bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constitutive phosphorylation of the FOXO1 transcription factor in gastric cancer cells correlates with microvessel area and the expressions of angiogenesis-related molecules
Authors: Kim Sue Youn , Yoon Jiyeon , Ko Young San , Chang Mee Soo , Park Jong-Wan , Lee Hee Eun , Kim Min A , Kim Ji Hun , Kim Woo Ho , Lee Byung Lan 
Published: June 2011

Abstract

Background
Although FOXO transcription factors may have an anti-angiogenic role, little is known about their role in tumor angiogenesis. The present study was performed to investigate the correlation between the constitutive expression of phosphorylated FOXO1 (pFOXO1) and angiogenesis in gastric cancer.

Methods
Immunohistochemistry was performed on tissue array slides containing 272 gastric carcinoma specimens, and the correlations between the cytoplasmic pFOXO1 expression in gastric cancer cells and CD34-immunopositive microvessel area (MVA) or the expressions of angiogenesis-related molecules were analyzed. In vitro analyses with Western blotting and semiquantitative reverse transcription-polymerase chain reaction were performed using the stable SNU-638 gastric cancer cell line transfected with lentivirus-delivered FOXO1 short hairpin RNA.

Results
The cytoplasmic expression of pFOXO1 in tumor cells was observed in 85% of gastric carcinoma cases, and was found to be positively associated with higher MVA (P = 0.048). Moreover, pFOXO1 expression was positively correlated with the expressions of several angiogenesis-related proteins, including hypoxia inducible factor-1α (HIF-1α, P = 0.003), vessel endothelial growth factor (P = 0.004), phosphorylated protein kinase B (P < 0.001), and nuclear factor-κB (P = 0.040). In contrast, the expression of pFOXO1 was not correlated with that of phosphorylated signal transducer and activator of transcription 3 or β-catenin. In addition, cell culture experiments showed that FOXO1 suppression increased the mRNA and protein expressions of HIF-1α.

Conclusion
Our results suggest that pFOXO1 expression in cancer cells plays a role in gastric cancer angiogenesis via mechanisms involving various angiogenesis-related molecules. Animal experiments are needed to confirm the anti-angiogenic role of FOXO1 in human gastric cancer.
Learning curves and long-term outcome of simulation-based thoracentesis training for medical students
Authors: Jiang Guanchao , Chen Hong , Wang Shan , Zhou Qinghuan , Li Xiao , Chen Kezhong , Sui Xizhao 
Published: June 2011

Abstract

Background
Simulation-based medical education has been widely used in medical skills training; however, the effectiveness and long-term outcome of simulation-based training in thoracentesis requires further investigation. The purpose of this study was to assess the learning curve of simulation-based thoracentesis training, study skills retention and transfer of knowledge to a clinical setting following simulation-based education intervention in thoracentesis procedures.

Methods
Fifty-two medical students were enrolled in this study. Each participant performed five supervised trials on the simulator. Participant's performance was assessed by performance score (PS), procedure time (PT), and participant's confidence (PC). Learning curves for each variable were generated. Long-term outcome of the training was measured by the retesting and clinical performance evaluation 6 months and 1 year, respectively, after initial training on the simulator.

Results
Significant improvements in PS, PT, and PC were noted among the first 3 to 4 test trials (p < 0.05). A plateau for PS, PT, and PC in the learning curves occurred in trial 4. Retesting 6 months after training yielded similar scores to trial 5 (p > 0.05). Clinical competency in thoracentesis was improved in participants who received simulation training relative to that of first year medical residents without such experience (p < 0.05).

Conclusions
This study demonstrates that simulation-based thoracentesis training can significantly improve an individual's performance. The saturation of learning from the simulator can be achieved after four practice sessions. Simulation-based training can assist in long-term retention of skills and can be partially transferred to clinical practice.
YKL-40 levels are independently associated with albuminuria in type 2 diabetes
Authors: Røndbjerg Anne K , Omerovic Emina , Vestergaard Henrik 
Published: June 2011

Abstract

Objective and design
YKL-40 is involved in inflammation and endothelial dysfunction, and is increased in patients with type 1 diabetes, with an independent association between increasing YKL-40 levels and increasing levels of albuminuria. YKL-40 is associated with atherosclerosis and an increased cardiovascular mortality in the general population. In the present study YKL-40 levels were examined in patients with type 2 diabetes (T2D) with increasing levels of albuminuria, known to be associated with an increased risk of cardiovascular disease.

Materials and methods
One-hundred-five patients with T2D were examined: 49 with normoalbuminuria (N, U-albumin/creatinine < 2.5 mg/mmol), 35 with persistent microalbuminuria (MA, 2.5-25 mg/mmol) and 21 with persistent macroalbuminuria/diabetic nephropathy (DN, > 25 mg/mmol). The control group consisted of 20 healthy individuals (C). Groups were matched according to age, gender and known duration of diabetes.

Results
Median levels (interquartile range) of serum YKL-40 were significantly higher in N and MA vs. C (86 (55-137) ng/ml and 84 (71-147) ng/ml, respectively vs. 41 (33-55) ng/ml, p < 0.01) and even higher in patients with DN (120 (83-220) ng/ml, p < 0.001 for all comparisons). YKL-40 levels correlated with urinary albumin/creatinine-ratio in the total group of participants (r = 0.41, p < 0.001). Significant intercorrelations of YKL-40 were found with age, duration of diabetes, systolic blood pressure, lipid levels, HbA1c and HOMA-IR. After adjustment for significant covariates, albuminuria was significantly associated with YKL-40 levels (r = 0.32, p = 0.006).

Conclusions
YKL-40 levels are elevated in patients with T2D with an independent association between increasing YKL-40 levels and increasing levels of albuminuria. The study suggests a role of YKL-40 in the progressing vascular complications in patients with T2D.
The impact of Metastasis Suppressor-1, MTSS1, on oesophageal squamous cell carcinoma and its clinical significance
Authors: Xie Fei , Ye Lin , Chen Jinfeng , Wu Nan , Zhang Zhiqian , Yang Yue , Zhang Lijian , Jiang Wen G 
Published: June 2011

Abstract

Background
Metastasis suppressor-1 (MTSS1) has been proposed to function as a cytoskeletal protein with a role in cancer metastasis. Recent studies have demonstrated the clinical significance of MTSS1 in certain type of cancers, yet the clinical relevance of MTSS1 in oesophageal squamous cell carcinoma (ESCC) has not been reported.

Methods
In this study, we assessed the expression levels of MTSS1 in tumours and its matched adjacent non-tumour tissues obtained from 105 ESCC patients. We also used ESCC cells with differing MTSS1 expression and assessed the influence of MTSS1 on ESCC cells.

Results
Down-regulation of MTSS1 expression was observed both in oesophageal tumour tissues and ESCC cancer cell lines. We also reported that MTSS1 expression was associated with tumour grade (p = 0.024), lymph node metastasis (p = 0.010) and overall survival (p = 0.035). Patients with high levels of MTSS1 transcripts had a favorable prognosis in comparison with those who had reduced or absent expression levels. Using over-expression and knockdown approach, we created sublines from ESCC cells and further demonstrated that MTSS1 expression in ESCC cells significantly influenced the aggressiveness of the oesophageal cancer cells, by reducing their cellular migration and in vitro invasiveness.

Conclusion
MTSS1 serves as a potential prognostic indicator in human ESCC and may be an important target for cancer therapy.
An improved spectral homotopy analysis method for solving boundary layer problems
Authors: Motsa Sandile Sydney , Marewo Gerald T , Sibanda Precious , Shateyi Stanford 
Published: June 2011

Abstract
This article presents an improved spectral-homotopy analysis method (ISHAM) for solving nonlinear differential equations. The implementation of this new technique is shown by solving the Falkner-Skan and magnetohydrodynamic boundary layer problems. The results obtained are compared to numerical solutions in the literature and MATLAB's solver. The results show that the ISHAM converges faster and gives accurate results.
Vpx rescues HIV-1 transduction of dendritic cells from the antiviral state established by type 1 interferon
Authors: Pertel Thomas , Reinhard Christian , Luban Jeremy 
Published: June 2011

Abstract

Background
Vpx is a virion-associated protein encoded by SIVSM, a lentivirus endemic to the West African sooty mangabey (Cercocebus atys). HIV-2 and SIVMAC, zoonoses resulting from SIVSM transmission to humans or Asian rhesus macaques (Macaca mulatta), also encode Vpx. In myeloid cells, Vpx promotes reverse transcription and transduction by these viruses. This activity correlates with Vpx binding to DCAF1 (VPRBP) and association with the DDB1/RBX1/CUL4A E3 ubiquitin ligase complex. When delivered experimentally to myeloid cells using VSV G-pseudotyped virus-like particles (VLPs), Vpx promotes reverse transcription of retroviruses that do not normally encode Vpx.

Results
Here we show that Vpx has the extraordinary ability to completely rescue HIV-1 transduction of human monocyte-derived dendritic cells (MDDCs) from the potent antiviral state established by prior treatment with exogenous type 1 interferon (IFN). The magnitude of rescue was up to 1,000-fold, depending on the blood donor, and was also observed after induction of endogenous IFN and IFN-stimulated genes (ISGs) by LPS, poly(I:C), or poly(dA:dT). The effect was relatively specific in that Vpx-associated suppression of soluble IFN-β production, of mRNA levels for ISGs, or of cell surface markers for MDDC differentiation, was not detected. Vpx did not rescue HIV-2 or SIVMAC transduction from the antiviral state, even in the presence of SIVMAC or HIV-2 VLPs bearing additional Vpx, or in the presence of HIV-1 VLPs bearing all accessory genes. In contrast to the effect of Vpx on transduction of untreated MDDCs, HIV-1 rescue from the antiviral state was not dependent upon Vpx interaction with DCAF1 or on the presence of DCAF1 within the MDDC target cells. Additionally, although Vpx increased the level of HIV-1 reverse transcripts in MDDCs to the same extent whether or not MDDCs were treated with IFN or LPS, Vpx rescued a block specific to the antiviral state that occurred after HIV-1 cDNA penetrated the nucleus.

Conclusion
Vpx provides a tool for the characterization of a potent, new HIV-1 restriction activity, which acts in the nucleus of type 1 IFN-treated dendritic cells.
Detection of Four Novel Polymorphisms in PrP gene of Pakistani sheep (Damani and Hashtnagri) and goats (Kamori and Local Hairy) breeds
Authors: Hussain Amjed , Babar Masroor E , Imran Muhammad , Haq Ikram U , Javed Muhammad M 
Published: June 2011

Abstract
Scrapie is a fatal neurodegenerative disorder of sheep and goats caused by post-translational conformational change in the host-encoded prion protein (PrPC). Susceptibility or resistance to scrapie has been associated with the presence of polymorphisms in the prion protein (PrP) gene. In the present study, we analyzed the PrP gene sequence to determine the frequency of polymorphisms in 56 sheep (28 each from Damani and Hashtnagri breeds) and 56 goats (28 each from Kamori and Local Hairy breeds). A total of 7 amino acid polymorphisms were detected in the PrP gene for sheep and 4 for goats. These amino acid polymorphisms were combined in 13 alleles and 15 genotypes in sheep and 5 alleles and 6 genotypes in goats. The overall frequency of the most sheep scrapie-resistant polymorphism (Q171R) was calculated to be 0.107. The most scrapie-susceptible polymorphism (A136V) was not detected in any of the studied sheep. The overall frequency of scrapie-associated polymorphism (H143R) in goats was found to be 0.152. Along with already known amino acid polymorphisms, two novel polymorphisms were also detected for each of sheep (Q171N and T191I) and goats (G22C and P63L). However, the overall frequency of these polymorphisms was extremely low.
BioGraph: unsupervised biomedical knowledge discovery via automated hypothesis generation
Authors: Liekens Anthony ML , De Knijf Jeroen , Daelemans Walter , Goethals Bart , De Rijk Peter , Del-Favero Jurgen 
Published: June 2011

AbstractWe present BioGraph, a data integration and data mining platform for the exploration and discovery of biomedical information. The platform offers prioritizations of putative disease genes, supported by functional hypotheses. We show that BioGraph can retrospectively confirm recently discovered disease genes and identify potential susceptibility genes, outperforming existing technologies, without requiring prior domain knowledge. Additionally, BioGraph allows for generic biomedical applications beyond gene discovery. BioGraph is accessible at http://www.biograph.be.
Substitution rate variation at human CpG sites correlates with non-CpG divergence, methylation level and GC content
Authors: Mugal Carina F , Ellegren Hans 
Published: June 2011

Abstract
Background
A major goal in the study of molecular evolution is to unravel the mechanisms that induce variation in the germ line mutation rate and in the genome-wide mutation profile. The rate of germ line mutation is considerably higher for cytosines at CpG sites than for any other nucleotide in the human genome, an increase commonly attributed to cytosine methylation at CpG sites. The CpG mutation rate, however, is not uniform across the genome and, as methylation levels have recently been shown to vary throughout the genome, it has been hypothesized that methylation status may govern variation in the rate of CpG mutation.

Results
Here, we use genome-wide methylation data from human sperm cells to investigate the impact of DNA methylation on the CpG substitution rate in introns of human genes. We find that there is a significant correlation between the extent of methylation and the substitution rate at CpG sites. Further, we show that the CpG substitution rate is positively correlated with non-CpG divergence, suggesting susceptibility to factors responsible for the general mutation rate in the genome, and negatively correlated with GC content. We only observe a minor contribution of gene expression level, while recombination rate appears to have no significant effect.

Conclusions
Our study provides the first direct empirical support for the hypothesis that variation in the level of germ line methylation contributes to substitution rate variation at CpG sites. Moreover, we show that other genomic features also impact on CpG substitution rate variation.
Changes in gill H+-ATPase and Na+/K+-ATPase expression and activity during freshwater acclimation of Atlantic salmon (Salmo salar)
Authors: Bystriansky Jason S. , Schulte Patricia M. 
Published: June 2011

SUMMARYFew studies have examined changes in salmon gill ion transporter expression during the transition from seawater to freshwater, a pivotal moment in the salmonid life cycle. Seawater-acclimated Atlantic salmon were transferred to freshwater and blood and gill tissue were sampled over 30 days of acclimation. Salmon held in seawater had stable plasma osmolality and sodium and chloride levels throughout the experiment. Following freshwater exposure, plasma sodium and chloride levels and total osmolality decreased significantly before returning towards control levels over time. Gill H+-ATPase activity increased by more than 45% 14 days after exposure to freshwater, whereas H+-ATPase mRNA levels were not affected by the salinity change. Within 4 days of freshwater exposure, gill Na+/K+-ATPase activity increased ∼43% over control levels, remaining significantly higher until the 30 day sampling group when it declined back to control levels. This increase in activity was associated with a more than 7-fold increase in Na+/K+-ATPase isoform α1a mRNA level and a ∼60% decrease in Na+/K+-ATPase isoform β1b mRNA level. The mRNA levels of Na+/K+-ATPase isoforms α1c and α3 did not change as a result of freshwater exposure. The time courses for mRNA expression of the small membrane protein FXYD 11 and the β1-subunit were very similar, with levels increasing significantly 7 days following freshwater exposure before subsiding back to control levels at 30 days. Taken together, these data suggest an important role for Na+/K+-ATPase in freshwater acclimation in Atlantic salmon.
A tale of three taxes: photo-gyro-gravitactic bioconvection
Authors: Williams C. Rosie , Bees Martin Alan 
Published: June 2011

SUMMARYThe term bioconvection encapsulates the intricate patterns in concentration, due to hydrodynamic instabilities, that may arise in suspensions of non-neutrally buoyant, biased swimming microorganisms. The directional bias may be due to light (phototaxis), gravity (gravitaxis), a combination of viscous and gravitational torques (gyrotaxis) or other taxes. The aim of this study is to quantify experimentally the wavelength of the initial pattern to form from an initially well-mixed suspension of unicellular, swimming green algae as a function of concentration and illumination. As this is the first such study, it is necessary to develop a robust and meticulous methodology to achieve this end. The phototactic, gyrotactic and gravitactic alga Chlamydomonas augustae was employed, with various red or white light intensities from above or below, as the three not altogether separable taxes were probed. Whilst bioconvection was found to be unresponsive to changes in red light, intriguing trends were found for pattern wavelength as a function of white light intensity, depending critically on the orientation of the illumination. These trends are explored to help unravel the mechanisms. Furthermore, comparisons are made with theoretical predictions of initial wavelengths from a recent model of photo-gyrotaxis, encouragingly revealing good qualitative agreement.
Electrolocation based on tail-bending movements in weakly electric fish
Authors: Sim Miyoung , Kim DaeEun 
Published: June 2011

SUMMARYWeakly electric fish generate an electric field with their electric organ to navigate in space, detect objects and communicate with conspecifics. Several studies have examined how electric fish identify objects with their electroreceptors and use electric images for electrolocation. It has been argued that sensor readings from electroreceptors along the rostrocaudal line allow fish to determine the location of a target object. It is well known that the ratio between the maximal slope and the maximal amplitude of the electric image can allow the discrimination of object distances, regardless of object size and conductivity. In order to understand the temporal pattern of electric images, we used a model of electric field perturbation. Using the model, we suggest that the temporal pattern generated at an electrosensor during tail bending is another cue that can be used by the fish to discriminate object distances. The time course of electric sensor signals from a specific electroreceptor when tail-bending movements are applied can provide information about the lateral distance of a target object.
How do tiger moths jam bat sonar?
Authors: Corcoran Aaron J. , Barber Jesse R. , Hristov Nickolay I. , Conner William E. 
Published: June 2011

SUMMARY
The tiger moth Bertholdia trigona is the only animal in nature known to defend itself by jamming the sonar of its predators – bats. In this study we analyzed the three-dimensional flight paths and echolocation behavior of big brown bats (Eptesicus fuscus) attacking B. trigona in a flight room over seven consecutive nights to determine the acoustic mechanism of the sonar-jamming defense. Three mechanisms have been proposed: (1) the phantom echo hypothesis, which states that bats misinterpret moth clicks as echoes; (2) the ranging interference hypothesis, which states that moth clicks degrade the bats' precision in determining target distance; and (3) the masking hypothesis, which states that moth clicks mask the moth echoes entirely, making the moth temporarily invisible. On nights one and two of the experiment, the bats appeared startled by the clicks; however, on nights three through seven, the bats frequently missed their prey by a distance predicted by the ranging interference hypothesis (∼15–20 cm). Three-dimensional simulations show that bats did not avoid phantom targets, and the bats' ability to track clicking prey contradicts the predictions of the masking hypothesis. The moth clicks also forced the bats to reverse their stereotyped pattern of echolocation emissions during attack, even while bats continued pursuit of the moths. This likely further hinders the bats' ability to track prey. These results have implications for the evolution of sonar jamming in tiger moths, and we suggest evolutionary pathways by which sonar jamming may have evolved from other tiger moth defense mechanisms.
Anterior lateral eyes ofLycosa tarantula(Araneae: Lycosidae) are used during orientation to detect changes in the visual structure of the substratum
Authors: Ortega-Escobar Joaquin 
Published: June 2011

SUMMARYPrevious studies in the wolf spider Lycosa tarantula (Linnaeus 1758) have shown that homing is carried out by path integration and that, in the absence of information relative to the sun's position or any pattern of polarized light, L. tarantula obtains information as to the angle it must turn to home through the anterior lateral eyes (ALEs). In the present study, spiders were trained to walk over a black-and-white grating and afterwards tested either over a white substratum, the same substratum used for training or the same substratum rotated 90 deg (two groups: ALEs covered and only ALEs uncovered; they were tested first without their eyes covered and then with their eyes covered). The directional bearing was measured both in training and test conditions. Under the white or the same substratum in test conditions, the directional bearing had the same mean direction and a distribution similar to that of the training sessions. When the substratum was rotated 90 deg, the directional bearing had the same mean direction but the distribution was significantly different from that of the training sessions. Moreover, if ALEs were covered, spiders behaved as if the substratum had not been rotated and the directional bearing distribution was similar to that of the training sessions. But, if ALEs were the only eyes uncovered, spiders behaved as if no eyes were covered and directional bearing distribution was similar to that of the test condition. It is suggested that, when homing, L. tarantula uses both idiothetic information and visual information gathered through ALEs. These findings present the first evidence that spiders can use the visual structure of the substratum to return home.