bluuebunny/crossref_metadata_2025_split huggingface dataset:
SOMFA on Large Diverse Xenoestrogen Dataset: The Effect of Superposition Algorithms and External Regression Tools
Authors: Korhonen Samuli‐Petrus , Tuppurainen Kari , Asikainen Arja , Laatikainen Reino , Peräkylä Mikael 
Published: March 2007

AbstractSelf‐Organizing Molecular Field Analysis (SOMFA) comes with a built‐in regression methodology, the Self‐Organizing Regression (SOR), instead of relying on external methods such as PLS. In our recent paper, we presented a proof of the equivalence among SOR, SIMPLS, and NIPALS with one principal component. Thus, the modest performance of SOMFA on complex datasets can be primarily attributed to the low performance of the SOMFA regression methodology. In this paper, the SOR, originally proposed along with the SOMFA analysis, and external multi‐component regression methods Multi‐Component SOR (MCSOR) and SIMPLS are used to evaluate the performance of SOMFA. The performance gain achieved by external regression tools is assessed using the TBG and SADLER benchmark datasets and a large and diverse xenoestrogen dataset containing activity data for five different estrogen receptors. The effect of polarizibility descriptor and two superposition techniques on the predictive ability of SOMFA is also evaluated. The results clearly indicate that for diverse datasets SOMFA clearly benefits from the use of external regression tools instead of the SOR regression. On the other hand, no clear difference was observed between the two superposition techniques. The polarizability descriptor generated predictive models as a stand‐alone descriptor but clear improvement in the accuracy of the prediction is achieved when the polarizability descriptor is combined with the electrostatic field descriptor.
Gross anatomy and characteristics of the reproductive system of the land snail Archachatina marginata ovum (Pfeiffer) during the breeding season
Authors: Egonmwan Rosemary I 
Published: March 2007

AbstractThe changes that occurred in the reproductive system during the breeding season of the land snail Archachatina marginata ovum (Pfeiffer) were investigated from April to July 2005 in collections obtained from snail hunters. These changes were divided into four stages (juvenile stage, mating readiness, egg production and post reproductive), which are described. The observations on the changes in the reproductive organs of A. marginata ovum suggest that the adult population is vulnerable during the breeding season. Management guidelines that will enhance commercial production of the snails are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Conjugated linoleic acid versus high-oleic acid sunflower oil: effects on energy metabolism, glucose tolerance, blood lipids, appetite and body composition in regularly exercising individuals
Authors: Lambert Estelle V. , Goedecke Julia H. , Bluett Kerry , Heggie Kerry , Claassen Amanda , Rae Dale E. , West Sacha , Dugas Jonathan , Dugas Lara , Meltzer Shelly , Charlton Karen , Mohede Inge 
Published: March 2007

The aim of this study was to measure the effects of 12 weeks of conjugated linoleic acid (CLA) supplementation on body composition, RER, RMR, blood lipid profiles, insulin sensitivity and appetite in exercising, normal-weight persons. In this double-blind, randomised, controlled trial, sixty-two non-obese subjects (twenty-five men, thirty-seven women) received either 3·9 g/d CLA or 3·9 g high-oleic acid sunflower oil for 12 weeks. Prior to and after 12 weeks of supplementation, oral glucose tolerance, blood lipid concentrations, body composition (dual-energy X-ray absorptiometry and computerised tomography scans), RMR, resting and exercising RER and appetite were measured. There were no significant effects of CLA on body composition or distribution, RMR, RER or appetite. During the oral glucose tolerance tests, mean plasma insulin concentrations (0, 30, 120 min) were significantly lower (P = 0·04) in women who supplemented with CLA (24·3 (sd9·7) to 20·4 (sd8·5) μU/ml) compared to high-oleic acid sunflower oil control (23·7 (sd9·8) to 26·0 (sd8·8) μU/ml). Serum NEFA levels in response to oral glucose were attenuated in both men and women in the CLA (P = 0·001) compared to control group. However, serum total cholesterol and LDL-cholesterol concentrations decreased in both groups and HDL-cholesterol concentrations decreased in women over 12 weeks (P = 0·001,P = 0·02,P = 0·02, respectively). In conclusion, mixed-isomer CLA supplementation had a favourable effect on serum insulin and NEFA response to oral glucose in non-obese, regularly exercising women, but there were no CLA-specific effects on body composition, energy expenditure or appetite.
Salivary immunoglobulin A response at rest and after exercise following a 48 h period of fluid and/or energy restriction
Authors: Oliver Samuel J. , Laing Stewart J. , Wilson Sally , Bilzon James L. J. , Walters Robert , Walsh Neil P. 
Published: March 2007

The aim was to investigate the effects of a 48 h period of fluid, energy or combined fluid and energy restriction on salivary IgA (s-IgA) responses at rest and after exercise. Thirteen healthy males (age 21 (sem1) years) participated in four randomised 48 h trials. In the control trial participants received their estimated energy (12 154 (sem230) kJ/d) and water (3912 (sem140) ml/d) requirements. On fluid restriction (FR) participants received their energy requirements and 193 (sem19) ml water/d to drink and on energy restriction (ER) participants received their water requirements and 1214 (sem25) kJ/d. Fluid and energy restriction (F+ER) was a combination of FR and ER. After 48 h, participants performed a 30 min treadmill time trial (TT) followed by rehydration (0–2 h) and refeeding (2–6 h). Unstimulated saliva was collected at 0, 24 and 48 h, post-TT, and 2 and 6 h post-TT. Saliva flow rate (sflw) and s-IgA (ELISA) remained unchanged in control conditions and on ER. However, 48 h on FR decreased sflw (64 %) which most probably accounted for the increase in s-IgA concentration (P < 0·01). Despite a decrease in sflw (54 %), s-IgA concentration did not increase on F+ER, resulting in a decreased s-IgA secretion rate by 24 h (0 h: 20 (sem2); 24 h: 12 (sem2) μg/min;P < 0·01). Post-TT s-IgA secretion rate was not lower compared with 48 h on any trial. s-IgA secretion rate returned to within 0 h values by 6 h post-TT on F+ER. In conclusion, a 24–48 h period of combined F+ER decreased s-IgA secretion rate but normalisation occurred upon refeeding.
Effects of trans-10, cis-12 conjugated linoleic acid on the expression of uncoupling proteins in hamsters fed an atherogenic diet
Authors: Ribot Joan , Portillo Maria P. , Picó Catalina , Teresa Macarulla M. , Palou Andreu 
Published: March 2007

It is known that conjugated linoleic acid (CLA) feeding decreases body adiposity but the mechanisms involved are not clear. The aim of this study was to analyse whether alterations in uncoupling protein (UCP) expression in white and brown adipose tissues (WAT and BAT, respectively) and in skeletal muscle may be responsible for the effect of trans-10, cis-12 CLA on the size of body fat depots in hamsters. Animals were divided into three groups and fed an atherogenic diet with different amounts of trans-10, cis-12 CLA (0 control, 0·5, or 1 g/100 g diet) for 6 weeks. CLA feeding reduced adipose depot weights, but had no effect on body weight. Leptin mRNA expression decreased in both subcutaneous and perirenal WAT depots, in accordance with lower adiposity, whereas resistin mRNA expression was not changed. Animals fed CLA had lower UCP1 mRNA levels in BAT (both doses of CLA) and in perirenal WAT (the low dose), and lower UCP3 mRNA levels in subcutaneous WAT (the high dose). UCP2 mRNA expression in WAT was not significantly affected by CLA feeding. Animals fed the high dose of CLA showed increased UCP3 and carnitine palmitoyl transferase-I (CPT-I) mRNA expression levels in skeletal muscle. In summary, induction of UCP1 or UCP2 in WAT and BAT is not likely to be responsible for the fat-reduction action of CLA, but the increased expression of UCP3 in skeletal muscle, together with a higher expression of CPT-I, may explain the previously reported effects of dietary CLA in lowering adiposity and increasing fatty acid oxidation by skeletal muscle.
Rapid-prototyped temporal bone and inner-ear models replicated by adjusting computed tomography thresholds
Authors: Suzuki M , Hagiwara A , Ogawa Y , Ono H 
Published: March 2007

AbstractPurpose:This study aimed to investigate the validity of adjusting computed tomography thresholds in order to replicate a temporal bone model suitable for dissection training and education.Materials and methods:A simulated three-dimensional model of a human temporal bone was prototyped using selective laser sintering. The powder layers were laser-fused, based on detailed computed tomography data, and accumulated to create a three-dimensional structure. The computed tomography threshold value of the stapes was modified on standard triangular language file in order to replicate the stapes. The intensity value was determined to select the fluid lumen of the inner ear and the bone surface, in order to replicate the inner ear.Results:The model could be shaved, using surgical instruments, in the same manner as during real surgery. The stapes could be reproduced, making this model even more realistic than a previous version. The inner ear was recreated, along with the surrounding bony wall and the ossicles.Conclusion:This model facilitates dissection training and easy understanding of the relation between the labyrinth and the surrounding structures.
The emerging pharmacotherapeutic significance of the breast cancer resistance protein (ABCG2)
Authors: Hardwick L J A , Velamakanni S , van Veen H W 
Published: March 2007

The breast cancer resistance protein (also termed ABCG2) is an ATP‐binding cassette transporter, which mediates the extrusion of toxic compounds from the cell, and which was originally identified in relation to the development of multidrug resistance of cancer cells. ABCG2 interacts with a range of substrates including clinical drugs but also substances such as sterols, porphyrins and a variety of dietary compounds. Physiological functions of ABCG2 at both cellular and systemic levels are reviewed. For example, ABCG2 expression in erythrocytes may function in porphyrin homeostasis. In addition, ABCG2 expression at apical membranes of cells such as hepatocytes, enterocytes, endothelial and syncytiotrophoblast cells may correlate to protective barrier or secretory functions against environmental or clinically administered substances. ABCG2 also appears influential in the inter‐patient variation and generally poor oral bioavailability of certain chemotherapeutic drugs such as topotecan. As this often precludes an oral drug administration strategy, genotypic and environmental factors altering ABCG2 expression and activity are considered. Finally, clinical modulation of ABCG2 activity is discussed. Some of the more recent strategies include co‐administered modulating agents, hammerhead ribozymes or antisense oligonucleotides, and with specificity in cell targeting, these may be used to reduce drug resistance and increase drug bioavailability to improve the profile of chemotherapeutic efficacy versus toxicity. While many such strategies remain in relative infancy at present, increased knowledge of modulators of ABCG2 could hold the key to novel approaches in medical treatment.British Journal of Pharmacology(2007)151, 163–174. doi:10.1038/sj.bjp.0707218
The fatter the better? Perivascular adipose tissue attenuates vascular contraction through different mechanisms
Authors: Brandes R P 
Published: March 2007

Adipose tissue releases several hormones and autacoids and expansion of the adipose tissue and excessive obesity is a risk factor for hypertension. Perivascular adipose tissue, on the other hand, has been reported to lower the vascular tone through the release of a transferable, thermosensitive, non‐lipid factor. In this issue of the British Journal of Pharmacology, Gao et al. (2007) report that a factor generated by the adipose tissue also stimulates the generation of NO by endothelium and that NO is the predominant mediator of adipose tissue‐induced relaxation in endothelium‐intact vessels (88 words).British Journal of Pharmacology (2007) 151, 303–304; doi:10.1038/sj.bjp.0707229
In situ molecular identification of the Ntf4 MAPK expression sites in maturing and germinating pollen
Authors: Coronado Maria‐Jose , Testillano Pilar S. , Wilson Cathal , Vicente Oscar , Heberle‐Bors Erwin , Risueño Maria‐Carmen 
Published: March 2007

Background information. MAPKs (mitogen‐activated protein kinases) are involved in the transduction of different signals in eukaryotes. They regulate different processes, such as differentiation, proliferation and stress response. MAPKs act through the phosphorylation cascade, being the last element that phosphorylates the final effector of the cell response. They are activated when their threonine and tyrosine residues are phosphorylated. Ntf4, a MAPK with a molecular mass of 45 kDa, has been reported to be expressed in pollen and seeds. Biochemical studies have indicated that the expression and the activation of Ntf4 is regulated during pollen maturation, although an increase of the activation is observed when the pollen is hydrated, just at the beginning of the germination. However, nothing is known about its subcellular localization.Results. In the present study, the in situ expression and subcellular localization of Ntf4 have been analysed during the tobacco pollen developmental pathway. Cryosections, freeze‐substitution and cryo‐embedding in Lowicryl K4M were used as processing techniques for subsequent immunofluorescence, immunogold labelling and in situ hybridization assays. During pollen maturation, Ntf4 showed an increase in expression, as demonstrated by in situ hybridization, and specific subcellular distributions. We found that the protein was expressed from mid bicellular pollen stage until the pollen was mature. In germinating pollen, the protein increased after the initiation of germination. Translocation of the protein to the nucleus was found at specific stages; the presence of Ntf4 in the nucleus was found in the last stage of the pollen maturation and in germinating pollen. Double immunofluorescence and immunogold labelling with anti‐Ntf4 (AbC4) and anti‐P‐MAPK (phosphorylated MAPK) antibodies revealed the co‐localization of both epitopes in the nucleus at late developmental stages.Conclusions. The temporal and spatial pattern of the expression sites of Ntf4 has been characterized during pollen development, indicating that Ntf4 is a ‘late gene’ that is upregulated during maturation and germination, with a possible role in the gametophytic function. The translocation of the Ntf4 protein from the cytoplasm to the nucleus at late pollen developmental stages, and its co‐localization with the P‐MAPK epitope in several nuclear sites, indicates a relationship between the Ntf4 nuclear translocation and its active state.
Protein disulfide-isomerase mediates delivery of nitric oxide redox derivatives into platelets
Authors: Bell Susannah E. , Shah Chirag M. , Gordge Michael P. 
Published: March 2007

S-nitrosothiol compounds are important mediators of NO signalling and can give rise to various redox derivatives of NO: nitrosonium cation (NO+), nitroxyl anion (NO−) and NO• radical. Several enzymes and transporters have been implicated in the intracellular delivery of NO from S-nitrosothiols. In the present study we have investigated the role of GPx (glutathione peroxidase), the L-AT (L-amino acid transporter) system and PDI (protein disulfide-isomerase) in the delivery of NO redox derivatives into human platelets.
Washed human platelets were treated with inhibitors of GPx, L-AT and PDI prior to exposure to donors of NO redox derivatives (S-nitrosoglutathione, Angeli's salt and diethylamine NONOate). Rapid delivery of NO-related signalling into platelets was monitored by cGMP accumulation and DAF-FM (4-amino-5-methylamino-2′7′-difluorofluorescein) fluorescence.
All NO redox donors produced both a cGMP response and DAF-FM fluorescence in target platelets. NO delivery was blocked by inhibition of PDI in a dose-dependent manner. In contrast, inhibition of GPx and L-AT had only a minimal effect on NO-related signalling.
PDI activity is therefore required for the rapid delivery into platelets of NO-related signals from donors of all NO redox derivatives. GPx and the L-AT system appeared to be unimportant in rapid NO signalling by the compounds used in the present study. This does not, however, exclude a possible role during exposure of cells to other S-nitrosothiol compounds, such as S-nitrosocysteine. These results further highlight the importance of PDI in mediating the action of a wide range of NO-related signals.
Exploring the Crisis Readiness Perceptions of Hotel Managers in the UK
Authors: Rousaki Barbara , Alcott Peter 
Published: March 2007

Organisations such as hotels ‘live’ and ‘evolve’ around and in an environment where stability is no longer the norm. In such a volatile environment, it is crucial for hospitality leaders to have a well-reasoned strategic plan, as well as to be flexible and farsighted enough to be aware when alterations to it are required. Preparing for the unseen calls for versatility, which is the very foundation of organisational crisis management. This exploratory study applied the construct ‘crisis readiness’ proposed by Reilly (1987) with the purpose of examining the relationship of organisation size, prior experience with crisis and managers' job level with crisis readiness within the lodging industry in the United Kingdom. The study is based on questionnaires sent to individual hospitality managers about their perceptions of their firms' readiness for crises. An online survey instrument was developed to measure perceived crisis readiness, from its managers' perspective. In the sample of hotel managers surveyed, the 93 respondents reported on agreement that their organisation is ready for crisis and moderate likelihood of their organisation experiencing a crisis. The study found strong support for the hypothesis that prior experience with crisis is associated with increasing crisis readiness perceptions and weak support for the hypotheses that increasing size and higher job levels are associated with higher perceived crisis readiness scores. Data on these relationships are useful in determining which factors play a part in improving a hotel's crisis management plans and offer suggestions for those hotels interested in increasing their readiness for crisis.
Community structure or function: effects of environmental stress on benthic macroinvertebrates at different spatial scales
Authors: FELD CHRISTIAN K. , HERING DANIEL 
Published: March 2007

Summary1. This study investigated the relation of benthic macroinvertebrates to environmental gradients in Central European lowland rivers. Taxonomic structure (taxa) and functional composition (metrics) were related to gradients at four different spatial scales (ecoregion, catchment, reach and site). The environmental variables at the catchment‐, reach‐ and site scales reflected the intensity of human impact: catchment and floodplain land use, riparian and floodplain degradation, flow regulation and river bank and bed modification.2. Field surveys and GIS yielded 130 parameters characterising the hydromorphology and land use of 75 river sections in Sweden, the Netherlands, Germany and Poland. Two hundred and forty‐four macroinvertebrate taxa and 84 derived community metrics and biotic indices such as functional guilds, diversity and composition measures were included in the analysis.3. Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA) showed that hydromorphological and land use variables explained 11.4%, 22.1% and 15.8% of the taxa variance at the catchment (‘macro’), reach (‘meso’) and site (‘micro’) scales, respectively, compared with 14.9%, 33.2% and 21.5% of the variance associated with the derived metrics. Ecoregion and season accounted for 10.9% and 20.5% of the variance of the taxonomic structure and functional composition, respectively.4. Partial CCA (pCCA) and RDA (pRDA) showed that the unique variance explained was slightly higher for taxa than for metrics. By contrast, the joint variance explained for metrics was much higher at all spatial scales and largest at the reach scale. Environmental variables explained 46.8% of metric variance and 32.4% of taxonomic structure.5. Canonical Correspondence Analysis and RDA identified clear environmental gradients along the two main ordination axes, namely, land use and hydromorphological degradation. The impact of catchment land use on benthic macroinvertebrates was mainly revealed by the proportion of urban areas. At the reach scale, riparian and floodplain attributes (bank fixation, riparian wooded vegetation, shading) and the proportion of large woody debris were strong predictors of the taxonomic structure and functional composition of benthic macroinvertebrates. At the site scale, artificial substrata indicated human impact, particularly the proportion of macro‐ and mesolithal used for bank enforcement (rip–rap).6. Our study revealed the importance of benthic macroinvertebrate functional measures (functional guilds, composition and abundance measures, sensitivity and tolerance measures, diversity measures) for detecting the impact of hydromorphological stress at different spatial scales.
Erythropoietin/erythropoietin receptor system is involved in angiogenesis in human neuroblastoma
Authors: Ribatti D , Poliani P L , Longo V , Mangieri D , Nico B , Vacca A 
Published: March 2007

Aims:  Previous studies have shown that increased vascularity is associated with tumour progression in human neuroblastoma (NB). The involvement of erythropoietin (Epo) in tumour angiogenesis has also been reported. The aim of this study was to correlate microvascular density and Epo/Epo‐receptor (EpoR) expression in endothelial and tumour cells to the clinical stage of NB.Methods and results:  Specimens of NB obtained from 20 patients were investigated immunohistochemically by using anti‐CD31, anti‐Epo and anti‐EpoR antibodies. The extent of angiogenesis was found to be up‐regulated in advanced disease. In keeping with this observation, Epo/EpoR expression in tumour and endothelial cells, respectively, was also highly correlated with the extent of angiogenesis and higher clinical stage.Conclusions:  The correlation of Epo/EpoR expression with angiogenesis and tumour progression suggests the presence of a loop in the Epo–EpoR system. Epo is secreted by tumour cells and affects vascular endothelial cells via its receptor, promoting tumour angiogenesis in a paracrine manner. Data suggest that Epo represents an important mediator in NB angiogenesis. Understanding the mechanisms of NB angiogenesis provides the basis for a rational approach to the development of antiangiogenic therapy in patients affected by NB.