bluuebunny/crossref_metadata_2025_split huggingface dataset:
Decomposition of health inequality by determinants and dimensions
Authors: Lauridsen JØrgen , Christiansen Terkel , Gundgaard Jens , Häkkinen Unto , Sintonen Harri 
Published: August 2006

AbstractThe study integrates two methodologies so that income‐related inequality in general health can be decomposed into contributions from socio‐demographic characteristics to each of the dimensions defining general health. It is found that these relative contributions vary substantially across dimensions. For policy purposes such information is valuable as it indicates at which population groups and at which aspects of health efforts to reduce inequalities in health should be targeted. Copyright © 2006 John Wiley & Sons, Ltd.
The effects of expanding patient choice of provider on waiting times: evidence from a policy experiment
Authors: Dawson Diane , Gravelle Hugh , Jacobs Rowena , Martin Stephen , Smith Peter C. 
Published: August 2006

AbstractLong waiting times for inpatient treatment in the UK National Health Service have been a source of popular and political concern, and therefore a target for policy initiatives. In the London Patient Choice Project, patients at risk of breaching inpatient waiting time targets were offered the choice of an alternative hospital with a guaranteed shorter wait. This paper develops a simple theoretical model of the effect of greater patient choice on waiting times. It then uses a difference in difference econometric methodology to estimate the impact of the London choice project on ophthalmology waiting times. In line with the model predictions, the project led to shorter average waiting times in the London region and a convergence in waiting times amongst London hospitals. Copyright © 2006 John Wiley & Sons, Ltd.
Fast rate coding in hippocampal CA3 cell ensembles
Authors: Leutgeb Stefan , Leutgeb Jill K. , Moser Edvard I. , Moser May‐Britt 
Published: August 2006

AbstractEnvironments with overlapping features are represented by distinct patterns of activity in the hippocampus, enabling information to be stored and retrieved with minimal interference. This orthogonalization of correlated inputs is thought to take place within the hippocampus itself. However, the orthogonalization process has been shown to take days to develop in CA1. This prolonged time course is in striking contrast to the fast encoding of behavioral memory by the hippocampus. To explore this apparent paradox, we asked whether orthogonalization depended on the type of remapping exhibited by the hippocampal network. We have previously distinguished two types of remapping, global remapping, which results in the activation of different assemblies of place fields, and rate remapping, which encodes differences between cue constellations by substantial changes in firing rate without a change in the place code. Global remapping has previously been shown to be expressed immediately at novel locations. Here we asked if rate remapping follows a slower time course. Ensemble activity was recorded simultaneously from CA3 and CA1 in rats exposed to two similar, novel environments. It was found that rate changes in response to novel sensory cue configurations can form immediately, just as during global remapping, in particular in CA3. The fast encoding of both spatial and nonspatial information in CA3 is consistent with a role for the autoassociative CA3 circuitry in the acquisition and expression of episodic memories. © 2006 Wiley‐Liss, Inc.
Dissociating the past from the present in the activity of place cells
Authors: de Hoz Livia , Wood Emma R. 
Published: August 2006

AbstractIt has been proposed that declarative memories can be dependent on both an episodic and a semantic memory system. While the semantic system deals with factual information devoid of reference to its acquisition, the episodic system, characterized by mental time travel, deals with the unique past experience in which an event took place. Episodic memory is characteristically hippocampus‐dependent. Place cells are recorded from the hippocampus of rodents and their firing reflects many of the key characteristics of episodic memory. For example, they encode information about “what” happens “where,” as well as temporal information. However, when these features are expressed during an animal's behavior, the neuronal activity could merely be categorizing the present situation and could therefore reflect semantic memory rather than episodic memory. We propose that mental time travel is the key feature of episodic memory and that it should take a form, in the awake animal, similar to the replay of behavioral patterns of activity that has been observed in hippocampus during sleep. Using tasks designed to evoke episodic memory, one should be able to see memory reactivation of behaviorally relevant sequences of activity in the awake animal while recording from hippocampus and other cortical structures. © 2006 Wiley‐Liss, Inc.
Water quality andCryptosporidiumdistribution in an upland water supply catchment, Cumbria, UK
Authors: Sturdee A. , Foster I. , Bodley‐Tickell A. T. , Archer A. 
Published: August 2006

AbstractFour micro‐catchment (MC) areas were identified to represent the main terrain types of a remote, sparsely populated upland valley catchment of 18 km2in Cumbria, UK. These were improved land with good grazing (IB), steeply sloping land with rough grazing (SG), wet moorland with sparse grazing (WM) and enclosed woodland that excluded livestock and deer (EW). Each MC contained the origin of a small stream that flowed into Swindale Beck, the river draining the valley. The water quality during the 14‐month study, as judged by chemical and physical parameters, was excellent, but it could not be regarded as pristine because of the frequent presence ofCryptosporidiumoocysts arising from livestock and wild mammal faeces. Oocysts (0·2–5·6 l−1) detected by genus‐specific immunofluorescent antibody were found in 32% of 188 water samples tested: ranking order EW 44%, IB 34%, Beck 30%, SG and WM 26%. Similarly, oocysts were identified in 9·5% of 1730 faecal samples. Small wild mammals (28%), calves (15·7%) and lambs (8·1%) were the dominant sources, whereas adult livestock (1·8%) and large wild mammals (4·8%) were less important. Autumn showed the highest occurrence of oocysts for both water and faecal samples. No hydrological controls were found to have a significant impact on the occurrence or concentration of oocysts in the main river or in the MCs, suggesting that their presence is controlled by seasonal changes in pathogen prevalence in the animal reservoir. Copyright © 2006 John Wiley & Sons, Ltd.
Hydrological importance of an unusual hazard in a mountainous basin: flood and landslide
Authors: Haritashya Umesh K. , Singh Pratap , Kumar Naresh , Singh Yatveer 
Published: August 2006

AbstractThe Bhagirathi River, a proglacial melt water stream of the Gangotri Glacier, is the principal source of the Ganges river system. The upper part of the basin lies in the high altitude region of the Garhwal Himalayas and is extensively covered by glaciers. We provide hydro‐meteorological insight into a severe storm that produced unusual high rains in June 2000 in the uppermost part of the Bhagirathi River. This storm was concentrated upstream of Gangotri town and triggered landslides/rockslides at several locations between the glacier snout and Gangotri town. One of the major rockslides blocked the Bhagirathi River at Bhujbas, about 3 km downstream of the Gangotri Glacier snout, creating an artificial lake at this location. High stream flow in the river, generated by rapid runoff response from mountain slopes along with melt runoff from the glacier, quickly increased the level of water stored in the artificial lake. Daily rainfall in this region rarely exceeds 10 mm, while total rainfall during this 6‐day storm was 131·5 mm. This unusual rain event occurred during the tourist season in June, consequently trapping a large number of tourists and vendors in this area. Sudden release of stored water generated floods that created havoc downstream of the artificially created lake. This paper presents the hydrological and meteorological information related to such an unusual and devastating event observed in the high altitude region of the Himalayas. Copyright © 2006 John Wiley & Sons, Ltd.
In vivobiostability of shore 55D polyether polyurethanes with and without fluoropolymer surface modifying endgroups
Authors: Ward Robert , Anderson James , McVenes Rick , Stokes Ken 
Published: August 2006

AbstractPolyether polyurethanes are subject to autooxidation and environmental stress cracking (ESC) because of interactions with lysosomal oxygen‐free radicals. Oxidation can also be catalyzed by and caused by direct (redox) reaction with transition metal ions (metal ion oxidation, MIO). The source of the ions is corrosion of metallic parts within an implanted device. A previous study on a Shore 80A polyether polyurethane modified with fluoropolymer surface modifying end groups demonstrated improved biostability over unmodified controls. We predicted that this could be extrapolated to the inherently more biostable Shore 55D version (E55DF). While it is difficult to demonstrate significant biodegradation in the harder polymers within a reasonable time frame, we did see excellent biologic autooxidation and ESC resistance for both E55DF and its unmodified Shore 55D (P55D) control. E55DF was slightly, but significantly more resistant to MIO than P55D. This was particularly evident in molecular weight distributions with P55D exhibiting a large decrease in number average molecular weight compared to no change for E55DF. Both were markedly superior to the softer Shore 80A control. It does appear that one can extrapolate acceleratedin vivobiostability results with the softer polymers to their harder analogues. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
In vivo biostability of polyether polyurethanes with fluoropolymer surface modifying endgroups: Resistance to biologic oxidation and stress cracking
Authors: Ward Bob , Anderson James , McVenes Rick , Stokes Ken 
Published: August 2006

AbstractA series of Shore 80A polyether polyurethanes were synthesized with from 0 to 6% fluoropolymer surface modifying endgroups (SME) to provide the bulk properties of the polyurethane with the surface properties of the fluoropolymer. It was theorized that the fluoropolymer would migrate to the surface, forming a monolayer barrier to the oxidants and crack‐driving agents released by macrophages and foreign body giant cells in vivo. In a 12‐week biostability screening test, samples strained to 400% elongation appeared to be highly stable. In a longer‐term study, the fluoropolymer SME significantly delayed, but did not completely prevent the onset of microcracking and the development of environmental stress cracking in strained samples. Even so, the 4 and 6% SME polymers explanted at 2 years performed significantly better than the control. FTIR analysis did not correlate with SME concentration, but increased hydrogen‐bonding index and loss of aliphatic ether (autoxidation) did correlate with the visual appearance and density of microcracks. Significant molecular weight reductions were seen for the SME‐free control, but were small (within instrumental error) for the polymers with SME. The use of fluoropolymer as a SME does appear to be warranted as a means to improve polyether polyurethane biostability. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Osteoprecursor cell response to strontium‐containing hydroxyapatite ceramics
Authors: Xue Weichang , Moore Jessica L. , Hosick Howard L. , Bose Susmita , Bandyopadhyay Amit , Lu W.W. , Cheung Kenneth M.C. , Luk Keith D.K. 
Published: August 2006

AbstractThe objective of this study was to investigate the in vitro bioactivity of strontium‐containing hydroxyapatite (Sr‐HA), and its effect on cellular attachment, proliferation, and differentiation. The effect of Sr‐HA has been compared with that of hydroxyapatite (HA), which is widely used in orthopedics and dentistry. Sr‐HA ceramic containing 10 mol % was prepared. The bioactivity of Sr‐HA was evaluated in vitro by immersion in simulated body fluid (SBF). After immersion in SBF, Sr‐HA exhibited greater ability to induce apatite precipitation on its surface than did HA. The possible effects on cell behavior of Sr‐HA were examined by culturing osteoprecursor cells (OPC1) on materials surfaces. Cell shape and cell‐material interactions were analyzed by scanning electron microscope (SEM) and the MTT assay was used to determine cell proliferation on samples. When compared with HA, Sr‐HA promoted better OPC1 cell attachment and proliferation, and showed no deleterious effects on extracellular matrix formation and mineralization. Confocal scanning microscopy was used to assess the expression of specific osteoblast proteins: alkaline phosphatase (ALP) and osteopontin (OPN). The results obtained indicate that the presence of Sr stimulates OPC1 cell differentiation, and enhances ALP and OPN expression. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
In vitro differentiation of hepatic progenitor cells from mouse embryonic stem cells induced by sodium butyrate
Authors: Zhou Qing‐Jun , Xiang Li‐Xin , Shao Jian‐Zhong , Hu Ruo‐Zhen , Lu Yong‐Liang , Yao Hang , Dai Li‐Cheng 
Published: August 2006

AbstractRecently it was shown that embryonic stem (ES) cells could differentiate into hepatocytes both in vitro and in vivo, however, prospective hepatic progenitor cells have not yet been isolated and characterized from ES cells. Here we presented a novel 4‐step procedure for the differentiation of mouse ES cells into hepatic progenitor cells and then hepatocytes. The differentiated hepatocytes were identified by morphological, biochemical, and functional analyses. The hepatic progenitor cells were isolated from the cultures after the withdrawal of sodium butyrate, which was characterized by scant cytoplasm, ovoid nuclei, the ability of rapid proliferation, expression of a series of hepatic progenitor cell markers, and the potential of differentiation into hepatocytes and bile duct‐like cells under the proper conditions that favor hepatocyte and bile epithelial differentiation. The differentiation of hepatocytes from hepatic progenitor cells was characterized by a number of hepatic cell markers including albumin secretion, upregulated transcription of glucose‐6‐phophatase and tyrosine aminotransferase, and functional phenotypes such as glycogen storage. The results from our experiments demonstrated that ES cells could differentiate into a novel bipotential hepatic progenitor cell and mature into hepatocytes with typical morphological, phenotypic and functional characteristics, which provides an useful model for the studies of key events during early liver development and a potential source of transplantable cells for cell‐replacement therapies. J. Cell. Biochem. 100: 29–42, 2007. © 2006 Wiley‐Liss, Inc.
Chondrocyte apoptosis is not essential for cartilage calcification: Evidence from an in vitro avian model
Authors: Pourmand Eric P. , Binderman Itzhak , Doty Stephen B. , Kudryashov Valery , Boskey Adele L. 
Published: August 2006

AbstractThe calcification of cartilage is an essential step in the process of normal bone growth through endochondral ossification. Chondrocyte apoptosis is generally observed prior to the transition of calcified cartilage to bone. There are, however, contradictory reports in the literature as to whether chondrocyte apoptosis is a precursor to cartilage calcification, a co‐event, or occurs after calcification. The purpose of this study was to test the hypothesis that chondrocyte apoptosis is not a requirement for initial calcification using a cell culture system that mimics endochondral ossification. Mesenchymal stem cells harvested from Stages 21–23 chick limb buds were plated as micro‐mass cultures in the presence of 4 mM inorganic phosphate (mineralizing conditions). The cultures were treated with either an apoptosis inhibitor or stimulator and compared to un‐treated controls before the start of calcification on day 7. Inhibition of apoptosis with the caspase inhibitor Z‐Val‐Ala‐Asp (O‐Me)‐fluoromethylketone (Z‐VAD‐fmk) caused no decreases in calcification as indicated by radioactive calcium uptake or Fourier transform infrared (FT‐IR) analysis of mineral properties. When apoptosis was inhibited, the cultures showed more robust histological features (including more intense staining for proteoglycans, and more intact cells within the nodules as well as along the periphery of the cells as compared to untreated controls), more proliferation as noted by bromo‐deoxyuridine (BrdU) labeling, decreases in terminal deoxynucleotidyl transferase (Tdt)‐mediated dUTP nick‐end labeling (TUNEL) staining, and fewer apoptotic bodies in electron microscopy. Stimulation of apoptosis with 40–120 nM staurosporine prior to the onset of calcification resulted in inhibition of calcium accretion, with the extent of total calcium uptake significantly decreased, the amount of matrix deposition impaired, and the formation of abnormal mineral crystals. These results indicate that chondrocyte apoptosis is not a pre‐requisite for calcification in this culture system. J. Cell. Biochem. 100: 43–57, 2007. © 2006 Wiley‐Liss, Inc.
Insulin‐like growth factors induce apoptosis as well as proliferation in LIM 1215 colon cancer cells
Authors: Fu Ping , Thompson Julian A. , Leeding Kerri S. , Bach Leon A. 
Published: August 2006

AbstractThe insulin‐like growth factor (IGF) system plays an important role in cell proliferation and survival. However, more recently, a small number of studies have shown that IGFs induce apoptosis in some cells. Our initial studies showed this occurred in LIM 1215 colon cancer cells but not RD rhabdomyosarcoma cells. IGFs induced both proliferation and apoptosis in LIM 1215 cells, and the induction of apoptosis was dose‐dependent. [R54, R55]IGF‐II, which binds to the IGF‐I receptor with normal affinity but does not bind to the IGF‐II receptor, induced apoptosis to the same extent as IGF‐II, whereas [L27]IGF‐II, which binds to the IGF‐I receptor with 1000‐fold reduced affinity, had no effect on apoptosis. These results suggest that the IGF‐I receptor is involved in induction of apoptosis. Western blot analyses demonstrated that Akt and Erk1/2 were constitutively activated in RD cells. In contrast, phosphorylation of Akt and Erk1/2 were transient and basal expression of Akt protein was lower in LIM 1215 cells. Analysis of apoptosis‐related proteins showed that IGFs decreased pro‐caspase‐3 levels and increased expression of pro‐apoptotic Bad in LIM 1215 cells. IGFs co‐activate proliferative and apoptotic pathways in LIM 1215 cells, which may contribute to increased cell turnover. Since high turnover correlates with poor prognosis in colorectal cancer, this study provides further evidence for the role of the IGF system in its progression. J. Cell. Biochem. 100: 58–68, 2007. © 2006 Wiley‐Liss, Inc.
Nuclear localization of liver X receptor α and β is differentially regulated
Authors: Prüfer Kirsten , Boudreaux Jeanne 
Published: August 2006

AbstractActivity of nuclear receptors is regulated by their nuclear localization. Liver X receptors (LXR) α and β are nuclear receptors that regulate transcription of genes for cholesterol metabolism, cholesterol transport, and lipogenesis. While LXR α and β are very similar in structure and exhibit similar ligand binding properties, their physiological roles are quite different. Since the LXRs fall into a class of receptors that move between the nucleus and cytoplasm, experiments were conducted to determine whether LXR α and LXR β show differences in their nuclear localization pattern. To determine the location of each receptor, cell lines stably expressing yellow fluorescent protein (YFP) chimeras with either LXR α or LXR β were examined. Retention in the nucleus of the chimeric proteins in the presence or absence of ligands was assessed using fluorescence microscopy coupled with digitonin permeabilization assays. Surprisingly, differences were found between LXR α and LXR β. Whereas unliganded LXR α was retained in the nucleus, unliganded LXR β was partially exported. Mutations were then introduced into putative nuclear localization sequences (NLS) to determine which sequences are important for nuclear localization and function. Mutation in one such sequence abolished nuclear localization of LXR α, whereas the analogous change in LXR β had a much less dramatic effect. Mutations in analogous putative NLS also differentially affected transcriptional activation by LXR α and LXR β. These data demonstrate for the first time that nuclear retention and localization as well as function of LXR α and LXR β are differentially regulated. J. Cell. Biochem. 100: 69–85, 2007. © 2006 Wiley‐Liss, Inc.
Limited plasticity of mesenchymal stem cells cocultured with adult cardiomyocytes
Authors: Gallo Maria Pia , Ramella Roberta , Alloatti Giuseppe , Penna Claudia , Pagliaro Pasquale , Marcantoni Andrea , Bonafé Francesca , Losano Gianni , Levi Renzo 
Published: August 2006

AbstractIn order to assess, in a controlled in vitro model, the differentiation potential of adult bone marrow derived stem cells we have developed a coculture procedure using adult rat cardiomyocytes and mesenchymal stem cells (MSCs) from transgenic GFP positive rats. We investigated in the cocultured MSCs the time course of cellular processes that are difficult to monitor in in vivo experiments. Adult rat cardiomyocytes and adult rat MSCs were cocultured for up to 7 days and analyzed by confocal microscopy. Several markers were studied by immunofluorescence technique. The fluorescent ST‐BODIPY‐Dihydropyridine was used to label calcium channels in living cells. Intracellular calcium was monitored with the fluorescent probe X‐Rhod‐1. Immunofluorescence experiments showed the presence of connexin‐43 between cardiomyocytes and MSCs and between MSCs, while no sarcomeric structures were observed at any time of the coculture. We looked at the expression of calcium channels and development of voltage‐dependent calcium signaling in cocultured MSCs. MSCs showed a time‐dependent increase of labeling of ST‐BODIPY‐Dihydropyridine, reaching a relatively strong level after 72 h of coculture. The treatment with a non‐fluorescent DHP, Nifedipine, completely abolished ST‐BODIPY labeling. We investigated whether depolarization could modulate intracellular calcium. Depolarization‐induced calcium transients increased in MSCs in relation to the coculture time. We conclude that MSCs cocultured with adult cardiomyocytes present preliminary evidence of voltage‐dependent calcium modulation uncoupled with the development of nascent or adult myofibrils, thus showing a limited lineage specification and a low plasticity to differentiate in a full cardiomyocyte‐like phenotype. J. Cell. Biochem. 100: 86–99, 2007. © 2006 Wiley‐Liss, Inc.