bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient Cell-seeding into Scaffolds Improves Bone Formation
Authors: Hasegawa T. , Miwa M. , Sakai Y. , Niikura T. , Lee S.Y. , Oe K. , Iwakura T. , Kurosaka M. , Komori T.
Published: June 2010

Bone marrow stromal cells (BMSCs)/β-tricalcium phosphate (β-TCP) composites have attracted a great deal of attention in bone tissue engineering. If more effective bone regeneration is to be achieved, efficient cell-seeding systems need to be clarified. In this study, we investigated the number of cells contained in composites, and the in vitro/vivo osteogenic differentiation capacity of composites using 4 conventional systems of seeding rat BMSCs into β-TCP: soak, low-pressure, pipette, and syringe systems. The highest number of cells was contained in the composites from the syringe group. Moreover, after two-week osteogenic induction in vitro, the composites in the syringe group exhibited the highest osteogenic potential, which continued at 8 weeks after subcutaneous implantation in vivo. Our results indicated that efficient and appropriate cell-seeding could improve in vitro/vivo bone formation in composites and thus make a potential clinical contribution to successful bone tissue engineering. Abbreviations: BMSCs, bone marrow stromal cells; β-TCP, β-tricalcium phosphate; S-D, Sprague-Dawley; kPa, kilopascal; ALP, alkaline phosphatase; N, Newton; DNA, deoxyribonucleic acid; OCN, osteocalcin; ANOVA, analysis of variance; PLSD, protected least-significant difference; and HE, hematoxylin and eosin.
Feasibility and Effectiveness of a Pilot Health Promotion Program for Adults With Type 2 Diabetes
Authors: Kluding Patricia M. , Singh Rupali , Goetz Jeanine , Rucker Jason , Bracciano Sarah , Curry Natasha
Published: June 2010

Purpose

The purpose of this pilot study was to assess the feasibility and effectiveness of an intense health promotion program in older adults with diabetes. The program combined individually prescribed and supervised exercise with nutrition and education programs on glycemic control and aerobic fitness.

Methods

Various recruitment and retention strategies were analyzed for effectiveness. Out of 28 potential subjects assessed for eligibility, 6 subjects with type 2 diabetes (2 male and 4 female; all white; age, 60.2 ± 4.7 years) participated in the 10-week intervention. Aerobic and resistance exercise was performed on alternate days (3-4 days per week), with individualized nutrition counseling and diabetes health education sessions once weekly. The primary outcome measures were aerobic fitness and glycemic control (A1C), and secondary outcome measures included body mass index (BMI), self-efficacy, and symptoms of neuropathy. Changes in outcomes were assessed using descriptive statistics and paired t test analysis (α = .05).

Results

Following the intervention, subjects had improvements that approached significance in A1C and pain, with significant improvements in self-efficacy.

Conclusions

A systematic approach to analysis of feasibility revealed issues with recruitment and retention that would need to be addressed for future studies or clinical implementation of this program. However, for the subset of subjects who did complete the intervention, adherence was excellent, and satisfaction with the program was confirmed by exit interview comments. Following participation in this pilot health promotion program, subjects had meaningful improvements in glycemic control, pain, and self-efficacy.
Predicting the timing of leaving home and related developmental tasks: Parents’ and children’s perspectives
Authors: Seiffge-Krenke Inge
Published: June 2010

In this longitudinal study, we examined the changes in romantic activity, parental support, and the quality of parents’ marital relationships as predictors of the timing of leaving home in a sample of 93 children and their parents. During their adolescent years, on-time leavers received decreasing levels of parental support and were more romantically active, compared with late leavers or those later residing with their parents. The lower romantic activity of the two latter groups continued throughout emerging adulthood. No differences between the three groups emerged with respect to professional career. Parents’ marital quality had no impact on the timing of leaving home. The children’s and parents’ retrospective evaluations of the timing of leaving home were similar, but mothers perceived the transition as being more stressful than fathers did.
Draining ties: Tie quality versus content in low-income women’s social networks when displaced by redevelopment
Authors: Garshick Kleit Rachel
Published: June 2010

Public housing redevelopment has the potential to disrupt resident social support social networks. In reaction to Curley’s (2009) finding that some relocated residents from the Maverick HOPE VI site were able to slough off non-reciprocal social support ties — ”draining ties” — this paper hypothesizes that relocation does not alter patterns of interaction. That is, if someone depended on neighbors for social support, they continued to do so; if someone was avoidant, they continued to do that. A promising direction for social interventions to support residents in their relocation may be to more deliberately help relocated residents maintain social support networks, so that those who were avoiding “draining ties” in public housing do not lose out on potentially beneficial social ties in their new settings.
Efficacy of exercise and ultrasound in patients with lumbar spinal stenosis: a prospective randomized controlled trial
Authors: Goren Ahmet , Yildiz Necmettin , Topuz Oya , Findikoglu Gulin , Ardic Fusun
Published: June 2010

Objective: To assess the effectiveness of therapeutic exercises alone and in combination with a single physical agent — ultrasound — in patients with lumbar spinal stenosis.

Design: Randomized, prospective, controlled trial.

Setting: Department of Physical Medicine and Rehabilitation, University Hospital.

Subjects: Forty-five patients presenting with symptoms of neurological claudication and magnetic resonance image-proven lumbar spinal stenosis were assigned to one of three groups: ultrasound plus exercise group (group 1, n =15), sham ultrasound plus exercise group (group 2, n= 15) and no exercise — no treatment group (control group, n = 15).

Interventions: Stretching and strengthening exercises for lumbar, abdominal, leg muscles as well as low-intensity cycling exercises were given as therapeutic exercises. Ultrasound was applied with 1 mHz, 1.5 W/cm2 intensity, in continuous mode on the back muscle for 10 minutes in group 1 while ultrasound on/off mode was applied in group 2.

Main outcome measures: Before and after a three-week period, all subjects were evaluated by pain, disability, functional capacity and consumption of analgesic.

Results: Thirty-two of the participants were women and 13 were men, with an average age of 53.2 ± 12.68 years (range 25—82 years). After a three-week treatment period, leg pain decreased in group 1 (—1.47 ± 3.02) and group 2 (—2.47 ± 3.75) compared with the control group (P<0.05). Disability score decreased in group 1 (—3.94 ± 7.20) and group 2 (—7.80 ± 10.26) compared with control group (P<0.05). We did not find any statistically significant difference between groups 1 and 2 (P>0.05). The amount of analgesic consumption is significantly less in the group with ultrasound application compared to that in the control group (P<0.05).

Conclusion: The results of our study suggest that therapeutic exercises are effective for pain and disability in patients with lumbar spinal stenosis and that addition of ultrasound to exercise therapy lowers the analgesic intake substantially.
Opioids and anxiety
Authors: Colasanti A , Rabiner EA , Lingford-Hughes A , Nutt DJ
Published: June 2010

The opioid system plays a crucial role in the neural modulation of anxiety. The involvement of opioid ligands and receptors in physiological and dysfunctional forms of anxiety is supported by findings from a wide range of preclinical and clinical studies, including clinical trials, experimental research, and neuroimaging, genetic, and epidemiological data. In this review we provide a summary of studies from a variety of research disciplines to elucidate the role of the opioid system in the neurobiology of anxiety. First, we report data from preclinical studies using animal models to examine the modulatory role of central opioid system on defensive responses conducive to fear and anxiety. Second, we summarize the human literature providing evidence that clinical and experimental human studies are consistent with preclinical models. The implication of these data is that activation of the opioid system leads to anxiolytic responses both in healthy subjects and in patients suffering from anxiety disorders. The role of opioids in suppressing anxiety may serve as an adaptive mechanism, collocated in the general framework of opioid neurotransmission blunting acute negative and distressing affective responses.
Cohort Decomposition for Markov Cost-Effectiveness Models
Authors: Hazen Gordon
Published: June 2010

Cohort analysis is a widespread tool for computing expected costs and quality-adjusted life years (QALYs) in Markov models for medical cost-effectiveness analyses. Although not always explicitly identified, such models commonly have multiple simple factors, or components. In these, a health state consists of a multiple component vector, one component for each factor, and arbitrary combinations of components are possible. The authors show here that when the model does not assume any probabilistic dependence among these factors, then a standard cohort analysis may be decomposed into several independent cohort analyses, one for each factor, and the results may be combined to produce desired expected costs and QALYs. These single-factor cohort analyses are not only simpler but also computationally more efficient. The authors derive the appropriate formulas for this cohort decomposition in discrete time and give several examples of their use based on published cost-effectiveness analyses. Explicitly identifying the simple factors of which a model is composed allows these factors to be portrayed graphically. Graphical depiction of the simple factors that comprise a model reduces model complexity, makes model formulation easier and more transparent, and thereby facilitates peer inspection and critique.
Positional cluster-like headache. A case report of a neurovascular compression between the third cervical root and the vertebral artery
Authors: Créac’h Christelle , Duthel Robert , Barral Fabrice , Nuti Christophe , Navez Malou , Demarquay Genevieve , Laurent Bernard , Peyron Roland
Published: June 2010

Symptomatic cluster-like headaches have been described with lesions of the trigeminal and parasympathetic systems. Here, we report the case of a 44-year-old woman with continuous auricular pain and a positional cluster-like headache associated with red ear syndrome. Clinical data and morphological investigations raised the hypothesis of a neurovascular compression between the C3 root and vertebral artery. Neurosurgical exploration found a fibrosis surrounding both the C3 root and the vertebral artery. The excellent outcome after microvascular cervical decompression suggests a causal relationship between the cluster-like headache and the vertebral constraint on the C3 root.
Factors influencing Malaysian public attitudes to agro-biotechnology
Authors: Amin Latifah , Ahmad Jamil , Md. Jahi Jamaluddin , Md. Nor Abd. Rahim , Osman Mohamad , Mahadi Nor Muhammad
Published: June 2010

Despite considerable research in advanced countries on public perceptions of and attitudes to modern biotechnology, limited effort has been geared towards developing a structural model of public attitudes to modern biotechnology. The purpose of this paper is to identify the relevant factors influencing public attitudes towards genetically modified (GM) soybean, and to analyze the relationship between all the attitudinal factors. A survey was carried out on 1,017 respondents from various stakeholder groups in the Klang Valley region. Results of the survey have confirmed that attitudes towards complex issues such as biotechnology should be seen as a multifaceted process. The most important factors predicting support for GM soybean are the specific application-linked perceptions about the benefits, acceptance of risk and moral concern while risk and familiarity are significant predictors of benefit and risk acceptance. Attitudes towards GM soybean are also predicted by several general classes of attitude.
Default Risk Characteristics of Poll-Based Bond Spreads
Authors: M. Jayadev , Jacob Joshy
Published: June 2010

Poor liquidity of corporate bonds in emerging markets deters reliable estimation of credit spreads. As an alternative, credit spreads based on poll data are introduced in India. These spreads are used for pricing new credit instruments and for valuation of bond portfolios. We examine the credit risk characteristics of these spreads based on the structural models of bond pricing. We find that the spreads are largely deter-mined by the proxies of default probability and recovery rate. Also, the relation between spreads and important credit risk variables is as predicted by the models. These results support the use of poll-based credit spreads. Introducing poll-based spreads in less liquid corporate bond markets is likely to offer a reliable basis for pricing credit instruments and derivatives.
Volatility in Indian Stock Markets
Authors: Krishnan R. , Mukherjee Conan
Published: June 2010

This article attempts to identify, from among the family of Generalised Autoregressive Conditional Heteroscedasticity (GARCH) models, the model that best describes the Indian stock market volatility by (a) building volatility models using the traditional GARCH models that accounts for asymmetry; (b) selecting a suitable model by nesting through Box-Cox transformation, a family of GARCH models. Our results confirm the stylised fact of the presence of leverage effects in the stock market. But contrary to popular belief, our results show that (a) it is the smaller shocks that affect the returns in the Indian stock market and dominate the news impact curve than the larger shocks; (b) nesting exercise has narrowed down to two entirely different sets of models that could describe equally well the returns data of the Indian stock market; but overall results indicate that a non-linear model that uses the conditional standard deviation with an exponent that accounts for smaller shocks may be preferable to explaining time-varying volatility in Indian stock returns data. (c) Another feature typical of the Indian stock market but unexplored so far, the non-trading days, has been found to be accounting for a sizable portion of the return variance, contributing almost one-fourth as much to volatility as any trading day.
Reproducibility of high-resolution optical coherence tomography in multiple sclerosis
Authors: Syc Stephanie B , Warner Christina V , Hiremath Girish S , Farrell Sheena K , Ratchford John N , Conger Amy , Frohman Teresa , Cutter Gary , Balcer Laura J , Frohman Elliot M , Calabresi Peter A
Published: June 2010

Optical coherence tomography (OCT) is a non-invasive method to quantify neurodegeneration as an outcome in multiple sclerosis clinical trials; however, no data exist on Cirrus spectral domain optical coherence tomography (SD-OCT) reproducibility in patients with multiple sclerosis. The objective of this study was to determine the protocol for achieving optimal inter-visit, inter-rater, and intra-rater reproducibility for studies performed on healthy controls and multiple sclerosis patients utilizing novel high-definition SD-OCT. This is a prospective study of inter-visit, inter-rater, and intra-rater reproducibility in multiple sclerosis patients ( n = 58) and healthy controls ( n = 32) on Cirrus-HD SD-OCT. Excellent reproducibility of average and quadrantic retinal nerve fiber layer (RNFL) thickness values, average macular thickness (AMT), and total macular volume (TMV) [measured by intraclass correlation coefficient (ICC)] was found for inter-visit (healthy controls: mean RNFL = 0.97, quadrant range = 0.92—0.97, AMT = 0.97, TMV = 0.92), inter-rater (MS: mean RNFL = 0.97, quadrant = 0.94—0.98, AMT = 0.99, TMV = 0.96; healthy controls: mean RNFL = 0.97, quadrant = 0.94—0.97, AMT = 0.98, TMV = 0.99), and intra-rater (MS patients: mean RNFL = 0.99, quadrant = 0.83—0.99, AMT = 0.97, TMV = 0.98) reproducibility. The reproducibility of retinal measures derived by Cirrus HD-OCT, especially quadrantic values, is excellent. Specific procedures for OCT acquisition and analysis of retinal imaging metrics using SD-OCT technology may improve the application of this novel technology in multiple sclerosis.
Perceptions of Community-Based Participatory Research in the Delta Nutrition Intervention Research Initiative
Authors: Downey Laura Hall , Castellanos Diana Cuy , Yadrick Kathy , Avis-Williams Amanda , Graham-Kresge Susan , Bogle Margaret
Published: June 2010

Lower Mississippi Delta Nutrition Intervention Research Initiative (Delta NIRI) is an academic–community partnership between seven academic institutions and three communities in Mississippi, Arkansas, and Louisiana. A range of community-based participatory methods have been used to develop sustainable nutrition intervention strategies. Focus groups were conducted with 22 faculty and staff members from the academic partners on the project to document their perceptions of community-based participatory processes in a federally funded, multi-academic–community partnership spanning a decade. Focus groups were conducted to glean insights or lessons from the experiences of academic personnel. Focus groups were transcribed and analyzed using the constant comparative method. Two researchers analyzed each transcript independently and reached consensus on the consistent themes. Participants candidly shared their experiences of working with community members to devise research plans, implement programs, and evaluate outcomes. The majority of faculty and staff members were attracted to this project by an excitement for conducting a more egalitarian and potentially more successful type of research. Yet each academic partner voiced that there was an underlying disconnect between community practices and research procedures during the project. Additional barriers to collaboration and action, located in communities and academic institutions, were described. Academic partners stressed the importance of open and ongoing communication, collective decision-making strategies, and techniques that support power sharing between all parties involved in the project. Findings from this research can inform academic–community partnerships and hopefully improve the community-based participatory research process implemented by academic institutions and communities.
Androgen receptor molecular biology and potential targets in prostate cancer
Authors: Wilson Elizabeth M.
Published: June 2010

The androgen receptor (AR) is a key transcriptional regulator and therapeutic target in prostate cancer. During androgen deprivation therapy to treat metastatic prostate cancer, surviving cells acquire increased AR signaling through a variety of mechanisms, one of which is enhanced interactions with AR coactivators. One recently identified AR-specific coregulator expressed only in human and nonhuman primates is the melanoma antigen gene protein-A11 (MAGE-11). MAGE-11 increases AR transcriptional activity through direct interactions with AR and other coactivators, and its levels increase during prostate cancer progression to castration-recurrent growth. The MAGE-11 gene is located at Xq28 on the human X chromosome as part of an X-linked MAGE gene family of cancer—testis antigens. MAGE-11 stabilizes AR when androgen levels are low, and functions in a transcriptional hub to promote AR-mediated gene activation. The evolutionary development and organization of the MAGE-11 gene within the cancer—testis antigen family suggests that MAGE-11 provides a gain-of-function to AR among primates in both normal physiology and cancer, and may serve as a therapeutic target in the treatment of advanced prostate cancer.
Influence of compatibiliser blends on mechanical and thermal properties of polymer–clay nanocomposites
Authors: Hetzer M. , Zhou H. X. , Poloso T. , De Kee D.
Published: June 2010

The effects of compatibiliser molecular weight, temperature of the first mixing zone of the extruder and nanoclay loading on the mechanical and thermal properties of polymer–clay nanocomposites (PCNs) were investigated. It was found that the molecular weight of the compatibiliser, the temperature of the first mixing zone of the extruder and the nanoclay content have significant effects on the mechanical and thermal properties of the polyethylene–clay nanocomposites. The blending of the high and low molecular weight compatibilisers allowed a more efficient interface between the nanoclay and the polymer matrix. Coupling a more efficient bonding with the high shear in the first mixing zone of the extruder at a low temperature produced an intercalated/exfoliated nanoclay filler resulting in enhanced mechanical properties of the PCNs.
Properties of SiCf/SiC composites fabricated by slurry infiltration and hot pressing
Authors: Yonathan P. , Lee J-H. , Kim H-T. , Yoon D-H.
Published: June 2010

Two-dimensional SiC fibre reinforced SiC ceramic matrix composites (SiCf/SiC) were fabricated by vacuum infiltration and hot pressing using a 200 nm thick pyrolytic carbon coated Tyranno SA3 fabric and 50 nm sized β-SiC powder. Hot pressing was carried out at 1750°C for 3 h in an Ar atmosphere under a pressure of 20 MPa. Al2O3–Y2O3–MgO sintering additive (10 wt-) and polyvinyl butyral resin (45 wt-) with respect to the matrix SiC were found to be the optimum contents for the high density composite. Vacuum infiltration with a force gradient produced much higher amount of slurry infiltration than simple dipping. Much improved density of 3·02 g cm−3, compared to the previous reports, was achieved for the SiC–SiCf containing approximately 67 vol.- of fibre. This composite showed a step increase with a stress–displacement behaviour during the three-point bending test due to the fibre reinforcement. The displacement for failure and flexural strength were 0·58 mm and 342 MPa respectively, which were much larger than those for monolithic SiC.
Elastic instabilities in dry, mesoporous minerals and their relevance to geological applications
Authors: Salje E. K. H. , Koppensteiner J. , Schranz W. , Fritsch E.
Published: June 2010

The collapse of minerals and mineral assemblies under external stress is modelled using a master curve where the stress failure is related to the relative, effective elastic moduli which are in turn related to the porosity of the sample. While a universal description is known not to be possible, we argue that for most porous materials such as shales, silica, cement phases, hydroxyapatite, zircon and also carbonates in corals and agglomerates we can estimate the critical porosity ϕc at which small stresses will lead to the collapse of the sample. For several samples we find ϕc ~0.5 with an almost linear decay of the bulk moduli with porosity at ϕc <0.5. The second scenario involves the persistence of elasticity for porosities until almost 1 whereby the bulk modulus decreases following a power law κ ~ (1–ϕm, m>2, between ϕ = 0.5 and ϕ = 1.
The endocytic adaptor Numb regulates thymus size by modulating pre-TCR signaling during asymmetric division
Authors: Aguado Rocio , Martin-Blanco Nadia , Caraballo Michael , Canelles Matilde
Published: June 2010

Stem cells must proliferate and differentiate to generate the lineages that shape mature organs; understanding these 2 processes and their interaction is one of the central themes in current biomedicine. An intriguing aspect is asymmetric division, by which 2 daughter cells with different fates are generated. Several cell fate determinants participate in asymmetric division, with the endocytic adaptor Numb as the best-known example. Here, we have explored the role of asymmetric division in thymocyte development, visualizing the differential segregation of Numb and pre-TCR in thymic precursors. Analysis of mice where Numb had been inhibited by expressing a dominant negative revealed enhanced pre–T-cell receptor (TCR) signaling and a smaller thymus. Conversely, Numb overexpression resulted in loss of asymmetric division and a larger thymus. The conclusion is that Numb determines the levels of pre-TCR signaling in dividing thymocytes and, ultimately, the size of the pool from which mature T lymphocytes are selected.
High mortality from Plasmodium falciparum malaria in children living with sickle cell anemia on the coast of Kenya
Authors: McAuley Charlotte F. , Webb Clare , Makani Julie , Macharia Alexander , Uyoga Sophie , Opi Daniel H. , Ndila Carolyne , Ngatia Antony , Scott John Anthony G. , Marsh Kevin , Williams Thomas N.
Published: June 2010

Although malaria is widely considered a major cause of death in young children born with sickle cell anemia (SCA) in sub-Saharan Africa, this is poorly quantified. We attempted to investigate this question through 4 large case-control analyses involving 7164 children living on the coast of Kenya. SCA was associated with an increased risk of admission to hospital both with nonmalaria diseases in general (odds ratio [OR] = 4.17; 95% confidence interval [CI], 1.95-8.92; P < .001) and with invasive bacterial diseases in particular (OR = 8.73; 95% CI, 4.51-16.89; P < .001). We found no evidence for a strongly increased risk of either uncomplicated malaria (OR = 0.43; 95% CI, 0.09-2.10; P = .30) or malaria complicated by a range of well-described clinical features of severity (OR = 0.80; 95% CI, 0.25-2.51; P = .70) overall; nevertheless, mortality was considerably higher among SCA than non-SCA children hospitalized with malaria. Our findings highlight both the central role that malaria plays in the high early mortality seen in African children with SCA and the urgent need for better quantitative data. Meanwhile, our study confirms the importance of providing all children living with SCA in malaria-endemic areas with effective prophylaxis.
Unsuspected diversity of Niphargus amphipods in the chemoautotrophic cave ecosystem of Frasassi, central Italy
Authors: Flot Jean-François , Wörheide Gert , Dattagupta Sharmishtha
Published: June 2010

Background

The sulfide-rich Frasassi caves in central Italy contain a rare example of a freshwater ecosystem supported entirely by chemoautotrophy.Niphargus ictus, the sole amphipod species previously reported from this locality, was recently shown to host the first known case of a freshwater chemoautotrophic symbiosis. Since the habitat ofN. ictusis highly fragmented and is comprised of streams and lakes with various sulfide concentrations, we conducted a detailed study to examine the potential genetic diversity of this species within Frasassi.

Results

By sequencing one nuclear (ITS) and two mitochondrial (COI and 12S) regions, we show that four partially sympatricNiphargusclades are present in Frasassi. Morphological and behavioral data obtained for three of these clades are perfectly congruent with this molecular delineation and make it possible to distinguish them in the field. Phylogenetic analyses of 28S ribosomal DNA sequences reveal that, among the four clades, only two are closely related to each other. Moreover, these four clades occupy distinct niches that seem to be related to the chemical properties and flow regimes of the various water bodies within Frasassi.

Conclusions

Our results suggest that four distinctNiphargusspecies are present in Frasassi and that they originated from three or four independent invasions of the cave system. At least two among the four species harborThiothrixepibionts, which paves the way for further studies of the specificity and evolutionary history of this symbiosis.
Periostin is up-regulated in high grade and high stage prostate cancer
Authors: Tischler Verena , Fritzsche Florian R , Wild Peter J , Stephan Carsten , Seifert Hans-Helge , Riener Marc-Oliver , Hermanns Thomas , Mortezavi Ashkan , Gerhardt Josefine , Schraml Peter , Jung Klaus , Moch Holger , Soltermann Alex , Kristiansen Glen
Published: June 2010

Background

Expression of periostin is an indicator of epithelial-mesenchymal transition in cancer but a detailed analysis of periostin expression in prostate cancer has not been conducted so far.

Methods

Here, we evaluated periostin expression in prostate cancer cells and peritumoural stroma immunohistochemically in two independent prostate cancer cohorts, including a training cohort (n = 93) and a test cohort (n = 325). Metastatic prostate cancers (n = 20), hormone refractory prostate cancers (n = 19) and benign prostatic tissues (n = 38) were also analyzed.

Results

In total, strong epithelial periostin expression was detectable in 142 of 418 (34.0%) of prostate carcinomas and in 11 of 38 benign prostate glands (28.9%). Increased periostin expression in carcinoma cells was significantly associated with high Gleason score (p < 0.01) and advanced tumour stage (p < 0.05) in the test cohort. Whereas periostin expression was weak or absent in the stroma around normal prostate glands, strong periostin expression in tumour stroma was found in most primary and metastatic prostate cancers. High stromal periostin expression was associated with higher Gleason scores (p < 0.001). There was a relationship between stromal periostin expression and shortened PSA relapse free survival times in the training cohort (p < 0.05).

Conclusions

Our data indicate that periostin up-regulation is related to increased tumour aggressiveness in prostate cancer and might be a promising target for therapeutical interventions in primary and metastatic prostate cancer.
Obesity induced by a pair-fed high fat sucrose diet: methylation and expression pattern of genes related to energy homeostasis
Authors: Lomba Almudena , Milagro Fermín I , García-Díaz Diego F , Marti Amelia , Campión Javier , Martínez J Alfredo
Published: June 2010

Background

The expression of some genes controlling energy homeostasis could be regulated by epigenetic mechanisms that may play a role in body weight regulation. Thus, it is known that various nutritional factors affect DNA methylation. In order to assess whether the macronutrient composition of the diet could be related to the epigenetic regulation of gene expression and with obesity development, we investigated the effects on methylation and expression patterns of two pair-fed isocaloric diets in rats: control (rich in starch) and HFS (rich in fat and sucrose).

Results

The pair-fed HFS diet induced higher weight gain and adiposity as compared to the controls as well as liver triglyceride accumulation and oxidative stress. Feeding the HFS diet impaired glucose tolerance and serum triglycerides and cholesterol. Liver glucokinase expression, a key glycolytic gene, remained unaltered, as well as the mRNA values of fatty acid synthase and NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 6 (NDUFB6) in liver and visceral adipocytes, which regulate lipogenesis and mitochondrial oxidative metabolism, respectively. Liver expression of hydroxyacyl-coenzyme A dehydrogenase (HADHB), a key gene of β-oxidation pathway, was higher in the HFS-fed animals. However, the methylation status of CpG islands in HADHB and glucokinase genes remained unchanged after feeding the HFS diet.

Conclusions

These results confirm that the distribution and type of macronutrients (starch vs. sucrose, and percent of fat) influence obesity onset and the associated metabolic complications. HFS diets produce obesity independently of total energy intake, although apparently no epigenetic (DNA methylation) changes accompanied the modifications observed in gene expression.
The phosphatidylinositol 4-kinase PI4KIIIα is required for the recruitment of GBF1 to Golgi membranes
Authors: Dumaresq-Doiron Karine , Savard Marie-France , Akam Salima , Costantino Santiago , Lefrancois Stephane
Published: June 2010

Sorting from the Golgi apparatus requires the recruitment of cytosolic coat proteins to package cargo into trafficking vesicles. An important early step in the formation of trafficking vesicles is the activation of Arf1 by the guanine nucleotide exchange factor GBF1. To activate Arf1, GBF1 must be recruited to and bound to Golgi membranes, a process that requires Rab1b. However, the mechanistic details of how Rab1 is implicated in GBF1 recruitment are not known. In this study, we demonstrate that the recruitment of GBF1 also requires phosphatidylinositol 4-phosphate [PtdIns(4)P]. Inhibitors of PtdIns(4)P synthesis or depletion of PI4KIIIα, a phosphatidylinositol 4-kinase localized to the endoplasmic reticulum and Golgi, prevents the recruitment of GBF1 to Golgi membranes. Interestingly, transfection of dominant-active Rab1 increased the amount of PtdIns(4)P at the Golgi, as detected by GFP-PH, a PtdIns(4)P-sensing probe. We propose that Rab1 contributes to the specificity and timing of GBF1 recruitment by activating PI4KIIIα. The PtdIns(4)P produced then allows GBF1 to bind to Golgi membranes and activate Arf1.
The p75NTR intracellular domain generated by neurotrophin-induced receptor cleavage potentiates Trk signaling
Authors: Ceni Claire , Kommaddi Reddy Peera , Thomas Rhalena , Vereker Emily , Liu Xiaoyang , McPherson Peter S. , Ritter Brigitte , Barker Philip A.
Published: June 2010

The p75 neurotrophin receptor (p75NTR) potentiates Trk signaling, but the underlying mechanisms remain uncertain. Here, we examine the relationship between p75NTR cleavage and Trk signaling. We found that, in PC12 cells, nerve growth factor (NGF) induces rapid and robust α-secretase- and γ-secretase-dependent cleavage of p75NTR, releasing the resulting intracellular domain into the cytosol. Brain-derived neurotrophic factor similarly induces p75NTR cleavage in primary cerebellar granule neurons. p75NTR cleavage occurs by means of Trk-dependent activation of MEK-Erk signaling and induction of α-secretase activity, and is independent of ligand binding to p75NTR. Neurons and PC12 cells lacking p75NTR display defects in neurotrophin-dependent Akt activation. Normal Akt activation is rescued using full-length p75NTR or the p75 intracellular domain, but not cleavage-resistant p75NTR. We then demonstrate that NGF-dependent growth arrest of PC12 cells requires p75NTR cleavage and generation of the intracellular domain. We conclude that generation of the soluble p75NTR intracellular domain by Trk-induced cleavage plays a fundamental role in Trk-dependent signaling events.
Visualizing extravasation dynamics of metastatic tumor cells
Authors: Stoletov Konstantin , Kato Hisashi , Zardouzian Erin , Kelber Jonathan , Yang Jing , Shattil Sanford , Klemke Richard
Published: June 2010

Little is known about how metastatic cancer cells arrest in small capillaries and traverse the vascular wall during extravasation in vivo. Using real-time intravital imaging of human tumor cells transplanted into transparent zebrafish, we show here that extravasation of cancer cells is a highly dynamic process that involves the modulation of tumor cell adhesion to the endothelium and intravascular cell migration along the luminal surface of the vascular wall. Tumor cells do not damage or induce vascular leak at the site of extravasation, but rather induce local vessel remodeling characterized by clustering of endothelial cells and cell-cell junctions. Intravascular locomotion of tumor cells is independent of the direction of blood flow and requires β1-integrin-mediated adhesion to the blood-vessel wall. Interestingly, the expression of the pro-metastatic gene Twist in tumor cells increases their intravascular migration and extravasation through the vessel wall. However, in this case, Twist expression causes the tumor cells to switch to a β1-integrin-independent mode of extravasation that is associated with the formation of large dynamic rounded membrane protrusions. Our results demonstrate that extravasation of tumor cells is a highly dynamic process influenced by metastatic genes that target adhesion and intravascular migration of tumor cells, and induce endothelial remodeling.
Experimental Study of Stall in an Airfoil with Forced Airflow Provided by an Integrated Cross-Flow Fan
Authors: Askari S , Shojaeefard M H , Goudarzi K
Published: June 2010

The objective of this article is to experimentally determine the stall characteristics of the FanWing airfoil. The experiments have been performed at various angles of attack, tip speed ratios, Reynolds numbers, and flap deflection angles. The experiments showed that the lift coefficient and stall angle of attack of the airfoil (value of angle of attack at which the lift-to-drag ratio is maximum) increase and its drag coefficient decreases with the tip speed ratio; however, its stall angle of attack decreases with the Reynolds number. Thus, high Reynolds number flows over this airfoil are more prone to separation and stall, and therefore, the tip speed ratio must be increased by enhancing the rotational speed or the angle of attack must be reduced to avoid stall and separation. It was perceived that the lift coefficient curve gives the maximum value at 40° < α < 50° (α is the angle of attack) interval, depending on the tip speed ratio and the Reynolds number. Experiments revealed that the airfoil lift coefficient increases significantly with the flap deflection angle, and therefore, a feasible option for bypassing the stall problem is to increase the flap deflection angle instead of the angle of attack for providing the required lift. Detailed analysis of the experimental results showed no relation between the flap angle and angle of attack.
Consistency, Verification, and Validation of Turbulence Models for Reynolds-Averaged Navier—stokes Applications
Authors: Rumsey C L
Published: June 2010

In current practice, it is often difficult to draw firm conclusions about turbulence model accuracy when performing multi-code computational fluid dynamics studies ostensibly using the same model because of inconsistencies in model formulation or implementation in different codes. This article describes an effort to improve the consistency, verification, and validation of turbulence models within the aerospace community through a website database of verification and validation cases. Some of the variants of two widely used turbulence models are described, and two independent computer codes (one structured and one unstructured) are used in conjunction with two specific versions of these models to demonstrate consistency with grid refinement for several representative problems. Naming conventions, implementation consistency, and thorough grid resolution studies are key factors necessary for success.
Optimization of planform and cruise conditions of a transport flying wing
Authors: Martinez-Val R , Perez E , Puertas J , Roa J
Published: June 2010

The flying wing is a promising concept for the mid long-term commercial aviation. After the previously published conceptual design of a 300-seat class flying wing, the present article carries out a parametric analysis to optimize its planform and analyse the suitable cruise conditions to achieve the highest efficiency of such configuration. The figures of merit chosen for the optimization are the direct operating cost and the maximum take-off weight per passenger, for a specified constant range of 10 000 km. The design has to respect five relevant constraints: wingspan (limited to 80 m), cabin width, wing tip chord, number of passengers, and cruise lift coefficient. The optimum aircraft fulfilling all constraints cruises at 45 000–47 000 ft and M = 0.82, has an aspect ratio of 6.3 and taper ratio of 0.10, and carries about 280 passengers in three-class seating. This aircraft is about 20 per cent more efficient than conventional wide bodies of similar size, in terms of trip fuel.
Development of a model capable of predicting the performance of piston ring—cylinder liner-like tribological interfaces
Authors: Felter C L , Vølund A , Imran T , Klit P
Published: June 2010

Friction in the piston ring package (piston, piston rings, and liner) is a major source of power consumption in large two-stroke marine diesel engines. In order to improve the frictional and wear performance, knowledge about the tribological interface between piston rings and liner is needed. The work described in this article addresses the subject from both an experimental and a theoretical perspective. First, a one-dimensional numerical model based on the Reynolds equation is presented. It uses a pressure—density relation for the modelling of cavitation. The viscosity is assumed to depend on a measured temperature only; thus, it is not necessary to include the energy equation. Conservation of oil is ensured throughout the domain by considering the amount of oil outside the lubricated interface. A model for hard contact through asperities is also included. Second, a laboratory-scale test rig is described. Results from a number of experimental tests with different geometries and running speeds are presented. Finally, a comparison between the measured friction force and simulated values is given. Good correlation between the measurements and the simulations has been observed, especially when running at a high speed. This article represents the first steps in the pursuit of being able to accurately model the interface between a piston ring and the cylinder liner in large two-stroke diesel engines.
Teaching Note—An Animated Demonstration of the Uncapacitated Network Simplex Algorithm
Authors: Baloukas Thanasis , Paparrizos Konstantios , Sifaleras Angelo
Published: June 2010

Operations Research (OR) instructors use visualizations to help teach graph algorithms and data structures. Algorithm visualization is an illustration of abstract concepts included in computer algorithms, making use of either static or dynamic (animated) computer graphics. In this paper we present new software that includes an animated demonstration of the uncapacitated primal network simplex algorithm. The aim of the animation software is twofold. First, it aims to help OR students understand the algorithm. The algorithm is difficult to grasp for many students because it generates a sequence of rooted trees. Second, it aims to enable OR instructors to explain each iteration of the algorithm visually with minimal effort. The software can be used in combinatorial optimization, graph theory, and similar courses. The software has been implemented as a Java applet, is freely available and highly interactive, and can be accessed through the Web. The software shows the solution process through textual information and depicts the relevant steps in pseudo code using multiple views.
Controversies Surrounding the Use of Etomidate for Rapid Sequence Intubation in Patients with Suspected Sepsis
Authors: Edwin Stephanie B , Walker Pamela L
Published: June 2010

Objective:

To evaluate the risk of adrenal insufficiency following a single dose of etomidate in patients with suspected sepsis requiring rapid sequence intubation.

Data Sources:

A literature search was conducted using PubMed, MEDLINE, EMBASE, and International Pharmaceutical Abstracts from the dates of database inception until April 2010, utilizing the terms adrenal insufficiency, etomidate, and sepsis.

Study Selection and Data Extraction:

Data were synthesized in a qualitative manner, as variable study designs were identified. All studies that evaluated the clinical association between etomidate-induced adrenal insufficiency and sepsis in adults were reviewed and included.

Data Synthesis:

A search of the literature revealed 7 studies that specifically evaluated clinical endpoints in septic adults receiving etomidate for induction prior to intubation. Three of the studies evaluated risk factors associated with adrenal insufficiency in critically ill patients. Each of these studies determined that etomidate exposure was independently associated with an inappropriate response to cosyntropin stimulation testing (CST). Two studies found no significant difference in hospital mortality rates when evaluating patients receiving induction with etomidate compared with alternative regimens. Three studies found an increased risk of adrenal insufficiency in patients exposed to etomidate. The majority of studies that evaluated the use of etomidate in sepsis were underpowered, leading to difficulty in establishing a causal relationship between drug-related adrenal insufficiency, morbidity, and mortality.

Conclusions:

Until further studies are available, etomidate should be reserved for hemodynamically unstable patients who cannot tolerate an alternative induction agent despite the administration of fluids or vasoactive agents.
Ridge structural equation modelling with correlation matrices for ordinal and continuous data
Authors: Yuan Ke‐Hai , Wu Ruilin , Bentler Peter M.
Published: June 2010

This paper develops a ridge procedure for structural equation modelling (SEM) with ordinal and continuous data by modelling the polychoric/polyserial/product‐moment correlation matrix R. Rather than directly fitting R, the procedure fits a structural model to Ra=R+aI by minimizing the normal distribution‐based discrepancy function, where a > 0. Statistical properties of the parameter estimates are obtained. Four statistics for overall model evaluation are proposed. Empirical results indicate that the ridge procedure for SEM with ordinal data has better convergence rate, smaller bias, smaller mean square error, and better overall model evaluation than the widely used maximum likelihood procedure.
Befriending for mental health problems: Processes of helping
Authors: Mitchell Gemma , Pistrang Nancy
Published: June 2010

Background. One avenue for addressing the social consequences of mental health problems is through befriending, a supportive relationship in which one‐to‐one companionship is provided on a regular basis. Although there is some evidence that befriending can improve psychological and social functioning, little is known about how it works.

Objective. This qualitative study aimed to understand the helping processes occurring in befriending relationships, from the perspectives of both befriendees and befrienders.

Method. Semi‐structured interviews were conducted individually and jointly with eight befriendees and their corresponding befrienders. Thematic analysis was carried out on the data set of 23 interviews.

Results. The analysis generated nine themes concerning qualities of the relationship valued by befriendees and befrienders (e.g., empathy and mutuality), processes of making meaning (e.g., considering alternative perspectives), and how change was effected in befriendees' lives (e.g., learning how to have healthier relationships with others). The accounts emphasized the importance of the quality of the relationship itself, and highlighted aspects of the relationship that were sometimes difficult to negotiate.

Conclusions. The findings suggest that befriending shares commonalities with other types of psychological help. However, it is also characterized by some particular challenges, such as establishing an empathic relationship and managing boundaries and endings.