bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maternal care influences neuronal survival in the hippocampus of the rat
Authors: Bredy Timothy W. , Grant Rebecca J. , Champagne Danielle L. , Meaney Michael J. 
Published: November 2003

AbstractMaternal care during the first week of postnatal life influences hippocampal development and function (Liu et al., 2000; Nature Neurosci., 3, 799–806). Offspring reared by mothers who exhibit increased levels of pup licking/grooming (LG) show increased hippocampal synaptic density and enhanced spatial learning and memory. Using 5‐bromo‐2′‐deoxyuridine (BrdU), a thymidine analogue incorporated into cells during DNA synthesis, we examined the effects of early maternal care on hippocampal cell proliferation and neuronal survival in the rat. Twenty‐four hours following injection on day 7 of life (P7) there were no differences in BrdU labelling in the offspring of high‐ compared with low‐LG mothers, suggesting no maternal effect on the rate of proliferation at this age. However, 14 and 83 days following injection (P21 and P90), the offspring of high‐LG mothers had significantly more surviving BrdU‐labelled cells and BrdU–NeuN+‐colabelled neurons in the dentate gyrus subgranular zone and granule cell layer. At P21, the offspring of high‐LG mothers showed increased protein expression of basic fibroblast growth factor and significantly decreased levels of pyknosis. These findings suggest an influence of maternal care on neuronal survival in the hippocampus. Conversely, at the same time point there was a significantly higher level of hippocampal glial fibrillary acidic protein expression in the offspring of low‐LG mothers. These findings emphasize the importance of early maternal care for hippocampal development.
Adult‐born hippocampal neurons mature into activity‐dependent responsiveness
Authors: Jessberger Sebastian , Kempermann Gerd 
Published: November 2003

AbstractThe mammalian hippocampus is a highly plastic brain structure in which new neurons are generated throughout adulthood. Do these new neurons qualitatively and quantitatively participate in the activity‐dependent gene expression after challenging the hippocampus in a learning task? Adult mice were injected with bromodeoxyuridine (BrdU) to label dividing cells and indeed, individual BrdU‐labelled new neurons expressed the immediate early gene protein (IEGp) c‐fos during the acquisition phase of the Morris water maze task to the same extend as older granule cells. To assess the responsiveness of all new neurons we also analysed the expression patterns of three IEGps (c‐fos, zif268 and Homer1A) after kainic acid (KA)‐ or pentylenetetrazol (PTZ)‐induced seizures. We found that after a maturation period of between 2 and 5 weeks a comparable ratio of adult‐generated granule cells participated in IEGp‐expression as in the population of older granule cells. Thus, new neurons appear quantitatively integrated into hippocampal circuits, suggestive of a relevant contribution to hippocampal function.
Depression of mGluR‐mediated IPSCs by 5‐HT in dopamine neurons of the rat substantia nigra pars compacta
Authors: Paolucci E. , Berretta N. , Tozzi A. , Bernardi G. , Mercuri N. B. 
Published: November 2003

AbstractDopamine neurons of the substantia nigra pars compacta receive a prominent serotonin (5‐HT) projection from the dorsal raphe nucleus and important functional interactions between the serotonergic and the dopaminergic system have been postulated. In the present report we examined the role of 5‐HT in the modulation of the metabotropic glutamate receptor‐mediated inhibitory postsynaptic current (mGluR‐IPSC) in midbrain dopamine neurons, and we found a reversible depression of this synaptic response at concentrations of 5‐HT ranging from 100 nm to 30 µm (EC50 1.06 µm). This resulted in a shift towards excitation of the overall dopamine neuron response to glutamatergic synaptic input. This effect was not because of a direct modulation of the Ca2+‐sensitive K+ conductances underlying the mGluR‐IPSC, but was associated with a decrease in the intracellular calcium signal triggered by mGluR stimulation. Similar results were obtained with α‐methyl‐5‐hydroxytryptamine and 5‐methoxytryptamine, but not with 5‐carboxamidotryptamine or 1‐(3‐chlorophenyl) piperazine. No significant depression of the mGluR‐IPSC by 5‐HT was observed in the presence of the 5‐HT2 antagonist cinanserin or the 5‐HT4 receptor antagonist RS 23597–190, whereas the 5‐HT2C antagonist RS 102221 was ineffective. Our results demonstrate a powerful inhibition of the mGluR‐IPSC by 5‐HT in midbrain dopamine neurons, most probably through stimulation of 5‐HT2A and 5‐HT4 receptors.
Non‐calyceal excitatory inputs mediate low fidelity synaptic transmission in rat auditory brainstem slices
Authors: Hamann Martine , Billups Brian , Forsythe Ian D. 
Published: November 2003

AbstractPrincipal neurons of the medial nucleus of the trapezoid body (MNTB) receive a synaptic input from a single giant calyx terminal that generates a fast‐rising, large excitatory postsynaptic current (EPSC), each of which are supra‐threshold for postsynaptic action potential generation. Here, we present evidence that MNTB principal neurons receive multiple excitatory synaptic inputs generating slow‐rising, small EPSCs that are also capable of triggering postsynaptic action potentials but are of non‐calyceal origin. Both calyceal and non‐calyceal EPSCs are mediated by α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionate (AMPA) and N‐methyl‐d‐aspartate (NMDA) receptor activation; however, the NMDA receptor‐mediated response is proportionally larger at the non‐calyceal synapses. Non‐calyceal synapses generate action potentials in MNTB principal neurons with a longer latency and a lower reliability than the large calyceal input. They constitute an alternative low fidelity synaptic input to the fast and secure relay transmission via the calyx of Held synapse.
Context‐specific acquisition of location discrimination by hippocampal place cells
Authors: Hayman Robin M. A. , Chakraborty Subhojit , Anderson Michael I. , Jeffery Kathryn J. 
Published: November 2003

AbstractThe spatially localized firing of rodent hippocampal place cells is strongly determined by the local geometry of the environment. Over time, however, the cells can acquire additional inputs, including inputs from more distal cues. This is manifest as a change in firing pattern (‘remapping’) when the new inputs are manipulated. Place cells also reorganize their firing in response to non‐geometric changes in ‘context’, such as a change in the colour or odour of the environment. The present study investigated whether the new inputs acquired by place cells in one context were still available to the cells when they expressed their altered firing patterns in a new context. We found that the acquired information did not transfer to the new context, suggesting that the context inputs and the acquired inputs must interact somewhere upstream of the place cells themselves. We present a model of one possible such interaction, and of how such an interaction could be modified by experience in a Hebbian manner, thus explaining the context specificity of the new learning.
Interest Rate Volatility Prior to Monetary Union under Alternative Pre-Switch Regimes
Authors: Wilfling Bernd 
Published: December 2003

Abstract
The volatility of interest rates is relevant for many financial applications. Under realistic assumptions the term structure of interest rate differentials provides an important predictor of the term structure of interest rates. This paper derives the term structure of differentials in a situation in which two open economies plan to enter a monetary union in the future. Two systems of floating exchange rates prior to the union are considered, namely a free-float and a managed-float regime. The volatility processes of arbitrary-term differentials under the respective pre-switch arrangements are compared. The paper elaborates the singularity of extremely short-term (i.e. instantaneous) interest rates under extensive leaning-against-the-wind interventions and discusses policy issues.
Racial Metaphors: Interpreting Sex and AIDS in Africa
Authors: Stillwaggon Eileen 
Published: November 2003

AbstractWestern preconceptions regarding African sexuality distorted early research on the social context of AIDS in Africa and limited the scope of preventive policies. Key works cited repeatedly in the social science and policy literature constructed a hypersexualized pan–African culture as the main reason for the high prevalence of HIV in sub–Saharan Africa. Africans were portrayed as the social ‘Other’ in works marked by sweeping generalizations and innuendo, rather than useful comparative data on sexual behaviour. Although biomedical studies demonstrate the role of numerous factors that influence HIV transmission among poor people, a narrowly behavioural explanation dominated the AIDS–in–Africa discourse for over a decade and still circumscribes preventive strategies in Africa and elsewhere.
Scaling up Civil Society: Donor Money, NGOs and the Pastoralist Land Rights Movement in Tanzania
Authors: Igoe Jim 
Published: November 2003

AbstractTanzania's pastoralist land rights movement began with local resistance to the alienation of traditional grazing lands in Maasai and Barabaig communities. While these community–based social movements were conducted through institutions and relationships that local people knew and understood, they were not co–ordinated in a comprehensive fashion and their initial effectiveness was limited. With the advent of liberalization in the mid–1980s, they began to gain institutional legitimacy through the registration of pastoralist Non–Governmental Organizations (NGOs). Registered NGOs provided community leaders with a formal mechanism for co–ordinating local land movements and for advocating for land rights at the international level. The connections of pastoralist NGOs to disenfranchised communities, and their incorporation of traditional cultural institutions into modern institutional structures, resonated with the desires of international donors to support civil society and to create an effective public sphere in Tanzania, making these NGOs an attractive focus for donor funding. In spite of their good intentions, however, donors frequently overlooked the institutional impacts of their assistance on the pastoralist land rights movement and the formation of civil society in pastoralist communities. NGO leaders have become less accountable to their constituent communities, and the movement itself has lost momentum as its energies have been diverted into activities that can be justified in donor funding reports. A political movement geared towards specific outcomes has been transformed into group of apolitical institutions geared toward the process of donor funding cycles.
Agricultural Transformation and the Politics of Hydrology in Northern Thailand
Authors: Walker Andrew 
Published: November 2003

AbstractTensions over water resources in upland areas of northern Thailand are often attributed to reductions in water supply caused by forest clearing. This article argues that the hydrological evidence for such reductions in supply is very weak and that, rather, the key hydrological issue in upland catchments is a significant increase in water demand, especially during the dry season. The arguments are illustrated with a detailed examination of the Mae Uam catchment, located in Chiang Mai province, where the development of dry–season soybean cultivation appears to have tested the hydrological limit of the catchment, and even exceeded this limit in drier years. The author argues that a shift in focus from water supply to water demand has fundamentally important political implications. As long as the focus of public debate is on water supply, the regulatory focus will be on those resident in the forested upland areas that are seen as being crucial in securing downstream flows. But if the water management focus is shifted to water demand, then regulatory attention must shift to the diverse sources of demand that exist throughout the hydrological system.
Mid‐Level Officials as Policy Makers: Anti‐Corporatist Policy Change in the Swedish Employers’ Confederation, 1982–1985
Authors: Johansson Joakim 
Published: November 2003

The aim of the article is to provide an account of the process of policy change in the Swedish Employers’ Confederation (SAF), 1982–1985, implying a shift from a pro‐corporatist to an anti‐corporatist view on interest representation within decision‐making bodies of public authorities in the sphere of labour market and working life issues. In this respect, the study throws new light on the fall of the ‘Swedish model’ of industrial relations, by stressing the central policy‐making role of a few individuals occupying their positions in the mid level, rather than in the leadership level, of the huge SAF hierarchy.Given the formal structure of SAF and its statutes, SAF seems to be the least likely organisation to show signs of policy making in the mid level. Therefore, the case study also contributes to the general discourse about policy making in organisations, foremost by challenging mainstream rational choice theory assumptions of the role of the formal leadership in processes of policy change.Being based on studies in the archives of SAF, the article reveals the mechanisms explaining why a few mid‐level officials were successful in anchoring a minority standpoint into the basically ‘model‐friendly’ leadership of SAF. The argument put forward is that the key to an understanding of this case of minority influence is to consider the mid‐level officials’ strategic use of different kinds of information‐based persuasion and propaganda techniques. In fact, the policy‐making mid‐level officials belonged to a specific activist subgroup within SAF with its main base in SAF's department of information.
Working together: supporting projects through action learning*
Authors: Booth Andrew , Sutton Anthea , Falzon Louise 
Published: November 2003

AbstractRecent years have seen tremendous growth in knowledge management projects within the NHS. Project staff must acquire rapidly a wide range of task‐related skills. Conventional training courses may be inappropriately timed or unavailable to project staff. Action learning provides a group‐based means of meeting skills deficits associated with project management and delivery. This paper describes an action learning set for project staff on five knowledge management projects within Trent Region. A brief evaluation aimed to identify most and least useful and most and least enjoyable features of the action learning set. Comments on the facilitation and the content of the action learning sessions are analysed. Action learning is feasible in meeting the training needs of project staff. It may also provide a means of meeting the shared learning needs of communities of practice within a virtual environment. Knowledge management does not merely involve management and delivery within innovative projects but also requires exploiting shared learning across projects.
In vitro effects of 2‐methoxyestradiol on canine tumour cells
Authors: Marr A. K. , Thamm D. H. , Kurzman I. D. , Vail D. M. , MacEwen E. G. 
Published: November 2003

AbstractThe in vitro antiproliferative, apoptotic and cell‐cycle effects of 2‐methoxyestradiol (2ME2), an endogenous oestrogen metabolite, were investigated using a variety of canine tumour cell lines. The cells were cultured under standard conditions and incubated with varying concentrations of 2ME2. Inhibition of tumour cell proliferation was evaluated using a tetrazolium‐based colorimetric assay. DNA content analysis was performed using propidium iodide staining and flow cytometry. Cytologic analysis with Leukostat staining solution and Hoechst 33342 staining and Annexin V‐fluorescein isothiocyanate (FITC) fluorescence were used to quantify cell‐cycle distribution and apoptosis induction. Tumour cell proliferation was inhibited by 50% at concentrations of 2ME2 ranging from 0.88 to 7.67 µM, depending on the cell line tested. Profound G2/M phase arrest, an increase in binucleate cells and induction of apoptosis were observed in all cell lines tested, in a dose‐dependent manner. Based on these results, this compound has potential as an agent for the treatment of canine cancer and warrants further investigation. The canine lymphoma cell line, 1771, was inhibited at concentrations that may be achievable in vivo.
The comparative biology of skeletal metastasis
Authors: Lester P. A. , Keller E. T. 
Published: November 2003

AbstractBone metastasis, a very common sequelae of cancer, is often associated with great morbidity. Understanding the biology of bone metastases may lead to therapeutic interventions to target the metastases. In addition to replacing bone marrow elements, the presence of tumour cells in bone modulates the normal bone remodelling process. Some tumours result in primarily osteolytic bone lesions, whereas others are associated with osteoblastic bone lesions. In either case, the resulting changes in the bone structure result in weakened bone that induces pain and is predisposed to fracture. The mechanisms through which cancer cells modulate bone remodelling are not clearly defined, but ongoing research using a variety of animal models will hopefully provide clues to prevent or slow the progress of bone metastases.
Pathways Leading from BarA/SirA to Motility andVirulence Gene Expression inSalmonella
Authors: Teplitski Max , Goodier Robert I. , Ahmer Brian M. M. 
Published: December 2003

ABSTRACTThebarAandsirAgenes ofSalmonellaentericaserovar Typhimurium encode a two-component sensor kinase and a response regulator, respectively. This system increases the expression of virulence genes and decreases the expression of motility genes. In this study, we examined the pathways by which SirA affects these genes. We found that the master regulator of flagellar genes,flhDC, had a positive regulatory effect on the primary regulator of intestinal virulence determinants,hilA, but thathilAhad no effect onflhDC. SirA was able to repressflhDCin ahilAmutant and activatehilAin anflhDCmutant. Therefore, although theflhDCandhilAregulatory cascades interact,sirAaffects each of them independently. A form of BarA lacking the two N-terminal membrane-spanning domains, BarA198, autophosphorylates in the presence of ATP and transfers the phosphate to purified SirA. Phosphorylated SirA was found to directly bind thehilAandhilCpromoters in gel mobility shift assays but not theflhD,fliA,hilD, andinvFpromoters. Given that the CsrA/csrBsystem is known to directly affect flagellar gene expression, we tested the hypothesis that SirA affects flagellar gene expression indirectly by regulatingcsrAorcsrB. ThesirAgene did not regulatecsrAbut did activatecsrBexpression. Consistent with these results, phosphorylated SirA was found to directly bind thecsrBpromoter but not thecsrApromoter. We propose a model in which SirA directly activates virulence expression viahilAandhilCwhile repressing the flagellar regulon indirectly viacsrB.
Role of Leukotriene B4Receptors in the Development of Atherosclerosis: Potential Mechanisms
Authors: Subbarao Krishnaprasad , Jala Venkatakrishna R. , Mathis Steven , Suttles Jill , Zacharias Wolfgang , Ahamed Jasimuddin , Ali Hydar , Tseng Michael T. , Haribabu Bodduluri 
Published: December 2003

Objective—Leukotriene B4(LTB4), a potent leukocyte chemoattractant, is known to promote several inflammatory diseases, including atherosclerosis. We sought to determine mechanisms through which LTB4modulates atherosclerosis in cell lines expressing LTB4receptors, BLT-1, and in mice deficient in BLT-1 as well as macrophage cell lines derived from BLT-1+/+and BLT-1−/−mice.Methods and Results—Analysis of global changes in gene expression induced by LTB4in rat basophilic leukemia cells (RBL-2H3) expressing the human BLT-1 showed highest-fold increase in expression of fatty acid translocase/CD36 and the chemokine MCP1/JE/CCL2 , which are critical in atherogenesis. To determine the importance of BLT-1 in atherogenesis, we crossed BLT-1-null mice with apolipoprotein (apo)-E-deficient mice, which develop severe atherosclerosis. Deletion of BLT-1 significantly reduced the lesion formation in apo-E−/−mice only during initiating stages (4 and 8 weeks) but had no effect on the lesion size in mice fed atherogenic diet for 19 weeks. Macrophage cell lines from BLT-1-deficient mice expressed the low-affinity LTB4receptor, BLT-2, and exhibited chemotaxis to LTB4.Conclusions—The effects of LTB4in atherosclerosis are likely mediated through the high-affinity BLT-1 and the low-affinity BLT-2 receptors. LTB4promotes atherosclerosis by chemo-attracting monocytes, by providing an amplification loop of monocyte chemotaxis via CCL2 production, and by converting monocytes to foam cells by enhanced expression of CD36 and fatty acid accumulation.
Defective B-cell-negative selection and terminal differentiation in the ICF syndrome
Authors: Blanco-Betancourt Carla E. , Moncla Anne , Milili Michèle , Jiang Yun Liang , Viegas-Péquignot Evani M. , Roquelaure Bertrand , Thuret Isabelle , Schiff Claudine 
Published: December 2003

AbstractImmunodeficiency, centromeric region instability, and facial anomalies (ICF) syndrome is a rare autosomal recessive disease. Mutations in the DNA methyltransferase 3B (DNMT3B) gene are responsible for most ICF cases reported. We investigated the B-cell defects associated with agammaglobulinemia in this syndrome by analyzing primary B cells from 4 ICF patients. ICF peripheral blood (PB) contains only naive B cells; memory and gut plasma cells are absent. Naive ICF B cells bear potentially autoreactive long heavy chain variable regions complementarity determining region 3's (VHCDR3's) enriched with positively charged residues, in contrast to normal PB transitional and mature B cells, indicating that negative selection is impaired in patients. Like anergic B cells in transgenic models, newly generated and immature B cells accumulate in PB. Moreover, these cells secrete immunoglobulins and exhibit increased apoptosis following in vitro activation. However, they are able to up-regulate CD86, indicating that mechanisms other than anergy participate in silencing of ICF B cells. One patient without DNMT3B mutations shows differences in immunoglobulin E (IgE) switch induction, suggesting that immunodeficiency could vary with the genetic origin of the syndrome. In this study, we determined that negative selection breakdown and peripheral B-cell maturation blockage contribute to agammaglobulinemia in the ICF syndrome. (Blood. 2004;103:2683-2690)
Mast cell–mediated inflammatory responses require the α2β1 integrin
Authors: Edelson Brian T. , Li Zhengzhi , Pappan Loretta K. , Zutter Mary M. 
Published: December 2003

AbstractAlthough the α2β1 integrin is widely expressed and has been extensively studied, it has not been previously implicated in mast cell biology. We observed that α2 integrin subunit-deficient mice exhibited markedly diminished neutrophil and interleukin-6 responses during Listeria monocytogenes– and zymosan-induced peritonitis. Since exudative neutrophils of wild-type mice expressed little α2β1 integrin, it seemed unlikely that this integrin mediated neutrophil migration directly. Here, we demonstrate constitutive α2β1 integrin expression on peritoneal mast cells. Although α2-null mice contain normal numbers of peritoneal mast cells, these α2-null cells do not support in vivo mast cell–dependent inflammatory responses. We conclude that α2β1 integrin provides a costimulatory function required for mast cell activation and cytokine production in response to infection.