bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of liming on utilization of 59Fe‐chelates by lettuce (Lactuca sativa L.)
Authors: Ylivainio Kari , Jaakkola Antti , Aksela Reijo 
Published: August 2006

AbstractA pot experiment was conducted to determine the utilization of iron (Fe) by lettuce (Lactuca sativa L. cv. Australian gelber). Iron was applied as 59Fe in inorganic and chelated form, particularly biodegradable chelate, 59Fe‐EDDS. Two stereoisomeric forms of ethylenediaminedisuccinate: [S,S]‐EDDS and a mixture of EDDS containing 25% [S,S]‐EDDS, 25% [R,R]‐EDDS, and 50% [S/R]/[R/S]‐EDDS, ethylenediaminetetraaceticacid (EDTA) and ethylenediimino bis(2‐hydroxyphenyl)acetic acid (EDDHA) were used as ligands. Lettuce was grown in unlimed and limed quartz sand with nitrate as the sole source of nitrogen. Liming decreased lettuce yields but had no effect on Fe concentrations, indicating that Fe concentrations were a poor indicator of Fe bioavailability within the plant. In unlimed sand, utilization of 59Fe from all 59Fe‐chelates was on the same level (2.8%–3.6%). In limed sand, only 59Fe‐EDDHA maintained the 59Fe utilization on a level (3%) comparable to that in unlimed sand. Although the utilization of 59Fe from the other chelates decreased to 0.6%–1.1% after liming, Fe concentrations were not affected due to the increased uptake of indigenous Fe. The most biodegradable form of EDDS, namely 59Fe‐EDDS(S,S), provided 59Fe for lettuce as efficiently as the mixture of 59Fe‐EDDS stereoisomers and the 59Fe‐EDTA. Utilization of 59Fe in inorganic form was 0.5% and 0.03% in unlimed and limed sand, respectively. This study shows that biodegradable ligands are able to serve as chelators to sustain Fe availability in calcareous environments. They may be of use especially in drip irrigation, where ligand accumulations may pose a threat to groundwater quality.
Microbial C, N, and P relationships in moisture‐stressed soils of Potohar, Pakistan
Authors: Khan Khalid Saifullah , Joergensen Rainer Georg 
Published: August 2006

AbstractIn 11 rain‐fed arable soils of the Potohar plateau, Pakistan, the amounts of microbial‐biomass C (Cmic), biomass N (Nmic), and biomass P (Pmic) were analyzed in relation to the element‐specific total storage compartment, i.e., soil Corg, Nt, and Pt. The effects of climatic conditions and soil physico‐chemical properties on these relationships were highlighted with special respect to crop yield levels. Average contents of soil Corg, Nt, and Pt were 3.9, 0.32, and 0.61 mg (g soil)–1, respectively. Less than 1% of Pt was extractable with 0.5 M NaHCO3. Mean contents of Cmic, Nmic, and Pmic were 118.4, 12.0, and 3.9 µg (g soil)–1. Values of Cmic, Nmic, Pmic, soil Corg, and Nt were all highly significantly interrelated. The mean crop yield level was closely connected with all soil organic matter– and microbial biomass–related properties, but showed also some influence by the amount of precipitation from September to June. Also the fraction of NaHCO3‐extractable P was closely related to soil organic matter, soil microbial biomass, and crop yield level. This reveals the overwhelming importance of biological processes for P turnover in alkaline soils.
Clonal and seasonal shifts in communities of saprotrophic microfungi and soil enzyme activities in the mycorrhizosphere of Salix spp.
Authors: Baum Christel , Hrynkiewicz Katarzyna 
Published: August 2006

AbstractThe species‐specific microbial root and rhizosphere colonization contributes essentially to the plant nutrient supply. The species number and colonization densities of cultivable saprotrophic microfungi and the activities of nutrient‐releasing soil enzymes (protease, acid and alkaline phosphatase, arylsulfatase) were investigated in the rhizosphere of one low mycorrhizal (Salix viminalis) and one higher mycorrhizal (S. × dasyclados) willow clone at a Eutric Cambisol in N Germany. After soil washing, in total 32 and 28 saprotrophic microfungal species were isolated and identified microscopically from the rhizosphere of S. viminalis and S. × dasyclados, respectively. The fungal species composition changed within the growing season but the species number was always lower under S. × dasyclados than under S. viminalis. Under both willow clones, the fungal colonization density was largest in spring, and the species number was largest in autumn. Acid‐phosphatase activity (p < 0.001) and protease activity (p < 0.003) were significantly affected by the Salix clone, whereas arylsulfatase and alkaline‐phosphatase activities did not show clone‐specific differences. All enzyme activities reached their maxima in the summer sampling. Rhizosphere colonization with Acremonium butyri, Cladosporium herbarum, and Penicillium janthinellum contributed significantly to explain the activities of acid phosphatase. Rhizosphere colonization with Cylindrocarpon destructans, Penicillium spinulosum, Plectosphaerella cucumerina, and Trichoderma polysporum contributed significantly to explain the arylsulfatase activities. Effects of the saprotrophic fungal colonization densities on the protease activities in the rhizosphere were low. Acid‐ and alkaline‐phosphatase and arylsulfatase activities in the rhizosphere soil were stronger affected by the composition of the saprotrophic fungal communities than by the Salix clone itself. In conclusion, the colonization density of some saprotrophic microfungi in the rhizosphere contributed to explain shifts in soil‐enzyme activities of the P and S cycles under different willow clones.
Heavy‐metal mobilization and uptake by mycorrhizal and nonmycorrhizal willows (Salix × dasyclados)
Authors: Baum Christel , Hrynkiewicz Katarzyna , Leinweber Peter , Meißner Ralph 
Published: August 2006

AbstractEctomycorrhizal fungi have been shown to affect metal transfer from the soil to the host plant, but the use of these fungi for increased phytoextraction of heavy metals has been scarcely investigated. Therefore, a two‐factorial pot experiment was conducted with Salix × dasyclados and (1) two contaminated soils with different concentrations of NH4NO3‐extractable metals and (2) two strains of the ectomycorrhizal fungus Paxillus involutus (one strain originating from a noncontaminated site—Pax1, and another from a contaminated site—Pax2). The inoculation with Pax2 increased the phytoavailability of Cd in the soils. Inoculation with both fungal strains increased the stem and root biomass, but had no effect on metal concentrations in the stems. Decreased Cd and increased Cu concentrations were observed in the roots of inoculated willows. The inoculation with P. involutus increased Cd (up to 22%), Zn (up to 48%), and Cu content in the stems. Decreased Pb content (Cu and Pb content were always <1 mg per plant) occurred in the stems from plants at the soil with the higher concentration of NH4NO3‐extractable metals. Contrary to this, in the soil with lower concentrations of NH4NO3‐extractable metals, the inoculation had no significant effects on the total uptake of Zn and Cu and even caused decreased Cd (Pax2) and Pb (Pax1) contents in the stems. Strain Pax2 had higher colonization densities, but the plants had lower mycorrhizal dependencies in the contaminated soils than after inoculation with the strain Pax1. Generally, metal extractability in the soils substantially affected the mycorrhizal dependency and heavy‐metal uptake of the willows. We concluded, that the inoculation with P. involutus offers an opportunity to particularly increase the phytoextraction of Zn, but the metal extractability and fungal strain effects have to be tested.
Silicon pools and fluxes in soils and landscapes—a review
Authors: Sommer Michael , Kaczorek Danuta , Kuzyakov Yakov , Breuer Jörn 
Published: August 2006

AbstractSilicon (Si) is the second‐most abundant element in the earth's crust. In the pedosphere, however, huge spans of Si contents occur mainly caused by Si redistribution in soil profiles and landscapes. Here, we summarize the current knowledge on the different pools and fluxes of Si in soils and terrestrial biogeosystems. Weathering and subsequent release of soluble Si may lead to (1) secondarily bound Si in newly formed Al silicates, (2) amorphous silica precipitation on surfaces of other minerals, (3) plant uptake, formation of phytogenic Si, and subsequent retranslocation to soils, (4) translocation within soil profiles and formation of new horizons, or (5) translocation out of soils (desilication). The research carried out hitherto focused on the participation of Si in weathering processes, especially in clay neoformation, buffering mechanisms for acids in soils or chemical denudation of landscapes. There are, however, only few investigations on the characteristics and controls of the low‐crystalline, almost pure silica compounds formed during pedogenesis. Further, there is strong demand to improve the knowledge of (micro)biological and rhizosphere processes contributing to Si mobilization, plant uptake, and formation of phytogenic Si in plants, and release due to microbial decomposition. The contribution of the biogenic Si sources to Si redistribution within soil profiles and desilication remains unknown concerning the pools, rates, processes, and driving forces. Comprehensive studies considering soil hydrological, chemical, and biological processes as well as their interactions at the scale of pedons and landscapes are necessary to make up and model the Si balance and to couple terrestrial processes with Si cycle of limnic, fluvial, or marine biogeosystems.
Observations on the presence of E domain variants of estrogen receptor‐α in the breast tumors
Authors: Kumar Vijay L. , Kumar Suresh , Srivastava Anurag , Kumar Vijay 
Published: August 2006

AbstractBackground and ObjectivesEstrogen receptor‐α (ER‐α) that exists as multiple splice variants, has been widely used as a prognostic marker in the management of breast cancer. Here we have analyzed the hormone binding E domain splice variants of ER‐α in the breast tumors with reference to the immunoreactive receptor.MethodsThirty breast cancer patients undergoing surgery at the All India Institute of Medical Sciences, New Delhi, were analyzed for the splice variants of E domain by RT‐PCR. The ER level was determined by ELISA and the samples were considered positive if the receptor levels were ≥ 15 fmol/mg protein.ResultsOur results show that exon 4 and 5 deletions were prevalent in both ER‐positive and ER‐negative categories. While most ER‐positive cases expressed wild‐type (wt) exon 6 + 7, nearly 40% of ER‐negative cases showed deletion of exon 6 + 7. Therefore, deletion of exon 6 + 7 or masking of epitopes could lead to underestimation of ER by ELISA. All the metastasis and recurrence cases had undetectable levels of ER. A significant number of node‐positive cases expressed immunoreactive ER and wt exon 6 + 7 (r = 0.509, P < 0.37).ConclusionsEstimation of ER levels combined with composite analysis of ER variants may be a better prognostic marker for breast cancer. J. Surg. Oncol. 2006;94:332–337. © 2006 Wiley‐Liss, Inc
One‐Pot Synthesis of an Alternating Copolyimide Based on Regioselective Reaction of a Non‐Symmetrical Alicyclic Dianhydride
Authors: Kudo Kazuaki , Yoshizawa Takuya , Hamada Takashi , Li Jun , Sakamoto Seiji , Shiraishi Shinsaku 
Published: August 2006

AbstractSummary: Four constitutionally isomeric copoly(amide acid)s (coPAAs), two alternating and two random, have been successfully obtained from the same combination of one non‐symmetrical alicyclic tetracarboxylic dianhydride (1.0 molar equivalents) and two symmetric aromatic diamines (0.5 molar equivalents each) by only slightly changing the reaction procedures. When the reaction mixture is subjected to chemical imidization conditions without isolation of coPAAs, the corresponding copolyimides (coPIs) are obtained in one pot. All of the coPIs are slightly yellow amorphous powders and the solubility of them is similar to each other. The glass transition temperatures of the alternating coPIs are lower in comparison to those of the random coPIs.Schematic of the possible arrangement of monomers in the copoly(amide acid)s/copolyimides synthesized here.magnified imageSchematic of the possible arrangement of monomers in the copoly(amide acid)s/copolyimides synthesized here.
Dual action on promoter demethylation and chromatin by an isothiocyanate restored GSTP1 silenced in prostate cancer
Authors: Wang L. G. , Beklemisheva A. , Liu X. M. , Ferrari A. C. , Feng J. , Chiao J. W. 
Published: August 2006

AbstractProstate carcinoma is characterized by the silencing of π‐class glutathione S‐transferase gene (GSTP1), which encodes a detoxifying enzyme. The silencing of GSTP1, due to aberrant methylation at the CpG island in the promoter/5′‐UTR, occurs in the vast majority of prostate tumors and precancerous lesions. It is a pathologic marker and probably an underlying cause of oxidative damage and inflammation at tumor initiation. Inhibition of the aberrant promoter methylation could therefore be an effective mean to prevent carcinogenesis. Several isothiocyanates, including phenethyl isothiocyanate (PEITC), found naturally in cruciferous vegetables, induced growth arrest and apoptosis in prostate cancer cells in culture and xenografts. The effects of PEITC to reactivate GSTP1 were investigated. Exposure of prostate cancer LNCaP cells to PEITC inhibited the activity and level of histone deacetylases (HDACs), and induced selective histone acetylation and methylation for chromatin unfolding. Concurrently PEITC demethylated the promoter and restored the unmethylated GSTP1 in both androgen‐dependent and ‐independent LNCaP cancer cells to the level found in normal prostatic cells, as quantified by methylation‐specific PCR and pyrosequencing. The dual action of PEITC on both the DNA and chromatin was more effective than 5′‐Aza‐2′‐deoxycytidine, sodium butyrate, or trichostatin A (TSA), and may de‐repress the methyl‐binding domain (MBD) on gene transcription. The PEITC‐mediated cross‐talk between the DNA and chromatin in demethylating and reactivating GSTP1 genes, which is critically inactivated in prostate carcinogenesis, underlines a primary mechanism of cancer chemoprevention. Consequently, new approaches could be developed, with isothiocyanates to prevent and inhibit malignancies. © 2006 Wiley‐Liss, Inc.
A new approximation for pore pressure accumulation in marine sediment due to water waves
Authors: Jeng D.‐S. , Seymour B. R. , Li J. 
Published: August 2006

AbstractThe residual mechanism of wave‐induced pore water pressure accumulation in marine sediments is re‐examined. An analytical approximation is derived using a linear relation for pore pressure generation in cyclic loading, and mistakes in previous solutions (Int. J. Numer. Anal. Methods Geomech. 2001; 25:885–907; J. Offshore Mech. Arctic Eng. (ASME) 1989; 111(1):1–11) are corrected. A numerical scheme is then employed to solve the case with a non‐linear relation for pore pressure generation. Both analytical and numerical solutions are verified with experimental data (Laboratory and field investigation of wave–
sediment interaction. Joseph H. Defrees Hydraulics Laboratory, School of Civil and Environmental Engineering, Cornell University, Ithaca, NY, 1983), and provide a better prediction of pore pressure accumulation than the previous solution (J. Offshore Mech. Arctic Eng. (ASME) 1989; 111(1):1–11). The parametric study concludes that the pore pressure accumulation and use of full non‐linear relation of pore pressure become more important under the following conditions: (1) large wave amplitude, (2) longer wave period, (3) shallow water, (4) shallow soil and (5) softer soils with a low consolidation coefficient. Copyright © 2006 John Wiley & Sons, Ltd.
Effects of selective unilateral dorsal root(s) rhizotomy on micturition reflex in anesthetized rats
Authors: Tsai Ming‐Cheng , Tang Chih‐Yung , Chang Ya‐Ting , Cheng Chen‐Li , Liao Jiuan‐Miaw , Lee Shin‐Da , Pan Shwu‐Fen , Chen Mei‐Jung , Huang Pei‐Chen , Lin Tzer‐Bin 
Published: August 2006

AbstractPurpose:To clarify the contributions of sensory inputs and glutamate transmissions to the spinal micturition reflex.Materials and Methods:Cystometrogram and external urethral sphincter electromyogram activities evaluated the L6 and/or S1 levels.Results:Changes in intravesicular pressure (IVP) in response to saline infusion (0.1 ml/min) were found after unilateral dorsal root rhizotomy at the L6 level, which showed significant increases in threshold pressure (rhizotomized vs. control: 14.25 ± 0.82 vs. 8.40 ± 0.69 cmH2O,P < 0.01, n = 28), post‐voiding pressure (7.66 ± 0.56 vs. 5.42 ± 0.52 cmH2O,P < 0.01, n = 28), holding duration (135.06 ± 23.6 vs. 77.73 ± 13.56 sec,P < 0.05, n = 28), and inter‐contraction interval (140.62 ± 23.29 vs. 82.40 ± 13.57 sec,P < 0.05, n = 28). Several (mean = 2.32 ± 1.31 vs. 0.12 ± 0.21,P < 0.01, n = 28,P < 0.01, n = 28) non‐voiding contractions with gradual increase in IVP were found ahead of voiding contraction after rhizotomy. An additional dorsal root rhizotomy at the ipsilateral S1 level caused further increases in urodynamic parameters (threshold pressure, 18.18 ± 1.67 cmH2O,P < 0.01; post‐voiding pressure 8.07 ± 0.96 cmH2O,P < 0.01; holding duration, 211.44 ± 42.54 sec,P < 0.01; inter‐contraction interval, 264.2 ± 59.99 sec,P < 0.05; non‐voiding contractions, 4.41 ± 2.12,P < 0.01, n = 7). Intrathecal glutamate (100 µM, 10 µl) ameliorated all the pathological conditions induced by unilateral dorsal root rhizotomy at the L6 level in a dose dependent manner (ED50 = 1.25 ± 10−5). Intrathecal CNQX (6‐cyano‐7‐nitroquinoxaline‐2,3‐dione; 100 µM, 10 µl) and APV (D‐2‐amino‐5‐phosphonovaleric acid; 100 µM, 10 µl) injections after rhizotomy at the L6 level induced disturbances similar to that caused by an additional rhizotomy at ipsilateral S1 level. Wherease, glutamate (100 µM, 10 µl) reversed the disturbances caused by CNQX but showed no effect on that by APV.Conclusions:Acute partial sensory deprivation caused acute impaired micturition reflex in rat models. In addition, glutamatergic NMDA and AMPA receptors are important for mediating these impairments in micturition reflex. Neurourol. Urodynam. 25:820–827, 2006. © 2006 Wiley‐Liss, Inc.
Wirkungs‐ und Resistenzmechanismen der β‐Lactam‐Antibiotika: Penicillin‐bindende Proteine, β‐Lactamasen und Signalproteine
Authors: Heisig Peter 
Published: August 2006

AbstractMechanistisch lassen sich drei Wege der Resistenzentwicklung gegen β‐Lactam‐Antibiotika unterscheiden, die teilweise allein, teilweise aber auch in Kombination zur Entwicklung von klinisch relevanter Resistenz geführt haben: die Reduktion der Antibiotikakonzentration an der Zielstruktur, die Produktion inaktivierender Enzyme und die Bildung modifizierter Zielstrukturen.
β‐Lactamasen: Ein Gegner, der nicht besiegt werden kann
Authors: Theuretzbacher Ursula 
Published: August 2006

AbstractDie Bildung von β‐Lactamasen ist der häufigste Resistenzmechanismus bei β‐Lactam‐Antibiotika. Nicht nur neue β‐Lactamasen, sondern vor allem Effizienzsteigerung der schon lange bekannten Enzyme, die Kombination verschiedener Resistenzmechanismen und die erleichterte Übertragbarkeit gemeinsam mit anderen Resistenzen durch mobile genetische Elemente gewährleisten diesem Thema eine fortdauernde Aktualität.
Methicillin‐resistenter Staphylococcus aureus: β‐Lactam‐Resistenz “trifft” Virulenz
Authors: Linde Hans‐Jörg , Lehn Norbert 
Published: August 2006

AbstractCA‐MRSA sind weltweit ein emerging pathogen außerhalb von medizinischen Einrichtungen. Sie betreffen Patienten ohne Risikofaktoren, insbesondere auch Kinder und Erwachsene im jüngeren Alter. Typischerweise kommt es zu Haut‐ und Weichteilinfektionen, die häufig mit Komplikationen verlaufen (multipel, rezidivierend, seltener Endokarditis, Osteomyelitis, septische Arthritis). Seltene schwere Komplikationen sind nekrotisierende Pneumonien, nekrotisierende Fasziitis, Purpura fulminans und Waterhouse‐Friderichsen‐Syndrom. Als besonderen Virulenzfaktor weisen CA‐MRSA u.a. das Panton‐Valentine‐Leukozidin auf. Die Stämme sind resistent gegen alle β‐Lactam‐Antibiotika. Zur Therapie sind Clindamycin, Doxycyclin, Moxifloxacin, Co‐Trimoxazol, Linezolid, Glykopeptide und Daptomycin geeignet. Die Sanierung des Trägerstatus ist aufwändig und verlangt eine sorgfältige Planung. Um eine weitere Verbreitung zu verhindern, sind verbesserte diagnostische, therapeutische und hygienische Maßnahmen bei niedergelassenen Ärzten und in Krankenhäusern nötig.
Unerwünschte Wirkungen der β‐Lactam‐Antibiotika: Widerspruch zu Ehrlichs Paradigma der selektiven Toxizität
Authors: Sendzik Judith , Stahlmann Ralf 
Published: August 2006

AbstractTrotz der unerwünschten Wirkungen der β‐Lactam‐Antibiotika insbesondere auf das gastrointestinale System und in Form von Überempfindlichkeitsreaktionen, sind die Vertreter dieser Substanzklasse als gut verträgliche antibakterielle Therapeutika anzusehen. Dies wird auch durch den weit verbreiteten Einsatz in der Pädiatrie unterstrichen. Ein rationaler Einsatz der β‐Lactam‐Antibiotika und die Möglichkeit eine Überempfindlichkeit auf diese Arzneimittelgruppe mit Hilfe von genauer Anamnese, Hauttests und Blutanalysen einzugrenzen, kann die Risiken einer β‐Lactam‐Therapie minimieren.
Pharmakokinetik und Pharmakodynamik der β‐Lactame: Was wir über β‐Lactame wissen und was wir wissen möchten
Authors: Sörgel Fritz , Bulitta Jürgen , Landersdorfer Cornelia 
Published: August 2006

AbstractDurch die Entwicklung der β‐Lactame wurde schon früh die Bedeutung von Pharmakokinetik deutlich. Neue hochspezifische Analysemethoden wie die LC‐MS/MS haben das Studium der Pharmakokinetik von β‐Lactamen und ihren Metaboliten sehr vorangebracht. LC‐MS/MS und Mikrodialyse sind viel versprechende Methoden zur Bestimmung der Gewebepenetration von β‐Lactamen. Kleine chemische Veränderungen an β‐Lactam‐Molekülen brachten teilweise bedeutende Verbesserungen der Pharmakokinetik und Wirksamkeit. β‐Lactame sind Substrate von Transportern, was nicht nur im Magen‐Darm‐Trakt und in der Niere wichtig ist. Obwohl β‐Lactame ein Eckpfeiler in der Antibiotika‐Therapie sind, gibt es auch heute noch viele offene Fragen. Wir brauchen mehr Studien zur Pharmakokinetik und Pharmakodynamik im Menschen, insbesondere in schwerkranken Patienten. Populationspharmakokinetische Modelle und Monte‐Carlo‐Simulationen sollten die Grundlage sein, um das Studiendesign neuer großer Wirksamkeitsstudien zu optimieren. Als eine der wichtigsten Fragen sollte die mögliche Überlegenheit von kontinuierlicher oder verlängerter Infusion gegenüber Kurzzeitinfusion untersucht werden.
Neue Waffe gegen β‐Lactamasen?
Authors: Bennack Edith , Holzgrabe Ulrike 
Published: August 2006

AbstractGegen die beste Waffe Gram‐negativer Bakterien gegen β‐Lactam‐Antibiotika, die β‐Lactamasen, war bisher kein Suizid‐Inhibitor uneingeschränkt erfolgreich. Während sich β‐Lactamasen vom Serin‐Protease‐Typ, der weitaus größeren Gruppe der β‐Lactamasen, wenigstens mittels Clavulansäure, Sulbactam und Tazobactam hemmen ließen, so können diese, aber auch Carbapenem und Imipenem, die Lactam‐Hydrolyse durch die Metallo‐β‐Lactamasen nicht mehr verhindern.
Papillary thyroid carcinoma in a 9‐year‐old girl with ataxia‐telangiectasia
Authors: Brasseur Benoit , Beauloye Véronique , Chantrain Christophe , Daumerie Chantal , Vermylen Christiane , Waignein Frédéric , Brichard Bénédicte 
Published: August 2006

AbstractA 9‐year‐old female with ataxia‐telangiectasia (AT) presenting with papillary thyroid carcinoma and lymph nodes involvement is reported. We discuss this novel association, the general risk of neoplasic complications in these patients, the natural history of thyroid carcinoma in the pediatric population and the potential link between thyroid carcinogenesis and ataxia‐telangiectasia mutated gene (ATM) mutation. We also expose our therapeutic attitude, according to both clinical status and particular genetic background of our patient. Pediatr Blood Cancer 2008;50:1058–1060. © 2006 Wiley‐Liss, Inc.