bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amyloid peptide inhibits ATP release from human erythrocytes
Authors: Misiti Francesco , Orsini Federica , Clementi M. Elisabetta , Masala Daniele , Tellone Ester , Galtieri Antonio , Giardina Bruno 
Published: December 2008

The oxygen required to meet metabolic needs of all tissues is delivered by the erythrocyte, a small, flexible cell, which, in mammals, is devoid of a nucleus and mitochondria. Despite its simple appearance, this cell has an important role in its own distribution, enabling the delivery of oxygen to precisely meet localized metabolic need. When an erythrocyte enters in a hypoxic area, a signalling pathway is activated within the cell resulting in the release of ATP in amounts adequate to activate purinergic receptors on vascular endothelium, which trigger secretion of nitric oxide and other factors resulting in vasodilatation. Among other mechanisms, binding of deoxyhemoglobin to the cytoplasmic domain of the anion-exchange protein band 3 is probably involved in this pathway. The present study investigates the effect of amyloid β peptide exposure on this molecular mechanism. We report that deoxygenated human erythrocytes fail to release ATP following 24 h exposure to amyloid β peptide. Concurrently, amyloid β peptide induces caspase 3 activation. Preincubation of amyloid β peptide treated erythrocytes with a specific inhibitor of caspase 3 prevents amyloid-induced caspase 3 activation and restores the erythrocyte’s ability to release ATP under deoxygenated conditions. Since the activity of red cell phosphofructokinase, a key step in glycolytic flux, is not modified within the red cell following amyloid peptide exposure, it is likely that ATP release reduction is not dependent on glycolytic flux alterations. It has also been suggested that the heterotrimeric G protein, Gi, and adenylyl cyclase are downstream critical components of the pathway responsible for ATP release. We show that cAMP synthesis and ATP release are not failed in amyloid-peptide-treated erythrocytes in response to incubation with mastoparan 7 or forskolin plus 3-isobutyl-1-methyl xanthine, agents that stimulate cAMP synthesis. In conclusion, these results indicate that amyloid β peptide inhibits ATP release from deoxygenated erythrocytes by activating red cell caspase 3, suggesting a pathophysiologic role for vascular amyloid peptide in Alzheimer’s disease.
Therapeutic effect and mechanism of proanthocyanidins from grape seeds in rats with TNBS-induced ulcerative colitis
Authors: Li Xiao-Li , Cai Yong-Qing , Qin Hong , Wu Yong-Jie 
Published: December 2008

The aim of the study was to investigate the therapeutic effect and mechanism of proanthocyanidins from grape seeds (GSPE) in the treatment of ulcerative colitis (UC). Rats were intragastrically administered different doses of GSPE (100, 200, and 400 mg/kg) per day for 7 days after UC was twice-induced by intracolonic injection of 2,4,6-trinitrobenzene sulfonic acid (TNBS)dissolved in 50% ethanol. Sulfasalazine (SASP) at 200 mg/kg was used as a positive control drug. Macroscopic and microscopic damage scores and changes in weight/length ratio (mg/mm) of colon segments were analyzed. The levels of malonyldialdehyde (MDA), interleukin (IL)-1β, IL-2, IL-4, and myeloperoxidase (MPO) activity in the colon tissues and MPO activity in the serum were all measured by biochemical methods or double antibody sandwich ELISA methods. Compared with the TNBS control group, GSPE treatment facilitated recovery of pathologic changes in the colon after insult with TNBS, as demonstrated by increased body weight (p < 0.01) and decreased colonic weight/length ratio (p < 0.01); GSPE also notably reduced the colonic macroscopic and microscopic damage scores (p < 0.01). The MPO activity in colon tissues and serum of rats treated with GSPE was significantly lower than that in the TNBS control group. The MDA and IL-1β levels of colon tissues were also decreased in GSPE groups. The intestinal antiinflammatory effect of GSPE was accompanied by a significant improvement of IL-2 and IL-4 levels in the colon tissues of rats in the high-dose GSPE group (p < 0.05). Compared with the SASP group, GSPE groups had no significant difference in the therapeutic effect (p > 0.05). GSPE exerts a beneficial antiinflammatory effect in the acute phase of TNBS-induced colitis in rats by downregulating some of the mediators involved in the intestinal inflammatory response, inhibiting inflammatory cell infiltration and antioxidation damage, promoting damaged tissue repair to improve colonic oxidative stress, decreasing production of proinflammatory cytokines IL-1β, and increasing production of antiinflammatory cytokines IL-2 and IL-4.
Detrimental effects of nicotine on the acute gastric mucosal injury induced by ethanol: role of asymmetric dimethylarginine
Authors: Zhang Zhe , Zhou Yuan , Zou Yi-You , Wang Li , Yang Zhi-Chun , Guo Ren , Li Dai , Peng Jun , Li Yuan-Jian 
Published: December 2008

The aim of this study was to determine whether asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase (NOS), is responsible for the detrimental effects of nicotine on ethanol-induced gastric mucosal injury and its underlying mechanisms. Gastric mucosal injury was induced by an injection of ethanol in the stomach in rats. Animals were pretreated with nicotine for 28 days before ethanol injection. The gastric mucosal ulcer index (UI) and the levels of ADMA and NO in gastric juice were determined. In vitro, the cultured mucosal epithelial cells were treated with nicotine in the presence or absence of ethanol. The concentration of ADMA in the culture medium and the ratio of cell apoptosis were measured, and the effect of nicotine or ADMA alone on cell apoptosis was also examined. In rats treated with ethanol, the UI and ADMA levels were increased and the NO level was decreased, and these effects of ethanol were augmented by pretreatment with nicotine. Administration of nicotine alone did not show significant impact on UI, ADMA level, or NO level. In vitro, incubation of human epithelial cells with ethanol induced cell injury accompanied by increased ADMA levels in the culture medium, an effect which was amplified in the presence of nicotine. Similarly, ethanol was able to induce epithelial cell apoptosis that was exacerbated by nicotine. Incubation of epithelial cells with nicotine alone did not induce cell apoptosis, but administration of ADMA alone did induce cell apoptosis. The results suggest that the gastric mucosal injury induced by ethanol is augmented by nicotine, which is related to the increased ADMA level.
The spatial scale of habitat selection by red deer
Authors: Schaefer James A. , Morellet Nicolas , Pépin Dominique , Verheyden Hélène 
Published: December 2008

Accounting for spatial scale is essential for understanding habitat selection, but few studies have used spatial statistics to reveal the characteristic scale at which organisms respond to their environment. We studied habitat selection by GPS-tracked red deer ( Cervus elaphus L., 1758) in the Pyrenees Mountains, France, by applying a geostatistical model that compares autocorrelation of a resource between used and available sites to uncover the scale at which animals assess habitat. Using an artificial landscape, we demonstrated that the model can handle discrete habitat classes. Based on conventional hierarchical analysis, deer selected for open habitat, especially meadow, and avoided coniferous forest, more strongly at the coarse level of the home range than GPS locations. Home ranges exhibited generally lower autocorrelation in elevation and meadow habitat than random locations within the population range, indicative of preference for high habitat heterogeneity. Mean maximum discrepancy in autocorrelation, which was more pronounced at the level of the home range than GPS locations, occurred at 830 m for meadow habitat and at 1511 m for elevation, suggesting that red deer responded to their environment at this scale. Our study demonstrates how spatial statistics can serve as an instructive complement to conventional approaches to habitat selection.
Acute phase nematode infection reduces resting metabolic rate in both protein-sufficient and protein-deficient mice
Authors: Tu T. , Phillips A. T. , Koski K. G. , Scott M. E. 
Published: December 2008

The objective of this study was to investigate whether protein deficiency concurrent with the acute phase of infection with the murine nematode Heligmosomoides bakeri (Durette-Desset, Kinsella and Forrester, 1972; Tenora and Barus, 2001) affected the resting metabolic rate (RMR) in BALB/c mice, and whether deworming caused RMR to return to normal. Mice fed either a protein-sufficient (PS, 24%) or protein-deficient (PD, 3%) diet were infected with 100 larvae, and then treated with an anthelmintic drug on 9 and 14 days postinfection (dpi). RMR was measured on –2, 2, 7, and 19 dpi. The results showed that protein deficiency did not affect RMR at any of these times. RMR was unchanged immediately following infection (2 vs. –2 dpi) at the time when larvae are first embedded in the serosal musculture. Surprisingly, at 7 dpi when larvae migrate from the serosal musculture into the intestinal lumen, RMR was significantly lower in both diet groups compared with earlier time points. This reduced RMR persisted even after deworming. Possible reasons for these results are discussed.
Facilitative interactions between the Eurasian badger (Meles meles), the red fox (Vulpes vulpes), and the invasive raccoon dog (Nyctereutes procyonoides) in Białowieża Primeval Forest, Poland
Authors: Kowalczyk R. , Jędrzejewska B. , Zalewski A. , Jędrzejewski W. 
Published: December 2008

Based on radio-tracking of Eurasian badgers ( Meles meles (L., 1758)), red foxes ( Vulpes vulpes (L., 1758)), and raccoon dogs ( Nyctereutes procyonoides (Gray, 1834)) and observations at burrows conducted in Białowieża Primeval Forest (eastern Poland) in 1996–2002, we addressed the hypothesis that facilitative interactions between a native (badger) and an alien (raccoon dog) species contributed to the invasion success of the latter. In winter, 88% of badger setts were occupied by both badgers and raccoon dogs, 4% by badgers and red foxes, and 4% by all three species. In summer, only 20% of badger setts were cohabited by other carnivore species (10% by raccoon dogs and 10% by foxes). Duration of occupation of badger setts by raccoon dogs averaged 117 days (SE = 21 days). Seasonal variation in raccoon dog use of badger setts was explained by changes in ambient temperature: the lower was the temperature, the higher was the rate of sett occupation by raccoon dogs. When wintering in the same sett, badgers and raccoon dogs used different parts of the sett. We conclude that facilitation by badgers (through habitat amelioration and refuge from cold and predation) makes the realized niche of raccoon dogs larger than predicted from their fundamental niche. The facilitating role of badger is stronger in winter, which is a critical period for raccoon dog survival in the temperate and boreal zone.
Addressing uncertainty and remaining potential in a mature field. A case study from the Tertiary of Lake Maracaibo, Venezuela
Authors: Martin Charlotte A. L. 
Published: December 2008

Abstract
The Urdaneta West Field is located on the western margin of Lake Maracaibo in northern Venezuela. Biodegraded oil (12–15° API) is reservoired in Tertiary sandstones and produced through a series of lateral wells. The productive sandstones of the Icotea and Misoa Formations are thin, calculated as 0.5–4.5 m (1.5–15 ft) vertical thickness, and of limited lateral extent. This heterogeneity, coupled with heavy oil, results in poor fluid communication and low recovery efficiency. During 2004, a full field review was undertaken to address future development. Despite production from the Icotea and Misoa Formations, subsurface uncertainty was identified as a major issue due to the clustered nature of field development, complex depositional and structural environments, and reservoir fluid characteristics. In order to rank and mitigate reservoir uncertainties, a series of static models were built. The first phase of static modelling used a simple structural framework and reservoir interval averages to generate minimum, mid- and maximum volume cases. Dynamic simulation of these identified two major areas of uncertainty impacting oil-in-place and productivity – net sandbody connectivity and hydrocarbon contact. Two further phases of static and dynamic modelling concentrated on evaluating the full range of these uncertainties within a detailed structural framework.
Fault seal mapping – incorporating geometric and property uncertainty
Authors: Freeman S. R. , Harris S. D. , Knipe R. J. 
Published: December 2008

Abstract
In this paper, we present workflows, key relationships and results of multiple stochastic fault seal analyses conducted on geocellular geological or (static) reservoir grids. Ranges of uncertainties are computed from new and published datasets for the different input relationships (e.g. throw, VShale to VClay, fault clay prediction, fault rock clay content to permeability); these are used as input into stochastic modelling processes and the impact of each is assessed. The power of stochastic modelling to focus interpretation and risking effort is reviewed. Reducing the uncertainty distributions from the published data ranges has a massive impact on the range of predicted fault seal properties. Halving the uncertainties associated with the computation of the transmissibility multiplier, for instance, reduces this range from 7 to 1–1.5 orders of magnitude of the base‐case value (no uncertainty). Importantly, when combined together, the median predictions from each individual parameter do not lead to the median value for the final prediction; average relationships combined together will not therefore produce the average final prediction. This is a powerful result for two reasons: first, current geological modelling packages use global trends to define fault properties and so are likely to predict spurious results; and secondly, reducing the uncertainty on specific relationships by around 50% is an achievable goal. Locally calibrated datasets and relationships (field‐specific) based on carefully characterized samples should allow for this improvement in prediction accuracy. This paper presents a review of fault seal techniques, published data and the potential pitfalls associated with the analyses.
Realizing complex carbonate facies, diagenetic and fracture properties with standard reservoir modelling software
Authors: Pöppelreiter Michael C. , Balzarini Maria A. , Hansen Birger , Nelson Ronald 
Published: December 2008

Abstract
Geocellular modelling of diagenetically altered carbonates is challenging as geometries and pore systems often appear irregular. It has long been recognised, however, that tectonic evolution forms a framework that can influence patterns of carbonate facies, diagenesis and fracturing, the combination of which determines reservoir geometries and properties. Unravelling these processes can reveal trends that were not evident from well data alone. Such trends are useful in building geocellular models that extrapolate reservoir properties along them and can be used for economic screening of undrilled areas. This paper shows how standard reservoir modelling software can be used to model complex geology. In particular, it is shown how a carbonate reservoir model was constructed based on concepts of facies, burial diagenesis, hydrocarbon charge and fracturing. Workflows are discussed that were employed to distribute reservoir properties related to these processes.
Modelling of dipping clinoform barriers within deltaic outcrop analogues from the Cretaceous Western Interior Basin, USA
Authors: Howell John , Vassel Åsmund , Aune Tanja 
Published: December 2008

Abstract
Deltaic reservoirs typically contain seaward‐dipping surfaces termed clinoforms. Shale and carbonate cements covering clinoforms can frequently form a barrier or baffle to horizontal flow within reservoirs, However, clinoforms are not typically included in static or flow simulation models because they are often not identified in well data and little is known about their 3D geometry. High quality outcrops such as Cretaceous deposits of the US Western Interior Seaway provide an ideal opportunity to study clinoform geometry and shape, and to model their effects on flow. Within this study, two deltaic systems have been studied. The first is the Ferron Delta which crops out in the Wasatch Plateau, central Utah and is a highstand complex comprised of a number of small, overlapping lobes. Clinoforms are common and their 3D geometry is controlled by the position of the lobes. Large growth fault structures within the lobes add to the potential reservoir complexity. The forced regressive Panther Tongue Delta crops out in the Book Cliffs of Utah and is comprised of downstepping lobes with internal clinoforms. Data for modelling included traditional sedimentary logs, photomontages and calibrated photo logs. Models were built in IRAP RMS using a variety of modelling techniques from simple Truncated Gaussian Simulations on a regular grid to object modelling of shale barriers within a dipping grid designed to follow the clinoforms. The models were flow simulated as a means of comparing the different techniques for representing the heterogeneity results show that not modelling clinoforms explicitly in a dipping grid can lead to significant overestimates in the forecasted production; water injection in a down depositional dip position is optimum, and that there are only limited production differences between highstand and lowstand deltas.
Multiscale geological reservoir modelling in practice
Authors: Ringrose Philip S. , Martinius Allard W. , Alvestad Jostein 
Published: December 2008

Abstract
Geological systems exhibit variability and structure at a wide range of scales. Geological modelling of subsurface petroleum reservoirs has generally focused on the larger scales, driven by the types of measurement available and by computation limitations. Implementation of explicitly multiscale models of petroleum reservoirs is now realistically achievable and has proven value. This paper reviews the main approaches involved and discusses current limitations and challenges for routine implementation of multiscale modelling of petroleum-bearing rock systems. The main questions addressed are: (a) how many scales to model and upscale; (b) which scales to focus on; (c) how to best construct model grids; and (d) which heterogeneities matter most? The main future challenges identified are the need for improved handling of variance and more automated construction of geological and simulation grids.
Biological Research in the Evolution of Cancer Surgery: A Personal Perspective
Authors: Fisher Bernard 
Published: December 2008

AbstractDuring the 19th, and for most of the 20th century, malignant tumors were removed by mutilating radical anatomic dissection. Advances such as anesthesia, asepsis, and blood transfusion made possible increasingly more radical operations. There was no scientific rationale for the operations being performed. Surgery in the 20th century was dominated by the principles of William S. Halsted, who contended that the bloodstream was of little significance as a route of tumor cell dissemination; a tumor was autonomous of its host; and cancer was a local-regional disease that spread in an orderly fashion based on mechanical considerations. Halsted believed that both the extent and nuances of an operation influenced patient outcome and that inadequate surgical skill was responsible for the failure to cure. A new surgical era arose in 1957, when cancer surgery began to be influenced by laboratory and clinical research, with results contrary to Halstedian principles. A new hypothesis resulted in a scientific basis for cancer surgery. Clinical trials supported the thesis that operable cancer is a systemic disease and that variations in local-regional therapy are unlikely to substantially affect survival. Complex host-tumor relationships were shown to affect every aspect of cancer and, contrary to Halsted's thesis, the bloodstream is of considerable importance in tumor dissemination. Clinical trials also have shown that less radical surgery is justified. Studies have shown that improved survival can be achieved with systemic therapy after surgery. Such therapy can reduce both the incidence of distant disease and the tumor recurrence at the tumor site after minimal surgery. The use of systemic therapy in patients who have no identifiable metastatic disease is a drastic departure from previous strategies. New technological innovations resulting from engineering research have improved the quality of life of patients by eliminating the need for some surgical procedures. Because cancer is apt to be a systemic disease, however, clinical trials are necessary to determine the effect of these modalities on patient outcome. Although technological developments will continue to play a role in cancer therapy, research in molecular biology and genetics will dictate the future status of cancer treatment and, ultimately, the future of surgery. [Cancer Res 2008;68(24):10007–20]
Cancer Stem Cells Are Enriched in the Side Population Cells in a Mouse Model of Glioma
Authors: Harris Molly A. , Yang Hyuna , Low Benjamin E. , Mukherje Joydeep , Guha Abhijit , Bronson Roderick T. , Shultz Leonard D. , Israel Mark A. , Yun Kyuson 
Published: December 2008

Abstract
The recent identification of cancer stem cells (CSCs) in multiple human cancers provides a new inroad to understanding tumorigenesis at the cellular level. CSCs are defined by their characteristics of self-renewal, multipotentiality, and tumor initiation upon transplantation. By testing for these defining characteristics, we provide evidence for the existence of CSCs in a transgenic mouse model of glioma, S100β-verbB;Trp53. In this glioma model, CSCs are enriched in the side population (SP) cells. These SP cells have enhanced tumor-initiating capacity, self-renewal, and multipotentiality compared with non-SP cells from the same tumors. Furthermore, gene expression analysis comparing fluorescence-activated cell sorting–sorted cancer SP cells to non-SP cancer cells and normal neural SP cells identified 45 candidate genes that are differentially expressed in glioma stem cells. We validated the expression of two genes from this list (S100a4 and S100a6) in primary mouse gliomas and human glioma samples. Analyses of xenografted human glioblastoma multiforme cell lines and primary human glioma tissues show that S100A4 and S100A6 are expressed in a small subset of cancer cells and that their abundance is positively correlated to tumor grade. In conclusion, this study shows that CSCs exist in a mouse glioma model, suggesting that this model can be used to study the molecular and cellular characteristics of CSCs in vivo and to further test the CSC hypothesis. [Cancer Res 2008;68(24):10051–9]