processes. In this regard, whether cytokine polarization occurs and to what degrees various subsets of cytokine-producing T cells mediate GVHD or GVL has been an active area of research using cytokine or cytokine antibody infusion or genetically deficient mice. This study takes a different approach that allows simultaneous investigation into both the mechanisms underlying GVHD reactions and the efficacy of HSV-tk suicide gene-based T-cell deletion. A source of donor T cells, splenocytes from mice transgenic for HSV-tk controlled by elements of either the interleukin-2 (IL-2) or IL-4 promoters (IL-2-tk and IL-4-tk, respectively) was used, thus allowing investigation into the roles of T1 and T2 cells in ongoing GVHD reactions. To assess treatment rather than prevention of GVHD, GCV was started at peak disease. Remarkably, treatment at this late time point rescued mice from the clinical effects of GVHD caused by T cells expressing either transgene. Thus, both T1 and T2 cells play an important role in clinical GVHD in a minor histocompatibility antigen-mismatched setting. In addition, because clinical disease was reversible even at its maximum, these observations provide controlled evidence that this strategy of treating ongoing GVHD could be effective clinically.