bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of topoisomerase IIα expression by a DNA sequence-specific polyamide
Authors: Hochhauser Daniel , Kotecha Minal , O'Hare Caroline , Morris Peter J. , Hartley Janet M. , Taherbhai Zarmeen , Harris Dorothy , Forni Claudia , Mantovani Roberto , Lee Moses , Hartley John A. 
Published: January 2007

Abstract
Topoisomerase IIα (topo IIα) is an important target for several chemotherapeutic agents, including etoposide and doxorubicin. Confluent cells express low levels of topo IIα and are resistant to etoposide treatment. Repression of transcription in confluent cells is mediated by binding of the transcription factor NF-Y to inverted CCAAT motifs within the topo IIα promoter. To block the repressive binding of NF-Y, a polyamide (JH-37) was designed to bind to the flanking regions of selected CCAAT sites within the topo IIα promoter. Electrophoretic mobility shift assays and DNase I footprinting assays showed occupancy of the inverted CCAAT sites by JH-37. Chromatin immunoprecipitation assays confirmed in vivo inhibition of NF-Y binding to the topo IIα promoter. Following incubation of confluent NIH3T3 cells with JH-37, increased expression of topo IIα mRNA and protein was detectable. This correlated both with increased DNA double-strand breaks as shown by comet assay and decreased cell viability following exposure to etoposide. Polyamides can modulate gene expression and chemosensitivity of cancer cells. [Mol Cancer Ther 2007;6(1):346–54]
Chrysin inhibits expression of hypoxia-inducible factor-1α through reducing hypoxia-inducible factor-1α stability and inhibiting its protein synthesis
Authors: Fu Beibei , Xue Jing , Li Zhaodong , Shi Xianglin , Jiang Bing-Hua , Fang Jing 
Published: January 2007

Abstract
Chrysin is a natural flavonoid and has been shown recently to have anticancer effects. However, the mechanisms that chrysin inhibits cancers are not well known. In this study, we investigated the effects of chrysin on expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor in human prostate cancer DU145 cells. Chrysin inhibited insulin-induced expression of HIF-1α by reducing its stability. Chrysin increases ubiquitination and degradation of HIF-1α by increasing its prolyl hydroxylation. In addition, chrysin interfered with interaction between HIF-1α and heat shock protein 90. Chrysin was also found to inhibit HIF-1α expression through AKT signaling. Inhibition of HIF-1α by chrysin resulted in abrogation of vascular endothelial growth factor expression. Finally, we showed that chrysin inhibited DU145 xenograft-induced angiogenesis in nude mice. Taken together, these results suggest that chrysin is a potent inhibitor of HIF-1α and provide a new sight into the mechanisms of chrysin against cancers. [Mol Cancer Ther 2007;6(1):220–6]
Effect of population and gender on chemotherapeutic agent–induced cytotoxicity
Authors: Huang Rong Stephanie , Kistner Emily O. , Bleibel Wasim K. , Shukla Sunita J. , Dolan M. Eileen 
Published: January 2007

Abstract
Large interindividual variance is observed in both response and toxicity associated with chemotherapy. Our goal is to identify factors that contribute to chemotherapy-induced toxicity. To this end, we used EBV-transformed B-lymphoblastoid HapMap cell lines derived from 30 Yoruban trios (African descent) and 30 Centre d' Etude du Polymorphisme Humain (CEPH) trios (European descent) to evaluate population- and gender-specific differences in cytotoxicity of carboplatin, cisplatin, daunorubicin, and etoposide using a high-throughput, short-term cytotoxicity assay. The IC50 was compared for population- and gender-specific differences for the four drugs. We observed large interindividual variance in IC50 values for carboplatin, cisplatin, daunorubicin, and etoposide for both Yoruban and CEPH populations (range from 8- to 433-fold). Statistically significant differences in carboplatin and daunorubicin IC50 were shown when comparing Yoruban cell lines (n = 89) to CEPH cell lines (n = 87; P = 0.002 and P = 0.029, respectively). This population difference in treatment induced cytotoxicity was not seen for either cisplatin or etoposide. In the Yoruban population, cell lines derived from females were less sensitive to platinating agents than males [median carboplatin IC50, 29.1 versus 24.6 μmol/L (P = 0.012); median cisplatin IC50, 7.0 versus 6.0 μmol/L (P = 0.020) in female and male, respectively]. This difference was not observed in the CEPH population. These results show that population and gender may affect risk for toxicities associated with certain chemotherapeutic agents. [Mol Cancer Ther 2007;6(1):31–6]
Low-Frequency Variability in the Midlatitude Baroclinic Atmosphere Induced by an Oceanic Thermal Front
Authors: Feliks Yizhak , Ghil Michael , Simonnet Eric 
Published: January 2007

AbstractThis study examines the flow induced by an east–west-oriented oceanic thermal front in a highly idealized baroclinic model. Previous work showed that thermal fronts could produce energetic midlatitude jets in an equivalent-barotropic atmosphere and that barotropic instabilities of this jet had dominant periods of 25–30 and 65–75 days.The present study extends this work to a two-mode baroclinic free atmosphere. The baroclinic jet produced in this case is subject to both barotropic and baroclinic instabilities. A barotropic symmetric instability propagates westward with periods of roughly 30 days and is similar to those found in the equivalent-barotropic model. A baroclinic instability results in standing-dipole anomalies and oscillates with a period of 6–8 months. A mixed barotropic–baroclinic instability results in anomalies that propagate northward, perpendicular to the jet, with a period of 2–3 months. The later anomalies are reminiscent of the 70-day oscillation found over the North Atlantic in observed fields.The atmospheric flow has two distinct states: the flow in the high-energy state exhibits two large gyres and a strong eastward jet; its antisymmetric component is dominant. The low-energy flow is characterized by small gyres and a weak jet.The model’s dynamics depends on the layer-depth ratio. When the model is nearly equivalent-barotropic, symmetric oscillatory modes dominate. As the two layers become nearly equal, antisymmetric oscillatory modes become significant and the mean energy of the flow increases.When the oceanic thermal front’s strength T* is weak (T* ≤ 1.5°C), the flow is steady. For intermediate values of the strength (1.5°C &lt; T* &lt; 3°C), several oscillatory instabilities set in. As the frontal strength increases further (T* ≥ 3°C), the flow becomes more turbulent. These results all depend on the atmospheric model’s horizontal resolution being sufficiently high.
Dynamics of Eddy-Driven Low-Frequency Dipole Modes. Part II: Free Mode Characteristics of NAO and Diagnostic Study
Authors: Luo Dehai , Gong Tingting , Lupo Anthony R. 
Published: January 2007

Abstract
Through calculating the scatter diagrams of the streamfunction (ψP or ψT) versus potential vorticity (PV) (qP or qT), where ψP and ψT are the planetary-scale streamfunction and total streamfunction, respectively, and using a weakly nonlinear NAO model proposed in Part I of this paper, it is suggested that negative- and positive-phase NAO events may approximately correspond to free modes even though driven by synoptic-scale eddies. In a planetary-scale field, the qP(ψP) scatter diagram of an NAO event exhibits a linear multivalued functional relationship in a narrow region for the negative phase, but exhibits a linear single-valued functional relationship during the positive phase. It was also found that there is no steepening of the slope of the main straight line in the qP(ψP) scatter diagrams for two phases of the NAO event. Instead, the slope of the straight line in the scatterplots is time independent throughout the life cycle of the NAO event.
However, when synoptic-scale eddies are included in the streamfunction field, the qT(ψT) scatter diagram of the negative-phase NAO event shows a trend toward steepening during the intensification phase, and this tendency reverses during the decay phase. During the positive NAO phase the slope of the qt(ψT) scatter diagram shoals during the intensification phase and then steepens during the decay phase. Thus, it appears that the steepening and shoaling of the scatter diagrams of the streamfunction versus PV for the negative- and positive-phase NAO events are attributed to the effect of synoptic-scale eddies that force NAO events to form. Diagnostic studies using both composite and unfiltered fields of observed NAO events are presented to confirm these conclusions.
Geomorphology, ecology and river channel habitat: mesoscale approaches to basin-scale challenges
Authors: Newson M. D. , Newson C. L. 
Published: January 2007

The physical component of river channel (instream) habitat is of acknowledged significance, particularly in headwater streams; furthermore, physical habitats have been heavily impacted by human needs for river services: principally flood defence (channel modification) and water resources (flow regulation). Despite the control exercised on physical habitats by fluvial geomorphology (channel shape, bed material size, bedforms and bars) and flow regime (including the varying hydraulics of flow around these forms), their interaction has hitherto lacked a distinctive spatial formulation and biological validation. This article describes the challenges faced by a need (in both theoretical and practical areas) to understand the detail of physical habitat conditions in stream channels. A number of mesoscale approaches are emerging, both from ecology and geomorphology. We outline the field validation of a ‘habitat hydraulics’ approach to the interaction between river discharge and channel form. Qualitative ‘flow types’ are shown to be representative of discrete hydraulic conditions within mesoscale units of the channel bed described as ‘physical biotopes’. The approach is compared with parallel ecological research on ‘mesohabitats’ and ‘functional habitats’. The extent, pattern and discharge-variability of physical biotopes can be surveyed in the field and used as a spatial guide to biological sampling (in this case for benthic invertebrates). Biological patterns (at the scale sampled here) appear to respond first to the river continuum concept’s longitudinal zonation of the channel, but there is a marked secondary signal in statistical analyses from the pattern of biotopes. Given the promise of the physical biotope approach, its logical extension in predictive mode is via the hierarchical concepts shared by freshwater ecologists and geomorphologists; however, there is little agreement on scale terminology, hierarchical principles and, above all, a truly geo-morphological channel classification, based on reaches, into which mesoscale habitat typologies could be fed. Assuming a relationship between biological diversity and that of physical biotopes it should be the aim of river managers, whether intervening in the channel form or its flow regime, to optimize certain parameters of the pattern of biotopes; these parameters should be a focus for future research. Both the rapid survey and proper description of these patterns will benefit from the application of remote-sensing technology, improved instruments for microscale hydraulic studies and a GIS approach based upon the spatial principles of landscape ecology.
The species-area relationship: new challenges for an old pattern
Authors: Lomolino Mark V. 
Published: January 2007

The species-area relationship (i.e., the relationship between area and the number of species found in that area) is one of longest and most frequently studied patterns in nature. Yet there remain some important and interesting questions on the nature of this relationship, its causality, quantification and application for both ecologists and conservation biologists. Traditionally, the species-area relationship describes the very general tendency for species number to increase with island area; a relationship whose slope declines (but remains positive) as area increases. The true relationship, however, may be much more complicated than this, and may in many cases approximate a sigmoidal relationship. On small islands, species number may vary independently of island area. Species richness then increases as we consider larger islands, but the curve eventually slows and asymptotes or levels off when richness equals that of the the source or mainland pool. The relationship may also include a secondary phase of increase in richness if island area becomes large enough to allow in situ speciation. Causal explanations for this relationship may, therefore, need to be multifactorial and include a range of processes from disturbance and stochastic variation in habitat quality on the very small islands, to ecological interactions, immigration, extinction and, finally, evolution on the larger islands.
Optical remote-sensing techniques for the assessment of forest inventory and biophysical parameters
Authors: Wulder Mike 
Published: January 2007

Forests are the most widely distributed ecosystem on the earth, affecting the lives of most humans daily, either as an economic good or an environmental regulator. As forests are a complex and widely distributed ecosystem, remote sensing provides a valuable means of monitoring them. Remote-sensing instruments allow for the collection of digital data through a range of scales in a synoptic and timely manner. Accordingly, a variety of image-processing techniques have been developed for the estimation of forest inventory and biophysical parameters from remotely sensed images. The use of remotely sensed images allows for the mapping of large areas efficiently and in a digital manner that allows for accuracy assessment and integration with geographic information systems. This article provides a summary of the image-processing methods which may be applied to remotely sensed data for the estimation of forest structural parameters while also acknowledging the various limitations that are presented. Current advancements in remote-sensor technology are increasing the information content of remotely sensed data and resulting in a need for new analysis techniques. These advances in sensor technology are occurring concurrently with changes in forest management practices, requiring detailed measurements intended to enable ecosystem-level management in a sustainable manner. This review of remote-sensing image analysis techniques, with reference to forest structural parameters, illustrates the dependence between spatial resolution to the level of detail of the parameters which may be extracted from remotely sensed imagery. As a result, the scope of a particular investigation will influence the type of imagery required and the limits to the detail of the parameters that may be estimated. The complexity of parameters that may be extracted can be increased through combinations of image-processing techniques. For example, multitemporal analysis of image radiance values or multispectral image classification maps may be analysed to undertake the assessment of such forest characteristics as area of forest disturbances, forest succession and development, or sustainability of forest management practices. Further, the combination of spectral and spatial information extraction techniques shows promise for increasing the accuracy of estimates of forest inventory and biophysical parameters.
Domestication and the origins of agriculture: an appraisal
Authors: Mannion A. M. 
Published: January 2007

The first domestications of plants and animals, which occurred between 10 K years and 5 K years BP, and which underpinned the inception of agricultural systems, represent a major turning point in cultural and environmental history. Whilst much has been written on these topics, new archaeological discoveries and the development of new methods of data collection require that these issues should be reappraised. One example of a new archaeological discovery is that of evidence for rice cultivation prior to 10 K years BP in the middle Yangtze Basin of China. This region is now considered to be the likely centre of rice domestication and, because of the discovery of settlement structures, it may have been home to China’s oldest civilization. In addition, further age determination may establish this region of China as the earliest centre of agricultural innovation, instead of southwest Asia. New methods of age estimation, notably by radiocarbon, have necessitated a reappraisal of the origins of agriculture in Mesoamerica, whilst biomolecular techniques are contributing to the identification of the wild relatives of domesticated plants and animals. Genetic analysis has also been applied to modern human populations in order to establish the relationships between different groups and thus to attempt to determine the movement of peoples in prehistory. Such relationships in Europe have been related to the spread of agriculture from its centre of origin in southwest Asia, although this is speculative rather than conclusive. Despite these advances, however, there is still no unequivocal evidence as to why agriculture was initiated.
Genetic polymorphism of metabolic enzymes modifies the risk of chronic solvent-induced encephalopathy
Authors: Kezic Sanja , Calkoen Florentine , Wenker Mira AM , Jacobs John JL , Verberk Maarten M 
Published: January 2007

In the present study, we investigate whether genetic polymorphism in enzymes involved in the metabolism of organic solvents influences susceptibility to chronic solvent encephalopathy (CSE), which is one of the major effects of long-term exposure to organic solvents. Polymorphisms in the genes encoding CYP1A1, CYP2E1, EPHX1, GSTM1, GSTT1 and GSTP1 enzymes were determined in a group of male CSE patients ( N = 97) and controls ( N = 214). The selection of the patients was based on a standard diagnostic protocol, including interviews, neuropsychological tests and questionnaires directed to somatic, cognitive and mood symptoms and exposure, in combination with well-defined decision rules. As controls, healthy workers of similar socio-economic background, without memory problems and with no known exposure to organic solvents, were included in the study. Comparing patients and controls, higher frequencies of the variant *5B allele of the CYP2E1 gene (OR: 5.8; 95% CI: 1.8-18.8) and of the variant GSTP1*C allele (OR: 0.40; 95% CI: 0.17-0.94) were found. Homozygous carriers of the exon 4 EPHX1 Arg139 variant allele had a lower risk (OR:0.25; 95% CI: 0.06-1.13). The present study indicates that genetic polymorphism of CYP2E1, EPHX1 and GSTP1 modify the risk of developing CSE.
The cost of blood transfusions in cancer patients: a reanalysis of a Canadian economic evaluation
Authors: Dranitsaris George 
Published: January 2007

Background. Cancer patients undergoing chemotherapy are at an increased risk for anemia. Hence, they are high consumers of allogenic blood transfusions. In 1997, an economic evaluation was undertaken at the Princess Margaret Hospital to estimate the cost of a transfusion in cancer patients. The analysis relied on published costing information and on an internal review of patient resource utilization. Overall, the cost of a blood transfusion was estimated at Can$599. Since 1997, there have been some major changes in the management of Canada's blood supply and within the Princess Margaret Hospital. Methods. In order to evaluate how these changes affected the cost of a transfusion in cancer patients, the original 1997 economic database was reanalyzed using updated 1999 costing information obtained from Canadian Blood Services (CBS) and from the Princess Margaret Hospital. Results. The reanalysis suggested that the cost of a blood transfusion in cancer patients increased from Can$599 in 1997 to Can$731 in 1999. The major incremental costs responsible for this increase were additional screening tests, increased opportunity costs for donors and a modest rise in distribution and administration within the hospital. Costs that were no longer relevant in 1999 were the cost of treating transfusion-related infections. Conclusions. These results support the findings of the original publication that a unit of blood is a highly resource intensive commodity which requires that each blood unit be used appropriately. Therefore, preventative strategies that would reduce the use of blood products have to be identified and implemented.
Reproducibility of treatment methodologies detailed in contemporary clinical trial reports
Authors: Dooley Michael Joseph , Vernon Joanne 
Published: January 2007

Objective. To assess the reproducibility of treatment methodology detailed in contemporary published clinical trial reports. Design. Published articles focusing on clinical trials involving the administration of chemotherapy for the treatment of cancer were selected. The data required for the administration of chemotherapy was determined by an experienced oncology pharmacist. Outcome measures. The degree of potential impact of the omission of relevant detail was assessed. The overall reproducibility of the methodology was then classified as reproducible, reproducible with further literature evaluation, or not reproducible without communication with the authors. Results. Ninety-two articles were reviewed. Ninety percent of articles omitted data required to enable reproduction of the methodology. Of these, 5.4% omitted essential data which could only be obtained by communication with the authors. Over 57% of articles required further detailed literature evaluation before the methodology could be reproduced. A number of articles contained errors or ambiguity. Discussion. The focus of the article and journal contributed to the completeness of the methodology. Guidelines for the preparation of manuscripts for publication in biomedical journals need to be reviewed. Practitioners and editors must be cognizant of the limitations of published methodologies. Conclusion. A significant number of articles contained omissions, ambiguity and even errors, which would prevent the methodology being reproduced. The majority of methodologies could be reproduced with the interpretation of an experienced oncology pharmacist, or by utilising resources for detailed literature evaluation.