bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mast Cell-Mediated Changes in Smooth Muscle Contractility during Mouse Giardiasis
Authors: Li Erqiu , Zhao Aiping , Shea-Donohue Terez , Singer Steven M. 
Published: July 2007

ABSTRACT

Giardia intestinalis
is a significant cause of diarrheal disease worldwide. Infections in animal models have been shown to cause changes in gastrointestinal transit that depend on adaptive immune responses and are mediated, in part, through neuronal nitric oxide synthase. Nitric oxide is an inhibitory neurotransmitter, and we therefore investigated potential excitatory pathways that might be involved in the response to
Giardia
infection. Infected mice exhibited increased spontaneous and cholecystokinin (CCK)-induced contractions of longitudinal smooth muscle. In contrast, enhanced contractile responses were not observed in response to acetylcholine, 5-hydroxytryptamine, or the protease-activated receptor-1 agonist peptide TFFLR.
Giardia
-induced changes in smooth muscle function appear to be mediated primarily by mast cells, as both spontaneous and CCK-induced contractions were blocked by pretreatment with either ketotifen or compound 48/80. Together, these data support a model in which CCK release triggers mast cell degranulation, leading to increases in smooth muscle contractility. These contractions, coupled with nitric oxide-mediated muscle relaxation, promote intestinal transit and parasite elimination.
The health benefits of interactive video game exercise
Authors: Warburton Darren E.R. , Bredin Shannon S.D. , Horita Leslie T.L. , Zbogar Dominik , Scott Jessica M. , Esch Ben T.A. , Rhodes Ryan E. 
Published: July 2007

The purpose of this study was to evaluate the effectiveness of interactive video games (combined with stationary cycling) on health-related physical fitness and exercise adherence in comparison with traditional aerobic training (stationary cycling alone). College-aged males were stratified (aerobic fitness and body mass) and then assigned randomly to experimental (n = 7) or control (n = 7) conditions. Program attendance, health-related physical fitness (including maximal aerobic power (VO2 max), body composition, muscular strength, muscular power, and flexibility), and resting blood pressure were measured before and after training (60%–75% heart rate reserve, 3 d/week for 30 min/d for 6 weeks). There was a significant difference in the attendance of the interactive video game and traditional training groups (78% ± 18% vs. 48% ± 29%, respectively). VO2 max was significantly increased after interactive video game (11% ± 5%) but not traditional (3% ± 6%) training. There was a significantly greater reduction in resting systolic blood pressure after interactive video game (132 ± 6 vs. 123 ± 6 mmHg) than traditional (131 ± 7 vs. 128 ± 8 mmHg) training. There were no significant changes in body composition after either training program. Attendance mediated the relationships between condition and changes in health outcomes (including VO2 max, vertical jump, and systolic blood pressure). The present investigation indicates that a training program that links interactive video games to cycle exercise results in greater improvements in health-related physical fitness than that seen after traditional cycle exercise training. It appears that greater attendance, and thus a higher volume of physical activity, is the mechanism for the differences in health-related physical fitness.
Time-of-day variation in cardiovascular response to maximal exercise testing in coronary heart disease patients taking a beta-blocker
Authors: Dufour Doiron Monique , Prud’homme Denis , Boulay Pierre 
Published: July 2007

The aim of this study was to investigate the effect of a beta-blocker (atenolol and metoprolol) on exercise heart rate (HR) and rate pressure product (RPP) during a morning and afternoon maximal exercise test (maxET) in patients with coronary heart disease (CHD). Twenty-one CHD patients (59.9 ± 8.9 years of age) treated with either atenolol or metoprolol participated in this study. All subjects underwent a morning and afternoon symptom-limited maximal exercise test (maxET) 2–3 h and 8–10 h after medication intake. No significant differences in exercise capacity (atenolol: 8.3 ± 1.9 vs. 8.3 ± 2.1 metabolic equivalents (METs); metoprolol: 8.8 ± 2.0 vs. 8.7 ± 2.0 METs) or rate of perceived exertion (atenolol: 7.4 ± 1.9 vs. 7.4 ± 1.7 METs; metoprolol: 7.2 ± 1.5 vs. 6.8 ± 0.9 METs) were observed between the 2 maxETs in either group. However, there was a discrepancy in cardiovascular and ischemic responses between morning and afternoon maxET. Subjects treated with atenolol demonstrated better overall control of HR and RPP during the afternoon maxET. The difference between morning and afternoon HRmax (11 ± 8 vs. 19 ± 9 beats·min–1; p = 0.05) was significantly higher in the metoprolol group, but did not attain significance for RPP (31 ± 30 vs. 54 ± 28 mmHg·beats·min–1·10−2; p = 0.09). Also, nearly one quarter of our subjects who had a normal morning maxET demonstrated an abnormal electrocardiogram response and (or) ischemia when exercise testing was done in the late afternoon. These changes were more prevalent in subjects taking metoprolol. The results of this study suggest that there is considerable time-of-day variation in the cardiovascular response to a maxET in CHD patients treated with a beta-blocker.
Electronic Structure, Magnetic Order and Interlayer Magnetic Couplings in Metallic Superlattices
Authors: Stoeffler Daniel , Gautier François 
Published: July 2007

The general trends for the electronic structure of perfect model superlattices AmBn are calculated using a real-space tight-binding model. The magnetic moments distribution and the interlayer magnetic couplings between ferromagnetic layers Am (A=Fe or Co) coupled by non-magnetic (B=V or Ru), nearly ferromagnetic (B=Pd) or antiferromagnetic (B=Cr) spacer layers Bn are obtained as a function of the spacer thickness n.
In a first part, we present the model we used for the calculation and the crystallographic structure of the considered superlattices (Fe/V, Fe/Cr, Co/Ru and Co/Pd). These considerations will be applied to the non-magnetic and nearly ferromagnetic cases to derive general trends for the magnetic interlayers couplings.
In a second part, we apply the method we presented previously to the superlattices with an antiferromagnetic spacer (Fe3Crn). Using first a “d” band calculation we show that the interlayer coupling energy can be understood in terms of a strong interfacial antiferromagnetic coupling and of a constrained magnetic wall in the Cr layer giving a rapidly oscillating coupling energy. An extension of the previous calculation taking into account the “spd” hybridization does not affect the previous conclusion. Finally we examine the distribution of magnetic moments and the stability of tilted antiferromagnetic Cr layers and we find that this magnetic structure is nearly degenerate with the collinear antiferromagnetic arrangement.
Chaos with Few Degrees of Freedom
Authors: Gutzwiller Martin C. 
Published: July 2007

As a mathematician, astronomer, and physicist, Poincaré was the first to study the phenomenon of chaos in classical mechanics, in particular the three-body-problem of the Moon orbiting around the Earth under the perturbation of the Sun. His work helps us to understand atomic and molecular physics, because our intuition in these areas is always based on a classical picture for the motion of the nuclei and electrons. The Moon's motion was found to be multi-periodic by the early observers; Newton explained the main frequencies and calculated the lowest terms in the corresponding Fourier expansion. But inspite of ingenious efforts, like the work of Hill involving as a starting point a periodic orbit of the full problem, Poincaré showed that perturbation theory is unable to guarantee the convergence of the Fourier expansion. In this traditional representation, the lunar trajectory would be restricted to a four-dimensional invariant torus although the available phase-space has eight dimensions.The invariant tori are destroyed because of increasing phase-lock due to perturbations, whenever the system is close to a resonance. The KAM-theorem gives a mathematical criterion for this loss, which is best seen in a surface of section for such simple systems as the Anisotropic and the Diamagnetic Kepler Problem (AKP and DKP). Instead of invariant tori, the flow in phase space involves a double foliation where each trajectory is the intersection of one leaf from the unstable foliation with a leaf from the stable foliation. Neighboring trajectories drift exponentially away from each other in the future along the unstable leaf, and approach each another in the stable leaf coming from the past. This situation, called “hard chaos”, also allows for a symbolic description of each trajectory in terms of a simple code like binary sequences in the AKP.Einstein showed that the usual connection with quantum mechanics is valid only for the case of “regular behavior”, i.e. the presence of invariant tori. For classically chaotic systems, VanVleck's expression for the propagator seems to be the best starting point, provided it is summed over all the classical trajectories that go from the source to the defector. Its trace becomes a sum over periodic orbits, which lends additional weight to Poincaré's emphasis on their importance in classical mechanics. In trying to understand the trace of an operator as a function of time, or the scattering phase-shift as a function of momentum, one runs into almost-periodic functions. They are able to mimic locally any arbitrary smooth function provided the spectrum of frequencies, although discrete, is rich enough. This unexpected, but smooth behavior can be seen as a symptom of quantum chaos, in contrast to the fractal nature of classical chaos.
Chick Hairy1 protein interacts with Sap18, a component of the Sin3/HDAC transcriptional repressor complex
Authors: Sheeba Caroline J , Palmeirim Isabel , Andrade Raquel P 
Published: July 2007

Abstract

Background
The vertebrate adult axial skeleton, trunk and limb skeletal muscles and dermis of the back all arise from early embryonic structures called somites. Somites are symmetrically positioned flanking the embryo axial structures (neural tube and notochord) and are periodically formed in a anterior-posterior direction from the presomitic mesoderm. The time required to form a somite pair is constant and species-specific. This extraordinary periodicity is proposed to depend on an underlying somitogenesis molecular clock, firstly evidenced by the cyclic expression of the chick hairy1 gene in the unsegmented presomitic mesoderm with a 90 min periodicity, corresponding to the time required to form a somite pair in the chick embryo. The number of hairy1 oscillations at any given moment is proposed to provide the cell with both temporal and positional information along the embryo's anterior-posterior axis. Nevertheless, how this is accomplished and what biological processes are involved is still unknown. Aiming at understanding the molecular events triggered by the somitogenesis clock Hairy1 protein, we have employed the yeast two-hybrid system to identify Hairy1 interaction partners.

Results
Sap18, an adaptor molecule of the Sin3/HDAC transcriptional repressor complex, was found to interact with the C-terminal portion of the Hairy1 protein in a yeast two-hybrid assay and the Hairy1/Sap18 interaction was independently confirmed by co-immunoprecipitation experiments. We have characterized the expression patterns of both sap18 and sin3a genes during chick embryo development, using in situ hybridization experiments. We found that both sap18 and sin3a expression patterns co-localize in vivo with hairy1 expression domains in chick rostral presomitic mesoderm and caudal region of somites.

Conclusion
Hairy1 belongs to the hairy-enhancer-of-split family of transcriptional repressor proteins. Our results indicate that during chick somitogenesis Hairy1 may mediate gene transcriptional repression by recruiting the Sin3/HDAC complex, through a direct interaction with the Sap18 adaptor molecule. Moreover, since sap18 and sin3a are not expressed in the PSM territory where hairy1 presents cyclic expression, our study strongly points to different roles for Hairy1 throughout the PSM and in the prospective somite and caudal region of already formed somites.
Collective properties of evolving molecular quasispecies
Authors: Stich Michael , Briones Carlos , Manrubia Susanna C 
Published: July 2007

Abstract

Background
RNA molecules, through their dual appearance as sequence and structure, represent a suitable model to study evolutionary properties of quasispecies. The essential ingredient in this model is the differentiation between genotype (molecular sequences which are affected by mutation) and phenotype (molecular structure, affected by selection). This framework allows a quantitative analysis of organizational properties of quasispecies as they adapt to different environments, such as their robustness, the effect of the degeneration of the sequence space, or the adaptation under different mutation rates and the error threshold associated.

Results
We describe and analyze the structural properties of molecular quasispecies adapting to different environments both during the transient time before adaptation takes place and in the asymptotic state, once optimization has occurred. We observe a minimum in the adaptation time at values of the mutation rate relatively far from the phenotypic error threshold. Through the definition of a consensus structure, it is shown that the quasispecies retains relevant structural information in a distributed fashion even above the error threshold. This structural robustness depends on the precise shape of the secondary structure used as target of selection. Experimental results available for natural RNA populations are in qualitative agreement with our observations.

Conclusion
Adaptation time of molecular quasispecies to a given environment is optimized at values of the mutation rate well below the phenotypic error threshold. The optimal value results from a trade-off between diversity generation and fixation of advantageous mutants. The critical value of the mutation rate is a function not only of the sequence length, but also of the specific properties of the environment, in this case the selection pressure and the shape of the secondary structure used as target phenotype. Certain functional motifs of RNA secondary structure that withstand high mutation rates (as the ubiquitous hairpin motif) might appear early in evolution and be actually frozen evolutionary accidents.
EuMicroSatdb: A database for microsatellites in the sequenced genomes of eukaryotes
Authors: Aishwarya Veenu , Grover Atul , Sharma Prakash C 
Published: July 2007

Abstract

Background
Microsatellites have immense utility as molecular markers in different fields like genome characterization and mapping, phylogeny and evolutionary biology. Existing microsatellite databases are of limited utility for experimental and computational biologists with regard to their content and information output. EuMicroSatdb (Eu karyotic MicroSat ellite
d
ata
b
ase) http://ipu.ac.in/usbt/EuMicroSatdb.htm is a web based relational database for easy and efficient positional mining of microsatellites from sequenced eukaryotic genomes.

Description
A user friendly web interface has been developed for microsatellite data retrieval using Active Server Pages (ASP). The backend database codes for data extraction and assembly have been written using Perl based scripts and C++. Precise need based microsatellites data retrieval is possible using different input parameters like microsatellite type (simple perfect or compound perfect), repeat unit length (mono- to hexa-nucleotide), repeat number, microsatellite length and chromosomal location in the genome. Furthermore, information about clustering of different microsatellites in the genome can also be retrieved. Finally, to facilitate primer designing for PCR amplification of any desired microsatellite locus, 200 bp upstream and downstream sequences are provided.

Conclusion
The database allows easy systematic retrieval of comprehensive information about simple and compound microsatellites, microsatellite clusters and their locus coordinates in 31 sequenced eukaryotic genomes. The information content of the database is useful in different areas of research like gene tagging, genome mapping, population genetics, germplasm characterization and in understanding microsatellite dynamics in eukaryotic genomes.
11C-choline vs. 18F-FDG PET/CT in assessing bone involvement in patients with multiple myeloma
Authors: Nanni Cristina , Zamagni Elena , Cavo Michele , Rubello Domenico , Tacchetti Paola , Pettinato Cinzia , Farsad Mohsen , Castellucci Paolo , Ambrosini Valentina , Montini Gian Carlo , Al-Nahhas Adil , Franchi Roberto , Fanti Stefano 
Published: July 2007

Abstract

Background
Multiple Myeloma (MM) is a B cell neoplasm causing lytic or osteopenic bone abnormalities. Whole body skeletal survey (WBSS), Magnetic resonance (MR) and 18F-FDG PET/CT are imaging techniques routinely used for the evaluation of bone involvement in MM patients.

Aim
As MM bone lesions may present low 18F-FDG uptake; the aim of this study was to assess the possible added value and limitations of 11C-Choline to that of 18F-FDG PET/CT in patients affected with MM.

Methods
Ten patients affected with MM underwent a standard 11C-Choline PET/CT and an 18F-FDG PET/CT within one week. The results of the two scans were compared in terms of number, sites and SUVmax of lesions.

Results
Four patients (40%) had a negative concordant 11C-Choline and 18F-FDG PET/CT scans. Two patients (20%) had a positive 11C-Choline and 18F-FDG PET/CT scans that identified the same number and sites of bone lesions. The remaining four patients (40%) had a positive 11C-Choline and 18F-FDG PET/CT scan, but the two exams identified different number of lesions. Choline showed a mean SUVmax of 5 while FDG showed a mean SUVmax of 3.8 (P = 0.042). Overall, 11C-Choline PET/CT scans detected 37 bone lesions and 18F-FDG PET/CT scans detected 22 bone lesions but the difference was not significant (P = 0.8).

Conclusion
According to these preliminary data, 11C-Choline PET/CT appears to be more sensitive than 18F-FDG PET/CT for the detection of bony myelomatous lesions. If these data are confirmed in larger series of patients, 11C-Choline may be considered a more appropriate functional imaging in association with MRI for MM bone staging.
Simian virus 40 in humans
Authors: Martini Fernanda , Corallini Alfredo , Balatti Veronica , Sabbioni Silvia , Pancaldi Cecilia , Tognon Mauro 
Published: July 2007

Abstract
Simian virus 40 (SV40) is a monkey virus that was administered to human populations by contaminated vaccines which were produced in SV40 naturally infected monkey cells.
Recent molecular biology and epidemiological studies suggest that SV40 may be contagiously transmitted in humans by horizontal infection, independently from the earlier administration of SV40-contaminated vaccines.
SV40 footprints in humans have been found associated at high prevalence with specific tumor types such as brain and bone tumors, mesotheliomas and lymphomas and with kidney diseases, and at lower prevalence in blood samples from healthy donors.
Contrasting reports appeared in the literature on the circulation of SV40 in humans by contagious transmission and its association, as a possible etiologic cofactor, with specific human tumors. As a consequence of the conflicting results, a considerable debate has developed in the scientific community. In the present review we consider the main results obtained by different groups investigating SV40 sequences in human tumors and in blood specimens, the putative role of SV40 in the onset/progression of specific human tumors, and comment on the hypotheses arising from these data.
Insecticidal activity of essential oil from Chamaecyparis formosensis Matsum
Authors: Kuo Pei-Min , Chu Fang-Hua , Chang Shang-Tzen , Hsiao Wen-Feng , Wang Sheng-Yang 
Published: July 2007

Abstract

Chamaecyparis formosensis is an endemic precious tree species grown in Taiwan. Based on the results obtained in our current study, the essential oil of C. formosensis wood possesses significant insecticidal activities. In an assay to assess mosquito larvicidal properties, the essential oil completely killed the larvae of Aedes aegypti and Aedes albopictus at a dosage of 100 μg ml-1 in water. Concentrations of the essential oil at a dosage of 0.16 mg cm-3 in air resulted in 100% mortality of silverfish after 2 h. It was found that the extractives of C. formosensis possess multiple bioactivities against insects. There is great potential for the development of insecticides for domestic application to kill mosquito larvae and silverfish based on this raw material.
Biochemotherapy of metastatic melanoma in patients with or without recently diagnosed brain metastases
Authors: Majer Martin , Jensen Randy L. , Shrieve Dennis C. , Watson Gordon A. , Wang Michael , Leachman Sancy A. , Boucher Kenneth M. , Samlowski Wolfram E. 
Published: July 2007

AbstractBACKGROUND.Brain metastases are an alarming complication of advanced melanoma, frequently contributing to patient demise. The authors performed a retrospective analysis to determine whether the treatment of metastatic melanoma with biochemotherapy would result in similar outcomes if brain metastases were first controlled with aggressive, central nervous system (CNS)‐directed treatment.METHODS.Seventy melanoma patients were treated with biochemotherapy for metastatic melanoma between 1999 and 2005. Of these, 20 patients had recently diagnosed brain metastases, whereas 50 did not. Brain metastases (if present) were treated with stereotactic radiosurgery ≥28 days prior to systemic therapy. All patients were treated with biochemotherapy consisting of either dacarbazine or temozolomide in combination with a 96‐hour continuous intravenous infusion of interleukin‐2 and subcutaneous interferon‐α‐2B. The primary endpoint was survival from the time of the initial diagnosis of metastatic disease.RESULTS.Median survival from the time of the diagnosis of metastatic melanoma was 15.8 months for patients with brain metastases and 11.1 months for those without CNS involvement (P = .26 by the log‐rank test; P = .075 by the Gehan Wilcoxon test). Dacarbazine‐based and temozolomide‐based regimens appeared similar with regard to their effect on overall survival and CNS disease progression. A plateau in further brain recurrences was observed in patients who survived for > 20 months.CONCLUSIONS.Data from the current study suggest that the outcome of biochemotherapy is comparable in patients with and those without brain metastases, if brain metastases are controlled with multidisciplinary treatment. Prolonged survival can be achieved in approximately 15% of patients, regardless of whether or not brain metastases are present. Cancer 2007. © 2007 American Cancer Society.
Ion‐Exchange Plasma Membranes for Fuel Cells on a Micrometer Scale
Authors: Roualdès S. , Schieda M. , Durivault L. , Guesmi I. , Gérardin E. , Durand J. 
Published: July 2007

AbstractRecent advances in miniaturization technology make polymer electrolyte membrane fuel cells very attractive as power sources for portable devices. Ion‐exchange membranes for microscale fuel cells are synthesized by plasma polymerization (using a precursor containing ion‐exchange groups) and intensively characterized. Ion‐exchange plasma membranes are thin, amorphous, and dense materials with no defects. Spectroscopic analyses reveal a polymer‐type matrix containing a rather high concentration of ion‐exchange groups. Under the best synthesis conditions, membranes show a satisfying ionic conduction level and a high compatibility with other active layers of fuel cells, making them suitable for insertion in such power‐supply devices.