bluuebunny/crossref_metadata_2025 huggingface dataset:
Climatology of UTLS ozone and the ratio of ozone and potential vorticity over northern Europe
Authors: Rao T. Narayana , Kirkwood S. , Arvelius J. , von der Gathen P. , Kivi R.
Published: November 2003

Annual and interannual variations of ozone in the upper troposphere and lower stratosphere (UTLS) region have been studied using ozonesonde data collected between 1994 and 2001 at several northern European stations. The climatology of ozone exhibits a prominent annual cycle in the UTLS region. The observed change in the phase of the annual cycle from late spring‐early summer at 500 hPa to spring at 200 hPa and to winter‐early spring at 100 hPa shows the switching of the ozone control from photochemical to dynamical. Traces of interannual variation in the lower stratosphere are seen not only in the upper troposphere but also in the middle troposphere (not necessarily always) indicating the dynamical influence on tropospheric ozone budget. Further, the correlation between ozone mixing ratio and potential vorticity (PV) is studied at three northern high‐latitude stations. As expected, a good correlation is found in the lower stratosphere, while the correlation is fair in the middle troposphere, except during summer over the European Arctic. This weak correlation at high latitudes indicates the dominance of photochemistry over dynamics in the presence of prolonged hours of solar illumination. The correlation coefficients derived at high latitudes are smaller than those reported at midlatitudes. This could be due to the greater number of tropopause folds at midlatitudes than at high latitudes and this eventually leads to the conclusion that the downward cross‐tropopause flux is greater at midlatitudes than at high latitudes. Absence of a significant north‐south gradient in the ozone/PV ratio in the lower stratosphere suggests that a single ozone/PV ratio (however, the ratio varies with month) can be used to convert global PV fluxes to ozone fluxes. A few cases of tropopause folds (only one case study is reported in the present study) are selected and studied in detail with the help of a very high frequency radar and meteorological analysis. The ratio between ozone and PV for these case studies agrees reasonably well with the climatological ratios.
Analysis of atmospheric mesoscale models for entry, descent, and landing
Authors: Kass D. M. , Schofield J. T. , Michaels T. I. , Rafkin S. C. R. , Richardson M. I. , Toigo A. D.
Published: November 2003

Each Mars Exploration Rover (MER) is sensitive to the Martian winds encountered near the surface during the entry, descent, and landing (EDL) process. These winds are strongly influenced by local (mesoscale) conditions. In the absence of suitable wind observations, wind fields predicted by Martian mesoscale atmospheric models have been analyzed to guide landing site selection. In order to encompass the available models and render them useful to the EDL engineering team, a series of statistical techniques was applied to the model results. These analyses cover the high‐priority landing sites during the expected landing times (1200–1500 LT). The number of sites studied is limited by the computational and analysis cost of the mesoscale models. The statistical measures concentrate on the effective mean wind (the wind as seen by the landing system) and on the vertical structure of the horizontal winds. Both aspects are potentially hazardous to the MER landing system. In addition, a number of individual wind profiles from the mesoscale model were processed into a form that can be used directly by the EDL Monte Carlo simulations. The statistical analysis indicates that the Meridiani Planum and Elysium landing sites are probably safe. The Gusev Crater and Isidis Basin sites may be safe, but further analysis by the EDL engineers will be necessary to quantify the actual risk. Finally, the winds at the Melas Chasma landing site (and presumably other Valles Marineris landing sites) are dangerous. While the statistical parameters selected for these studies were primarily of engineering and safety interest, the techniques are potentially useful for more general scientific analyses. One interesting result of the current analysis is that the depth of the convective boundary layer (and thus the resulting energy density) appears to be primarily driven by the existence of a well‐organized mesoscale (or regional) circulation, primarily driven by large‐scale topographic features at Mars.
Extracting science from Mössbauer spectroscopy on Mars
Authors: Wdowiak Thomas J. , Klingelhöfer Göstar , Wade Manson L. , Nuñez Jorge I.
Published: November 2003

Deployment by the Mars Exploration Rovers of backscatter Mössbauer spectrometers offers an incredible opportunity to (1) elucidate the iron mineralogies of rocks, soils, and atmospheric dust and (2) gain insight into the physical event by which the mineralogy came into existence and consequently acquire information having potential for yielding ancient planetary history relevant to broad issues including the question of life. Determining the mineralogy is done by subjecting raw data to reduction algorithms and generating products known as Mössbauer parameters, which are highly characteristic. Mixed mineralogies are treated through deconvolution. Through being able to exploit Mössbauer measurements made at different temperatures during the Martian diurnal variation, and utilizing spectra obtained of the same sample with both the 6.4 and 14.4 keV energy channels, characteristics beyond oxidation state and stoichiometry are accessible. These include temperature sensitive magnetic transitions that can be either abrupt or gradual, variation of Mössbauer parameters with temperature, and variation of composition with depth, all of which can be dependent upon past processing affecting initial crystallization or subsequent alteration (“weathering”). The goal is to arrive at an understanding of environments including the very ancient.
Tidally heated convection: Constraints on Europa's ice shell thickness
Authors: Tobie Gabriel , Choblet Gaël , Sotin Christophe
Published: November 2003

The thickness of Europa's ice shell is constrained with numerical experiments of thermal convection, including heterogeneous tidal heating. Thermal convection occurs in the stagnant lid regime with most of the tidal heating located in the bottom half of the layer. The addition of tidal heating mainly results in the increase of the temperature of the well‐mixed interior and in the decrease of the heat flux at the base of the ice layer. In many simulations, the ice in hot plumes is heated up to its melting point. This induces episodic upwellings (0.5 Ma) of partially molten ice up to the base of the conductive lid, with possible implications for the formation of lenticulae and chaos regions. The thickness of the convective ice shell in equilibrium with the heat flow from the silicate core is estimated to be about 20–25 km. Tidal dissipation and surface temperature variations create lateral variations of the ice shell thickness of about 5 km, with maxima near the equator at the Jovian and anti‐Jovian points and minima at midlatitudes. Surface heat flux is about 35–40 mW.m−2; it is almost constant all over Europa's surface, even though the tidal dissipation rate is four times larger at the poles than at the equator.
Atlantic Ocean circulation during the Younger Dryas: Insights from a new Cd/Ca record from the western subtropical South Atlantic
Authors: Came Rosemarie E. , Oppo Delia W. , Curry William B.
Published: November 2003

Benthic foraminiferal Cd/Ca from an intermediate depth, western South Atlantic core documents the history of southward penetration of North Atlantic Intermediate Water (NAIW). Cd seawater estimates (CdW) for the last glacial are consistent with the production of NAIW and its export into the South Atlantic. At ∼14.5 ka concurrently with the onset of the Bølling‐Allerød to Younger Dryas cooling, the NAIW contribution to the South Atlantic began to decrease, marking the transition from a glacial circulation pattern to a Younger Dryas circulation. High CdW in both the deep North Atlantic and the intermediate South Atlantic imply reduced export of deep and intermediate water during the Younger Dryas and a significant decrease in northward oceanic heat transport. A modern circulation was achieved at ∼9 ka, concurrently with the establishment of Holocene warmth in the North Atlantic region, further supporting a close linkage between deepwater variability and North Atlantic climate.
Biological effect of radiation‐degraded alginate on flower plants in tissue culture
Authors: Luan Le Q. , Hien Nguyen Q. , Nagasawa Naotsugu , Kume Tamikazu , Yoshii Fumio , Nakanishi Tomoko M.
Published: November 2003

Alginate with a weight‐average molecular mass (Mw) of approx. 9.04×105 Da was irradiated at 10–200 kGy in 4% (w/v) aqueous solution. The degraded alginate product was used to study its effectiveness as a growth promoter for plants in tissue culture. Alginate irradiated at 75 kGy with an Mw of approx. 1.43×104 Da had the highest positive effect in the growth of flower plants, namely limonium, lisianthus and chrysanthemum. Treatment of plants with irradiated alginate at concentrations of 30–200 mg/l increased the shoot multiplication rate from 17.5 to 40.5% compared with control. In plantlet culture, 100 mg/l irradiated alginate supplementation enhanced shoot height (9.7–23.2%), root length (9.7–39.4%) and fresh biomass (8.1–19.4%) of chrysanthemum, lisianthus and limonium compared with that of the untreated control. The survival ratios of the transferred flower plantlets treated with irradiated alginate were almost the same as the control value under greenhouse conditions. However, better growth was attained for the treated plantlets.
Enhancement of integrin‐mediated transfection of haematopoietic cells with a synthetic vector system
Authors: Uduehi Aima , Mailhos Carolina , Truman Hazel , Thrasher Adrian J. , Kinnon Christine , Hart Stephen L.
Published: November 2003

The aim of the present study was to develop and assess an integrin‐targeted synthetic vector system for the transfection of haematopoietic cell lines and dendritic cells. The vector consists of a cationic liposome, Lipofectin (L), a peptide that both targets integrins and binds to DNA (I) and plasmid DNA (D). These components interact electrostatically to form the LID vector complex. Transfection conditions were optimized for the ratio of vector components, the amount of DNA and transfection incubation time. The kinetic analysis of transgene expression revealed a peak of activity at about 24 h, followed by a rapid decline over the next 48 h. Targeted gene delivery was demonstrated by comparing transfected luciferase reporter gene levels using LID complexes containing integrin‐targeting peptide sequences with a control peptide. In addition, transfection levels of integrin‐targeted LID complexes were significantly enhanced by treatment of cells with PMA, which was also shown to activate integrin receptors and enhance binding to fibronectin. Under optimized conditions transfection efficiencies of 19% for TF‐1 cells, 28% for Jurkat cells and 10% for primary dendritic cells were achieved. The LID vector may thus find application for gene‐transfer experiments in haematopoietic cell lines and for the development of genetic vaccines using transfected dendritic cells.
Enzymic, spectroscopic and calorimetric studies of a recombinant dextranase expressed in Pichia pastoris
Authors: Beldarraín Alejandro , Acosta Niuris , Betancourt Lázaro , González Luis J. , Pons Tirso
Published: November 2003

Conformational stability and structural characterization of an rDex (recombinant dextranase) expressed in Pichia pastoris were studied by enzymic assays, fluorescence, CD and DSC (differential scanning calorimetry). We also identified two disulphide bridges (Cys9–Cys14, Cys484–Cys488) and two free Cys residues (Cys336, Cys415) that are not conserved between bacterial and fungal dextranases of GH‐49 (glycoside hydrolase family 49) by MALDI‐TOF (matrix‐assisted laser‐desorption ionization–time‐of‐flight) MS. Enzymic and fluorescence studies revealed that rDex is biological and conformationally stable at acidic pH, with maximum activity at pH 4.5–5.0, while CD spectra indicated a secondary structure basically composed of β‐sheets. rDex loses biological activity at neutral pH without total disruption of its conformation. In addition, rDex preserves its conformation close to 60 °C, but it is thermally denatured with appreciable aggregation at temperatures above 75 °C. DSC studies always displayed irreversible transitions and a strong dependence on the scan rate. Our combined analysis suggested that the denaturation process of rDex is under kinetic control, which is described reasonably well by the two‐state kinetic scheme.
The use of microcalorimetry to characterize tetanus neurotoxin, pertussis toxin and filamentous haemagglutinin
Authors: Krell Tino , Greco Frédéric , Nicolaï Marie‐Claire , Dubayle Jean , Renauld‐Mongénie Geneviève , Poisson Nadège , Bernard Isabelle
Published: November 2003

Tetanus neurotoxin (TeNT), pertussis toxin (PT) and pertussis filamentous haemagglutinin (FHA) are major virulence factors of Clostridium tetani and Bordetella pertussis, which are the causative agents of tetanus and whooping cough respectively. Inactivated forms of these virulence factors are the protein components of vaccines against these diseases. Here we report microcalorimetric studies to characterize these proteins. The microcalorimetric titration curves of TeNT with micelles of gangliosides GD1b, GT1b and GQ1b were biphasic. For these gangliosides a high‐affinity binding site (KD 45–277 nM) can be distinguished from a lower‐affinity binding event (KD 666–1190 nM). This is direct evidence for multiple binding sites for gangliosides of the 1b series at TeNT as proposed by Emsley et al. [Emsley, Fotinou, Black, Fairweather, Charles, Watts, Hewitt and Isaacs (2000) J. Biol. Chem. 275, 8889–8894]. In agreement with previous reports, no binding was observed for gangliosides GM1, GM2, GM3 and GD2. The thermal denaturation of TeNT was characterized by two unfolding transitions centred around 57.4 and 62.4 °C. The conversion of TeNT into the toxoid form by formaldehyde treatment was accompanied by a large increase in Tm (the midpoint of protein unfolding transition, that is, the temperature at which half the protein is denatured and the other half is still present in its native form). Fetuin and asialofetuin bound to PT with similar affinities (KD 420 and 335 nM respectively). Binding was largely enthalpy‐driven and counterbalanced by an unfavourable entropy change, indicating a loss of conformational flexibility. The latter could account for the observed inhibition of ATP binding after binding to fetuin. Furthermore, the molecular limits of mature PT subunit S5 were defined by MS and N‐terminal peptide sequencing. The differential‐scanning‐calorimetry thermogram of FHA shows four well‐resolved unfolding transitions, a finding consistent with the sequential denaturation of four structural domains.
Incorporation of whey proteins into cheese curd by using transglutaminase
Authors: Cozzolino Anna , Di Pierro Prospero , Mariniello Loredana , Sorrentino Angela , Masi Paolo , Porta Raffaele
Published: November 2003

A Ca2+‐independent microbial TGase (transglutaminase) isolated from Streptoverticillium mobaraense was used to obtain whey protein containing novel dairy products. We evaluated the difference both in the curd formation time as well as in the hardness and deformability of the cheese obtained from cow's milk in the presence or absence of the enzyme. The results of our experiments showed that the milk coagulation time was dependent on the step in cheese manufacture at which TGase was added. We analysed the deformability and the hardness of the dairy products obtained either by adding both TGase and the milk‐clotting enzyme to the milk sample at the same time or by adding TGase after treating the milk sample for 30 min with the clotting enzyme and cutting the obtained coagulum. TGase treatment conferred a strongly decreased protein content to derived whey. Moreover, when further amounts of whey were added to the milk during the manufacturing process in the presence of TGase, whey‐protein‐enriched dairy products could also be obtained. Our findings may lead to new biotechnologies for the re‐utilization of by‐products from dairy plants and contribute to reduction of environmental pollution from whey‐protein disposal.
Oxysterol and 9-cis-retinoic acid stimulate the group IIA secretory phospholipase A2 gene in rat smooth-muscle cells
Authors: ANTONIO Valérie , JANVIER Brigitte , BROUILLET Arthur , ANDREANI Marise , RAYMONDJEAN Michel
Published: November 2003

The inflammation that occurs during rheumatoid arthritis or atherosclerosis is characterized by the release of large amounts of sPLA2 (group IIA secretory phospholipase A2). We have shown previously that the sPLA2 promoter in SMC (smooth-muscle cells) is activated by interleukin-1β and cAMP-signalling pathways, through the interplay of multiple transcription factors [Antonio, Brouillet, Janvier, Monne, Bereziat, Andreani, and Raymondjean (2002) Biochem. J. 368, 415–424]. In the present study, we have investigated the regulation of sPLA2 gene expression in rat aortic SMCs by oxysterols. We found that oxysterol ligands that bind to the LXR (liver X receptor), including 25-HC (25-hydroxycholesterol) and 22(R)-HC, cause the accumulation of sPLA2 mRNA and an increased enzyme activity. Transient transfection experiments demonstrated that the sPLA2 promoter is synergistically activated by 22(R)-HC in combination with 9-cis-retinoic acid, a ligand for the LXR heterodimeric partner RXR (retinoid X receptor). Promoter activity was also increased in a sterol-responsive fashion when cells were co-transfected with LXRα/RXRα or LXRβ/RXRα. Mutagenesis studies and gel mobility-shift assays revealed that LXR/RXR heterodimers regulate sPLA2 transcription directly, by interacting with a degenerated LXRE (LXR response element) at position [−421/−406] of the sPLA2 promoter. Chromatin immunoprecipitation revealed the in vivo occupancy of LXR on the sPLA2 promoter. In addition, the orphan nuclear receptor LRH-1 (liver receptor homologue-1) potentiated the sterol-dependent regulation of the sPLA2 promoter by binding to an identified promoter element (TCAAGGCTG). Finally, we have demonstrated that oxysterols act independent of interleukin-1β and cAMP pathways to activate the sPLA2 promoter. In the present study, we have identified a new pathway activating sPLA2 gene expression in SMCs.
Structural and biochemical characterization of a new type of lectin isolated from carp eggs
Authors: GALLIANO Monica , MINCHIOTTI Lorenzo , CAMPAGNOLI Monica , SALA Alberto , VISAI Livia , AMORESANO Angela , PUCCI Piero , CASBARRA Annarita , CAUCI Marco , PERDUCA Massimiliano , MONACO Hugo L.
Published: November 2003

A previously unidentified glycoprotein present in the eggs of the carp (Cyprinus carpio) was isolated and structurally characterized. The protein binds to a Sepharose 4B matrix and can be eluted with 0.4 M N-acetylglucosamine. The protein has an apparent molecular mass of 26686.3 Da. On the basis of gel-filtration chromatography, the protein appears to be present in solution as a monomer. The sequence of its 238 amino acids, the position of its four disulphide bridges and the composition of its single N-linked carbohydrate chain were determined. The lectin shows a very low agglutinating activity for human A-type erythrocytes and interacts with both Gram-positive and -negative bacteria. These latter interactions are inhibited by N-acetylglucosamine. A database search shows that its amino acid sequence is similar to that of the members of an invertebrate lectin family that includes tachylectin-1. Tachylectin-1 is present in the amoebocytes of the horseshoe crab, Tachypleus tridentatus, and plays a role in the innate defence system of this species. Homologous genes are also present in other fish, having 85% identity with a gene expressed in the oocytes of the crucian carp (Carassius auratus gibelio) and 78% identity with a gene in the cDNA library of the zebrafish (Danio rerio).
Identification of a minimal promoter sequence for the human N-acetyltransferase Type I gene that binds AP-1 (activator protein 1) and YY-1 (Yin and Yang 1)
Authors: BUTCHER Neville J. , ARULPRAGASAM Ajanthy , POPE Catherine , MINCHIN Rodney F.
Published: November 2003

Human N-acetyltransferase Type I (NAT1) catalyses the acetylation of many aromatic amine and hydrazine compounds and it has been implicated in the catabolism of folic acid. The enzyme is widely expressed in the body, although there are considerable differences in the level of activity between tissues. A search of the mRNA databases revealed the presence of several NAT1 transcripts in human tissue that appear to be derived from different promoters. Because little is known about NAT1 gene regulation, the present study was undertaken to characterize one of the putative promoter sequences of the NAT1 gene located just upstream of the coding region. We show with reverse-transcriptase PCR that mRNA transcribed from this promoter (Promoter I) is present in a variety of human cell-lines, but not in quiescent peripheral blood mononuclear cells. Using deletion mutant constructs, we identified a 20 bp sequence located 245 bases upstream of the translation start site which was sufficient for basal NAT1 expression. It comprised an AP-1 (activator protein 1)-binding site, flanked on either side by a TCATT motif. Mutational analysis showed that the AP-1 site and the 3´ TCATT sequence were necessary for gene expression, whereas the 5´ TCATT appeared to attenuate promoter activity. Electromobility shift assays revealed two specific bands made up by complexes of c-Fos/Fra, c-Jun, YY-1 (Yin and Yang 1) and possibly Oct-1. PMA treatment enhanced expression from the NAT1 promoter via the AP-1-binding site. Furthermore, in peripheral blood mononuclear cells, PMA increased endogenous NAT1 activity and induced mRNA expression from Promoter I, suggesting that it is functional in vivo.
A neutral ceramidase homologue from Dictyostelium discoideum exhibits an acidic pH optimum
Authors: MONJUSHO Hatsumi , OKINO Nozomu , TANI Motohiro , MAEDA Mineko , YOSHIDA Motonobu , ITO Makoto
Published: November 2003

Ceramidases (CDases) are currently classified into three categories (acid, neutral and alkaline) based on their optimal pHs and primary structures. Here, we report the first exception to this rule. We cloned the CDase cDNA, consisting of 2142 nucleotides encoding 714 amino-acid residues, from the slime mould, Dictyostelium discoideum. The putative amino-acid sequence indicates 32–42% identity with various neutral CDases, but does not show any similarity to the acid and alkaline CDases, indicating the enzyme should be classified as a neutral CDase. However, overexpression of the cDNA in D. discoideum resulted in increased CDase activity at an acidic, but not a neutral pH range. Knockout of the gene in slime mould eliminated CDase activity at acidic pH. The recombinant enzyme expressed in the slime mould was purified and then characterized. Consequently, the purified CDase was found to exhibit the maximal activity at approx. pH 3.0. The singular pH dependency of slime mould CDase is not derived from the specific post-translational modification in the slime mould, because the enzyme showed an acidic pH optimum even when expressed in Chinese hamster ovary cells, whereas rat neutral-CDase exhibited a neutral pH optimum when expressed in slime mould.
Transcriptional regulation of methionine synthase by homocysteine and choline in Aspergillus nidulans
Authors: KACPRZAK Magdalena M. , LEWANDOWSKA Irmina , MATTHEWS Rowena G. , PASZEWSKI Andrzej
Published: November 2003

Roles played by homocysteine and choline in the regulation of MS (methionine synthase) have been examined in fungi. The Aspergillus nidulans metH gene encoding MS was cloned and characterized. Its transcription was not regulated by methionine, but was enhanced by homocysteine and repressed by choline and betaine. MS activity levels were regulated in a similar way. The repression by betaine was due to its metabolic conversion to choline, which was found to be very efficient in A. nidulans. Betaine and choline supplementation stimulated growth of leaky metH mutants apparently by decreasing the demand for methyl groups and thus saving methionine and S-adenosylmethionine. We have also found that homocysteine stimulates transcription of MS-encoding genes in Saccharomyces cerevisiae and Schizosaccharomyces pombe.
The loop between helix 4 and helix 5 in the monocarboxylate transporter MCT1 is important for substrate selection and protein stability
Authors: GALIĆ Sandra , SCHNEIDER Hans-Peter , BRÖER Angelika , DEITMER Joachim W. , BRÖER Stefan
Published: November 2003

Transport of lactate, pyruvate and the ketone bodies acetoacetate and β-hydroxybutyrate, is mediated in most mammalian cells by members of the monocarboxylate transporter family (SLC16). A conserved signature sequence has been identified in this family, which is located in the loop between helix 4 and helix 5 and extends into helix 5. We have mutated residues in this signature sequence in the rat monocarboxylate transporter (MCT1) to elucidate the significance of this region for monocarboxylate transport. Mutation of R143 and G153 resulted in complete inactivation of the transporter. For the MCT1(G153V) mutant this was explained by a failure to reach the plasma membrane. The lack of transport activity of MCT1(R143Q) could be partially rescued by the conservative exchange R143H. The resulting mutant transporter displayed reduced stability, a decreased Vmax of lactate transport but not of acetate transport, and an increased stereoselectivity. Mutation of K137, K141 and K142 indicated that only K142 played a significant role in the transport mechanism. Mutation of K142 to glutamine resulted in an increase of the Km for lactate from 5 mM to 12 mM. In contrast with MCT1(R143H), MCT1(K142Q) was less stereoselective than the wild-type. A mechanism is proposed that includes all critical residues.
A novel antimicrobial protein isolated from potato (Solanum tuberosum) shares homology with an acid phosphatase
Authors: FENG Jie , YUAN Fenghua , GAO Yin , LIANG Chenggang , XU Jin , ZHANG Changling , HE Liyuan
Published: November 2003

A novel antimicrobial protein (AP1) was purified from leaves of the potato (Solanum tuberosum, variety MS-42.3) with a procedure involving ammonium sulphate fractionation, molecular sieve chromatography with Sephacryl S-200 and hydrophobic chromatography with Butyl-Sepharose using a FPLC system. The inhibition spectrum investigation showed that AP1 had good inhibition activity against five different strains of Ralstonia solanacearum from potato or other crops, and two fungal pathogens, Rhizoctonia solani and Alternaria solani from potato. The full-length cDNA encoding AP1 has been successfully cloned by screening a cDNA expression library of potato with an anti-AP1 antibody and RACE (rapid amplification of cDNA ends) PCR. Determination of the nucleotide sequences revealed the presence of an open reading frame encoding 343 amino acids. At the C-terminus of AP1 there is an ATP-binding domain, and the N-terminus exhibits 58% identity with an/the acid phosphatase from Mesorhizobium loti. SDS/PAGE and Western blotting analysis suggested that the AP1 gene can be successfully expressed in Escherichia coli and recognized by an antibody against AP1. Also the expressed protein showed an inhibition activity the same as original AP1 protein isolated from potato. We suggest that AP1 most likely belongs to a new group of proteins with antimicrobial characteristics in vitro and functions in relation to phosphorylation and energy metabolism of plants.
Enhanced exposure of phosphatidylserine in human gastric carcinoma cells overexpressing the half-size ABC transporter BCRP (ABCG2)
Authors: WOEHLECKE Holger , POHL Antje , ALDER-BAERENS Nele , LAGE Hermann , HERRMANN Andreas
Published: November 2003

Members of the ABC (ATP-binding cassette) transporter super-family are emerging to be involved in lipid transport. In the present study, we studied the organization of phospholipids in the plasma membrane of EPG85-257 human gastric carcinoma cells overexpressing BCRP (breast cancer resistance protein, ABCG-2), a half-size transporter belonging to the ABCG subfamily. A significantly increased plasma membrane association of the PS (phosphatidylserine)-binding probe FITC–Annexin V in comparison with control cells was observed. Treatment of BCRP-overexpressing cells with the inhibitor Tryprostatin A decreased FITC–Annexin V binding almost to the control level. This suggests an enhanced exposure of PS in BCRP-overexpressing cells, which is dependent on functional BCRP. A role of BCRP in the transverse distribution of lipids in the plasma membrane is supported by the increased outward transport of the lipid analogue C6-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-PS in BCRP-overexpressing EPG85-257 cells and MCF-7 human breast cancer cells. As shown for BCRP-overexpressing EPG85-257 cells, enhanced outward redistribution of the lipid analogue is inhibited by Tryprostatin A as well as by reduction of BCRP expression on transfection with an anti-BCRP-ribozyme. We also observed an enhanced outward transport of C6-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-phosphatidylcholine in BCRP-overexpressing EPG85-257 cells, suggesting that the influence of BCRP on transverse lipid organization is not highly specific.
Regulation of hypoxia-inducible factor-1α by nitric oxide through mitochondria-dependent and -independent pathways
Authors: MATEO Jesús , GARCÍA-LECEA Marta , CADENAS Susana , HERNÁNDEZ Carlos , MONCADA Salvador
Published: November 2003

Nitric oxide (NO) has been reported both to promote and to inhibit the activity of the transcription factor hypoxia-inducible factor-1 (HIF-1). In order to avoid the pitfalls associated with the use of NO donors, we have developed a human cell line (Tet-iNOS 293) that expresses the inducible NO synthase (iNOS) under the control of a tetracycline-inducible promoter. Using this system to generate finely controlled amounts of NO, we have demonstrated that the stability of the α-subunit of HIF-1 is regulated by NO through two separate mechanisms, only one of which is dependent on a functional respiratory chain. HIF-1α is unstable in cells maintained at 21% O2, but is progressively stabilized as the O2 concentration decreases, resulting in augmented HIF-1 DNA-binding activity. High concentrations of NO (>1 µM) stabilize HIF-1α at all O2 concentrations tested. This effect does not involve the respiratory chain, since it is preserved in cells lacking functional mitochondria (ρ0-cells) and is not reproduced by other inhibitors of the cytochrome c oxidase. By contrast, lower concentrations of NO (<400 nM) cause a rapid decrease in HIF-1α stabilized by exposure of the cells to 3% O2. This effect of NO is dependent on the inhibition of mitochondrial respiration, since it is mimicked by other inhibitors of mitochondrial respiration, including those not acting at cytochrome c oxidase. We suggest that, although stabilization of HIF-1α by high concentrations of NO might have implications in pathophysiological processes, the inhibitory effect of lower NO concentrations is likely to be of physiological relevance.
Effect of menstrual cycle phase on the concentration of bioavailable 17-β oestradiol and testosterone and muscle strength
Authors: ELLIOTT K. J. , CABLE N. T. , REILLY T. , DIVER M. J.
Published: November 2003

To investigate the effect of changes in sex hormone concentration on muscle strength and the bioavailability of 17-β oestradiol (oestradiol) and testosterone, seven eumenorrheic females were tested during two phases of the menstrual cycle. Maximum voluntary isometric strength of the first dorsal interosseus muscle was measured during the early follicular and mid-luteal phases of the menstrual cycle. These phases were chosen for testing as the concentration of total oestradiol is significantly different in these two phases. Total oestradiol has been repeatedly associated with changes in muscle strength in females, whereas the effects of bioavailable oestradiol are unknown. The concentrations of total and bioavailable oestradiol and testosterone were measured in addition to the concentration of total progesterone. Concentrations of total progesterone and oestradiol were significantly different between the early follicular and mid-luteal phases of the menstrual cycle (P<0.05 and P<0.001 respectively). The concentration of total testosterone (0.7±0.2 and 0.8±0.1 nmol·l-1 respectively) and the ratio of total oestradiol to progesterone (153.0±251.2 and 108.5±27.8 respectively) did not change significantly between the early follicular and mid-luteal phases. Bioavailable testosterone (102.2±66.3 and 105.0±90.2 pmol·l-1 respectively) and bioavailable oestradiol (90.5±35.5 and 120.0±60.6 pmol·l-1 respectively) did not differ significantly between phases. There were no significant differences in muscle strength during the menstrual cycle (P=0.1). Mean maximum voluntary isometric force of the first dorsal interosseus muscle did not correlate significantly with the mean concentration of any reproductive hormone measured. These results indicate that cyclical variation in endogenous reproductive hormones does not affect muscle strength.
Investigation of the C242T polymorphism of NAD(P)H oxidase p22 phox gene and ischaemic heart disease using family-based association methods
Authors: SPENCE M. S. , McGLINCHEY P. G. , PATTERSON C. C. , ALLEN A. R. , MURPHY G. , BAYRAKTUTAN U. , FOGARTY D. G. , EVANS A. E. , McKEOWN P. P.
Published: November 2003

Ischaemic heart disease is a complex phenotype arising from the interaction of genetic and environmental factors. Excessive production of reactive oxygen species leading to endothelial dysfunction is believed to be important in the pathogenesis of ischaemic heart disease. The NAD(P)H oxidase system generates superoxide anions in vascular cells; however, the role of the C242T polymorphism of the NAD(P)H oxidase p22 phox gene in ischaemic heart disease is unclear due to contradictory results from case-control studies. Consequently, we applied family-based association tests to investigate the role of this polymorphism in ischaemic heart disease in a well-defined Irish population. A total of 1023 individuals from 388 families (discordant sibships and parent/child trios) were recruited. Linkage disequilibrium between the polymorphism and ischaemic heart disease was tested using the combined transmission disequilibrium test (TDT)/sib-TDT (cTDT) and pedigree disequilibrium test (PDT). Both cTDT and PDT analyses found no statistically significant excess transmission of either allele to affected individuals (P=0.30 and P=0.28, respectively). Using robust family-based association tests specifically designed for the study of complex diseases, we found no evidence that the C242T polymorphism of the p22 phox gene has a significant role in the development of ischaemic heart disease in our population.
Liver albumin synthesis in sepsis in the rat: influence of parenteral nutrition, glutamine and growth hormone
Authors: O'LEARY Michael J. , KOLL Michael , FERGUSON Colin N. , COAKLEY John H. , HINDS Charles J. , PREEDY Victor R. , GARLICK Peter J.
Published: November 2003

The effect of sepsis on liver synthesis of albumin remains controversial, with studies in man suggesting that synthesis increases, whereas in animals increased, decreased and unaltered synthesis have been reported. To reconcile these conflicting data, total and relative albumin synthesis was measured in rats 24 h after caecal ligation and puncture (CLP) by immunoprecipitation of albumin following a flooding dose of L-[4-3H]phenylalanine. Following CLP, animals were starved for 18 h and then received intravenous infusions of saline or parenteral nutrition (PN) with or without glutamine for 6 h. In animals receiving PN, parenteral injections of growth hormone (GH) or saline vehicle were also administered. Fractional rate of liver total protein synthesis was elevated and total albumin synthesis rate was reduced in all CLP groups when compared with non-operated animals. Total albumin synthesis was also lower in all animals receiving PN than those receiving saline alone, although these differences did not attain statistical significance, except for the group receiving PN+GH. Relative albumin synthesis was also reduced after CLP, and was significantly lower in animals receiving PN than in those receiving saline alone. These findings suggest that in sepsis hepatic protein synthesis is reprioritized away from the production of albumin towards the production of acute-phase proteins and that this change is not influenced by the provision of nutritional support, glutamine or the administration of GH.
Expression of androgen receptor and 5α-reductase types 1 and 2 in early gestation fetal lung: a possible correlation with branching morphogenesis
Authors: KIMURA Y. , SUZUKI T. , KANEKO C. , DARNEL A. D. , AKAHIRA J. , EBINA M. , NUKIWA T. , SASANO H.
Published: November 2003

The bioactive and potent androgen 5α-dihydrotestosterone (DHT) has been postulated to be involved in the development of branching morphogenesis in the human fetal lung, but its expression has not been examined. We therefore examined the expression of the androgen receptor (AR) and 5α-reductases (type 1 and type 2), which catalyse the conversion of testosterone into DHT, in the human fetal lung using immunohistochemistry and reverse transcription–PCR (RT-PCR). Immunoreactive AR was detected predominantly in the nuclei of epithelial cells of the budding component of the early gestational fetal lung. 5α-Reductase type 1 immunoreactivity was detected in the cytoplasm of epithelial cells, whereas immunoreactivity for 5α-reductase type 2 was not detected in the samples of human fetal lung examined. RT-PCR also confirmed the presence of AR and 5α-reductase in all fetal lung and epithelial cell lines. The results of our present study suggest that DHT may play an important role in epithelial cells, which might include precursor cells, in which both AR and 5α-reductases are expressed during branching morphogenesis of the human fetal lung.
Coupling of metabolism and cardiovascular response represents normal physiology
Authors: STEINBERG HELMUT O
Published: November 2003

In this issue of Clinical Science, Fugmann and co-workers demonstrate a highly integrated cardiovascular response to changes in plasma concentrations of glucose, triacylglycerols (triglycerides), fatty acids and insulin. Since the different substrates, alone and combined, evoked these changes, this response is likely to be a physiological one and directed towards minimizing the extent and duration of substrate elevations that could cause vascular dysfunction.
Revision of Habrosaurus Gilmore (Caudata; Sirenidae) and relationships among sirenid salamanders
Authors: Gardner James D.
Published: November 2003

The sirenid salamander Habrosaurus is revised and redescribed based on skull elements and vertebrae from the middle Campanian–middle Palaeocene of the North American Western Interior. Habrosaurus differs from the Cenozoic (Eocene–Recent) sirenids Siren and Pseudobranchus in a suite of cranial and vertebral plesiomorphies, one vertebral character of uncertain polarity and five apomorphies describing the structure of the dentary, atlas and tooth crowns. Two species are identified based on dental characters: the type species H. dilatus (late Maastrichtian–middle Palaeocene) has stout marginal and palatal teeth with bulbous crowns and prominent wear facets, whereas H. prodilatus sp. nov. (middle Campanian) has chisel‐like marginal teeth (palatal teeth unknown) with weaker wear facets. Habrosaurus is argued to be the geologically oldest, undoubted sirenid and the sister‐taxon of Siren + Pseudobranchus. Replacement of marginal teeth with a broad, horny beak in Siren and Pseudobranchus and the broad, bulbous marginal and palatal teeth in H. dilatus are proposed to be convergent strategies for achieving a crushing bite. The chisel‐like teeth of H. prodilatus are interpreted as being transitional to the more specialized, crushing dentition of H. dilatus.
Late Famennian gastropoda from south‐west England
Authors: Amler Michael R. W. , Heidelberger Doris
Published: November 2003

The gastropod fauna of the Upper Devonian Baggy and Pilton formations in south‐west England is revised and includes some 30 taxa. The topmost part of the Upper Famennian succession in Devon is represented by clastic near‐shore and shallow shelf sediments, indicating a short‐term transgressive phase (‘Strunian Transgression’). The sequence yields a highly diverse fauna dominated by brachiopods and ostracodes, locally supplemented by crinoids, bryozoans, trilobites and molluscs. The taxa ‘Patellostium’britannicum sp. nov., Angyomphalus (Angyomphalus) junius sp. nov. and Dictyotomaria eurocapillaria sp. nov. are erected; a junior homonym is replaced by Macrochilina? piltonensis nom. nov. The gastropod fauna displays an independent character, where latest Devonian faunal elements overlap with Late Palaeozoic taxa expressing a transition similar to that of the bivalves, brachiopods, echinoderms and corals, without a sharp faunal break at the Devonian/Carboniferous boundary. Apart from the Caenogastropoda, all subclasses of gastropods are represented. Members of the bellerophontoids, pleurotomarioids and loxonematoids are most abundant, followed by murchisonioids, naticimorphs, euomphalomorphs and platyceratoids. The various gastropod groups represent different ecological demands and trophic categories, and together with the accompanying fauna indicate that nearly all habitats and niches were occupied in the shallow South Laurussian Shelf.
The identity of the non‐marine ostracod Cypris subglobosa Sowerby from the intertrappean deposits of Peninsular India
Authors: Whatley Robin C. , Bajpai Sunil , Whittaker John E.
Published: November 2003

During an investigation of type collections in The Natural History Museum, London, made in India during the nineteenth century, the syntypes of Cypris subglobosa Sowerby have been re‐discovered. This species is shown to belong to the genus Paracypretta and to be confined to the Upper Cretaceous, and possibly Palaeocene, non‐marine intertrappean deposits of the Indian Deccan Volcanic Province. The numerous and widespread Recent and Quaternary records of this taxon are of a separate species that belongs to the genus Cypris. The examination of comparative material from a number of localities in India reveals the presence of two other contemporary species of ParacyprettaP. jonesi Bhatia and Rana and P. elizabethae sp. nov., which is formally described herein.
A novel lycopsid from the Upper Devonian of Jiangsu, China
Authors: Wang Yi , Berry Christopher M.
Published: November 2003

A new lycopsid, Monilistrobus yixingensis gen. et sp. nov., is described from the Wutung Formation (Famennian, Upper Devonian) of Jiangsu, China. The plant has many features typical of other Upper Devonian lycopsids, including dichotomous branching, helically arranged obovate expanded leaf bases, linear leaves with spiny appendages along the lateral margins, sporophylls widened proximally, and one elliptical sporangium attached to the adaxial surface. The most distinctive novel feature of the plant is that the modified sporophylls are arranged tightly into fertile zones or cone‐like structures that are separated by lengths of axes with more lax sterile microphylls only: therefore the cone‐like structures are strung along the branches like beads on a necklace.
TOP2A and HER‐2 gene amplification in fine needle aspirates from breast carcinomas
Authors: Bofin A. M. , Ytterhus B. , Hagmar B. M.
Published: November 2003

The TOP2A gene is located on chromosome 17 close to the HER‐2 gene. It encodes an enzyme involved in the regulation of cell proliferation. Using fluorescence in situ hybridization (FISH), we have examined fine needle aspiration smears from 42 cases of breast carcinoma with probes for TOP2A, HER‐2 and chromosome 17. We found that amplification of TOP2A is a frequent finding in breast cancer and is often but not exclusively accompanied by HER‐2 gene amplification. It is associated with high histological grade and oestrogen receptor (ER) negativity. TOP2A deletions may also be associated with high histological grade and loss of ER. TOP2A amplification in the absence of HER‐2 amplification may be associated with lower histological grade and ER positivity. Testing for TOP2A aberrations may be useful in the search for individually tailored treatment regimes for breast cancer.
Liquid‐based cytology as a tool for the performance of uCyt+TM and Urovysion® Multicolour‐FISH in the detection of urothelial carcinoma
Authors: Mian C. , Lodde M. , Comploj E. , Negri G. , Egarter‐Vigl E. , Lusuardi L. , Palermo S. , Marberger M. , Pycha A.
Published: November 2003

The aim of the study was to assess the value of liquid‐based urinary cytology as a tool to perform uCyt+ and Multicolour‐FISH in patients under follow‐up after urothelial cancer. Therefore, standard cytology was compared to liquid‐based cytology with the addition of the uCyt+ test, which traces the three monoclonal antibodies M344, LDQ10 and 19A211 in exfoliated urothelial cells; and Multicolour‐FISH (including centromere‐specific probes for chromosomes 3, 7, 17 and a locus‐specific probe for 9p21/p16) performed on thin‐layer specimens. UCyt+ showed an overall sensitivity of 86.2% and cytology of 45.0%. Overall sensitivity of both the tests combined was 90%. Sensitivity of Multicolour‐FISH was 96.4%. All conventional cytology diagnoses were confirmed by liquid‐based cytology. Liquid‐based cytology is a valid tool for the performance of adjunctive analyses, such as uCyt+ and Multicolour‐FISH, on residual cellular material.
Topoisomerase IIα gene (TOP2A) amplification and deletion in cancer – more common than anticipated
Authors: Järvinen T. A. H. , Liu E. T.
Published: November 2003

In solid tumours the predominant genetic mechanism for oncogene activation is through amplification of genes. The HER‐2 (also known as ErbB2/c‐erbB2/HER‐2/neu) oncogene is the most frequently amplified oncogene in breast cancer and is also commonly amplified in other forms of cancer. The HER‐2 amplicon also contains other biologically relevant genes with altered copy numbers, among these genes is the topoisomerase IIα (TOP2A). TOP2A gene is located adjacent to the HER‐2 oncogene at the chromosome location 17q12‐q21 and is either amplified or deleted, with equal frequency, in almost 90% of HER‐2 amplified primary breast tumours. Recent data suggest that amplification and deletion of TOP2A may account for both sensitivity and resistance to topoII‐inhibitor‐chemotherapy, depending on the specific genetic defect at the TOP2A locus.

In this issue of the Cytopathology, Bofin et al. present preliminary evidence for high prevalance of TOP2A amplification and deletion not only in the HER‐2 amplified breast tumours, but also in the primary breast tumours without the HER‐2 amplification. This finding together with the concept that TOP2A gene amplification and deletion seem to account for both relative chemosensitivity and resistance to topoII‐inhibitor therapy further highlights the importance of screening for TOP2A gene copy number aberrations when topoII‐inhibitors are considered either alone or in combination of other chemotherapeutic drugs for the treatment of cancer patients.