bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poly(ADP‐ribose) polymerase‐1, a novel partner of progesterone receptors in endometrial cancer and its precursors
Authors: Ghabreau Lina , Roux Jean Paul , Frappart Pierre‐Olivier , Mathevet Patrice , Patricot Louis Marc , Mokni Moncef , Korbi Sadok , Wang Zhao‐Qi , Tong Wei‐Min , Frappart Lucien 
Published: February 2004

AbstractEndometrial carcinomas are the most common malignancy of the female genital tract. Although the downregulation of the progesterone receptor (PR) in the progression of endometrioid carcinomas (ECs) has been well documented, the mechanism of PR alteration in endometrioid carcinogenesis is poorly understood. Recently, biochemical studies have shown that the DNA strand break‐sensing molecule poly(ADP‐ribose) polymerase (PARP‐1) was associated with the DNA binding domain of PR. In our present study, we show that in normal endometrial epithelium, the expression level of PARP‐1 protein is high in the proliferative phase but markedly decreases during the secretory phase. Interestingly, PARP‐1 expression gradually increases in nonatypical and atypical endometrial hyperplasia, reaching its highest level in grade I, and decreases significantly toward grade III ECs. Notably, PARP‐1 and PR expressions, in each stage, are positively correlated (p < 0.0001), with the exception of nonendometrioid carcinomas. Thus, these data suggest that PARP‐1 is substantially involved in the regulation of progesterone action in the development of ECs. © 2004 Wiley‐Liss, Inc.
Elevated hTERT mRNA levels: A potential determinant of bronchial squamous cell carcinoma (in situ)
Authors: Snijders Peter J.F. , Breuer Roderick H.J. , Sutedja Thomas G. , Egging Monique , Voorhorst Feja J. , Steenbergen Renske D.M. , van der Linden Hans C. , Risse Elle K. , Berkhof Johannes , de Vries Elisabeth G.E. , van der Zee Ate G.J. , Postmus Pieter E. , Meijer Chris J.L.M. , Smit Egbert F. 
Published: February 2004

AbstractExpression levels of hTERT mRNA were investigated by RT‐PCR in tissue specimens of patients with (Group A) and without (Group B) clinically overt bronchial carcinoma, respectively. Bronchial carcinoma (n = 9) and distant normal (n = 9) specimens were analyzed in Group A. The chance of carcinoma seemed to increase with increasing hTERT mRNA levels (OR = 6.04, 95% CI = 1.02–37). Group B was comprised of 21 patients who underwent autofluorescence bronchoscopy. After analysis of 66 bronchial biopsies the chance of prevalent carcinoma in situ or carcinoma increased with increasing hTERT mRNA levels (OR = 6.19, 95% CI = 1.55–25). Variables like age, gender, smoking history, history of cancer within the airways or the degree of lymphocyte infiltrate in the specimens did not modify this relation. In 7 Group B patients in whom bronchial cancer was diagnosed during follow‐up, biopsies taken before cancer diagnosis from both the area of the newly developed tumor and distantly from this area had been analyzed for hTERT expression. The median hTERT mRNA level in the biopsies from the area of future cancer was significantly higher than in biopsies taken from distant sites (p < 0.03). These data indicate that elevated hTERT mRNA is associated with an increased relative risk of prevalent and incident bronchial squamous cell carcinoma (in situ). © 2004 Wiley‐Liss, Inc.
Calix[8]arene‐mediated self‐assembly of tetrapeptide H‐Leu‐Leu‐Ile‐Leu‐OMe
Authors: Satheeshkumar K. S. , Vasu G. , Vishalakshi V. , Moni M. S. , Jayakumar R. 
Published: February 2004

AbstractConformational analysis of peptide 1, H‐Leu‐Leu‐Ile‐Leu‐OMe on complexing with macro cycle calix[8]arene has been carried out using 1H‐NMR and FTIR spectroscopic techniques. Stoichiometry of the complex formed in the 1:8 ratio was evidenced by a Job plot. NMR studies of the above peptide show a marked downfield shift and an increase in 3J values for NH resonances on complexing with calix[8]arene. The characteristic NOE connectivity between Ni+1H and CiαH confirm β‐sheet conformation in the complexed state. Both 1H‐NMR and FTIR results indicate that the α‐amino group of Leu I is proximal to the macrocycle and is involved in hydrogen bond formation with phenolic hydrogen atom of the calix[8]arene. This suggests that calix[8]arene provides a suitable platform for peptide 1 to self‐assemble in a parallel β‐sheet conformation. The nature of calix[8]arene interaction with peptide 1 has been studied using dynamic NMR studies, which concludes that a bifurcated hydrogen bonding interaction exists in the molecular interfaces of the assembly. Copyright © 2003 John Wiley & Sons, Ltd.
Identification of the substrate‐binding exosites of two snake venom serine proteinases: molecular basis for the partition of two essential functions of thrombin
Authors: Maroun R. C. , Serrano S. M. T. 
Published: February 2004

AbstractThe venom of the South American snake Bothrops jararaca contains two serine proteinases, bothrombin and the platelet‐aggregating enzyme PA‐BJ, which share 66% sequence identity. Each of these proteinases possesses one of the two essential procoagulant functions of thrombin—the clotting of fibrinogen and platelet aggregation. Thus, bothrombin clots fibrinogen but has no direct effect on platelets, unless in the presence of exogenous fibrinogen. PA‐BJ induces platelet aggregation by interacting with the protease‐activated platelet receptor without clotting fibrinogen. On the other hand, thrombin possesses two extended surfaces. One is composed of basic and hydrophobic residues (exosite I) and the other one of basic residues only (exosite II). These exosites are involved in the recognition of physiological macromolecular substrates. In order to identify the corresponding exosites in bothrombin and PA‐BJ and understand the molecular basis of the partition of the two procoagulant functions of thrombin among the two snake venom enzymes, we used molecular modeling to obtain models of their complexes with their natural substrates fibrinogen and a fragment of the protease‐activated platelet receptor, respectively. In analogy to thrombin, each of the enzymes presents two exosites. Nonetheless, the exosites contain a smaller proportion of basic residues than thrombin does (45–72%), reducing thus the functional diversity of the enzymes. In addition, the composition of exosite I is different in both enzymes. We identify those residues in exosite I that could contribute to the differences in specificity. Finally, allostery does not seem to mediate macromolecular substrate recognition by these enzymes. Copyright © 2003 John Wiley & Sons, Ltd.
Enhanced recognition of cystic fibrosis W1282X DNA point mutation by chiral peptide nucleic acid probes by a surface plasmon resonance biosensor
Authors: Corradini Roberto , Feriotto Giordana , Sforza Stefano , Marchelli Rosangela , Gambari Roberto 
Published: February 2004

AbstractPeptide nucleic acids (PNAs) containing an insert of three chiral monomers based on D‐lysine (‘chiral box’) were synthesized and used as probes in Biospecific Interaction Analysis (BIA) for the recognition of DNA containing the W1282X point mutation of the cystic fibrosis gene. Hybridization experiments carried out in solution showed enhanced mismatch recognition when compared with the analogous achiral PNAs and oligonucleotides. The signal intensity was lower, but the selectivity of the Biacore response was found to be much higher than that observed with achiral PNAs. The newly designed chiral PNA probes were also found to hybridize with a 1:1 mixture of normal (N‐W1282X) and mutated (M‐W1282X) DNA oligomers immobilized on the biosensor, thus allowing discrimination not only between a normal and a mutated sequence (healthy/homozygous), but also between homo‐ and heterozygous individuals. These results suggest that ‘chiral box’ PNAs are potential powerful tools for the analysis of single point mutations of biological/biomedical relevance. Copyright © 2003 John Wiley & Sons, Ltd.
Mapping of senescent cell antigen on brain anion exchanger protein (AE) isoforms using HPLC and fast atom bombardment ionization mass spectrometry (FAB‐MS)
Authors: Kay Marguerite M. , Goodman Joseph 
Published: February 2004

AbstractMolecular recognition of senescent cells involves oxidation of a crucial membrane protein leading to generation of a neoantigen, called ‘senescent cell antigen’ (SCA), and binding of physiologic autoantibodies. These IgG autoantibodies trigger macrophage removal of the cell prior to its lysis at a time when anion transport has decreased but the membrane is still grossly intact. The neoantigen SCA is generated by oxidation of a major anion transport protein called band 3 or anion exchange protein. In this study, we use IgG physiologic autoantibodies from senescent red cells to isolate SCA from brain, and HPLC and fast atom bombardment ionization mass spectrometry (FAB‐MS) to compare brain SCA to band 3. HPLC peptide maps of band 3 and SCA showed substantial homology, suggesting that SCA is a subset of band 3, and includes an estimated ≥45% of the band 3 molecule. FAB‐MS results indicate that residues matching all three band 3 isoforms (AE1, AE2 and AE3) are detected in SCA fractions. These findings suggest that other isoforms of band 3 may undergo the same aging changes that AE1 on red blood cells undergoes to generate SCA. This provides confirmation that SCA is on non‐erythroid cell types. Implications of these studies to the generation of neoantigens by oxidation and their recognition by autoantibodies to them are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Selection of antibody fragments specific for an α‐helix region of acylphosphatase
Authors: Degl'Innocenti Donatella , Taddei Niccolò , Ramazzotti Matteo , Stefani Massimo , Chiti Fabrizio , Ramponi Giampietro 
Published: February 2004

AbstractThe native state of common‐type acylphosphatase (AcP) elicits two α‐helices spanning residues 22–32 and 55–67 in the protein sequence. A peptide corresponding to the second α‐helix (helix‐2) of the protein was used to select phage antibodies consisting of a single chain fragment variable. The selection was performed in the presence of trifluoroethanol, a cosolvent known to induce the formation of helical structure in peptides and proteins. Phage scFv antibodies capable of binding the peptide specifically in a trifluoroethanol‐induced α‐helical conformation were isolated by affinity selection (biopanning). Some of these scFvs were also able to bind the native protein but not the peptide in a non‐helical unstructured state. This indicates that the structural determinant recognized by the selected antibodies is the α‐helical conformation of this specific region, rather than simply its amino acid sequence. This study shows that phage display libraries can be used to raise antibodies one can use as reagents able to target regions of a protein with a specific native‐like secondary structure. Copyright © 2004 John Wiley & Sons, Ltd.
CAD–ICAD complex structure derived from saturation transfer experiment and simulated annealing without using pairwise NOE information
Authors: Matsuda Tomoki , Nakajima Nobuyuki , Yamazaki Toshio , Nakamura Haruki 
Published: February 2004

AbstractSaturation transfer experiments were performed for the 2H‐ and 15N‐labeled mouse CAD domain of the caspase‐activated deoxyribonuclease and the CAD domain of its inhibitor to reveal the protein–protein complexed conformation. Based on the physical model for the spin diffusion, a novel method was developed to reconstruct the complexed structure using the simulated annealing calculation. The complementarity in the molecular surface shape and the electrostatic potential distribution provide a good measure for the assessment of the putative complexed conformation, despite much less experimental information than the conventional distance geometry calculation. Copyright © 2004 John Wiley & Sons, Ltd.
Differences in growth and yield in response to cadmium toxicity in cotton genotypes
Authors: Wu Feibo , Wu Hongxia , Zhang Guoping , Bachir Dango M. L. 
Published: February 2004

AbstractA greenhouse hydroponic experiment was conducted to study the effects of cadmium (Cd; 0, 0.1, 1.0, 10 μM in nutrient solution) on yield and yield components as well as Cd concentration and accumulation in three cotton genotypes (Simian 3, Zhongmian 16, Zhongmian 16–2). The results showed that Cd concentration in different organs increased with increasing Cd levels in the nutrient solution in the following order: root > petiole > xylem > fruiting branch, leaf > phloem in vegetative organs and seed coat, seed nut > boll shell > fiber in reproductive organs. There were significant genotypic differences in functional leaf and petiole Cd concentrations at 1 and 10 μM Cd treatments, with the cultivar Simian 3 showing higher Cd concentrations and greater reductions in lint yield than the other two genotypes.
Soil‐plant relationships, micronutrient contents, and cardenolide production in natural populations of Digitalis obscura
Authors: Roca‐Pérez Luis , Boluda Rafael , Pérez‐Bermúdez Pedro 
Published: February 2004

AbstractThe production of secondary metabolites by plants growing in natural populations is conditioned by environmental factors. In the present study, we have investigated the relationships among soil properties, micronutrients in soils and plants, and cardenolide production from wild Digitalis obscura (Scrophulariaceae) populations. Young and mature leaves and soil samples were collected in ten different populations, corresponding to three Mediterranean bioclimatic belts (Thermo‐, Meso‐, and Supramediterranean belts). Soil (total and EDTA‐extractable) and leaf micronutrients (Fe, Mn, Zn, and Cu), and leaf cardenolide accumulation have been determined. Significant negative correlations were observed between Fe, Mn or Zn concentration in leaves and soil pH, as well as between Fe or Mn in leaves and carbonate content of soils. Only EDTA‐extractable Mn was significantly correlated with Mn content in the plants. With regard to cardenolide content in leaves, this parameter was negatively correlated with Znleaf in young leaves and with Mnleaf in old leaves. Positively correlated, however, were Fe and cardenolide content in young leaves. The influence of environmental conditions and leaf micronutrient contents on cardenolide accumulation is discussed.
Vernachlässigte Phosphor‐ und Kaliumdüngung im ökologischen Landbau senkt die biologische Stickstofffixierung bei Rotklee und den Kornertrag bei nachfolgendem Hafer
Authors: Römer Wilhelm , Lehne Philipp 
Published: February 2004

AbstractIn Betrieben des ökologischen Landbaus spielt die biologische Stickstoff (N2)‐Fixierung der Leguminosen die entscheidende Rolle für den N‐Input. Eine nicht ausreichende Versorgung der Leguminosen mit Phosphor (P), Kalium (K) und Schwefel (S) vermindert deren N2‐Fixierungsleistung und damit das Gesamtpotenzial der pflanzlichen Produktion. Um diese Zusammenhänge deutlich zu machen, wurde aus einer Ackerfläche eines Betriebes des ökologischen Landbaus, der seit über drei Jahrzehnten weder Dünger noch Futter zugekauft hat, Boden entnommen und ein Gefäßversuch mit Rotklee und nachfolgend Hafer durchgeführt. Der Boden war ein toniger Schluff (Parabraunerde aus Löss, Südniedersachsen) mit einem pH (CaCl2) von 5,4 sowie 5 mg kg–1 laktatlöslichem P (CAL‐P) und 110 mg kg–1 laktatlöslichem K (CAL‐K). Pro Gefäß wurden dem Boden (Mitscherlichgefäße, 6 kg) 400 mg P als (i) Triplesuperphosphat (TSP), (ii) Rohphosphat (RP), (iii) Bioabfallkompost (BAK), (iv) TSP + 1000 mg K als K2SO4 (TSP+K) bzw. (v) nur 200 mg P als Rohphosphat (RP/2) zugegeben. Eine Kontrollvariante erhielt keinen Dünger.Die P‐Zufuhr führte zu einer signifikanten Erhöhung des P‐Gehalts in den Rotkleepflanzen und erhöhte deren Trockenmasse (TM)‐Ertrag um 60 bis 130 % sowie die N‐Mengen in den Pflanzen um 64 bis 139 %. Zwischen TSP und RP bestanden keine signifikanten Unterschiede. Der BAK wirkte beim N‐Ertrag signifikant besser als TSP oder RP. Die Variante TSP+K erbrachte bezogen auf die Kontrolle die höchsten Entzüge an P (343 %), K (228 %) und N (239 %) sowie den höchsten TM‐Ertrag (230 %). Dies ist ein Hinweis auf den Synergieeffekt von P, K und S auf die N2‐Bindung, der auch in der Kompostvariante wirksam war. Der nachgebaute Hafer erhöhte seinen Kornertrag auf 132 % (RP/2) bzw. bis auf 165 % (Varianten i–iv). Dies war auf eine erhöhte Kornzahl pro Rispe zurückzuführen. Die Ursachen lagen vor allem in der erhöhten P‐ und N‐Aufnahme (jeweils bis 172 %) des Hafers.
Effects of aerobic conditions in the rhizosphere of rice on the dynamics and availability of phosphorus in a flooded soil – A model experiment
Authors: Zhang Yongsong , Lin Xianyong , Werner Wilfried 
Published: February 2004

AbstractThe secretion of O2 by rice roots results in aerobic conditions in the rhizoshere compared to the bulk flooded soil. The effect of this phenomenon on the adsorption/desorption behavior and on the availability of phosphorus (P) in a flooded soil was investigated in a model experiment. An experimental set‐up was developed that imitates both O2 release and P uptake by the rice root. The results showed that O2 secretion significantly reduced P adsorption/retention and increased P desorption/release in the “rhizosphere” soil, compared to the anaerobic bulk soil. The P uptake by an anion exchange resin from both unfertilized and P‐amended soil was significantly increased.The results confirm that the O2 secretion is an important mechanism to enhance P availability and P uptake of rice under flooded conditions, where the “physico‐chemical” availability of P in the anaerobic bulk soil is strongly reduced. The decrease of P availability in the P‐amended flooded bulk soil was mainly associated with the almost complete transformation of the precedingly enriched Al‐P fraction into Fe‐bound P with extremely low desorption/release characteristics during the subsequent flooding.
Content and composition of free and occluded particulate organic matter in a differently textured arable Cambisol as revealed by solid‐state 13C NMR spectroscopy
Authors: Kölbl Angelika , Kögel‐Knabner Ingrid 
Published: February 2004

AbstractThe composition of functional light soil organic matter pools of arable Cambisols with a gradient in clay content was investigated. Soil texture differences originate from increasing loess admixture to the parent material (coarse‐grained tertiary sediments). Using density fractionation in combination with ultrasonic dispersion, two types of particulate organic matter (POM) were obtained: (1) free POM and (2) POM occluded in soil aggregates. Both POM fractions were analyzed by elemental analysis (C, N) and CPMAS 13C NMR spectroscopy. With increasing clay content the amount of organic carbon stored in the occluded POM fraction increased considerably, whereas the amounts of free POM were not related to the soil clay content. With increasing soil clay contents increasing proportions of O‐alkyl C and decreasing proportions of aryl C were found for both POM fractions. The occluded POM fraction showed a higher degree of degradation as indicated by lower amounts in O‐alkyl carbon. A lower degree of POM degradation was associated with higher clay contents. Higher soil clay contents promoted the conservation of POM with a low degree of alteration. This effect of soil texture was found to be highly significant when the aryl C : O‐alkyl C ratio was used as indicator for POM decomposition rather than the alkyl C : O‐alkyl C ratio.
Evolution of organic matter added to soils under cultivation conditions
Authors: Madrid Ramon , Valverde Madalena , Guillén Isidro , Sanchez Antonio , Lax Antonio 
Published: February 2004

AbstractThe development of an organic matter (OM) based on mixed sheep manure and peat, when it was incorporated into soils as fertilizer, was studied. The experiment was carried out in soils under almond tree culture, with drip irrigation and non irrigation regimes. Two doses, 10 and 4.5 kg tree–1, were assayed.Changes in the humic acid fraction one year after incorporation into soils showed oxidation and enrichment in condensed structures, as observed by an increase of the O*:H* ratio and a decrease of the H*:C* ratio, and also by FTIR spectra. The oxidative process was more significant in the coarser textured and also in the non‐irrigated soil. The evolution of the ratios Cext:Cox and CHA:CFA throughout the culture cycle was followed by sampling and chemical analysis of different forms of organic carbon. Evolution of Cext:Cox showed a uniform humification state in the irrigated soil, and a significant decrease in the non‐irrigated soil, at the beginning of the experiment. Curves of CHA:CFA evolution showed changes attributed to mineralization or drainage of the fulvic acids fraction, giving a maximum in spring in both soils and a final increase at the end of the cycle by drainage only in the irrigated soil.
Redox potential of bulk soil and soil solution concentration of nitrate, manganese, iron, and sulfate in two Gleysols
Authors: Mansfeldt Tim 
Published: February 2004

AbstractWhile the reduction of nitrate‐N, Mn(III,IV), Fe(III), and sulfate‐S in soil has been studied intensively in the laboratory, field research has received only limited attention. This study investigated the relationship between redox potential (EH) measured in bulk soil and concentrations of nitrate, Mn2+, Fe2+, and sulfate in the soil solution of two Gleysols differing in drainage status from the Marsh area of Schleswig‐Holstein, Northern Germany. The soils are silty‐sandy and developed from calcareous marine sediments. Redox potentials were monitored weekly with permanently installed Pt electrodes, and soil solution was obtained biweekly by ceramic suction cups from 10, 30, 60, and 150 cm depth over one year. Median EH at 10, 30, 60, and 150 cm depths was 470, 410, 410, and 20 mV in the drained soil and 500, 480, 30, and –170 mV in the undrained soil, respectively. A decrease in EH below critical values was accompanied in the soil solutions (pH 7.4 to 7.8) by disappearance of nitrate below 0 to 200 mV, appearance of Mn2+ below 350 mV, and Fe2+ below 0 to 50 mV. Both metals disappeared from soil solution after aeration. In the sulfide‐bearing environment of the 150 cm depth of the undrained soil, however, the sulfate concentrations were highest at such EH values at which sulfate should be unstable. This discrepancy was reflected in the fact that at this depth bulk soil EH was about 400 mV lower than soil solution EH (250 mV). When investigating the dynamics of nitrate, Mn, and Fe in soils, bulk soil EH provides semi‐quantitative information in terms of critical EH ranges. However, in sulfidic soil environments the interpretation of EH measured in bulk soil is uncertain.