bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of vermiculite and limestone to desulphurization and to the removal of dust during briquette combustion
Authors: Lu A. , Zhao D. , Li J. , Wang C. , Qin S.
Published: August 2004

Small domestic cooking furnaces are widely used in China. These cooking furnaces release SO2 gas and dust into the atmosphere and cause serious air pollution. Experiments were conducted to investigate the effects of vermiculite, limestone or CaCO3, and combustion temperature and time on desulphurization and dust removal during briquette combustion in small domestic cooking furnaces. Additives used in the coal are vermiculite, CaCO3 and bentonite. Vermiculite is used for its expansion property to improve the contact between CaCO3 and SO2 and to convey O2 into the interior of briquette; CaCO3 is used as a chemical reactant to react with SO2 to form CaSO4; and bentonite is used to develop briquette strength. Expansion of vermiculite develops loose interior structures, such as pores or cracks, inside the briquette, and thus brings enough oxygen for combustion and sulphation reaction. Effective combustion of the original carbon reduces amounts of dust in the fly ash. X-ray diffraction, optical microscopy, and scanning electron microscopy with energy dispersive X-ray analysis show that S exists in the ash only as anhydrite CaSO4, a product of SO2 reacting with CaCO3 and O2. The formation of CaSO4 effectively reduces or eliminates SO2 emission from coal combustion. The major factors controlling S retention are vermiculite, CaCO3 and combustion temperature. The S retention ratio increases with increasing vermiculite amount at 950°C. The S retention ratio also increases with increasing Ca/S molar ratio, and the best Ca/S ratio is 2-3 for most combustion. With 12 g of the original coal, 1 to 2 g of vermiculite, a molar Ca/S ratio of 2.55 by adding CaCO3, and some bentonite, a S retention ratio >65% can be readily achieved. The highest S retention ratio of 97.9% is achieved at 950°C with addition of 2 g of vermiculite, a Ca/S ratio of 2.55 and bentonite.
Mineralogical control on inorganic contaminant mobility in leachate from lead-zinc metallurgical slag: experimental approach and long-term assessment
Authors: Ettler V. , Piantone P. , Touray J.-C.
Published: August 2004

Lead, zinc and arsenic mobilization/attenuation processes during interactions between smelter slag and water show differences depending on the origin of the slag. The studied samples, waste from ore and car-battery processing, were submitted to long-term (365 days) batch leaching at two different initial pH values. The leachate analyses were input to the EQ3NR speciation-solubility code to speciate the solutions and determine the degree of saturation with respect to different phases, and a mineralogical investigation was made of the newly formed phases. An ‘oxidizing’ scenario can be proposed for slag waste disposal, considering that cerussite (PbCO3) at pH >6 becomes a major solubility-controlling phase for Pb, and newly formed hydrous ferric oxides (HFO – common secondary phases under oxidizing conditions) efficiently adsorb As. No efficient scavenging mechanism was found for Zn, which was progressively leached from the slag and in particular from the ore-processing slag. Quenched glass-rich slag from old car-battery processing was found to release significant amounts of Pb, especially in acidic environments. Neither slag would therefore be suitable for recycling for civil engineering purposes. Conversely, extremely low releases of Pb, Zn and As were observed for recent car-battery processing slag, which could therefore be considered for road construction.
Characterization and identification of mixed-metal phosphates in soils: the application of Raman spectroscopy
Authors: Lanfranco A. M. , Schofield P. F. , Murphy P. J. , Hodson M. E. , Mosselmans J. F. W. , Valsami-Jones E.
Published: August 2004

The development of protocols for the identification of metal phosphates in phosphate-treated, metalcontaminated soils is a necessary yet problematical step in the validation of remediation schemes involving immobilization of metals as phosphate phases. The potential for Raman spectroscopy to be applied to the identification of these phosphates in soils has yet to be fully explored. With this in mind, a range of synthetic mixed-metal hydroxylapatites has been characterized and added to soils at known concentrations for analysis using both bulk X-ray powder diffraction (XRD) and Raman spectroscopy.

Mixed-metal hydroxylapatites in the binary series Ca –Cd, Ca –Pb, Ca –Sr and Cd –Pb synthesized in the presence of acetate and carbonate ions, were characterized using a range of analytical techniques including XRD, analytical scanning electron microscopy (SEM), infrared spectroscopy (IR), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and Raman spectroscopy. Only the Ca –Cd series displays complete solid solution, although under the synthesis conditions of this study the Cd5(PO4)3OH end member could not be synthesized as a pure phase. Within the Ca –Cd series the cell parameters, IR active modes and Raman active bands vary linearly as a function of Cd content. X-ray diffraction and extended X-ray absorption fine structure spectroscopy (EXAFS) suggest that the Cd is distributed across both the Ca(1) and Ca(2) sites, even at low Cd concentrations.

In order to explore the likely detection limits for mixed-metal phosphates in soils for XRD and Raman spectroscopy, soils doped with mixed-metal hydroxylapatites at concentrations of 5, 1 and 0.5 wt.% were then studied. X-ray diffraction could not confirm unambiguously the presence or identity of mixed-metal phosphates in soils at concentrations below 5 wt.%. Raman spectroscopy proved a far more sensitive method for the identification of mixed-metal hydroxylapatites in soils, which could positively identify the presence of such phases in soils at all the dopant concentrations used in this study. Moreover, Raman spectroscopy could also provide an accurate assessment of the degree of chemical substitution in the hydroxylapatites even when present in soils at concentrations as low as 0.1%.
Optimization of some key geothermobarometers for pelitic metamorphic rocks
Authors: Holdaway M. J.
Published: August 2004

I will consider mainly geothermobarometry in medium-grade pelitic rocks, including the garnet-biotite (GB) geothermometer, the Grossular-Al silicate-plagioclase (GASP) geobarometer, and the muscovite-almandine-biotite-sillimanite (MABS) geobarometer. For GB (Holdaway, 2000) experimental data and estimated biotite ΔWTi were used to optimize two exchange parameters and four biotite Margules parameters. Using stepwise linear regression, experimental vs. calculated T were constrained to lie on a line with slope of one and intercept of zero, maximizing r2. The best model involves experiments by Ferry and Spear (1978) and Perchuk and Lavrent’eva (1983), suggesting minimal viAl in the Ferry and Spear product biotite. For GASP (Holdaway, 2001), end-member experimental data do not adequately constrain the equilibrium. I used the GB model above, and allowed the end-member curve to rotate about the best-constrained part of the GASP end-member data. The end-member curve was further constrained with the kyanite-sillimanite (K-S) boundary using published chemical data on 76 pelitic schist samples from 11 localities, rejecting Low-Grs and low-An samples. The Fuhrman and Lindsley (1988) plagioclase model gives the best results. For MABS, work in progress involves 61 samples from the 11 localities which have muscovite analyses. Biotite Margules parameters were based on the GB model and McMullin et al. (1991). The MABS end-member curve was calibrated by comparison of P values determined using trial MABS data and GASP results. The P values for the 61 samples agree well with the K-S boundary, and sillimanite-bearing rocks of west-central Maine all fall in the sillimanite field. Preliminary biotite values are: GAnn = –5149198 – 412.05 T, WAlFe = –14023 + 28.14 T, WAlMg = –259582 + 308.44 T, WTiFe = 124842 – 98.67 T, WTiMg = –186148 + 271.72 T. For geobarometry, the Berman (1988, revised 1992) database was used with adjustable H and S of grossular for GASP and H and S of annite for MABS. The accuracy of currently available databases, activity models and mole fraction models is not adequate for good geothermobarometry, without further refinement. Adjustable parameters tend to compensate for error in activity models, mole fraction models and databases.
Arsenopyrite and As-bearing pyrite from the Roudný deposit, Bohemian Massif
Authors: Zachariáš J. , Frýda J. , Paterová B. , Mihaljevič M.
Published: August 2004

The major- and trace-element chemistry of pyrite and arsenopyrite from the mesothermal Roudný gold deposits was studied by electron microprobe and laser ablation ICP-MS techniques. In total, four generations of pyrite and two of arsenopyrite were distinguished. The pyrite is enriched in As through an Fe (AsxS1–x)2substitution mechanism. The As-rich zones of pyrite-2 (up to 4.5 wt.% As) are also enriched in gold (up to 20 ppm), lead (commonly up to 220 ppm, exceptionally up to 1500 ppm) and antimony (commonly <600 ppm, rarely up to 1350 ppm). Positive correlation of As and Au in the studied pyrites is not coupled with an Fe deficiency, in contrast to Au-rich As-bearing pyrites in Carlintype gold deposits. The As-rich pyrite-2 coprecipitated with the Sb-rich (1 –4.2 wt.%) and Au-rich (40 –150 ppm) arsenopyrite-1. The younger arsenopyrite-2 is significantly less enriched in these elements (0 –70 ppm of Au).

The chemical zonality of pyrites in the Roudný gold deposits reflects the chemical evolution of orebearing fluids that are not observed in any other mineral phases. The data available suggest relatively high activity of sulphur and low activities of arsenic and gold during crystallization of the older pyrite generation (pyrite-1). Later, after particular dissolution of pyrite-1, Au-rich As-bearing pyrite-2 and arsenopyrite precipitated. These facts suggest a marked increase in the arsenic and gold activities in ore-bearing fluids. The As-content of pyrite-2 decreases in an oscillatory manner from the core to the rim, reflecting changes in the As activity or/and in theP-Tconditions. The As-bearing pyrites were formed at temperatures of at least 320–330°C, based on arsenopyrite thermometers and fluid inclusion data.
Thermodynamics of mixing and ordering in pyrope — grossular solid solution
Authors: Vinograd V. L. , Sluiter M. H. F. , Winkler B. , Putnis A. , Hålenius U. , D. Gale J. , Becker U.
Published: August 2004

Static lattice energy calculations have been combined with cluster expansion formalism to predict pairwise ordering interactions in the pyrope–grossular solid solution. The ordering interactions, the Js, have been then used to calculate the activity-composition relations over a wide temperature range with the help of the Cluster Variation Method. It is shown that short-range ordering in the system is driven by size mismatch. The prediction of the right signs and magnitudes of the ordering interaction energies requires separation of the mixing enthalpy into the configuration-dependent (chemical) and the configuration-independent (elastic) components. The study predicts the existence of a miscibility gap below 500°C.
Heat capacity of lazulite, MgAl2(PO4)2(OH)2, from 35 to 298 K and a (S–V) value for P2O5 to estimate phosphate entropy
Authors: Brunet F. , Morineau D. , Schmid-Beurmann P.
Published: August 2004

The heat capacity of synthetic lazulite, MgAl2(PO4)2(OH)2, has been measured between 35 and 298 K by means of low-temperature adiabatic calorimetry. A lazulite third-law entropy (S2980) value of 204(3) J K–1 mol–1 was retrieved after extrapolation of the lazulite heat capacity by a cubic temperature function, down to absolute temperature. Identical measurements on α-Al2O3 yielded S2980 = 51.2 J mol–1 K–1 instead of the recommended 50.94 J mol–1 K–1 value. This new lazulite third-law entropy along with other phosphate entropy data either derived from low-temperature adiabatic calorimetry or experimental phase equilibria under pressure and temperature, were computed to retrieve a (S–V)P2O5 value of 57.4(2.9) to predict phosphate entropies from oxide summation. The predicted third-law entropy for trolleite, Al4(PO4)3(OH)3, amounts to 285.4(8.5) J mol–1 K–1 ~13% higher than the previously published value. We propose a new formation enthalpy from the elements of –6504.2 kJ mol–1 and a new third-law entropy of 281.7 J mol–1 K–1 for trolleite, compatible with the predicted entropy from oxide summation as well as with the published brackets on the trolleite = berlinite + corundum + water reaction.
Characterization of ammonioleucite (NH4)[AlSi2O6] and ND4-ammonioleucite (ND4)[AlSi2O6] using IR spectroscopy and Rietveld refinement of XRD spectra
Authors: Andrut M. , E. Harlov D. , Najorka J.
Published: August 2004

Ammonioleucite, (NH4)[AlSi2O6], and its deuterated analogue ND4-ammonioleucite (ND4)[AlSi2O6] have been synthesized in 20–150 mg amounts at 300°C and 500 MPa in 5 mm wide, 4 cm long Au capsules using Rene’ metal hydrothermal autoclaves. The resultant product consists of 20–30 mm-size single tetragonal crystals as well as 50 –100 mm wide clumps of ingrown crystals. Infrared (IR) spectra obtained from powdered samples are assigned on the basis of Td symmetry for both the ammonium and deutero-ammoniumion. They show triply degenerate vibrational bands (i.e. v3 and v4), some overtones, and combination modes from NH4+ and ND4+. While Td symmetry for NH4+ in ammonioleucite is not strictly correct due to distortion of the NH+4 molecule, the non-cubic field is not large enough at room temperature to cause a substantial splitting in the bands. However, this perturbation is documented in the IR spectra by a substantial increase in the FWHH as well as the occurrence of shoulders on the broadened bands. In contrast, at lower temperatures, the observed band splittings in the former triply degenerated states of v3 and v4 could be explained by an effective local field with D2 symmetry.

Rietveld refinement indicates that ammonioleucite, like leucite, has a tetragonal structure with space group symmetry I41/a. Here the NH4+ molecule replaces the K+ cation on the 8-fold co-ordinated W site, which has m symmetry. Substitution of NH4+ for K+ in the leucite structure results in an increase of the cell parameter a, whereas c is slightly reduced. The mean  bond length of ammonioleucite is increased in comparison to leucite from 3.00 to 3.12 Å whereas the mean  bond length of 1.65 Å remains unchanged. This results in an increase in the volume of the polyhedron hosting the NH4+ molecule as well as a decrease in distortion for structural channels parallel to the <111> direction, formed by the arrangement of the six-fold rings, on which the W cations are located. The same effect is also observed, in general, when Rb+ or Cs+ is substituted for K+ in leucite.
Pb-Si ordering in sheet-oxychloride minerals: the super-structure of asisite, nominally Pb7SiO8Cl2
Authors: Welch M. D.
Published: August 2004

The original structure determination of asisite, nominally Pb7SiO8Cl2, has been re-evaluated in the light of electron-diffraction data (TEM) on the original sample material. Electron diffraction patterns indicate a super-structure based upon a metrically tetragonal 26-cation-site super-sheet motif (14x14x23 Å). Given the strong ordering of elements substituting for Pb in closely-related litharge-based oxychlorides (parkinsonite, symesite, kombatite, schwartzembergite), the asisite superstructure is inferred to be due to strong ordering of Si within the PbO sheet. The original chemical analyses of asisite given by Rouse et al. (1988) are shown to be consistent with such a super-structure, which has a 12Pb:1Si cation ratio. A new formula for asisite is proposed that is based upon this superstructure: Pb12(SiO4)O8Cl4 (Z = 8). The structure of asisite determined by Rouse et al. (1988) is that of the average Pb/Si-disordered tetragonal sub-cell (I4/mmm: 4x4x23 Å) and belies the highly ordered real state. The structure of the tetragonal sub-cell has been re-determined here: R = 5.6% for 178 unique Fo > 4σFo and an anisotropic model. A significantly reduced 72% occupancy of the Pb(2) site was found that implies the nominal formula Pb7SiO8Cl2, thus confirming the findings of Rouse et al. (1988). Comparisons with kombatite and symesite support the assignment of Si to Pb(2) and imply that Si in asisite is also likely to be in tetrahedral coordination, with the apical oxygen cross-linking PbO sheets. However, because most of the key information relating to the location of Si is provided by the super-lattice reflections, the inability of X-ray diffraction to register these reflections introduces a significant ambiguity into the interpretation of Pb/Si ordering behaviour in this mineral.
Refractory gold ores in Archaean greenstones,Western Australia: mineralogy, gold paragenesis, metallurgical characterization and classification
Authors: Vaughan J. P. , Kyin A.
Published: August 2004

Mesothermal gold ores in the Archaean Yilgarn Craton of Western Australia are dominated by a pyrite ± arsenopyrite ± pyrrhotite sulphide assemblage. Many of these ores are refractory to varying degrees and require treatment by roasting, bacterial oxidation or finer milling. The most common sulphide ore types can be sub-divided broadly into pyritic (pyrite±pyrrhotite) and arsenical types (pyrite+arsenopyrite± pyrrhotite). Arsenical ores vary from highly refractory to free-milling. Arsenopyrite in highly refractory ores is finer grained, As-deficient (27 –32.5 at.% As), contains high average concentrations of submicroscopic gold (60 –270 ppm), but does not contain inclusions of particulate gold. Arsenopyrite in free-milling ores is coarser grained, less As-deficient to slightly As-rich (30 –35 at.% As), contains low or negligible concentrations of submicroscopic gold, but contains inclusions and fracture fillings of particulate gold. In some refractory arsenical ores, pyrite also contains moderately high levels of submicroscopic gold (20 –40 ppm), the concentration of which is directly related to As content of the pyrite.

Pyritic ores are free-milling to mildly refractory, or rarely moderately refractory. Pyrite in pyritic ores contains negligible to low levels of submicroscopic gold (<5 ppm). Other reasons for refractory behaviour in pyritic ores include very fine-grained native gold inclusions in pyrite, or the presence of gold-bearing tellurides.

It is concluded that submicroscopic gold is incorporated into the crystal lattices of arsenopyite and arsenical pyrite at sub-greenschist to lower greenschist-facies temperatures, and is progressively expelled as inclusions and fracture fillings of native gold in sulphides, and ultimately into the gangue, as recrystallization proceeds through upper greenschist- into amphibolite-facies temperatures, during deformation and burial. Submicroscopic gold is expelled more rapidly from pyrite than arsenopyrite.

Pyrrhotite progressively replaces primary pyrite at higher temperatures, but rarely contains gold. Finally, a metallurgical classification scheme for refractory ores is presented which incorporates the above mineralogical conclusions.
Acid leaching and dissolution of major sulphide ore minerals: processes and galvanic effects in complex systems
Authors: Abraitis P. K. , D. Pattrick R. A. , Kelsall G. H. , Vaughan D. J.
Published: August 2004

The kinetics and mechanisms of dissolution of the major base metal sulphide minerals, pyrite, chalcopyrite, galena and sphalerite in acidic (chloride) media have been investigated. Minerals were ground in air, then dissolved in air-equilibrated solutions at pH 2.5, while monitoring the redox potential. Solution samples were analysed by ICP-AES and HPLC, and surfaces of residual sulphides analysed using XPS. Dissolution of aerial oxidation products on pyrite particles in the first 15 min apparently led to a sulphur-rich surface, and was followed by slower dissolution of pyrite itself, driven by oxygen reduction, and resulting in net production of protons. Chalcopyrite dissolution resulted in a Cu, S-rich (near) surface layer, accompanied by net consumption of protons. Apparently incongruent dissolution of galena and sphalerite may reflect the formation of elemental S at the surface. The rates of dissolution of chalcopyrite, galena and sphalerite in the presence of pyrite were determined, respectively, as 18, 31 and 1.5 times more rapid than in single-mineral experiments. These data were consistent with galvanically-promoted mineral oxidation of the other sulphides in the presence of pyrite. In the case of galena, the experimental data suggested extensive release of Pb ions and development of a sulphur-rich surface during galvanically-promoted dissolution.
Applying Support Vector Machines for Gene ontology based gene function prediction
Authors: Vinayagam Arunachalam , König Rainer , Moormann Jutta , Schubert Falk , Eils Roland , Glatting Karl-Heinz , Suhai Sándor
Published: August 2004

Background

The current progress in sequencing projects calls for rapid, reliable and accurate function assignments of gene products. A variety of methods has been designed to annotate sequences on a large scale. However, these methods can either only be applied for specific subsets, or their results are not formalised, or they do not provide precise confidence estimates for their predictions.

Results

We have developed a large-scale annotation system that tackles all of these shortcomings. In our approach, annotation was provided through Gene Ontology terms by applying multiple Support Vector Machines (SVM) for the classification of correct and false predictions. The general performance of the system was benchmarked with a large dataset. An organism-wise cross-validation was performed to define confidence estimates, resulting in an average precision of 80% for 74% of all test sequences. The validation results show that the prediction performance was organism-independent and could reproduce the annotation of other automated systems as well as high-quality manual annotations. We applied our trained classification system to Xenopus laevis sequences, yielding functional annotation for more than half of the known expressed genome. Compared to the currently available annotation, we provided more than twice the number of contigs with good quality annotation, and additionally we assigned a confidence value to each predicted GO term.

Conclusions

We present a complete automated annotation system that overcomes many of the usual problems by applying a controlled vocabulary of Gene Ontology and an established classification method on large and well-described sequence data sets. In a case study, the function for Xenopus laevis contig sequences was predicted and the results are publicly available at ftp://genome.dkfz-heidelberg.de/pub/agd/gene_association.agd_Xenopus.
Cloning and expression analysis of cDNAs corresponding to genes activated in cucumber showing systemic acquired resistance after BTH treatment
Authors: Bovie Catherine , Ongena Marc , Thonart Philippe , Dommes Jacques
Published: August 2004

Background

Infection of plants by necrotizing pathogens can lead to the rapid and localized induction of a complex set of defense responses resulting in a restriction of pathogen growth and spread. Subsequently, an increase of plant resistance against a broad spectrum of pathogens is observed systemically. This plant immunity is known as Systemic Acquired Resistance. To identify components of the transduction pathway, we cloned and analysed the expression pattern of several mRNAs accumulating in cucumber plants after induction of Systemic Acquired Resistance.

Results

We tested on cucumber different compounds known to induce systemic acquired resistance. Among these, BTH (benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester) proved to be very effective. mRNA RT-PCR differential display was used to identify mRNA sequences induced 24 hours after the application of 10 μM BTH to cucumber plants. A cDNA library constructed from cucumber plants sprayed with 10 μM BTH was screened to get corresponding full length cDNAs. Among the identified cDNAs were those coding for a putative ras-related GTP-binding protein, a putative beta-1,4-N-Acetylglucosaminyltranferase III and a putative pathogenesis related protein. The time course of accumulation of the three corresponding mRNAs was analysed by northern blotting in plants treated by BTH or in plants infected by Colletotrichum lagenarium.

Conclusions

The mRNA RT-PCR differential display technique allowed the identification of three genes possibly involved in Systemic Acquired Resistance in cucumber. Pathogenesis-related proteins are known to be involved in plant defence against pathogens. GTP-binding protein and N-acetylglucosaminyltranferase III have been reported to be components of signal transduction pathways in mammals and plants.
External decontamination of wild leeches with hypochloric acid
Authors: Aydin Atakan , Nazik Hasan , Kuvat Samet Vasfi , Gurler Nezahat , Ongen Betigul , Tuncer Serdar , Hocaoglu Emre , Kesim Sinan Nur
Published: August 2004

Background

Medicinal leech, Hirudo medicinalis, has been used in plastic and reconstructive surgery, to relieve venous congestion and to improve the microrevascularization of flaps. In many countries, wild leeches are still provided from local markets and utilised with antibiotic prophylaxies. In this research, results of identification of bacteria in the transport fluid is reported, oral and intestinal floras and the antibiograms of the identified microorganisms are investigated. Also, to avoid possible infections, the ability of hypochloric acid, a disinfectant, to suppress the relevant microorganisms without changing the life style and behavior of leeches in terms of sucking function, is investigated.

Methods

Bacterial identifications and antibiograms of oral and intestinal flora and transport medium were performed for 10 leeches. The optimum concentration of hypochloric acid which eliminated microorganisms without affecting the viability and sucking function of the leeches were determined by dilution of hypochloric acid to 100, 50, 25, 12.5, 6.25 ppm concentrations in different groups of 25 leeches. Finally, 20 leeches were applied atraumatically to the bleeding areas of rats, the duration of suction was determined and compared statistically between the leeches treated and not treated with hypochloric acid solution.

Results

Aeromonas hydrophilia was the most commonly identified microorganism and found to be resistant to first generation cephalosporins, frequently used in prophylaxis at surgical wards. In the next stages of the study, the leeches were subjected to a series of diluted hypochloric acid solutions. Although disinfection of the transport material and suppression of the oral flora of hirudo medicinalis were successful in 100, 50, 25, 12.5, 6.25 ppm concentrations; 12.5 ppm solution was the greatest concentration in which hirudo medicinalis could survive and sucking function was not affected significantly.

Conclusions

External decontamination of wild leeches with 12.5 ppm hypochloric acid enables bacterial suppression without causing negative effects on leech sucking function and life.
No evidence for involvement of SDHD in neuroblastoma pathogenesis
Authors: De Preter Katleen , Vandesompele Jo , Hoebeeck Jasmien , Vandenbroecke Caroline , Smet Jöel , Nuyts Annick , Laureys Geneviève , Combaret Valérie , Van Roy Nadine , Roels Frank , Van Coster Rudy , Praet Marleen , De Paepe Anne , Speleman Frank
Published: August 2004

Background

Deletions in the long arm of chromosome 11 are observed in a subgroup of advanced stage neuroblastomas with poor outcome. The deleted region harbours the tumour suppressor gene SDHD that is frequently mutated in paraganglioma and pheochromocytoma, which are, like neuroblastoma, tumours originating from the neural crest. In this study, we sought for evidence for involvement of SDHD in neuroblastoma.

Methods

SDHD was investigated on the genome, transcriptome and proteome level using mutation screening, methylation specific PCR, real-time quantitative PCR based homozygous deletion screening and mRNA expression profiling, immunoblotting, functional protein analysis and ultrastructural imaging of the mitochondria.

Results

Analysis at the genomic level of 67 tumour samples and 37 cell lines revealed at least 2 bona-fide mutations in cell lines without allelic loss at 11q23: a 4bp-deletion causing skip of exon 3 resulting in a premature stop codon in cell line N206, and a Y93C mutation in cell line NMB located in a region affected by germline SDHD mutations causing hereditary paraganglioma. No evidence for hypermethylation of the SDHD promotor region was observed, nor could we detect homozygous deletions. Interestingly, SDHD mRNA expression was significantly reduced in SDHD mutated cell lines and cell lines with 11q allelic loss as compared to both cell lines without 11q allelic loss and normal foetal neuroblast cells. However, protein analyses and assessment of mitochondrial morphology presently do not provide clues as to the possible effect of reduced SDHD expression on the neuroblastoma tumour phenotype.

Conclusions

Our study provides no indications for 2-hit involvement of SDHD in the pathogenesis of neuroblastoma. Also, although a haplo-insufficient mechanism for SDHD involvement in advanced stage neuroblastoma could be considered, the present data do not provide consistent evidence for this hypothesis.
Vitamin D deficiency and causative factors in the population of Tehran
Authors: Hashemipour Sima , Larijani Bagher , Adibi Hossein , Javadi Ebrahim , Sedaghat Mojtaba , Pajouhi Mohammad , Soltani Akbar , Shafaei Ali Reza , Hamidi Zohreh , Fard Ali Reza Khalili , Hossein-Nezhad Arash , Booya Fargol
Published: August 2004

Background

There are multiple studies in different countries regarding the prevalence of vitamin D deficiency. These studies showed high prevalence of vitamin D deficiency in Asian countries. This study tries to elucidate the prevalence of vitamin D deficiency and its influencing factors in population of Tehran.

Methods

1210 subjects 20–64 years old were randomly selected. 25 (OH) D serum levels were measured. Duration of exposure to sunlight, the type of clothing and level of calcium intake and BMI were quantified based on a questionnaire.

Results

A high percentage of vitamin D deficiency was defined in the study population. Prevalence of severe, moderate and mild Vitamin D deficiency was 9.5%, 57.6% and 14.2% respectively. Vitamin D serum levels had no significant statistical relation with the duration of exposure to sunlight, kind of clothing and BMI. Calcium intake in the normal vitamin D group was significantly higher than the other groups (714.67 ± 330.8 mg/day vs 503.39 ± 303.1, 577.93 ± 304.9,595.84 ± 313.6). Vitamin D serum levels in young and middle aged females were significantly lower than the older group.

Conclusions

Vitamin D deficiency has a high prevalence in Tehran. In order to avoid complications of vitamin D deficiency, supplemental dietary intake seems essential.
Human cytokine-induced killer cells have enhanced in vitro cytolytic activity via non-viral interleukin-2 gene transfer
Authors: Nagaraj Srinivas , Ziske Carsten , Schmidt-Wolf Ingo GH
Published: August 2004

Modulation of the immune system by genetically modified immunological effector cells is of potential therapeutic value in the treatment of malignancies. Interleukin-2 (IL-2) is a crucial cytokine which induces potent antitumor response. Cytokine-induced killer cells (CIK) have been described as highly efficient cytotoxic effector cells capable of lysing tumor cell targets and are capable of recognizing these cells in a non-MHC restricted fashion. Dendritic cells (DC) are the major antigen presenting cells. This study evaluated the antitumor effect of CIK cells which were non-virally transfected with IL-2 and co-cultured with pulsed and unpulsed DC. Human CIK cells generated from peripheral blood were transfected in vitro with plasmid encoding for the human IL-2. Transfection involved a combination of electrical parameters and a specific solution to deliver plasmid directly to the cell nucleus by using the Nucleofector® electroporation system. Nucleofection resulted in the production of IL-2 with a mean of 478.5 pg/106 cells (range of 107.6–1079.3 pg /106 cells/24 h) compared to mock transfected CIK cells (31 pg/106 cells) (P = 0.05). After co-culturing with DC their functional ability was assessed in vitro by a cytotoxicity assay. On comparison with non-transfected CIK cells co-cultured with DCs (36.5 ± 5.3 %), transfected CIK cells co-cultured with DC had a significantly higher lytic activity of 58.5 ± 3.2% (P = 0.03) against Dan G cells, a human pancreatic carcinoma cell line.
Virology on the Internet: the time is right for a new journal
Authors: Garry Robert F
Published: August 2004

Virology Journal is an exclusively on-line, Open Access journal devoted to the presentation of high-quality original research concerning human, animal, plant, insect bacterial, and fungal viruses. Virology Journal will establish a strategic alternative to the traditional virology communication process.
Pregnancy in patients with rheumatic diseases: obstetric management and monitoring
Authors: Branch D W
Published: August 2004

The obstetric management of the pregnant rheumatic patient is largely dictated by the specific disease and the degree to which it is associated with recognizable and treatable adverse obstetric outcomes, maternal or fetal. This review will cover the obstetric management of women with systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), rheumatoid arthritis (RA) and systemic sclerosis (SSc). Most experts agree that a co-ordinated management effort on the part of obstetricians and rheumatologists will likely yield the optimal achievable results.
Cytokines in recurrent miscarriage
Authors: Carp H
Published: August 2004

Cytokines act at all stages of pregnancy from implantation to parturition. This review examines their relevance in recurrent miscarriage. However, recurrent miscarriage may be due to an inherently abnormal embryo (e.g., chromosomal abberations) or maternal factors (e.g., uterine anomalies or antiphospholipid antibodies). In the former, cytokines are not causitive, but may be part of the mechanism of abortion. In the antiphospholipid syndrome, cytokines such as TNFa and IL-6 may be responsible for the associated thrombosis. Hence, an appropriate cytokine milieu could be responsible for whether the antibodies are pathogenic or merely an epiphenomenon. Natural killer cells seem to have a key role in immunosurveillance of the invading trophoblast. However, if activated by TNFa, natural killer cells may induce apoptosis in the trophoblast possibly leading to miscarriage. This action is inhibited by TGFb. Early ultrasound scanning and embryoscopy have revealed structural anomalies in karyotypically normal embryos which have terminated in first trimester missed abortion. Teratogens such as cyclophosphamide cause fetal demise by excessive apoptosis. Excessive apoptosis may be mediated by TNFa, TGFb and other cytokines. GM-CSF has been reported to prevent teratogenesis in laboratory animals. Both immunomodulation and hormonal support (progesterone or hCG supplements) have been used to improve the live birth rate in recurrently aborting women. Each may modulate the balance between various cytokines. Although neither hormonal support or immunopotentiation have been proven to be beneficial, the results and the role of cytokines themselves can only be assessed in trials of karyotypically normal embryos.
Celiac disease and inflammatory bowel disease in pregnancy
Authors: De Carolis S , Botta A , Fatigante G , Garofalo S , Ferrazzani S , Gasbarrini A , Caruso A
Published: August 2004

An adverse influence on reproductive life and obstetric complications are known to occur in women with celiac disease (clinical and subclinical disease) or inflammatory bowel diseases. Treatment can improve the pregnancy outcome; therefore, it is advisable that a clinical evaluation is performed by a joint team of obstetricians, internists and surgeons. The preconception clinical evaluation of the affected women is useful to focus on the different clinical aspects of the disease and to indicate specific therapeutic strategies. In this study a review of the literature regard to celiac disease and inflammatory bowel disease in pregnancy is presented
Pregnancy in rare autoimmune rheumatic diseases: UCTD, MCTD, myositis, systemic vasculitis and Beçhet disease
Authors: Doria A , Iaccarino L , Ghirardello A , Briani C , Zampieri S , Tarricone E , Gambari P F
Published: August 2004

The physiological adaptation of the immune system to pregnancy can potentially affect the course of all autoimmune rheumatic diseases (ARD), conversely the autoimmune processes characteristic of these conditions may compromise the foetal outcome. Unfortunately, very few reports on pregnancy outcome in patients with rare ARD are available. In this paper, we briefly review the data published until now on these disorders. Some general guidelines which were elaborated for more prevalent ARD seem to be valid also for such rare conditions: 1) patients should be correctly informed on the risk of becoming pregnant; 2) pregnancies should be planned when the disease is in remission since it increases the probability of successful maternal and foetal outcome; 3) patients should be regularly monitored during gestation and postpartum by a multidisciplinary team including rheumatologist, obstetrician, and neonatologist; 4) in the case of disease relapse an adequate treatment, even aggressive if necessary, should be recommended since active disease can be more detrimental for foetus than drugs; 5) pregnancies complicated by the onset of rare ARD have a particularly severe prognosis; in these cases a prompt treatment and very close clinical surveillance are indicated.
Autoimmunity, infertility and assisted reproductive technologies
Authors: Lockshin M D
Published: August 2004

Despite strongly held opinions, a trustworthy scientific basis for most statements about autoimmunity, autoimmune diseases and assisted reproductive technologies (ART) does not exist. It is not likely that autoimmunity causes infertility, nor that patients with autoimmune diseases are unusually infertile. When carefully monitored in selected patients, ART does not appear to harm patients who have preexisting autoimmune diseases, but the ovarian hyperstimulation syndrome and multiple gestation pregnancies impart independent risks. Stable autoimmune diseases without major organ damage probably do not affect the outcomes of ART pregnancies. Children born of ART pregnancies are apparently normal at birth, whether or not the genetic or birth mother has autoimmune disease, but long-term follow-up is not available. Male fertility is probably not altered by autoimmune disease. Fiscal, ethical and moral issues related to ART in patients with autoimmune diseases are beyond the scope of this discussion but remain important.
Antiphospholipid antibodies as cause of pregnancy loss
Authors: Meroni P L , di Simone N , Testoni C , D’Asta M , Acaia B , Caruso A
Published: August 2004

Antiphospholipid antibodies detected by lupus anticoagulant, anticardiolipin or anti-beta2 glycoprotein I assays were associated with fetal loss. Rather than being diagnostic tools only, antiphospholipid antibodies are thought to be pathogenic. The strongest demonstration of their pathogenic role lies in the ability to induce fetal resorptions - the experimental equivalents of the human fetal losses - when passively infused in pregnant naive animals. However, still debated is how the antibodies might induce the obstetrical manifestations. Thrombotic events at the placental levels might be related to endothelial cell activation, inhibition of protein C/S system and fibrinolysis as well as to Annexin V displacement. However, the thrombophilic state apparently cannot explain all the miscarriages and a direct antibody-mediated damage on the trophoblast has been suggested. During differentiation to syncytium, trophoblasts express cell membrane anionic phospholipids that can bind beta2 glycoprotein I, the main cationic phospholipid binding protein recognized by the antiphospholipid antibodies. Adhered b2-glycoprotein I might be recognized by the antibodies that, once bound, strongly interfere with in vitro trophoblast cell maturation so resulting in a defective placentation. These mechanisms have been suggested to play a role in early fetal loss, while thrombotic events would be responsible for miscarriages late in the pregnancy.
Short and long-term maternal outcomes in patients with phospholipid antibodies
Authors: Parke A
Published: August 2004

By definition patients with phospholipid antibody (aPL) syndrome develop clinical thrombotic events and frequently fail to complete pregnancy successfully. Pregnancy is a physiological state known to trigger clinical thrombosis in aPL syndrome patients. This paper will review the short-term effects of pregnancy on aPL patients as well as the long-term outcome of aPL women who have attempted pregnancy.
Neonatal lupus syndromes
Authors: Buyon J P , Rupel A , Clancy R M
Published: August 2004

The neonatal lupus syndromes (NLS), while quite rare, carry significant mortality and morbidity in cases of cardiac manifestations. Although anti-SSA/Ro-SSB/La antibodies are detected in .85% of mothers whose fetuses are identified with congenital heart block (CHB) in a structurally normal heart, when clinicians applied this testing to their pregnant patients, the risk for a woman with the candidate antibodies to have a child with CHB was at or below 1 in 50. While the precise pathogenic mechanism of antibody-mediated injury remains unknown, it is clear that the antibodies alone are insufficient to cause disease and fetal factors are likely contributory. In vivo and in vitro evidence supports a pathologic cascade involving apoptosis of cardiocytes, surface translocation of Ro and La antigens, binding of maternal autoantibodies, secretion of profibrosing factors (e.g., TGFb) from the scavenging macrophages and modulation of cardiac fibroblasts to a myofibroflast scarring phenotype. The spectrum of cardiac abnormalities continues to expand, with varying degrees of block identified in utero and reports of late onset cardiomyopathy (some of which display endocardial fibroelastosis). Moreover, there is now clear documentation that incomplete blocks (including those improving in utero with dexamethasone) can progress postnatally, despite the clearance of the maternal antibodies from the neonatal circulation. Better echocardiographic measurements which identify first degree block in utero may be the optimal means of approaching pregnant women at risk. Prophylactic therapies, including treatment with intravenous immunoglobulin, await larger trials. In order to achieve advances at both the bench and bedside, national research registries established in the US and Canada are critical.
Autoantibodies associated with reproductive failure
Authors: Shoenfeld Y , Blank M
Published: August 2004

Autoimmune factors are involved in some of the cases of reproductive failure. These factors entail several autoantibodies, especially in patients having systemic lupus erythematosus (SLE) or the antiphospholipid syndrome (APS). These autoantibodies include mainly antibodies directed to phospholipid such as cardiolipin, phosphatidylserine, phosphatidylethanolamine or phospholipids binding glycoproteins such as b2glycoprotein-I, annexin V, prothrombin and protein-Z. There are also some other autoantibodies directed to laminin-I, thromboplastin, mitochondrial antibodies of the M5 type, corpus luteum, prolactin, poly (ADP-ribose), thyroglobulin and more, which were also found in SLE or APS patients with reproductive failure. Moreover, the presence of additional autoantibodies directed to actin, enolase, cubilin and others, needs further investigation to support a firm association to reproductive failure in women. Future studies are likely to help to determine and expand the number of autoantibodies screened in these patients, as well as by the use of proteomics technology, to determine peptides resembling the epitope specificities associated with the specific clinical manifestations.
Ovarian failure in systemic lupus erythematosus patients treated with pulsed intravenous cyclophosphamide
Authors: Katsifis G E , Tzioufas A G
Published: August 2004

Pulsed intravenous cyclophosphamide is considered as standard therapy for lupus nephritis and several other severe manifestations of systemic lupus erythematosus (SLE). While the response rate to intravenous cyclophosphamide is substantial, concern has arisen about its toxicity. In addition to increased susceptibility to infection, bone marrow suppression, alopecia, hemorrhagic cystitis and malignancy, ovarian failure is an important side effect associated with the use of cyclophosphamide. Prior research on cyclophosphamide-treated women has consistently demonstrated that the risk of sustained amenorrhea depends on the age of the patient and the cumulative dose received. Sustained amenorrhea is difficult to avoid in women 32 years or older, even with very short intravenous cyclophosphamide courses. Younger women seem to have a substantially lower incidence of ovarian failure, but this side effect may be far more problematic for these patients. In these young women the risk may be modulated by the prior SLE disease duration, the presence of anti-U1RNP antibodies and anti-Ro antibodies. Co-treatment with gonadotropin-releasing hormone agonists may preseserve the future fertility and ovarian function in young women. Ovarian banking before administration of cyclophosphamide should be considered in selected patients.
Understudied and underrecognised
Authors: Coghill Dave
Published: August 2004

That Zwi & York (2004) have opened the discussion on adult attention-deficit hyperactivity disorder (ADHD) is to be applauded. Their main conclusion is that the diagnostic validity of adult ADHD remains uncertain and that further study is needed. This is based on a review of the ADHD concept in childhood and the longitudinal studies that have followed children with ADHD into adulthood.
Psychosis, victimisation and childhood disadvantage
Authors: Bebbington Paul E. , Bhugra Dinesh , Brugha Traolach , Singleton Nicola , Farrell Michael , Jenkins Rachel , Lewis Glyn , Meltzer Howard
Published: August 2004

Background

Adverse early circumstances may be more common in people who later develop psychotic disorders.

Aims

To use data from the second British National Survey of Psychiatric Morbidity to examine associations between psychotic disorders and a number of early victimisation experiences.

Method

Psychiatric disorders were identified through structured assessment of adults resident in private households in Britain (n=8580). Respondents were asked whether they had experienced selected events displayed on cards.

Results

Compared with respondents with other psychiatric disorders or with none, the prevalence of every experience bar one was significantly elevated in those with definite or probable psychosis. The largest odds ratio was for sexual abuse. Controlling for depressed mood somewhat reduced the odds ratios for the individual experiences.

Conclusions

In people with psychosis, there is a marked excess of victimising experiences, many of which will have occurred during childhood. This is suggestive of a social contribution to aetiology.