bluuebunny/crossref_metadata_2025 huggingface dataset:
Working with police to help children exposed to violence
Authors: Osofsky Joy D. , Rovaris Michael , Hammer Jill Hayes , Dickson Amy , Freeman Nancy , Aucoin Katherine
Published: August 2004

Children's exposure to community and domestic violence is a major problem in our country. Exposure to violence can contribute to negative short‐ and longer‐term outcomes for children that includes significant risk for later violent behavior. Prevention and intervention programs for children exposed to violence benefit from creative strategies and collaborations to identify and reach children earlier in order to prevent or reduce the risk. This article describes the development and implementation of the Violence Intervention Program for Children and Families, which represents a partnership with the New Orleans Police Department. It was designed to raise awareness, provide training, identify children earlier after the trauma, and provide interventions and treatment services for traumatized children and families. Over the course of the 10 years of the program, the results of the education and collaboration showed increased sensitivity of police officers to traumatized children and greater success in early referrals for intervention and treatment. Raising awareness at local and national levels of the important preventive role that police–mental‐health collaborations can play is a crucial component of the work. With recognition of the effects of trauma and appropriate interventions, it is possible to help children stay on track developmentally by supporting positive social and emotional development and preventing the risk of later violence. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 593–606, 2004.
Life‐course events, social networks, and the emergence of violence among female gang members
Authors: Fleisher Mark S. , Krienert Jessie L.
Published: August 2004

Using data gathered from a multi‐year field study, this article identifies specific life‐course events shared by gang‐affiliated women. Gangs emerge as a cultural adaptation or pro‐social community response to poverty and racial isolation. Through the use of a social‐network approach, data show that violence dramatically increases in the period between gang affiliation and first pregnancy and decreases with pregnancy and childbirth. Policy recommendations addressing the delivery of services are offered within the context of gang women's personal networks. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 607–622, 2004.
Preventing youth violence through the promotion of community engagement and membership
Authors: Zeldin Shepherd
Published: August 2004

Youth policy in the United States reflects the public assumption that adolescence is a time of storm and stress and that youth are therefore in need of protection and control from their communities. These and other beliefs about youth distance adults from youth in their communities and, equally important, distract attention and debate from the full range of policy responses available to address youth violence. The purpose of this policy analysis is to explore youth engagement in community decision‐making as a public response to violence. A broad body of research indicates that youth engagement reduces the likelihood of interpersonal violence and delinquency, while concurrently promoting community membership and the development of positive youth competencies and emotional well being. Given that youth engagement is a viable policy option, the challenge will be to integrate youth into their communities as contributing citizens rather than regard them as objects of concern. Towards that end, the analysis offers six policy directions. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 623–641, 2004.
Studies of the roles of ADP‐ribosylation factors and phospholipase D in phorbol ester‐induced membrane ruffling
Authors: Hiroyama Masami , Exton John H.
Published: August 2004

In this study, we have explored the roles of ADP‐ribosylation factors (ARFs), phospholipase D (PLD) isozymes, and arfaptins in phorbol ester (PMA)‐induced membrane ruffling in HeLa cells. PMA stimulation induced ruffling and translocated cortactin to the plasma membrane. The cortactin translocation was inhibited by dominant negative (DN)‐ARF6, DN‐ARF1, and DN‐Rac1, but not by DN‐RhoA and DN‐Cdc42. The inability of DN‐forms of ARF6, ARF1, and Rac1 to affect PLD activity in response to PMA indicated that this enzyme was not activated via these small G proteins and that its activation was not essential for the induction of ruffling. Endogenous‐ARF1, ‐ARF6, and ‐Rac1 existed in the ruffling region along with cortactin after PMA stimulation. DN‐ARF1 had no effect on the ruffling induced by DA‐ARF6 or DA‐Rac1, and DN‐ARF6 had no effect on that induced by DA‐ARF1 or DA‐Rac1. On the other hand DN‐Rac1 suppressed the effect of DA‐ARF6 but not that of DA‐ARF1. These results suggest that PMA causes membrane ruffling via an ARF6‐Rac1 pathway and also an ARF1 pathway operating in parallel. Overexpression of PLD1 and PLD2 inhibited PMA‐induced cortactin translocation and actin–cortactin complex formation, supporting the view that these enzymes are not required for ruffling, but actually suppress it. We conclude that PMA‐induced membrane ruffling is caused via ARF6‐Rac1 and ARF1 pathways operating in parallel and that PLD may be inhibitory. © 2004 Wiley‐Liss, Inc.
Screening, library‐assisted identification and validated quantification of 23 benzodiazepines, flumazenil, zaleplone, zolpidem and zopiclone in plasma by liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization
Authors: Kratzsch Carsten , Tenberken Oliver , Peters Frank T. , Weber Armin A. , Kraemer Thomas , Maurer Hans H.
Published: August 2004

A liquid chromatographic/mass spectrometric assay with atmospheric pressure chemical ionization (LC/APCI‐MS) is presented for fast and reliable screening and identification and also for precise and sensitive quantification in plasma of the 23 benzodiazepines alprazolam, bromazepam, brotizolam, camazepam, chlordiazepoxide, clobazam, clonazepam, diazepam, flunitrazepam, flurazepam, desalkylflurazepam, lorazepam, lormetazepam, medazepam, metaclazepam, midazolam, nitrazepam, nordazepam, oxazepam, prazepam, temazepam and tetrazepam, triazolam, their antagonist flumazenil and the benzodiazepine BZ1 (omega 1) receptor agonists zaleplone, zolpidem and zopiclone. It allows confirmation of the diagnosis of an overdose situation and monitoring of psychiatric patients' compliance. The analytes were isolated from plasma using liquid–liquid extraction and were separated on a Merck LiChroCART column with Superspher 60 RP Select B as the stationary phase. Gradient elution was performed using aqueous ammonium formate and acetonitrile. After screening and identification in the scan mode using the authors' LC/MS library, the analytes were quantified in the selected‐ion monitoring mode. The quantification assay was fully validated. It was found to be selective proved to be linear from sub‐therapeutic to over therapeutic concentrations for all analytes, except bromazepam. The corresponding reference levels the assay's accuracy and precision data for all studied substances are listed. The accuracy and precision data were within the required limits with the exception of those for bromazepam. The analytes were stable in frozen plasma for at least 1 month. The validated assay was successfully applied to several authentic plasma samples from patients treated or intoxicated with various benzodiazepines or with zaleplone, zolpidem or zopiclone. It has proven to be appropriate for the isolation, separation, screening, identification and quantification of the drugs mentioned above in plasma for clinical toxicology, e.g. in cases of poisoning, and forensic toxicology, e.g. in cases of driving under the influence of drugs. Copyright © 2004 John Wiley & Sons, Ltd.
Mass spectrometric analysis of low molecular mass polyesters by laser desorption/ionization on porous silicon
Authors: Arakawa Ryuichi , Shimomae Yukiyasu , Morikawa Hidemi , Ohara Kazuma , Okuno Shoji
Published: August 2004

A low molecular mass polyester was analyzed by desorption/ionization on porous silicon (DIOS) mass spectrometry. The results were compared with those of matrix‐assisted laser desorption ionization (MALDI) mass spectrometry using matrixes of α‐cyano‐4‐hydroxycinnamic acid (CHCA) and 10,15,20‐tetrakis(pentafluorophenyl)porphyrin (F20TPP). The CHCA matrix was not suitable for characterization of low molecular mass components of the polyester because the matrix‐related ions interfered with the component ions. On the other hand, the F20TPP matrix showed no interference because no matrix‐related ions appeared below m/z 822. However, the solvent selection for determining optimal conditions of sample preparation was limited, because F20TPP does not dissolve readily in any of the available organic solvents. In the DIOS spectra, the polymer ions were observed at high sensitivity without a contaminating ion. No matrix is needed for DIOS spectra of low molecular mass polyesters, facilitating sample preparation and selectivity of a precursor ion in post‐source decay measurements. Copyright © 2004 John Wiley & Sons, Ltd.
Electron ionization mass spectrometry as a tool for the investigation of the ortho effect in fragmentation of some Schiff bases derived from amphetamine analogs
Authors: Błachut Dariusz , Danikiewicz Witold , Olejnik Marian , Czarnocki Zbigniew
Published: August 2004

The electron ionization‐induced fragmentation patterns of three forensically relevant Schiff bases, originating from the condensation between 2‐, 3‐ and 4‐methoxyamphetamine and the corresponding ketones, were studied. The proposed fragmentation routes and ion structures are supported by high‐resolution data and B/E linked‐scan and mass‐analyzed ion kinetic energy spectra. The rationalization of the ortho effect, which is responsible for the formation of the [M − OCH3] fragment in the case of the imine bearing ortho‐substituted methoxy group, is given. Copyright © 2004 John Wiley & Sons, Ltd.
High mass accuracy in‐source collision‐induced dissociation tandem mass spectrometry and multi‐step mass spectrometry as complementary tools for fragmentation studies of quaternary ammonium herbicides
Authors: Núñez Oscar , Moyano Encarnación , Galceran Maria Teresa
Published: August 2004

Fragmentation studies using both an ion‐trap mass analyzer and a hybrid quadrupole time‐of‐flight (Q‐TOF) mass spectrometer were performed in order to establish the fragmentation pathways of organic molecules. A general strategy combining MSn data (n = 1–4) in an ion‐trap analyzer with tandem mass spectrometry and in‐source collision‐induced dissociation tandem mass spectrometry (CID MS/MS) in a Q‐TOF instrument was applied. The MSn data were used to propose a tentative fragmentation pathway following genealogical relationships. When several assignments were possible, MS/MS and in‐source CID MS/MS (Q‐TOF) allowed the elemental compositions of the fragments to be confirmed. Quaternary ammonium herbicides (quats) were used as test compounds and their fragmentation pathways were established. The elemental composition of the fragments was confirmed using the TOF analyzer with relative errors <0.0023 Da. Some fragments previously reported in the literature were reassigned taking advantage of the high mass resolution and accuracy of the Q‐TOF instrument, which made it possible to solve losses where nitrogen was involved. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous determination of capecitabine and its metabolite 5‐fluorouracil by column switching and liquid chromatographic/tandem mass spectrometry
Authors: Siethoff Christoph , Orth Matthias , Ortling Andrea , Brendel Erich , Wagner‐Redeker Winfried
Published: August 2004

A liquid chromatographic/tandem mass spectrometric method was developed and validated for the quantitation of capecitabine and its metabolite 5‐fluorouracil in human plasma. The simultaneous determination of both analytes was achieved by a column switching method using a trapping column and two analytical columns with different stationary phases. Isocratic elution was used for the separation of capecitabine on a C18 column whereas 5‐fluorouracil was separated using gradient elution on an non‐polar carbon phase. The calibration curves were linear for both compounds with a correlation factor (R2) > 0.9993 for 5‐fluorouracil and >0.9942 for capecitabine. The assay was validated in the concentration range 5.00–1000 ng ml−1 for both compounds. The intra‐day precision was better than 10% for 5‐fluorouracil and better than 11% for capecitabine whereas the inter‐day precision was better than 8% for 5‐fluorouracil and better than 14% for capecitabine. Copyright © 2004 John Wiley & Sons, Ltd.
Liquid chromatographic/electrospray ionization mass spectrometric identification of the oxidation end‐products of metformin in aqueous solutions
Authors: Collin F. , Khoury H. , Bonnefont‐Rousselot D. , Thérond P. , Legrand A. , Jore D. , Gardès‐Albert M.
Published: August 2004

Metformin is an antihyperglycemic drug that exhibits some antioxidant properties. HO•‐induced oxidation of metformin was studied in aqueous solution, in both aerated and deaerated conditions. Gamma radiolysis of water was used to generate HO• free radicals, capable of initiating one‐electron oxidation of metformin. Oxidation end‐products were identified by direct infusion mass spectrometry (MS) and high‐performance liquid chromatography/mass spectrometry (HPLC/MSn): for every product, structure elucidation was based on its mass (simple mass spectra confirmed by HPLC/MS). In addition, fragmentation spectra (MS2, MS3 and MS4) and the determination of deuterium–hydrogen exchange sites provided valuable information allowing the complete identification of some of the end‐products. At low radiation dose, four products were identified as primary ones, since they result from the direct attack of HO• radicals on metformin. These primary oxidation end‐products were identified respectively as hydroperoxide of metformin, covalent dimer of metformin, methylbiguanide and 2‐amino‐4‐imino‐5‐methyl‐1,3,5‐triazine. At high radiation dose, seven other products were identified as secondary ones, resulting from the HO•‐induced oxidation of the primary end‐products. A reaction scheme was postulated for the interpretation of the results. Copyright © 2004 John Wiley & Sons, Ltd.
Triple quadrupole linear ion trap mass spectrometer for the analysis of small molecules and macromolecules
Authors: Hopfgartner Gérard , Varesio Emmanuel , Tschäppät Viviane , Grivet Chantal , Bourgogne Emmanuel , Leuthold Luc Alexis
Published: August 2004

Recently, linear ion traps (LITs) have been combined with quadrupole (Q), time‐of‐flight (TOF) and Fourier transform ion cyclotron resonance (FT‐ICR) mass spectrometery (MS). LITs can be used either as ion accumulation devices or as commercially available, stand‐alone mass spectrometers with MSn capabilities. The combination of triple quadrupole MS with LIT technology in the form of an instrument of configuration QqLIT, using axial ejection, is particularly interesting, because this instrument retains the classical triple quadrupole scan functions such as selected reaction monitoring (SRM), product ion (PI), neutral loss (NL) and precursor ion (PC) while also providing access to sensitive ion trap experiments. For small molecules, quantitative and qualitative analysis can be performed using the same instrument. In addition, for peptide analysis, the enhanced multiply charged (EMC) scan allows an increase in selectivity, while the time‐delayed fragmentation (TDF) scan provides additional structural information. Various methods of operating the hybrid instrument are described for the case of the commercial Q TRAP (AB/MDS Sciex) and applications to drug metabolism analysis, quantitative confirmatory analysis, peptides analysis and automated nanoelectrospray (ESI‐chip‐MS) analysis are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Anionic copper complex fragmentations from enkephalins under low‐energy collision‐induced dissociation in an ion trap mass spectrometer
Authors: Bossée Anne , Afonso Carlos , Fournier Françoise , Tasseau Olivier , Pepe Claude , Bellier Bruno , Tabet Jean‐Claude
Published: August 2004

Peptide metallation with Cu2+ was explored in the negative ESI mode using an ion trap mass spectrometer. Under these conditions, the [(M − 3H) + CuII]− species formed were investigated under low‐energy collision‐induced dissociation conditions. MS2 experiments indicate a very different behavior of CuII metallated complexes compared with [M − H]− species. CuII induces an easy loss of CO2 and specific side‐chain cleavages (by radical losses) at the C‐terminal residue, as observed previously by prompt ‘in source’ dissociation experiments. The loss of CO2 yields an unstable carbylide that leads to further dissociations involving the migration of a proton or a hydrogen radical (through the reduction of CuII). Multistage MS3 experiments were carried out to rationalize this behavior. Fragmentation pathways are proposed in order to explain the product ions observed. The side‐chain radical loss at the C‐terminus was demonstrated to be a consecutive process. Finally, evidence is provided that the specific side‐chain cleavages can be used for the differentiation of Leu/Ile and Gln/Lys residues when they are located at the C‐terminus. The existence of a zwitterionic form in the case of the anionic YGGFK–CuII complex is proposed. Copyright © 2004 John Wiley & Sons, Ltd.
Mass spectrometry of N‐linked oligosaccharides using atmospheric pressure infrared laser ionization from solution
Authors: Tan Phillip V. , Taranenko Nelli I. , Laiko Victor V. , Yakshin Mikhail A. , Prasad Coorg R. , Doroshenko Vladimir M.
Published: August 2004

An atmospheric pressure (AP) infrared (IR) laser ionization technique, implemented on a quadrupole ion trap mass spectrometer, was used to analyze underivatized, N‐linked oligosaccharides in solution. Experiments were conducted on an atmospheric pressure infrared ionization from solution (AP‐IRIS) ion source which differed from previous AP IR matrix‐assisted laser desorption/ionization (MALDI) interfaces in that the ion source operated in the absence of an extraction electric field with a higher power 2.94 µm IR laser. The general term ‘IRIS’ is used as the mechanism of ionization differs from that of MALDI, and is yet to be fully elucidated. The AP‐IRIS ion source demonstrated femtomole‐level sensitivity for branched oligosaccharides. AP‐IRIS showed ∼ 16 times improved sensitivity for oligomannose‐6 and the core‐fucosylated glycan M3N2F over optimal results obtainable on a AP UV‐MALDI with a 2,4,6‐trihydroxyacetophenone matrix. Comparison between IR and UV cases also showed less fragmentation in the IR spectrum for a glycan with a conserved trimannosyl core, core‐substituted with fucose. A mixture of complex, high‐mannose and sialylated glycans resulted in positive ion mass spectra with molecular ion peaks for each sugar. Tandem mass spectrometry of the sodiated molecular ions in a mixture of glycans revealed primarily glycosidic (B, Y) cleavages. The reported results show the practical utility of AP‐IRIS while the ionization mechanism is still under investigation. Copyright © 2004 John Wiley & Sons, Ltd.
Atmospheric pressure chemical ionization and atmospheric pressure photoionization for simultaneous mass spectrometric analysis of microbial respiratory ubiquinones and menaquinones
Authors: Geyer Roland , Peacock Aaron D. , White David C. , Lytle Cory , Van Berkel Gary J.
Published: August 2004

An atmospheric pressure photoionization (APPI) source and an atmospheric pressure chemical ionization (APCI) source were compared for the selective detection of microbial respiratory ubiquinone and menaquinone isoprenologues using tandem mass spectrometry. Ionization source‐ and compound mass‐dependent parameters were optimized individually for both sources, using the available quinone standards. Detection levels for the two ion sources were determined with ubiquinone‐6 (UQ6) and menaquinone‐4 (MK4, vitamin K2) standards using flow injection analysis and selected reaction monitoring (SRM). With APPI the calculated lower limit of detection (LLOD) was 1.7 fmol µl−1 for UQ6 and 2.2 fmol µl−1 for MK4 at a signal‐to‐noise ratio of 3. These LLODs were at least three times lower than with APCI. The selectivity of detection afforded by SRM detection reduced complex mixture analysis to 3 min per sample by eliminating the need for chromatographic separations. The detection method was successfully applied to quinone quantification in a variety of environmental samples and cell cultures. Adequate amounts of respiratory quinones can be extracted and quantified from samples containing as low as 2 × 107 cells. Copyright © 2004 John Wiley & Sons, Ltd.
Gas‐phase acidity of D‐glucose. A density functional theory study
Authors: Salpin Jean‐Yves , Tortajada Jeanine
Published: August 2004

The gas‐phase acidity of D‐glucopyranose was studied by means of B3LYP calculations combined with 6–31G(d,p) or 6–31+G(d,p) standard basis sets. For each anomer, deprotonation of the various primary and secondary hydroxyl groups was considered. As in solution, the anomeric hydroxyl is found to be the most acidic for both anomers, but only when the 6–31+G(d,p) basis set is used for geometry optimization. Deprotonation of the anomeric hydroxyl induces an important C(1)O endocyclic bond elongation and subsequently promotes an energetically favored ring‐opening process as attested by the very small calculated activation barriers. The results also suggest that interconversion between the various deprotonated α‐ and β‐anomers may easily occur under slightly energetic conditions. B3LYP/6–311+G(2df,2p) calculations led to the an absolute gas‐phase acidity of ΔacidGo298(α‐D‐glucose) = 1398 kJ mol−1. This estimate matches well the only experimental value available to date. Finally, this study again confirms that the use of diffuse functions on heavy atoms is necessary to describe anionic systems properly and to achieve good relative and absolute gas‐phase acidities. Copyright © 2004 John Wiley & Sons, Ltd.
Open‐access high‐resolution mass spectrometry in early drug discovery
Authors: Thomas Steven R. , Gerhard Ute
Published: August 2004

Techniques such as mass spectrometry and NMR spectroscopy form an essential part of the medicinal chemist's toolbox for characterizing and assessing the purity of new molecules. Empowering medicinal chemists to gain early insight into their reaction products has a direct impact on productivity. Devolution of cutting‐edge techniques from the specialist to the bench chemist also frees the specialist to concentrate on solving the more demanding of analytical problems. For open‐access techniques to be taken up, they must be robust and be able to handle differing sample concentrations and varying sample complexities. This paper details the implementation of high‐resolution liquid chromatography/mass spectrometry in open access to aid the medicinal chemist in characterizing desired products and identifying unexpected rearrangements, by‐products and complete unknowns. Copyright © 2004 John Wiley & Sons, Ltd.
Extraribosomal cyclic tetradepsipeptides beauverolides: profiling and modeling the fragmentation pathways
Authors: Jegorov Alexandr , Paizs Bela , Kuzma Marek , Zabka Martin , Landa Zdenek , Sulc Miroslav , Barrow Mark P. , Havlicek Vladimir
Published: August 2004

Profiling of cyclic tetradepsipeptides beauverolides was tested as a chemotaxonomic tool for fungal strain identification/discrimination. Two new tetradepsipeptides, beauverolides Q and R, were characterized by tandem mass spectrometry. Specific elimination of 113 atomic mass units from both protonated and sodiated molecules of beauverolides is ubiquitous for all 12 most dominant congeners evaluated in this profiling study. Reconstruction of the total ion chromatogram, according to this neutral fragment release, was used for data filtering and selectivity enhancement. Selective ring opening and fragment ion formation of beauverolide I are discussed in detail utilizing high‐level theoretical modeling of the fragmentation pathways. Copyright © 2004 John Wiley & Sons, Ltd.
Cerebrospinal fluid from patients with dementia contains increased amounts of an unknown factor
Authors: White Linda R. , Gårseth Mari , Aasly Jan , Sonnewald Ursula
Published: August 2004

Increased levels of an unidentified peak have been found in cerebrospinal fluid (CSF) from patients with Alzheimer's disease or vascular dementia compared to the level in healthy controls using proton magnetic resonance spectroscopy. No increase was found in patients with amyotrophic lateral sclerosis. Reexamination of spectra from a study published previously (Gårseth et al. [2000] J. Neurosci. Res. 60:779–782), however, shows that this peak was also elevated significantly in CSF from patients with Huntington's disease compared to that in controls. The level in patients with Parkinson's disease, where dementia develops in up to 40% of patients, was not elevated significantly compared to that in controls. To the best of our knowledge, this peak has not yet been identified and we therefore find it appropriate to temporarily designate the name “dementia associated factor” (DAF), although there is as yet no certainty that this substance is specific for these conditions. Apart from a significantly increased level of glutamine in CSF from patients with vascular dementia compared to that in controls, no other significant difference was found for any other metabolite measured in the patient groups using proton magnetic resonance spectroscopy. © 2004 Wiley‐Liss, Inc.
Activity‐dependent expression of Egr1 mRNA in somatosensory cortex of developing rats
Authors: Patra Ramesh C. , Blue Mary E. , Johnston Michael V. , Bressler Joseph , Wilson Mary Ann
Published: August 2004

The rat barrel field in somatosensory cortex is a well‐characterized model of neocortical development, with activity‐dependent and activity‐independent components. Egr1 encodes an inducible transcription factor that is required for certain forms activity‐dependent plasticity. This study examines Egr1 mRNA expression in the developing barrel field under basal conditions and after short‐term deprivation or stimulation of whiskers. Egr1 mRNA was measured with in situ hybridization at postnatal Day (P) 6, P9, P12, P15, and P21. For short‐term deprivation, whiskers were trimmed close to the skin and Egr1 mRNA was examined 3 hr later. For controlled stimulation of a single whisker, surrounding whiskers were trimmed, a wire was glued to the designated whisker, and animals were placed in an AC magnetic field pulsed at 2 Hz, 10 mT rms for 15 min. Egr1 mRNA was examined 30 min later. At P6, basal Egr1 mRNA in the barrel field was very low and was increased only slightly by stimulation (P < 0.05). At each of the later ages, there was a large increase in Egr1 mRNA in stimulated versus deprived barrels (P < 0.001). Egr1 mRNA expression after whisker stimulation increased exponentially with age through P15 (P < 0.001) and then declined between P15 and P21. The onset of Egr1 responses to whisker stimulation at P9 and the striking increase in activity‐dependent Egr1 mRNA expression in the second postnatal week suggest that this transcription factor may play a role in activity‐dependent processes that occur in this developmental period, such as maturation of barrel cortex circuitry. © 2004 Wiley‐Liss, Inc.
Elevated serotonin is involved in hyperactivity but not in the paradoxical effect of amphetamine in mice neonatally lesioned with 6‐hydroxydopamine
Authors: Avale María Elena , Nemirovsky Sergio Iván , Raisman‐Vozari Rita , Rubinstein Marcelo
Published: August 2004

The neonatal lesion with 6‐hydroxydopamine (6‐OHDA) in rodents induces juvenile hyperactivity and paradoxical hypolocomotor response to psychostimulants, in striking contrast to what is observed when similar lesions are carried out in adults. The early disruption of central dopaminergic pathways is followed by increased striatal serotonin (5‐HT) contents although the functional role of this neurodevelopmental adaptation remains unclear. The aim of the present study is to investigate the participation of this neurochemical imbalance in the main behavioral phenotypes of this model. To this end, mice received a neonatal administration of 6‐OHDA that induced an 80% striatal dopamine depletion together with 70% increase in 5‐HT. Serotoninergic hyperinnervation was evidenced further by increased [3H] citalopram autoradiographic binding and 5‐HT transporter immunohistochemistry in striatal sections. To investigate whether elevated 5‐HT was implicated in hyperactivity, we treated control and 6‐OHDA neonatally lesioned mice with the selective irreversible tryptophan hydroxylase inhibitor p‐chlorophenylalanine (PCPA) to induce 5‐HT depletion. Normalization of striatal 5‐HT in 6‐OHDA neonatally lesioned mice to control levels reversed hyperactivity to normal locomotor scores, whereas the same extent of 5‐HT depletion did not affect spontaneous locomotor activity of control mice. In turn, the paradoxical response to amphetamine in neonatal DA‐depleted mice was not prevented by PCPA treatment. Taken together, our results suggest that the increased striatal 5‐HT that follows neonatal DA depletion is involved in hyperlocomotor behavior but not in the paradoxical calming response to amphetamine observed in this mouse model. © 2004 Wiley‐Liss, Inc.
Human neural stem/progenitor cells, expanded in long‐term neurosphere culture, promote functional recovery after focal ischemia in Mongolian gerbils
Authors: Ishibashi Satoru , Sakaguchi Masanori , Kuroiwa Toshihiko , Yamasaki Mami , Kanemura Yonehiro , Shizuko Ichinose , Shimazaki Takuya , Onodera Masafumi , Okano Hideyuki , Mizusawa Hidehiro
Published: August 2004

Transplantation of human neural stem cells (NSCs) is a promising potential therapy for neurologic dysfunctions after the hyperacute stage of stroke in humans, but large amounts of human NSCs must be expanded in long‐term culture for such therapy. To determine their possible therapeutic potential for human stroke, human fetal neural stem/progenitor cells (NSPCs) (i.e., neurosphere‐forming cells) were isolated originally from forebrain tissues of one human fetus, and expanded in long‐term neurosphere culture (exceeding 24 weeks), then xenografted into the lesioned areas in the brains of Mongolian gerbils 4 days after focal ischemia. Sensorimotor and cognitive functions were evaluated during the 4 weeks after transplantation. The total infarction volume in the NSPC‐grafted animals was significantly lower than that in controls. Approximately 8% of the grafted NSPCs survived, mainly in areas of selective neuronal death, and were costained with antibodies against neuronal nuclei antibody (NeuN), microtubule associated protein (MAP‐2), glial fibrillary acidic protein (GFAP), and anti‐2′3′ cyclic nucleotide 3′‐phosphodiesterase (CNPase). Synaptic structures between NSPCs‐derived neurons and host neurons were observed. Furthermore, gradual improvement of neurologic functions was observed clearly in the NSPC‐grafted animals, compared to that in controls. Human NSPCs, even from long‐term culture, remarkably improved neurologic functions after focal ischemia in the Mongolian gerbil, and maintained their abilities to migrate around the infarction, differentiate into mature neurons, and form synapses with host neuronal circuits. These results indicate that in vitro‐expanded human neurosphere cells are a potential source for transplantable material for treatment of stroke. © 2004 Wiley‐Liss, Inc.
5‐HT1A, 5‐HT2, and GABAB receptors interact to modulate neurotransmitter release probability in layer 2/3 somatosensory rat cortex as evaluated by the paired pulse protocol
Authors: Torres‐Escalante José L. , Barral Jaime A. , Ibarra‐Villa María D. , Pérez‐Burgos Azucena , Góngora‐Alfaro José L. , Pineda Juan C.
Published: August 2004

Activation of γ‐aminobutyric acid B (GABAB) and 5‐hydroxytryptamine (5‐HT) receptors produces presynaptic inhibition at glutamatergic terminals in the rat neocortex. To evaluate interactions between these metabotropic receptors, field potentials were recorded in layer 2/3 of somatosensory cortex. In addition, the paired pulse (PP) protocol was used to measure changes in the ratio of the second/first extracellular synaptic potentials (S2/S1 ratio) as an index of glutamate release probability in the area. Lowering extracellular [Ca2+]o to 0.5 mM, increased the S2/S1 ratio by 318 ± 134%. 5‐HT (1 μM) increased the S2/S1 ratio by 61 ± 15%. In presence of the GABAA antagonist bicuculline (10 μM), 5‐HT increased the S2/S1 ratio by 98 ± 15%. This effect did not desensitize after two consecutive applications of the amine, and was dose dependent in the concentration range between 0.03–1 μM (EC50 = 2.36 × 10−7 mol/L). The increase of S2/S1 ratio induced by 5‐HT (1 μM) was blocked reversibly by the 5‐HT1A antagonist NAN‐190 (10–30 μM), but was unaffected by the selective GABAB antagonist CGP 52432 (1 μM). The action of 5‐HT was mimicked by the 5‐HT1A/7 agonist 8OH‐DPAT (10 μM), increasing the S2/S1 ratio by 84 ± 2%, a response that was unaffected by the 5‐HT2/7 antagonist ritanserin (2 μM). The 5‐HT1B agonist CP93129 (10 μM) had no effect. The GABAB agonist baclofen (1 μM) increased the S2/S1 ratio up to 308 ± 33%, which is similar to that produced by low [Ca2+]o. When the effect of baclofen was maximal, application of 5‐HT (1 μM) reversed the S2/S1 ratio back to 78 ± 27%, a result that was blocked by the 5‐HT2/7 antagonist ritanserin (100 nM). Notably, the interaction between the GABAB agonist and 5‐HT was order dependent, because enhancement of the S2/S1 ratio elicited by baclofen was not inhibited if 5‐HT was applied first. These results suggest a complex interaction between GABAB, 5‐HT1A, and 5‐HT2 receptors in layer 2/3 of rat somatosensory cortex. Activation of GABAB receptors induces PP facilitation (inhibits glutamate release) more efficiently than does activation of 5‐HT1A receptors. When the effect of GABAB receptor activation is maximal, however, the influence of 5‐HT changes to the opposite direction, inhibiting PP facilitation (increasing glutamate release) through activation of 5‐HT2 receptors. © 2004 Wiley‐Liss, Inc.
Spatial changes of soil solution and mineral composition in the rhizosphere of Norway‐spruce seedlings colonized by Piloderma croceum
Authors: Arocena Joselito M. , Göttlein Axel , Raidl Stefan
Published: August 2004

Ectomycorrhizae (ECM) or the root‐fungal association in forest ecosystems provide a unique soil microenvironment where soil properties and processes differ from the bulk soil. In this study, we would like to better understand the role of ECM systems in mineral weathering and its implications to soil formation and nutrient cycling in forest ecosystems. Specifically, we would like to document the spatial variations in the composition of soil solution and mineralogy of the rhizosphere as influenced by the ECM of Norway spruce + Piloderma croceum. Two‐month‐old seedlings of Norway spruce (control and colonized by P. croceum) were cultivated in special rhizotrons designed to allow spatial collection of soil solution. We used A and C horizons of a Dystric Cambisol collected from Höglwald forest near Munich. Micro suction cups (5 mm x 1mm) were installed in colonized and control rhizotrons, and soil solution was collected from September to November 2000. Our results show that the concentrations of NH$_4^+$, Ca2+, and Mg2+ in the soil solution were lower in <1.0 cm than in >3.0 cm distance from the roots of Norway spruce, due to the possible range of influence of Piloderma mycelium reaching about 2–3 cm from the surface of the mycorrhizal root. In the rhizotron with soil from the A horizon, a higher phosphorus content in Piloderma‐colonized seedlings was observed. X‐ray diffraction data indicate that chlorite and possibly mica are being transformed to 2:1‐expanding clay minerals (probably smectite) within <1.0 cm distance from roots. The spatial variations in soil solution composition and mineral transformation are likely to be due to Piloderma colonization and concentrated mycelial growth within <1.0 cm distance from the roots. This is also evident in more intricate growth of mycelia on surfaces of micaceous minerals as compared to quartz. We assume that Piloderma modifies soil solution and mineralogy through acquisition of essential elements for its own survival and/or for the uptake by plant roots. However, the presence of spontaneous infection with wildtype ECM in the control plots may have altered the influence of Piloderma and must be taken into consideration when interpreting our results.
Temperature functions of the rate coefficients of net N mineralization in sandy arable soils. Part II. Evaluation via field mineralization measurements
Authors: Heumann Sabine , Böttcher Jürgen
Published: August 2004

The aim of this study was to evaluate experimentally derived temperature functions for the rate coefficients of net N mineralization in sandy arable soils from NW Germany via field measurements. In part I of this paper (Heumann and Böttcher, 2004), different temperature functions for the rate coefficients of a two‐pool first‐order kinetic equation were derived by long‐term laboratory incubations at 3°C to 35°C. In this paper, field net N mineralization during winter of 25 plots was measured in undisturbed soil columns with a diameter of 20 cm to the depth of the Ap horizon. Mean simulated net N mineralization with the most adequate multiple functions corresponded also best with the mean of the measured values despite of an overestimation of about 10%. Distinctly larger deviations under use of other temperature functions (Arrhenius, Q10) were directly related to their deviations from mean, experimentally derived rate coefficients. Simulated net N mineralization in the soil columns was significantly correlated with measured values, regardless of the temperature functions. Yet the goodness of fit was generally relatively low due to the spatial variability of measured net N mineralization within replicate soil columns, although the mean CV (38%) was by far not extraordinary. The pool of slowly mineralizable N contributed considerably to net N mineralization during four to five winter months, on an average 10.0 kg N ha–1, about one third of total simulated N mineralization. Sometimes, it contributed even 21.3 kg N ha–1, which is almost sufficient to reach the EU drinking‐water limit for nitrate in these soils. Simulations with widely used functions that were once derived from loess soils overestimated mineralization from pool Nslow in the studied sandy arable soils by a factor of two.
Plant availability and leaching of (heavy) metals from ammonium‐, calcium‐, carbohydrate‐, and citric acid‐treated uranium‐mine‐dump soil
Authors: Gramss Gerhard , Voigt Klaus‐Dieter , Bergmann Hans
Published: August 2004

Remediation of an uranium‐mine soil from Settendorf (East Germany) includes phytoextraction under conditions which make its heavy metals more plant‐available but less leachable. A second way is active inhibition of heavy metal uptake by the plant. In a pot trial with Chinese cabbage (Brassica chinensis L.), planted and unplanted soil samples were daily irrigated with deionized water or aqueous solutions with a total of (g (kg soil)–1) CaCl2 (0.26 Ca), NH4Cl (1.39), casein, sucrose, citric acid (13), and an extract of rape (B. napus L.) shoots (13 DW) in a phytotron for 26 d. Water‐irrigated plants were also treated with a 50 mM citric acid solution (10.5 g (kg soil)–1) 6 and 7 d prior to harvesting. Total elements in plant tissue and soluble elements in aqueous extracts from control and postharvest soils were determined by ICP‐AES. Supplements of NH$_4^+$, and the NH$_4^+$‐generating casein and rape extract reduced soil pH during nitrification, and increased plant uptake of Cd, Cu, Ni, and Zn. Citric acid at 50 mM adjusted soil to pH 4.5–6.0 and enhanced uptake of all elements. Long‐term application of sucrose and citric acid increased pH and inhibited uptake of Cd, Cr, Cu, Ni, and Zn. Contemporarily, leaching of heavy metals and humic substances was lowest with Ca and NH$_4^+$ and highest with sucrose and citric acid amendments. It is concluded that Chinese cabbage grown for chelate‐assisted phytoextraction should be supplied with Ca and NH$_4^+$ to obtain a high plant biomass on soil with a low hazard of leaching. Metal uptake should be stimulated by application of chelator 7 d prior to harvesting. Undesired uptake of heavy metals by Chinese cabbage determined as food should be inhibited with carbohydrate amendments. Long‐term application of NH$_4^+$ or chelator, which reduces the solubility of certain elements but increases their uptake moderately, is recommended as a tool for continuous phytoextraction technologies.
Humusveränderungen nach Einbringung von Buche und Eiche in Kiefernreinbestände
Authors: Prietzel Jörg
Published: August 2004

In 16 älteren bayerischen Kiefernreinbeständen, die hinsichtlich Höhenlage, Klima, geologischem Ausgangssubstrat und Bodentyp eine breite Standortspalette umfassen, wurden die Auswirkungen einer vor 16 bis 83 Jahren erfolgten Einbringung von Laubholz (Eiche – Quercus petraea/robur; Buche – Fagus sylvatica) auf die Humusform und chemische Kenngrößen der Oh‐Lage (pH‐Wert, Basensättigung, C:N‐Verhältnis) untersucht. Die Bucheneinbringung führte in fast allen Beständen zu einer deutlichen, i. d. R. statistisch signifikanten Verbesserung der Humusform. Die stärksten Verbesserungen wurden für die ungünstigsten, biologisch inaktivsten Humusformen beobachtet. Der Humusformenwandel ging fast ausnahmslos mit einem signifikanten Anstieg des pH‐Werts und der Basensättigung sowie einer signifikanten Verengung des C:N‐Verhältnisses in der Oh‐Lage einher; auf besonders N‐armen Standorten mit C:N‐Verhältnissen über 30 blieb diese Verengung allerdings oftmals aus. Im Gegensatz zur Buche führte die Einbringung von Eiche zu einer systematischen Veränderung weder der Humusform noch des pH‐Werts oder der Basensättigung der Oh‐Lage. Trotz der unter den Buchenvoranbauten beobachteten strukturellen Verbesserung des Auflagehumus hin zu biologisch aktiveren Humusformen führte die Laubholzeinbringung nicht zu einer systematischen Veränderung der Mächtigkeit und Masse der organischen Auflage. Generell verringerten sich die Massen der Of‐Lagen; jene der Oh‐Lagen stiegen in gleichem Maße an. Im Mittel führte die Laubholzeinbringung in Kiefernreinbestände zu einem Rückgang des Corg‐Vorrats in der Humusauflage um 8 %. Der Corg‐Vorrat im oberen Mineralboden stieg nach Laubholzeinbringung im Durchschnitt um 9 % an. Auf 35 % der untersuchten Standorte stiegen die Corg‐Vorräte im Oberboden (Humusauflage und oberste 10 cm des Mineralbodens) nach Laubholzeinbringung um 5 bis 18 % an, auf 30 % der Standorte blieben sie mehr oder weniger konstant (Veränderungen kleiner als ±5 %), und auf 35 % der Standorte gingen sie um 5 bis 36 % zurück. Im Mittel aller Standorte nahm der Corg‐Vorrat im Oberboden nach Laubholzeinbringung um 5 % ab. Die Bucheneinbringung in Kiefernreinbestände führte zu einer ökologisch vorteilhaften Verlagerung von organischem Kohlenstoff aus der Humusauflage in den oberen Mineralboden. Sie stellt somit eine auf vielen Standorten Erfolg versprechende, mit geringen Nebenwirkungen (Humusschwund, CO2‐Emission, Verlust von Wasser‐ und Nährstoffspeichern) behaftete und nachhaltige waldbauliche Maßnahme zur Rehabilitation und biologischen Aktivierung versauerter, an Nährstoffen verarmter Oberböden dar.
Spatial distribution of earthworms [Lumbricidae] in recultivated soils of the Rhenish lignite‐mining area, Germany
Authors: Fründ Heinz‐Christian , Egbert Ellen , Dumbeck Gerhard
Published: August 2004

The spatial distribution of earthworms was studied by means of combined formalin expulsion and hand sorting in three arable fields of the Rhenish lignite‐mining area that differed in their recultivation age (6, 12, 24 yr). In addition, pH and the spatial distribution of penetration resistances were measured to see if they are corresponding with the distribution of earthworms. Already the 6 yr old field had a rich population of endogeic, anecic, and epigeic earthworms (119 ind. m–2, 48 g m–2, 6 species). This quantity was similar to the 24 yr old site. The 12 yr old field was only sparsely populated by earthworms (5 ind. m–2, 5 g m–2, 3 species). In the 6 yr old field, the spatial distribution pattern showed a center of maximal earthworm abundances, corresponding to the distributional pattern of penetration resistances. In the old field (24 yr), the species varied in their spatial distribution, and there was no correspondence with the distribution of penetration resistance. In general, the penetration resistance at the youngest site was clearly lower than at the two older sites. The earthworm population in the 6 yr old field can be explained by cocoons contained in the dumped material. A calculation using literature data on earthworm‐population dynamics shows that a founding population of 400–600 reproductive individuals per hectare and a continuity of favorable growth conditions during the time of soil management is necessary for the development of the situation found at the 6 yr old site in this study.
Effects of extensive land use and re‐wetting on diffuse phosphorus pollution in fen areas—results from a case study in the Drömling catchment, Germany
Authors: Rupp Holger , Meissner Ralph , Leinweber Peter
Published: August 2004

Fen‐soil cultivation in NE Germany resulted in severe peat degradation; therefore present and future management is aimed to restore degraded sites by re‐wetting. Evidence in the literature indicates that decreasing redox potentials in re‐wetted fens may result in an increased risk of diffuse water pollution with P. However, little is known about the impact of different fen‐preserving land‐management schemes on the redox potential in soil and on the P dynamics in adjacent surface water. We investigated effects of peat degradation and re‐wetting on redox potential and P mobilization on extensive grassland, re‐wetted intensive grassland, and alder swamp forest in the Drömling (Saxony‐Anhalt, Germany). The results showed that the redox potentials of peat lands were almost below the theoretical stability fields of Fe(III)‐containing minerals. The re‐wetted site was characterized by the highest concentrations of soluble reactive P (SRP) in surface water. Average SRP concentrations up to 0.36 mg l–1 indicated an increased P load. The concentration of SRP in the Ohre river, which is the central drainage channel of the Drömling catchment, significantly increased since 1996. The P concentrations of surface water were found to be indirectly correlated with the redox potentials.