bluuebunny/crossref_metadata_2025 huggingface dataset:
A new line symmetry distance based automatic clustering technique: Application to image segmentation
Authors: Saha Sriparna , Maulik Ujjwal
Published: February 2011

In this article, at first an automatic clustering technique using the concept of line symmetry property is developed. The proposed real‐coded variable string length genetic clustering technique (VGALS clustering) is able to evolve the number of clusters present in the data set automatically. Here assignment of points to different clusters is done based on the line symmetry based distance rather than the Euclidean distance. The cluster centers are encoded in the chromosomes, whose value may vary. A newly developed line symmetry based cluster validity index, LineSym‐index, is used as a measure of “goodness” of the corresponding partitioning. This validity index is able to correctly indicate the presence of clusters of different sizes as long as they are line symmetrical. A Kd‐tree based data structure is used to reduce the complexity of computing the line symmetry distance. The proposed technique is then applied to automatically segment different images. At first, the superiority of the proposed method to automatically segment the image data sets over Fuzzy C‐means clustering technique, well‐known mean‐shift based method and GAPS clustering with Sym‐index based method, are demonstrated for three remote sensing satellite images. Thereafter it is applied on several simulated T1‐weighted, T2‐weighted, and proton density normal and MS lesion magnetic resonance brain images. The proposed method is able to detect most of the regions well. Superiority of the proposed method over Fuzzy C‐means and Expectation Maximization clustering algorithms are demonstrated quantitatively. The automatic segmentation obtained by VGALS clustering technique is also compared with the available ground truth information. © 2011 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 21, 86–100, 2011
The kinetics of 18f‐fluorodeoxyglucose uptake in the choroid plexus
Authors: Rmeily‐Haddad Mireille , Balédent Olivier , Stoquart‐ElSankari Souraya , Sérot Jean‐Marie , Bailly Pascal , Meyer Marc‐Etienne
Published: February 2011

It is now clear that cerebrospinal fluid [CSF, produced by the choroid plexi (CP)] plays a fundamental role in brain pathophysiology and neurodegenerative processes. However, the CP's functional activity has only been studied in vitro. This article presents a new approach for studying the CP and the CSF with 18F‐fluorodeoxyglucose (FDG) positron emission tomography (PET). Ten elderly, non‐neurological patients underwent a 45‐min, dynamic FDG‐PET acquisition with scheduled 34 time frames. Our method provided successive images representing the FDG uptake dynamics, with calculation of three parameters of an exponential fitting function for the 34 frames and every voxel in the brain volume. Regions of interest in the CSF and CP were manually selected on the reconstructed map, and mean raw FDG uptake curves were reconstructed. We have monitored the kinetics of FDG uptake by the CP and the CSF during PET acquisition. The FDG kinetics in the CP differs markedly from those seen in the CSF and all other brain tissues. In our study population, the CP's final uptake intensity was significantly greater than that of the CSF. This work is an initial step toward using PET to evaluate CP functions in vivo. © 2011 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 21, 107–114, 2011.
Frequent walking, but not total physical activity, is associated with increased fracture incidence: A 5-year follow-up of an Australian population-based prospective study (AusDiab)
Authors: Nikander Riku , Gagnon Claudia , Dunstan David W , Magliano Dianna J , Ebeling Peter R , Lu Zhong X , Zimmet Paul Z , Shaw Jonathan E , Daly Robin M
Published: February 2011

Current public health physical activity (PA) guidelines recommend that older adults accumulate ≥ 2.5 hours per week of moderate- to vigorous-intensity PA to optimize health. The aim of this study was to examine (1) whether adults who meet the current PA guidelines are at reduced risk of fracture, (2) whether fracture risk varies by PA type/intensity and frequency, and (3) whether prolonged TV viewing, as a marker of sedentary behavior, is associated with fracture risk. This national, population-based prospective study with a 5-year follow-up included 2780 postmenopausal women and 2129 men aged 50 years or older. Incident nontraumatic clinical fractures were self-reported. Overall, 307 (6.3%) participants sustained at least one incident low-trauma fracture (women 9.3%, men 2.3%). Multivariate logistic regression, adjusting for age, body mass index (BMI), physical function, previous fracture history, smoking, and dietary calcium and serum 25-hydroxyvitamin D levels, showed that women who walked more than 3 hours per week or completed at least 6 weekly bouts of walking had a 51% and 56% increased fracture risk, respectively, compared with women who did no walking [odds ratio (OR) time = 1.51, 95% confidence interval (CI) 1.01–2.24; OR frequency = 1.56, 95% CI 1.07–2.27]. However, total and moderate to vigorous PA time and the accumulation of 2.5 hours per week or more of PA and TV viewing time were not associated with incident fractures. In men, there also was an increased fracture risk for those who walked more than 3 hours per week (OR = 2.30, 95% CI 1.06-4.97) compared with those who reported no walking. In conclusion, older adults who adhered to the current PA guidelines were not protected against fragility fractures, but more frequent walking was associated with an increased fracture risk. © 2011 American Society for Bone and Mineral Research.
Modulatory effects of connexin‐43 expression on gap junction intercellular communications with mast cells and fibroblasts
Authors: Pistorio Ashley L. , Ehrlich H. Paul
Published: February 2011

The influence of mast cells upon aberrant wound repair and excessive fibrosis has supportive evidence, but the mechanism for these mast cell activities is unclear. It is proposed that heterocellular gap junction intercellular communication (GJIC) between fibroblasts and mast cells directs some fibroblast activities. An in vitro model was used employing a rodent derived peritoneal mast cell line (RMC‐1) and human dermal derived fibroblasts. The influence of the expression of the gap junction channel structural protein, connexin 43 (Cx‐43) on heterocellular GJIC, the expression of microtubule β‐tubulin and microfilament α smooth muscle actin (SMA) were investigated. The knockdown of Cx‐43 by siRNA in RMC‐1 cells completely blocked GJIC between RMC‐1 cells. SiRNA knockdown of Cx‐43 within fibroblasts only dampened GJIC between fibroblasts. It appears Cx‐43 is the only expressed connexin (Cx) in RMC‐1 cells. Fibroblasts express other Cxs that participate in GJIC between fibroblasts in the absence of Cx‐43 expression. Heterocellular GJIC between RMC‐1 cells and fibroblasts transformed fibroblasts into myofibroblasts, expressing α SMA within cytoplasmic stress fibers. The knockdown of Cx‐43 in RMC‐1 cells increased β‐tubulin expression, but its knockdown in fibroblasts reduced β‐tubulin expression. Knocking down the expression of Cx‐43 in fibroblasts limited αSMA expression. Cx‐43 participation is critical for heterocellular GJIC between mast cells and fibroblasts, which may herald a novel direction for controlling fibrosis. J. Cell. Biochem. 112: 1441–1449, 2011. © 2011 Wiley‐Liss, Inc.
Entrepreneurial finance for job creation in the Arab world: strategy elements urgent as ever
Authors: Eid Florence
Published: February 2011

The challenge today for the economies of the Middle East and North Africa (MENA) countries is to leverage the opportunity from increased liquidity, invest in new job creation, and nurture key sectors for diversified and sustainable growth.
Leader characteristics and styles in the SMEs of the People's Republic of China during the global financial crisis
Authors: Wang Jinmin , Lee‐Davies Linda , Kakabadse Nada K. , Xie Zhijie
Published: February 2011

This empirical study explores successful views and characteristics of leaders and employees in the SMEs of the People's Republic of China during the global financial crisis.
Groundswell effect part I: a new concept emerging in the world of social networks
Authors: Madhavi C. Vasanta , Akbar M.
Published: February 2011

Company strategies for profitability and efficacy have to be reorganized as the diffusion of the new means of communication within online social networks is empowering people (customers, employees, managers, entrepreneurs, investors, students, and researchers) in terms of knowledge and technology transfers.
Groundswell effect part II: a quantitative indicator of company performance
Authors: Madhavi C. Vasanta , Akbar M.
Published: February 2011

A groundswell can be used to generate returns in firms and its economic effect can be measured.
Informatics for mass spectrometry‐based RNA analysis
Authors: Nakayama Hiroshi , Takahashi Nobuhiro , Isobe Toshiaki
Published: February 2011

Mass spectrometry (MS) allows the sensitive and direct characterization of biological macromolecules and therefore has the potential to complement the more conventional genetic and biochemical methods used for RNA characterization. Although MS has been used much less frequently for RNA research than it has been for protein research, recent technical improvements in both instrumentation and software make MS a powerful tool for RNA analysis because it can now be used to sequence, quantify, and chemically analyze RNAs. Mass spectrometry is particularly well suited for the characterization of RNAs associated with ribonucleoprotein complexes. This review focuses on the software and databases that can be used for MS‐based RNA studies. Software for the processing of raw mass spectra, the identification and characterization of RNAs by mass mapping, de novo sequencing, and tandem MS‐based database searching are available. © 2010 Wiley Periodicals, Inc., Mass Spec Rev 30:1000–1012, 2011
Triad stimulation frequency for cortical facilitation in cortical myoclonus
Authors: Hanajima R. , Terao Y. , Nakatani‐Enomoto S. , Okabe S. , Shirota Y. , Oominami S. , Matsumoto H. , Tsuji S. , Ugawa Y.
Published: February 2011

Background:

Abnormally enhanced cortical rhythmic activities have been reported in patients with cortical myoclonus. We recently reported a new triad‐conditioning transcranial magnetic stimulation (TMS) method to detect the intrinsic rhythms of the primary motor cortex (M1). Triad‐conditioning TMS revealed a 40‐Hz intrinsic rhythm of M1 in normal subjects. In this investigation, we study the motor cortical facilitation induced by rhythmic triple TMS pulses (triad‐conditioning TMS) in patients with cortical myoclonus.

Methods:

Subjects were 7 patients with cortical myoclonus (28–74 years old) and 13 healthy volunteers (30–71 years old). Three conditioning stimuli over M1 at the intensity of 110% active motor threshold preceded the test TMS at various interstimulus intervals corresponding to 10–200 Hz. The resulting amplitudes of conditioned motor evoked potentials recorded from the contralateral hand muscle were compared with those evoked by the test stimulus alone.

Results:

The facilitation at 25 ms (40 Hz) observed in normal subjects was absent in patients with cortical myoclonus. Instead, triad‐conditioning TMS induced facilitation at a 40 ms interval (25 Hz) in cortical myoclonus.

Discussions:

This change in the timing of facilitation may be explained by a shift of the most preferential intrinsic rhythm of M1, or by some dysfunction in the interneuronal network in cortical myoclonus. © 2011 Movement Disorder Society
Phosphodiesterase‐4 inhibition reduces proteolysis and atrogenes expression in rat skeletal muscles
Authors: Lira Eduardo C. , Gonçalves Dawit A.P. , Parreiras‐E‐Silva Lucas T. , Zanon Neusa M. , Kettelhut Isis C. , Navegantes Luiz C.C.
Published: February 2011

Phosphodiesterase (PDE) inhibition reduces skeletal muscle atrophy, but the underlying molecular mechanism remains unclear. We used microdialysis to investigate the effects of different PDE inhibitors on interstitial tyrosine concentration as well as proteolytic activity and atrogenes expression in isolated rat muscle. Rolipram, a PDE‐4–selective inhibitor, reduced the interstitial tyrosine concentration and rates of muscle protein degradation. The rolipram‐induced muscle cAMP increase was accompanied by a decrease in ubiquitin–proteasome system (UPS) activity and atrogin‐1 mRNA, a ubiquitin‐ligase involved in muscle atrophy. This effect was not associated with Akt phosphorylation but was partially blocked by a protein kinase A inhibitor. Fasting increased atrogin‐1, MuRF‐1 and LC3b expression, and these effects were markedly suppressed by rolipram. Our data suggest that activation of cAMP signaling by PDE‐4 blockade leads to inhibition of UPS activity and atrogenes expression independently of Akt. These findings are important for identifying novel approaches to attenuate muscle atrophy. Muscle Nerve 44: 371–381, 2011
Median nerve changes following steroid injection for carpal tunnel syndrome
Authors: Cartwright Michael S. , White David L. , Demar Samantha , Wiesler Ethan R. , Sarlikiotis Thomas , Chloros George D. , Yoon Joon Shik , Won Sun Jae , Molnar Joseph A. , Defranzo Anthony J. , Walker Francis O.
Published: February 2011

Introduction: Neuromuscular ultrasound is a painless, radiation‐free, high‐resolution imaging modality for assessment of the peripheral nervous system. The purpose of this study was to use neuromuscular ultrasound to assess the changes that occur in the median nerve after steroid injection for carpal tunnel syndrome (CTS). Methods: Ultrasound and nerve conduction studies were performed at baseline and 1 week, 1 month, and 6 months after steroid injection in 19 individuals (29 wrists) with CTS. Results: Significant changes were noted in median nerve cross‐sectional area (P < 0.001), mobility (P = 0.001), and vascularity (P = 0.042) at the distal wrist crease after steroid injection, and the nerve cross‐sectional area correlated with symptom score and electrodiagnostic parameters. Changes in the ultrasonographic parameters were seen within 1 week of injection. Conclusions: These findings suggest neuromuscular ultrasound is potentially helpful for the assessment of individuals undergoing treatment for CTS, as typical changes can be expected after successful treatment injection. Muscle Nerve 44: 25–29, 2011
Lower limb electromygraphy and kinematics of neuropathic diabetic patients during real‐life activities: Stair negotiation
Authors: Onodera Andrea N. , Gomes Aline A. , Pripas Denise , Mezzarane Rinaldo A. , Sacco Isabel C.N.
Published: February 2011

Introduction:

In this study we investigate the influence of diabetic neuropathy (DN) on lower limb electromyography (EMG) and kinematics during stair negotiation.

Methods:

Forty‐six adults (healthy and DN) performed stair ascent and descent tasks. Kinematic and EMG data were assessed unilaterally.

Results:

DN patients had lower ankle dorsiflexion while ascending and plantarflexion while descending. This reduced dorsiflexion compromises proper ankle and knee positions necessary for an efficient lifting action by the vastus lateralis (VL). The mechanical disadvantage of VL at the beginning of the stance triggered prolonged VL activation at the end of stair ascent. In stair descent, DN patients showed lower tibialis anterior activity in the early phase that can potentially impair the mechanism of impact absorption when the forefoot contacts the step.

Conclusions:

Our results reveal an adaptive motor strategy in DN patients to overcome the challenge of stair ascent, which promoted more biomechanical deficits. Muscle Nerve, 2011
Pattern of summation with fatigue and inhibition of calcium release in rat muscle
Authors: MacIntosh Brian R. , Glumpak Jennifer J. , Macnaughton Meredith B. , Rassier Dilson E.
Published: February 2011

Introduction:Fatigue disrupts muscle force summation and is associated with a decrease in cytoplasmic Ca2+ concentration. The purpose of this study was to compare summation during fatigue and recovery with summation during dantrolene‐induced inhibition of Ca2+ release.Methods:Rat medial gastrocnemius muscles were evaluated before and after fatigue, or during exposure to dantrolene. Summation was quantified by the ratio of the force transient associated with the final activation in a train of stimuli (Twf), obtained by subtraction of the force with one less stimulus, and the force of the twitch (Tw).Results:This ratio (Twf/Tw) decreased from 2.46 ± 0.11 (mean ± SEM) to 0.8 ± 0.1 during intermittent contractions, but was still significantly different from non‐fatigued muscle after 10 min of recovery. Dantrolene altered summation, as Twf/Tw was 1.7 ± 0.2 and 1.27 ± 0.15 at a low dose and a high dose, respectively.Conclusions:Inhibition of Ca2+ release alters summation, but repetitive stimulation leading to fatigue changes it more substantially. Muscle Nerve 44: 410–417, 2011
Modeling nerve conduction criteria for diagnosis of diabetic polyneuropathy
Authors: Dyck Peter J. , Carter Rickey E. , Litchy William J.
Published: February 2011

Introduction:In this study we aimed to determine which criteria are valid for nerve conduction (NC) diagnosis of typical diabetic sensorimotor polyneuropathy (DSPN).Methods:Eight criteria were assessed from among diabetes databases, the Rochester Diabetic Neuropathy Study (RDNS, N = 456), and in healthy subjects (RDNS‐HS, N = 330).Results:In the RDNS, the most frequent abnormal attributes (≤2.5th/≥97.5th percentile) are: fibular motor nerve conduction velocity (MNCV; 26.3%); sural sensory nerve conduction velocity (SNAP; 25.4%); tibial MNCV (24.8%); ulnar MNCV (21.3%); fibular F latency (16.9%); and ulnar F latency (16.0%). Normal deviate (from percentiles) composite scores of NC included: representative of neurophysiological abnormalities; sensitive and specific for diagnosis and useful for epidemiological surveys; randomized trials; and medical practice. By contrast, abnormality of one or more attributes in any nerve or abnormally of two most sensitive attributes performed poorly.Conclusions:Composite sum scores of normal deviates (from percentiles corrected for applicable variables) of sensitive NC attributes and with modifications, RDNS and AAN criteria performed acceptably for diagnosis of DSPN. Muscle Nerve 44: 340–345, 2011
Quality of life in complete spinal cord injury patients with a Brindley bladder stimulator compared to a matched control group
Authors: Martens Frank M.J. , den Hollander Philip P. , Snoek Govert J. , Koldewijn Evert L. , van Kerrebroeck Philip E.V.A. , Heesakkers John P.F.A.
Published: February 2011

Aims: To determine the effects on Quality of Life (QoL) of a Brindley procedure, which combines a sacral dorsal root rhizotomy to treat neurogenic detrusor overactivity with sacral anterior root stimulation to enable micturition, defecation, and penile erections in complete spinal cord injury (SCI) patients compared to a matched Control Group.

Methods: Cross‐sectional study. The Qualiveen questionnaire, SF‐36 questionnaire, and multiple choice questions about urinary continence and urinary tract infections were sent to 93 patients who had a Brindley stimulator implanted in the Netherlands and a matched Control Group of 70 complete SCI patients with neurogenic detrusor overactivity. Primary study outcomes were Specific Impact of Urinary Problems score and general QoL index of the Qualiveen.

Results: Response rates were 78% and 40% for patients with a Brindley stimulator and controls, respectively. Stimulators were still used for micturition in 46 (63%). These patients had a significant better Specific Impact of Urinary Problems score, general QoL index (Qualiveen), and continence rate, and less urinary tract infections compared to the Control Group. Patients also benefited of the rhizotomy with regard to QoL and continence rate if the stimulator was not used anymore. The subscales of the SF‐36 had better scores for the patients who used their stimulator as compared to those who did not use the stimulator and compared to the Control Group.

Conclusions: The Brindley stimulator for complete spinal cord injury patients improves Quality of Life, continence, and urinary tract infection rate compared to a matched Control Group. 30:551–555, 2011. © 2011 Wiley‐Liss, Inc.
Hand grip and pinch strength in patients with nocturnal enuresis: Is there a role of muscle strength in pathogenesis of enuresis?
Authors: Karabiber Hamza , Garipardic Mesut , Uzel Murat , Davutoglu Mehmet , Ozer Ali , Hasturk Ziyadeddin , Guler Ekrem
Published: February 2011

Aims

To examine the association of muscle strength with nocturnal enuresis.

Subjects and Methods

One hundred sixty‐three patients with monosymptomatic nocturnal enuresis (8–14 years old) were recruited from outpatient clinics. Two hundred eight healthy students served as the control group (8–14 years old) from two primary schools. Physical examinations and the age, gender, height, weight, dominant hand, and body mass of these children index were recorded. A calibrated, Jamar dynamometer was used to assess grip strength at the first two settings. A pinch gauge was used to assess the key pinch of the right and left hands of these children. Two measurements of each grip and pinch were obtained at 15 sec intervals and mean values were analyzed.

Results

The hand grip strength test and pinch was significantly lower in the enuretic group compared with the control group. These low results of the muscle strength in the enuretic group showed that whole body muscle weakness may contribute to the pathogenesis of enuresis as a possible etiological factor.

Conclusions

In this first study on the association of muscle strength with nocturnal enuresis, it was found that neuromuscular function is abnormal in enuretic patients. In this neuromuscular abnormality, the motor activity is affected. 30:525–528, 2011. © 2011 Wiley‐Liss, Inc.
A new reconstruction procedure in central schemes for hyperbolic conservation laws
Authors: Balaguer‐Beser A.
Published: February 2011

This paper presents a new point value reconstruction algorithm based on average values or flux values for central Runge–Kutta schemes in the resolution of hyperbolic conservation laws. This reconstruction employs a fourth‐order accurate approximation of point values of the solution at the two extrema and at the mid‐point of each cell. These point values are modified in order to enforce monotonicity and shape preserving properties. This correction has been applied essentially in the cells close to the maxima and minima of the solution and in these cases, it has been proven that the reconstruction is fourth‐order accurate. In the cells with a maximum or minimum of the solution, a correction has also been applied to such point values with the aim of ensuring that the resulting numerical solution has a non‐oscillatory behavior. Several standard one‐ and two‐dimensional test cases are used to verify high‐order accuracy, non‐oscillatory behavior and high‐resolution properties for smooth and discontinuous solutions, and also in their componentwise extension to the Euler gas dynamics equations. Copyright © 2011 John Wiley & Sons, Ltd.
Delamination analysis of composites by new orthotropic bimaterial extended finite element method
Authors: Ashari S. Esna , Mohammadi S.
Published: February 2011

The extended finite element method (XFEM) is further improved for fracture analysis of composite laminates containing interlaminar delaminations. New set of bimaterial orthotropic enrichment functions are developed and utilized in XFEM analysis of linear‐elastic fracture mechanics of layered composites. Interlaminar crack‐tip enrichment functions are derived from analytical asymptotic displacement fields around a traction‐free interfacial crack. Also, heaviside and weak discontinuity enrichment functions are utilized in modeling discontinuous fields across interface cracks and bimaterial weak discontinuities, respectively. In this procedure, elements containing a crack‐tip or strong/weak discontinuities are not required to conform to those geometries. In addition, the same mesh can be used to analyze different interlaminar cracks or delamination propagation. The domain interaction integral approach is also adopted in order to numerically evaluate the mixed‐mode stress intensity factors. A number of benchmark tests are simulated to assess the performance of the proposed approach and the results are compared with available reference results. Copyright © 2011 John Wiley & Sons, Ltd.
Between‐group Differences in the Patterning of Musculo‐skeletal Stress Markers: Avoiding Confounding Factors by Focusing on Qualitative Aspects of Physical Activity
Authors: Stefanović S. , Porčić M.
Published: February 2011

This paper presents a method for studying between‐group differences in physical activity patterns through the analysis of musculo‐skeletal stress markers (MSM). The specific aim was to develop a method that could overcome the problems related to confounding variables such as body size by shifting the analytical focus from the comparison of differences in intensity to the comparison of differences in kinds of activity. Instead of testing whether there are differences in the measures of central tendency of MSM scores between two groups, we proposed looking for differences in MSM covariation patterns. Formally, this is achieved through the statistical comparison of group‐specific MSM intercorrelation matrices. The null hypothesis is that the matrices are equal, and the statistical significance of the test statistic is obtained with a permutation test. In this way, the problem of confounding variables such as body size is mostly avoided because the procedure is based on the comparison of group‐specific sets of correlation coefficients which are scale‐free. The method was employed in a case study to investigate the differences in activity patterns between men and women from the Early Bronze Age population buried at the necropolis in Mokrin, Serbia. The null hypothesis of no difference between the male and female MSM correlation matrices was rejected (p = 0.0135). After the statistical significance of the difference was established, further investigation of male and female activity patterns was undertaken by means of principal component analysis (PCA) with varimax rotation. PCA results suggest that covariation between MSMs is stronger in the male sample. Success in demonstrating differences in activity patterns between sexes implies that the proposed method can be used to test for differences in physical activity between groups of individuals defined by criteria other than sex. Copyright © 2011 John Wiley & Sons, Ltd.
Maternal serum hCG, PAPP‐A and AFP as predictors of hemoglobin Bart disease at mid‐pregnancy
Authors: Tongprasert Fuanglada , Wanapirak Chanane , Tongsong Theera
Published: February 2011

Objective

To evaluate the ability of maternal serum‐free β‐human chorionic gonadotrophin (β‐hCG), pregnancy‐associated plasma protein‐A (PAPP‐A), and alpha fetoprotein (AFP) levels in the screening of fetuses with hemoglobin (Hb) Bart's disease among pregnancies at risk.

Materials and Methods

Pregnancies at risk for fetal Hb Bart's disease scheduled for cordocentesis at 18 to 22 weeks were recruited into the study. Maternal serum‐free β‐hCG, PAPP‐A, and AFP concentrations were measured before cordocentesis, and the final fetal diagnosis of Hb Bart disease was based on fetal Hb typing using high‐performance liquid chromatography.

Results

Of 57 recruited pregnancies, 11 had fetal Hb Bart's disease and 46 were unaffected. Maternal serum alpha‐fetoprotein (MSAFP) concentrations were significantly higher in women with fetal Hb Bart's disease than those with unaffected fetuses (median 99.53 vs 50.83, P < 0.001), whereas the concentrations of free β‐hCG and PAPP‐A were not significantly different between the two groups (P = 0.543 and 0.777, respectively).

Conclusion

Second‐trimester MSAFP may be clinically a useful screening test for fetal Hb Bart's disease among pregnancies at risk. Copyright © 2011 John Wiley & Sons, Ltd.
Reference ranges of fetal aortic and pulmonary valve diameter derived by STIC from 14 to 40 weeks of gestation
Authors: Tongprasert Fuanglada , Srisupundit Kasemsri , Luewan Suchaya , Sirichotiyakul Supatra , Piyamongkol Wirawit , Wanapirak Chanane , Tongsong Theera
Published: February 2011

Objective

To develop reference ranges of fetal aortic and pulmonary valve diameter derived from volume datasets of spatio‐temporal image correlation (STIC).

Methods

A cross‐sectional study was undertaken on low‐risk pregnancies with well‐established data from 14 to 40 weeks. Volume datasets of STIC were acquired for subsequent off‐line analysis. Aortic and pulmonary valve diameters were measured in STIC multiplanar view using 4D‐View version 9. Normal Z scores and centile reference ranges were constructed from these measurements against gestational age (GA) and biparietal diameter (BPD) as independent variables, using regression models for both mean and SD.

Results

A total of 606 volume datasets were successfully measured. Normal reference ranges for predicting mean values and SD of aortic and pulmonary valve diameter were constructed based on best‐fit equations (linear function) as follows: mean aortic diameter (mm) was modeled as a function of GA (weeks) and BPD (mm) as − 2.4838 + 0.2702× GA, (SD = 0.1482 + 0.0156× GA) and − 1.5952 + 0.0989× BPD (SD = 0.1672 + 0.00572× BPD). Mean pulmonary diameter was modeled as − 2.5924 + 0.2935× GA (SD = 0.2317 + 0.01524× GA) and − 1.6830 + 0.1083× BPD (SD = 0.1971 + 0.0059× BPD).

Conclusion

We have provided nomograms and Z scores of fetal aortic and pulmonary valve diameters. These reference ranges may be a useful tool in the assessment of fetal cardiac abnormalities. Copyright © 2011 John Wiley & Sons, Ltd.
Phosphoproteome analysis of the pathogenic bacterium Helicobacter pylori reveals over‐representation of tyrosine phosphorylation and multiply phosphorylated proteins
Authors: Ge Ruiguang , Sun Xuesong , Xiao Chuanle , Yin Xingfeng , Shan Weiran , Chen Zhuo , He Qing‐Yu
Published: February 2011

Increasing evidence shows that protein phosphorylation on serine (Ser), threonine (Thr) and tyrosine (Tyr) residues is a major regulatory post‐translational modification in the bacteria. To reveal the phosphorylation state in the Gram‐negative pathogenic bacterium Helicobacter pylori, we carried out a global and site‐specific phosphoproteomic analysis based on TiO2‐phosphopeptide enrichment and high‐accuracy LC‐MS/MS determination. Eighty‐two phosphopeptides from 67 proteins were identified with 126 phosphorylation sites, among which 79 class I sites were determined to have a distribution of 42.8:38.7:18.5% for the Ser/Thr/Tyr phosphorylation, respectively. The H. pylori phosphoproteome is characterized by comparably big size, high ratio of Tyr phosphorylation, high abundance of multiple phosphorylation sites in individual phosphopeptides and over‐representation of membrane proteins. An interaction network covering 28 phosphoproteins was constructed with a total of 163 proteins centering on the major H. pylori virulence factor VacA, indicating that protein phosphorylation in H. pylori may be delicately controlled to regulate many aspects of the metabolic pathways and bacterial virulence.
Label‐free quantitative proteomics and SAINT analysis enable interactome mapping for the human Ser/Thr protein phosphatase 5
Authors: Skarra Dana V. , Goudreault Marilyn , Choi Hyungwon , Mullin Michael , Nesvizhskii Alexey I. , Gingras Anne‐Claude , Honkanen Richard E.
Published: February 2011

Affinity purification coupled to mass spectrometry (AP‐MS) represents a powerful and proven approach for the analysis of protein–protein interactions. However, the detection of true interactions for proteins that are commonly considered background contaminants is currently a limitation of AP‐MS. Here using spectral counts and the new statistical tool, Significance Analysis of INTeractome (SAINT), true interaction between the serine/threonine protein phosphatase 5 (PP5) and a chaperonin, heat shock protein 90 (Hsp90), is discerned. Furthermore, we report and validate a new interaction between PP5 and an Hsp90 adaptor protein, stress‐induced phosphoprotein 1 (STIP1; HOP). Mutation of PP5, replacing key basic amino acids (K97A and R101A) in the tetratricopeptide repeat (TPR) region known to be necessary for the interactions with Hsp90, abolished both the known interaction of PP5 with cell division cycle 37 homolog and the novel interaction of PP5 with stress‐induced phosphoprotein 1. Taken together, the results presented demonstrate the usefulness of label‐free quantitative proteomics and statistical tools to discriminate between noise and true interactions, even for proteins normally considered as background contaminants.
Crystal structures of CmeR‐bile acid complexes from Campylobacter jejuni
Authors: Lei Hsiang‐Ting , Shen Zhangqi , Surana Priyanka , Routh Mathew D. , Su Chih‐Chia , Zhang Qijing , Yu Edward W.
Published: February 2011

The TetR family of transcription regulators are diverse proteins capable of sensing and responding to various structurally dissimilar antimicrobial agents. Upon detecting these agents, the regulators allow transcription of an appropriate array of resistance markers to counteract the deleterious compounds. Campylobacter jejuni CmeR is a pleiotropic regulator of multiple proteins, including the membrane‐bound multidrug efflux transporter CmeABC. CmeR represses the expression of CmeABC and is induced by bile acids, which are substrates of the CmeABC tripartite pump. The multiligand‐binding pocket of CmeR has been shown to be very extensive and consists of several positively charged and multiple aromatic amino acids. Here we describe the crystal structures of CmeR in complexes with the bile acids, taurocholate and cholate. Taurocholate and cholate are structurally related, differing by only the anionic charged group. However, these two ligands bind distinctly in the binding tunnel. Taurocholate spans the novel bile acid binding site adjacent to and without overlapping with the previously determined glycerol‐binding site. The anionic aminoethanesulfonate group of taurocholate is neutralized by a charge‐dipole interaction. Unlike taurocholate, cholate binds in an anti‐parallel orientation but occupies the same bile acid‐binding site. Its anionic pentanoate moiety makes a water‐mediated hydrogen bond with a cationic residue to neutralize the formal negative charge. These structures underscore the promiscuity of the multifaceted binding pocket of CmeR. The capacity of CmeR to recognize bile acids was confirmed using isothermal titration calorimetry and fluorescence polarization. The results revealed that the regulator binds these acids with dissociation constants in the micromolar region.
MOVPE growth and characterization of polar, semipolar and nonpolar InN on sapphire substrate
Authors: Moret Matthieu , Ruffenach Sandra , Briot Olivier , Gil Bernard
Published: February 2011

We have investigated the heteroepitaxy of indium nitride (InN) directly grown on nitridated sapphire substrates having different orientations. Growths were performed on C, A, M and R‐plane oriented sapphire in order to analyse the substrate orientation effect on the structural, optical and electronic properties of as‐grown InN. Atomic force microscopy imaging on the InN epilayers revealed different surface morphologies with crystallites well organized along a crystalline orientation of the layer. We have studied the structural anisotropy observed in these layers analysing high‐resolution X‐ray diffraction rocking curve experiments as a function of the in‐plane beam orientation. A‐plane oriented InN grown on R‐plane sapphire substrate shows a polarized photoluminescence anisotropy, with an anisotropy percentage of about 33%.
Are Herbal Compounds the Next Frontier for Alleviating Learning and Memory Impairments? An Integrative Look at Memory, Dementia and the Promising Therapeutics of Traditional Chinese Medicines
Authors: Jesky Robert , Hailong Chen
Published: February 2011

Recent advances in neuroscience have revealed a greater, in‐depth understanding of the complexities associated with memory. Contemporary theories hold that an integral relationship between memory formation, stabilization and consolidation revolve around plasticity of neuronal networks. The associated requisite receptors α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) andN‐methyl‐d‐aspartate (NMDA) and cellular mechanisms surrounding plasticity (posed to incite molecular functionality), also display strong correlations in the pathogenesis of dementias. When the brain is in a diseased state as a result of malignant neurotransmission (i.e. in Alzheimer's disease; AD), the homeostatic balance required for normal neuronal processes is disrupted, which leads to degeneration of neural circuitry. Present efforts to find new treatments aimed at reversing or halting neurodegeneration are immense, with increasing attention being placed on investigating various herbal medicines. A wide variety of herbal plants (i.e.Panax ginseng,Polygala tenuifolia,Acorus gramineusandHuperzia serrata, examined here within), extracts and compounds have, to date, already presented advantageous results when tested against known pathogenic markers related to AD‐associated dementia. The efficaciousness of herbal medicines appears to be a modulatory effect on neurotrophins, kinases and their substrates that, in turn, initiate or take part in intracellular cascades related to memory processes. Copyright © 2011 John Wiley & Sons, Ltd.
A theoretical study of HH σ bond activation catalyzed by VO2+ in gas phase
Authors: Chen Xiao‐Xia
Published: February 2011

The mechanism of HH σ bond activation catalyzed by VO(1A1/3A′) has been investigated by using density functional theory at the B3LYP/6‐311G(2d, p) level and the single‐point energy calculations were done at the CCSD/6‐311G (2d, p)//B3LYP/6‐311G(2d, p) level of theory using the geometries along the minimum energy pathway. According to our calculation results, the different reaction mechanisms were found for the singlet and triplet potential energy surfaces (PESs). Specially, the crossing points (CPs) between the different PESs have been located by means of the intrinsic reaction coordinate approach used by Yoshizawa et al, and corresponding minimum energy CPs that we obtained by the mathematical algorithm proposed by Harvey et al. has also been employed. In addition, the orbital interaction for ion‐molecule complexes 1IM1 and 3IM1 have been examined by fragment molecular orbital analysis. Finally, the frontier molecular orbital interaction analysis about 3TS1 and 3TS2 were used to gain useful information about the HH σ bond activation by VO. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Two‐ and three‐state conical intersections in the electron capture dissociation of disulfides: The importance of multireference calculations
Authors: Gámez José A. , Serrano‐andrés Luis , Yáñez Manuel
Published: February 2011

The SS bond cleavage produced upon electron attachment to disulfides was generally assumed to be an adiabatic process because the added electron occupies the σ*(SS) antibonding orbital. This is clearly the case in the parent HSSH compound, but not necessarily in XSSX′ derivatives, where the substituents X and X′ are different. Through the use of MS‐CASPT2 calculations, we have shown that the dissociation of the SS two‐center‐three‐electron bond in these asymmetric XSSX′ compounds requires the interaction of at least two states, in order to localize the extra electron in one of the fragments upon dissociation. This is actually the case for the CH3SSNH2 derivative, where the most favorable dissociation process locates the extra electron at the SCH3 moiety, the SCH3· + SNH dissociation limit being 66 kJ mol−1 higher in energy. The situation is still more complex when one of the substituents is an OH group, because, in this particular case, the most favorable process is the dissociation of the SO rather than the SS bond. Besides, the two dissociation limits CH3SS· + OH− and CH3SS− + OH· are accidentally degenerate, so the SO bond fission involves a three‐state conical intersection. This constitutes the first example of a three‐state crossing computed by accurate ab initio calculations involved in a nonphotochemical reaction. These findings highlight the necessity of using multireference approaches to appropriately describe the electron capture dissociation of disulfide bridges. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 111: 3316–3323, 2011
Boundary effect on the adsorption properties of H2 on charged MgCaHb complex
Authors: Lei Hong‐Wen , Zhang Hong
Published: February 2011

In this article, the equilibrium structure, binding energy, and electronic structure for charged Mg coated CaHb (a = 6, b = 6; a = 14, b = 10; a = 22, b = 14; a = 24, b = 14; a = 54, b = 18) are investigated by using all electrons density‐functional calculations. The boundary effect for the adsorption property of H2 on charged MgCaHb complex is investigated by using several structures based on benzene ring molecules. A method for calculating the pathways for the synthesis of MgCaHbn+ is presented here, and also the kinetic stability of these charged hydrogen‐covered MgCaHbn+ complexes is also discussed. We find that the Mg doped complex with appropriate charge can enhance adsorption of hydrogen molecular. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Brief Report: Ectopic Expression of Nup98-HoxA10 Augments Erythroid Differentiation of Human Embryonic Stem Cells
Authors: Ji Junfeng , Risueño Ruth M. , Hong Seokho , Allan David , Rosten Patty , Humphries Keith , Bhatia Mickie
Published: February 2011

Hox genes encode highly conserved transcription factors that have been implicated in hematopoietic development and self-renewal of hematopoietic stem cells (HSCs) and hematopoietic development. The potency of NUP98-HOXA10hd (NA10) on adult murine bone marrow HSC self-renewal prompted us to examine its effect on specification and proliferation of hematopoietic cells derived from human embryonic stem cells (hESCs). Here, we demonstrate that expression of NA10 in hESCs influences the hematopoietic differentiation program. The specific effect of NA10 is dependent on the developmental stage of hematopoietic emergence from hESCs. Overexpression of NA10 in either undifferentiated hESCs or early hemogenic precursors augmented the frequency of CD45− GlycophorinA+ cells and erythroid progenitors (blast-forming unit-erythrocyte). In contrast, targeted NA10 expression in primitive CD34+ cells committed to the hematopoietic lineage had no effect on erythropoietic capacity but instead increased hematopoietic progenitor proliferation. Our study reveals a novel neomorphic effect of NA10 in early human erythroid development from pluripotent stem cells.
Modeling the control of planar cell polarity
Authors: Axelrod Jeffrey D. , Tomlin Claire J.
Published: February 2011

A growing list of medically important developmental defects and disease mechanisms can be traced to disruption of the planar cell polarity (PCP) pathway. The PCP system polarizes cells in epithelial sheets along an axis orthogonal to their apical–basal axis. Studies in the fruitfly, Drosophila, have suggested that components of the PCP signaling system function in distinct modules, and that these modules and the effector systems with which they interact function together to produce emergent patterns. Experimental methods allow the manipulation of individual PCP signaling molecules in specified groups of cells; these interventions not only perturb the polarization of the targeted cells at a subcellular level, but also perturb patterns of polarity at the multicellular level, often affecting nearby cells in characteristic ways. These kinds of experiments should, in principle, allow one to infer the architecture of the PCP signaling system, but the relationships between molecular interactions and tissue‐level pattern are sufficiently complex that they defy intuitive understanding. Mathematical modeling has been an important tool to address these problems. This article explores the emergence of a local signaling hypothesis, and describes how a local intercellular signal, coupled with a directional cue, can give rise to global pattern. We will discuss the critical role mathematical modeling has played in guiding and interpreting experimental results, and speculate about future roles for mathematical modeling of PCP. Mathematical models at varying levels of inhibition have and are expected to continue contributing in distinct ways to understanding the regulation of PCP signaling. WIREs Syst Biol Med 2011 3 588–605 DOI: 10.1002/wsbm.138

This article is categorized under:

Developmental Biology > Developmental Processes in Health and Disease
Drug repurposing and adverse event prediction using high‐throughput literature analysis
Authors: Deftereos Spyros N. , Andronis Christos , Friedla Ellen J. , Persidis Aris , Persidis Andreas
Published: February 2011

Drug repurposing is the process of using existing drugs in indications other than the ones they were originally designed for. It is an area of significant recent activity due to the mounting costs of traditional drug development and scarcity of new chemical entities brought to the market by bio‐pharmaceutical companies. By selecting drugs that already satisfy basic toxicity, ADME and related criteria, drug repurposing promises to deliver significant value at reduced cost and in dramatically shorter time frames than is normally the case for the drug development process. The same process that results in drug repurposing can also be used for the prediction of adverse events of known or novel drugs. The analytics method is based on the description of the mechanism of action of a drug, which is then compared to the molecular mechanisms underlying all known adverse events. This review will focus on those approaches to drug repurposing and adverse event prediction that are based on the biomedical literature. Such approaches typically begin with an analysis of the literature and aim to reveal indirect relationships among seemingly unconnected biomedical entities such as genes, signaling pathways, physiological processes, and diseases. Networks of associations of these entities allow the uncovering of the molecular mechanisms underlying a disease, better understanding of the biological effects of a drug and the evaluation of its benefit/risk profile. In silico results can be tested in relevant cellular and animal models and, eventually, in clinical trials. WIREs Syst Biol Med 2011 3 323–334 DOI: 10.1002/wsbm.147

This article is categorized under:

Analytical and Computational Methods > Computational Methods
Performance and Microstructural Study on Soap Using Different Fatty Acids and Cations
Authors: Nadarajan Renugambaal , Ismail Razali
Published: February 2011

The desired benefits of the finished soap product are governed by a professional selection of appropriate raw materials, the manufacturing process or both. A better understanding of the crystallization of the soap microstructure is needed which has direct effects on the properties of final products. Soap microstructures and soap composition are not only determined by the length of hydrophobic fatty chain, saturation extent of fatty acid chain, fatty acid distribution but also by the cation effect. Thus, four different fatty acid compositions and the effect of sodium and potassium cations were studied. The performance of the potassium and sodium bar soaps prepared was monitored and was correlated with solid phase thermal analysis. The microstructural effect was examined using ATR‐FTIR, FESEM and XRD. The specific ion effect and ion interaction involving both cations and carboxylate anions on different chemical compositions was correlated.