bluuebunny/crossref_metadata_2025 huggingface dataset:
On the strong circular 5‐flow conjecture
Authors: Máčajová Edita , Raspaud André
Published: May 2006

The Strong Circular 5‐flow Conjecture of Mohar claims that each snark—with the sole exception of the Petersen graph—has circular flow number smaller than 5. We disprove this conjecture by constructing an infinite family of cyclically 4‐edge connected snarks whose circular flow number equals 5. © 2006 Wiley Periodicals, Inc. J Graph Theory
Mean Ramsey–Turán numbers
Authors: Yuster Raphael
Published: May 2006

A ρ‐mean coloring of a graph is a coloring of the edges such that the average number of colors incident with each vertex is at most ρ. For a graph H and for ρ ≥ 1, the mean Ramsey–Turán number RT(n, H,ρ − mean) is the maximum number of edges a ρ‐mean colored graph with n vertices can have under the condition it does not have a monochromatic copy of H. It is conjectured that $RT(n, K_ m, 2 - mean) = RT(n, K_ m, 2)$ where $RT(n, H, k)$ is the maximum number of edges a k edge‐colored graph with n vertices can have under the condition it does not have a monochromatic copy of H. We prove the conjecture holds for $K_ 3$. We also prove that $RT(n, H,\rho - mean) \leq RT(n, K_{\chi(H)},\rho - mean) + o(n^2)$. This result is tight for graphs H whose clique number equals their chromatic number. In particular, we get that if H is a 3‐chromatic graph having a triangle then $RT(n, H, 2 - mean) = RT(n, K_ 3, 2 - mean) + o(n^2) = RT(n, K_ 3, 2) + o(n^2) = 0.4n^2(1 + o(1))$. © 2006 Wiley Periodicals, Inc. J Graph Theory 53: 126–134, 2006
Evaluation of the efficacy of skin care products by laser
scanning microscopy
Authors: Teichmann A , Sadeyh Pour Soleh H , Schanzer S , Richter H , Schwarz A , Lademann J
Published: May 2006

The skin represents the largest organ of our organism
and is the barrier to the environment. UV sun radiation and
environmental hazards damage our skin. Therefore, it is the aim of
skin care products to protect the skin from damage and stimulate
the regeneration. The efficacy of skin care products for barrier
improvement is usually analyzed by transepidermal water loss
measurements (TEWL). This method is suitable for the investigation
of the untreated skin. Topically applied products can influence
the TEWL measurements. In vivo laser scanning microscopy is a new
approach for analyzing the barrier function of the skin. This
method is not disturbed by topically applied formulation. In the
present paper, laser scanning microscopy was used in comparison to
TEWL measurements for the characterization of the skin care
product Bedan-Gesichtscreme®
Applications of laser-induced fluorescence spectroscopy for the
determination of NADH in experimental neuroscience
Authors: Rex A , Fink F
Published: May 2006

There is an increasing need for continuously monitoring
changes in brain metabolism and neuronal activity, respectively.
The aim is to improve our understanding of mechanisms involved in
physiological as well as pathophysiological and behavioural
responses and to characterise drug actions. Changes of NADH
concentration in the brain can be regarded as an index of changes
in mitochondrial activity, which is closely related to neuronal
activity. During the last decade the determination of NADH
fluorescence by laser-induced fluorescence spectroscopy has become
a method of choice in the study of mitochondrial metabolism in
neuroscience. By now, small optical probes, providing excellent
temporal and spatial resolution and the development of reliable
and robust laser-based fluorescence detectors allow a widespread
use in preclinical research. Besides in vitro studies,
especially the assessment of changes in the NADH fluorescence
in vivo has been shown to provide valuable information on
brain function. Several applications are given, ranging from
studying drug action or the extent of brain lesion to the
measurement the time course of NADH concentration in a brain
region of an awake and behaving laboratory rat. Theoretical
aspects, opportunities, and limitations that have to be considered
during the implementation of fluorescence spectroscopy are
described. It is concluded, that measurement of NADH fluorescence
by laser-induced fluorescence spectroscopy is a suitable tool for
investigation of functional processes in the brain.
Matrix metalloproteinase 11 (MMP‐11; stromelysin‐3) and synthetic inhibitors
Authors: Matziari Magdalini , Dive Vincent , Yiotakis Athanasios
Published: May 2006

Matrix metalloproteinase (MMP)‐11, or Stromelysin 3, is a particular member of MMP family, a group of zinc‐dependent endopeptidases involved in matrix degradation and tissue remodeling. Despite intense efforts since its first characterization 15 years ago, its role and target substrates in different diseases remain largely unknown. While mice with MMP‐11 deficiency display no particular phenotype, analysis of different tumorigenesis models with these mice lead to the conclusion that MMP‐11 promotes tumor development. In contrast with other MMPs, MMP‐11 is unable to degrade any major extracellular matrix component and unlike most of other MMPs that are secreted as inactive proenzymes and activated extracellularly, MMP‐11 is secreted under active form. MMP‐11 may thus play a unique role in tissue remodeling processes, including those associated with tumor progression. Although MMP‐11 and other MMPs have been considered as promising targets to combat cancer, a first series of clinical trials using broad‐spectrum MMP inhibitors have not led to significant therapeutic benefits. These disappointing results highlight the need for better understanding of the exact role played by each MMP during the different stages of tumor progression. Among the different strategies to fill this gap, highly specific MMP inhibitors would be of great value. This review provides an update on the selectivity profile of phosphinic MMP‐11 synthetic inhibitors developed and discusses the opportunities and limitations to identify inhibitors able to fully discriminate MMP‐11 from the other MMPs. © 2006 Wiley Periodicals, Inc. Med Res Rev, 27, No. 4, 528–552, 2007
Energy decay for a nonlinear viscoelastic rod equations with dynamic boundary conditions
Authors: Zhang Hongwei , Hu Qingying
Published: May 2006

The purpose of this article is to prove the energy decay of the mixed problem for a nonlinear viscoelastic rod equation
equation image
with dynamic boundary conditions. Copyright © 2006 John Wiley & Sons, Ltd.
A solution method for the linear Chandrasekhar equation
Authors: Wegert Elias , von Wolfersdorf Lothar
Published: May 2006

The paper is devoted to the linearized H‐equation of Chandrasekhar and Ambarzumyan. A Stieltjes‐type transform reduces the equation to a boundary value problem for holomorphic functions in the upper half‐plane which is solved in closed form. Additional conditions ensure that the solutions Φ extend holomorphically to the lower half‐plane slit along a straight line segment. The solutions of the original problem are then determined from the boundary values of Φ on this slit.

The approach gives necessary and sufficient conditions for Fredholmness and describes all Fredholm parameters in terms of zeros of two functions 1–K and G associated with the kernel and the right‐hand side of the equation. Explicit formulas for the complete set of solutions are presented.

Die Arbeit ist der linearisierten H‐Gleichung von Chandrasekhar und Ambarzumyan gewidmet. Die Gleichung wird mit Hilfe einer modifizierten Stieltjes‐Transformation auf ein Randwertproblem für holomorphe Funktionen in der oberen Halbebene zurückgeführt das in geschlossener Form gelöst wird. Unter zusätzlichen Bedingungen können die Lösungen holomorph in die längs einer Strecke aufgeschnittene untere Halbebene fortgesetzt werden. Die Lösungen Φ des Ausgangsproblems werden dann aus den Randwerten von Φ längs des Schlitzes bestimmt. Der Zugang liefert notwendige und hinreichende Bedingungen dafür, dass der Operator Fredholmsch ist und charakterisiert alle Fredholmparameter mit Hilfe der Nullstellen zweier Funktionen 1–K und G, die dem Kern und der rechten Seite der Gleichung zugeordnet sind. Es werden explizite Darstellungen für die vollständige Lösungsmenge angegeben. Copyright © 2006 John Wiley & Sons, Ltd.
Modified wave operators for the fourth‐order non‐linear Schrödinger‐type equation with cubic non‐linearity
Authors: Segata Jun‐ichi
Published: May 2006

We consider the scattering problem for the fourth‐order non‐linear Schrödinger‐type equation:
equation image
We show the existence of the modified wave operators for the above equation with cubic case by imposing the mean zero condition for the final data. Copyright © 2006 John Wiley & Sons, Ltd.
An expansion theorem for two‐dimensional elastic waves and its application
Authors: Chen Kun‐Chu , Lin Ching‐Lung
Published: May 2006

We prove an Atkinson–Wilcox‐type expansion for two‐dimensional elastic waves in this paper. The approach developed on the two‐dimensional Helmholtz equation will be applied in the proof. When the elastic fields are involved, the situation becomes much harder due to two wave solutions propagating at different phase velocities. In the last section, we give an application about the reconstruction of an obstacle from the scattering amplitude. Copyright © 2006 John Wiley & Sons, Ltd.
Microbiologicals for deactivating mycotoxins
Authors: Schatzmayr Gerd , Zehner Florian , Täubel Martin , Schatzmayr Dian , Klimitsch Alfred , Loibner Andreas Paul , Binder Eva Maria
Published: May 2006

Mycotoxins are secondary metabolites of fungi affecting human and animal health. Five classes of mycotoxins are of major concern in animal husbandry, namely aflatoxins, trichothecenes, zearalenone, ochratoxins, and fumonisins. Due to their diverse structure these fungal toxins are able to cause a great variety of acute symptoms in animals. Clay minerals have been used in animal nutrition to bind mycotoxins, but the binders are only very specific for aflatoxins but not for other toxins. A novel strategy to control the problem of mycotoxicoses in animals is the application of microorganisms capable of biotransforming mycotoxins into nontoxic metabolites. The microbes act in the intestinal tract of animals prior to the resorption of the mycotoxins. A Eubacterium (BBSH 797) strain is able to deactivate trichothecenes by reduction of the epoxide ring (CAST, Mycotoxins, Risks in Plant, Animal and Human Systems, Task Force Report 139, Council of Agricultural Science and Technology, Ames Iowa 2003, p. 10.; Binder, E. M., Binder, J., Ellend, N., Schaffer, E. et al., in: Miraglia, M., van Egmond, H., Brera, C., Gilbert, J. (Eds.), Mycotoxins and Phycotoxins – Developments in Chemistry, Toxicology and Food Safety, Alaken, Fort Collins 1996, pp. 279–285). This strain was isolated out of bovine rumen fluid and the mode of action was proven in vitro and also in vivo. Further a novel yeast strain, capable of degrading ochratoxin A and zearalenone was isolated and characterized (Bruinink, A., Rasonyi, T., Sidler, C., Nat. Toxins 1999, 6, 173–177; Schatzmayr, G., Heidler, D., Fuchs, E., Mohnl, M. et al., Mycotoxin Res. 2003, 19, 124–128.) Due to the yeasts affiliation to the genus of Trichosporon and its property to degrade mycotoxins this strain was named Trichosporon mycotoxinivorans (Trichosporon MTV, 115).
SANICLAY: simple anisotropic clay plasticity model
Authors: Dafalias Yannis F. , Manzari Majid T. , Papadimitriou Achilleas G.
Published: May 2006

SANICLAY is a new simple anisotropic clay plasticity model that builds on a modification of an earlier model with an associated flow rule, in order to include simulations of softening response under undrained compression followingKoconsolidation. Non‐associativity is introduced by adopting a yield surface different than the plastic potential surface. Besides, the isotropic hardening of the yield surface both surfaces evolve according to a combined distortional and rotational hardening rule, simulating the evolving anisotropy. Although built on the general premises of critical state soil mechanics, the model induces a critical state line in the void ratio–mean effective stress space, which is a function of anisotropy. To ease interpretation, the model formulation is presented firstly in the triaxial stress space and subsequently, its multiaxial generalization is developed systematically, in a form appropriate for implementation in numerical codes. The SANICLAY is shown to provide successful simulation of both undrained and drained rate‐independent behaviour of normally consolidated sensitive clays, and to a satisfactory degree of accuracy of overconsolidated clays. The new model requires merely three constants more than those of the modified Cam clay model, all of which are easily calibrated from well‐established laboratory tests following a meticulously presented procedure. Copyright © 2006 John Wiley & Sons, Ltd.
Analysis of parameterized quadratic eigenvalue problems in computational acoustics with homotopic deviation theory
Authors: Chaitin‐Chatelin F. , van Gijzen M. B.
Published: May 2006

This paper analyzes a family of parameterized quadratic eigenvalue problems from acoustics in the framework of homotopic deviation theory. Our specific application is the acoustic wave equation (in 1D and 2D) where the boundary conditions are partly pressure release (homogeneous Dirichlet) and partly impedance, with a complex impedance parameter ζ. The admittance t = 1/ζ is the classical homotopy parameter. In particular, we study the spectrum when t → ∞. We show that in the limit part of the eigenvalues remain bounded and converge to the so‐called kernel points. We also show that there exist the so‐called critical points that correspond to frequencies for which no finite value of the admittance can cause a resonance. Finally, the physical interpretation that the impedance condition is transformed into a pressure release condition when |t| → ∞ enables us to give the kernel points in closed form as eigenvalues of the discrete Dirichlet problem. Copyright © 2006 John Wiley & Sons, Ltd.
Treatment of infective endocarditis with recombinant tissue plasminogen activator
Authors: Gunes Adalet Meral , Bostan Ozlem Mehtap , Baytan Birol , Semizel Evren
Published: May 2006

Infective endocarditis (IE) caused by microbial infection is virtually always fatal if untreated. High‐dose and long‐term antibiotic treatment is required to eradicate microorganisms. If increased risk of embolic events, persistent infection, and progressive cardiac failure are present, surgery is indicated. However, surgery can carry an increased risk of mortality and morbidity in critically ill children of whom other treatment options such as administering, a thrombolytic agent; recombinant tissue plasminogen activator (r‐tPA) could be an alternative choice. Here, we report a 14‐year‐old male with Down syndrome and acute myeloblastic leukemia, diagnosed with IE characterized by two large vegetations on aortic and mitral valves, who was successfully treated with r‐tPA. Pediatr Blood Cancer 2008;50:132–134. © 2006 Wiley‐Liss, Inc.
Personality, identity styles and authoritarianism: an integrative study among late adolescents
Authors: Duriez Bart , Soenens Bart
Published: May 2006

The relations between five personality factors, three identity styles, the prejudice dispositions of right‐wing authoritarianism (RWA), social dominance orientation (SDO) and racial prejudice were investigated in a Flemish‐Belgian late adolescent sample (N = 328). Results show that Openness to Experience and Agreeableness relate to racial prejudice but that these relations were fully mediated by RWA and SDO. In addition, results show that whereas RWA relates to Conscientiousness and lack of Openness to Experience, SDO relates to lack of Agreeableness and lack of Openness to Experience. The relation between Conscientiousness and RWA and between Openness to Experience and SDO was fully mediated by the identity styles. However, Openness to Experience had a direct influence on RWA and Agreeableness had a direct influence on SDO. The implications of these findings are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of poly(vinyl alcohol) fine particles as a novel biodegradable nucleating agent on the crystallization of poly(3‐hydroxybutyrate)
Authors: Alata H. , Hexig B. , Inoue Y.
Published: May 2006

The effect of poly(vinyl alcohol)(PVA) fine particles as the nucleating agent on the crystallization behavior of bacterial poly(3‐hydroxybutyrate)(PHB) was studied using differential scanning calorimetry measurements and polarized light microscope observation. The results were compared with the effect of PVA conventionally blended with PHB. The PVA fine particles were found to be able to greatly enhance the crystallization of PHB, while the conventionally blended PVA extremely retarded the crystallization of PHB. The nucleating effect of PVA fine particles is almost comparable to that of the talc powder. Considering the biodegradability and biocompatibility of PVA, the usage of PVA particle as a nucleating agent provides marked benefits over the currently employed nonbiodegradable nucleating agents, such as talc and boron nitride. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44:1813–1820, 2006
Viscometric study of gelatin in dilute aqueous solutions
Authors: Li Yi , Cheng Rongshi
Published: May 2006

The viscosities of aqueous solutions of gelatin at different temperatures were carefully measured in a common glass‐capillary Ubbelohde viscometer at dilute to extremely dilute concentrations. The adsorption effect that occurred in the viscosity measurements was theoretically analyzed and discussed. A theory based on Langmuir isotherms could adequately describe the existing data. Some structural information was obtained by the use of an iterative fitting procedure to treat the reduced viscosity data, which disclosed that individual gelatin chains underwent a coil‐to‐helix transition as the solution cooled from 40 to 15 °C. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1804–1812, 2006
Physiotherapy cuts the dose of botulinum toxin
Authors: Ramdharry Gita
Published: May 2006

Background and Purpose. Cervical dystonia is a complex chronic neurological disorder which is more commonly managed with pharmacological interventions. Method. This Case Report outlines the rehabilitation of a patient who was able to reduce the effective dose of botulinum toxin when physiotherapy management was added to a long term pharmacological regime. Conclusions. A good outcome is demonstrated from a combined physiotherapy and botulinum toxin intervention. Copyright © 2006 John Wiley & Sons, Ltd.
Are therapeutic ultrasound units a potential vector for nosocomial infection?
Authors: Schabrun Siobhan , Chipchase Lucy , Rickard Heather
Published: May 2006

Background and Purpose. Nosocomial infections present a widespread problem in today's healthcare environment, with a significant number of patients acquiring an infection annually. With the contemporary transition of immunocompromised and high‐risk patients to community‐based care, therapeutic ultrasound has the potential to be a vector of infection in the physiotherapy setting. The purpose of the present study was to determine the degree of contamination on therapeutic ultrasound transducer heads and ultrasound gel after routine clinical use, and to evaluate the efficacy of recommended infection control procedures. Method. The study consisted of two phases. Using a prospective cross‐sectional design, microbiological cultures were obtained from 44 transducer heads and 43 gels. Subjects were drawn from a variety of physiotherapy practice settings. All samples containing more than five colony forming units per cm2 were considered contaminated. Following these measurements, a repeated‐measures design was used to re‐evaluate the 44 transducer heads for the amount and type of bacteria present after cleaning with a 70% alcohol wipe. Results. Twenty‐seven per cent of transducer heads and 28% of gels were contaminated. Transducer heads showed fairly low levels of contamination across the sample, with the majority of organisms isolated found in normal skin and environmental flora. Gels were heavily contaminated with opportunistic and potentially pathogenic organisms, including Stenotrophomonas maltophilia, Staphylococcus aureus, Acinetobacter baumannii and Rhodotorula mucilaginosa. No multi‐resistant organisms were identified. Cleaning with 70% alcohol significantly reduced the level of contamination on transducer heads (p < 0.01). Conclusions. Therapeutic ultrasound equipment is a potential vector for nosocomial infection in physiotherapy patients. The risk of infection from transducer heads can be effectively removed by cleaning with 70% alcohol between patients. Further research into possible strategies to reduce the risk of infection from ultrasound gels is needed. Copyright © 2006 John Wiley & Sons, Ltd.
Reactions of platinum cluster ions with benzene
Authors: Liu Hongtao , Sun Shutao , Xing Xiaopeng , Tang Zichao
Published: May 2006

In this work, the cation and anion products of the reactions between platinum clusters produced by laser ablation and the benzene molecules seeded in argon have been studied using a high‐resolution reflectron time‐of‐flight mass spectrometer (RTOFMS). The dominant cation products are [C6nH6n − k]+ and [Ptm(C6H6)n]+ complexes, while the dominant anion products are dehydrogenated species, [C6H5PtH]−, [PtC12Hk]− and [PtmC6H4 · · · (C6H6)n]−, etc. Some important intermediate structures ([PtC6H6]+, [Pt(C6H6)2]+, [Pt2(C6H6)3]+, [C6H5PtH]−, [Pt2C6H4]−, [Pt3C6H4]− and [Pt4C6H4]−) have been analyzed using density functional theory (DFT) calculations. Different reaction mechanisms are proposed for platinum cluster cations and anions with benzene, respectively. Copyright © 2006 John Wiley & Sons, Ltd.
Liquid chromatography/tandem triple‐quadrupole mass spectrometry for determination of paclitaxel in rat tissues
Authors: Tong Xinyong , Zhou Jianping , Tan Yan
Published: May 2006

A liquid chromatography/tandem triple‐quadrupole mass spectrometry assay to quantify paclitaxel in rat tissue homogenates containing taxol or paclitaxel nanoliposome (PTX‐NLP) was developed and validated. Liquid‐liquid extraction with tert‐butyl methyl ether was used for tissue sample preparation and docetaxel was used as the internal standard. Paclitaxel and docetaxel were separated on a 200 mm × 4.6 mm × 5 µm C18 column and quantified using a triple‐quadrupole mass spectrometer operating in positive ion electrospray selective reaction monitoring mode (ESI+‐SRM) with a total run time of 6.0 min. The peak area of the m/z 876.3 → 307.9 transition of paclitaxel is measured versus that of the m/z 830.3 → 549.1 transition of docetaxel to generate the standard curves. The standard curves were linear over the concentration range of 0.2008–2008 ng/mL for different tissues. The method had high extraction recovery (>90%) and accuracy (>90%) with the intra‐day and inter‐day precision <15%. Frozen stability, freeze/thaw stability, extraction stability and solution stability at ambient temperature were examined, which indicated the tissue samples should be extracted within 5 days and avoid being frozen and thawed repeatedly over 5 times. Extracted samples after evaporation could be stored at −20°C for 20 days without drug degradation and no degradation was also observed after solution samples were left to stand at ambient temperature for 24 h. This assay was used to support an in vivo biodistribution study of PTX‐NLP in rats. Copyright © 2006 John Wiley & Sons, Ltd.
Evaluation of the internal temperatures of an 8.6 kDa protein cation exposed to a hot dispenser cathode employed in electron capture dissociation mass spectrometry
Authors: Yim Yong‐hyeon , Kim Byungjoo , Ahn Seonghee , So Hun‐Young , Lee Sunyoung , Oh Han Bin
Published: May 2006

The ‘effective’ internal temperature of an 8.6 kDa ubiquitin cation was estimated under electron capture dissociation (ECD) conditions, in which a dispenser cathode electron source was mounted just outside an ion cyclotron resonance (ICR) cell, i.e., axially displaced at a distance less than 1 cm from the rear trap plate of the ICR cell. In this ECD configuration, thermal activation of the molecular ions stored in the ICR cell was anticipated since the heated dispenser cathode (Tcathode surface > 1000°C) emitted a large amount of (both visible and infrared) radiation as well as electrons. An evaluation of the internal temperature of ubiquitin 6+ and 7+ cations was made by comparing our ECD fragmentation patterns with those obtained by McLafferty et al. (J. Am. Chem. Soc. 2002; 124: 6407) as a function of the ion temperature. In McLafferty's configuration, the heating (or thermal activation) effect of their filament source was minimal since the filament was displaced by a distance as far as 70 cm from their ICR cell. A careful comparison reveals that the fragmentation patterns obtained in this work are very similar to those previously measured at T ∼ 125°C. In terms of sequence coverage, our ECD configuration provides better results, and in particular without the aid of any other simultaneous activation method, such as thermal heating, infrared multiphoton irradiation, or collisional activation, except for the visible and infrared radiation from the heated cathode. Copyright © 2006 John Wiley & Sons, Ltd.
Development of a sensitive and rapid liquid chromatography/tandem mass spectrometry method for the determination of apomorphine in canine plasma
Authors: Yang B. , Zhu J. B. , Deng C. H. , Duan G. L.
Published: May 2006

A sensitive, rapid and specific quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of apomorphine (APO) in canine plasma. The analytes were prepared using one‐step liquid‐liquid extraction, and analyzed on a Waters Symmetry C18 column interfaced with triple quadrupole tandem mass spectrometer. A mixture of methanol/0.1% formic acid in water (70: 30, v/v) was employed as the isocratic mobile phase. Positive electrospray ionization was utilized as the ionization source. The analyte and clenbuterol (internal standard) were both detected using multiple reaction monitoring (MRM) mode. The limit of detection (LOD) obtained was 0.03 ng/mL. The assay was linear over the concentration range of 0.1–100 ng/mL, and provided good precision (RSD) and good accuracy (RE). The analyte was stable by using antioxidants throughout the whole study. The experimental results show that LC/MS/MS is a rapid and sensitive method to analyze APO in plasma. Finally, the proposed method was successfully applied to a pharmacokinetic study of APO after intranasal administration of 0.5 mg apomorphine to 10 healthy beagle dogs. Copyright © 2006 John Wiley & Sons, Ltd.
Top‐down analysis of basic proteins by microchip capillary electrophoresis mass spectrometry
Authors: Akashi Satoko , Suzuki Koichi , Arai Akihiro , Yamada Naoyuki , Suzuki Ei‐Ichiro , Hirayama Kazuo , Nakamura Shin , Nishimura Yoshifumi
Published: May 2006

A system of microchip capillary electrophoresis/electrospray ionization mass spectrometry (µchip‐CE/ESI‐MS) for rapid characterization of proteins has been developed. Capillary electrophoresis (CE) enables rapid analysis of a sample present in very small quantity, such as at femtomole levels, at high resolution. Faster CE/MS analysis is expected by downsizing the normal capillary to the microchip (µchip) capillary. Although rapidity and high resolution are advantages of CE separation, electroosmotic flow (EOF) instability caused by the interaction between proteins and the microchannel surface results in low reproducibility in the analysis of basic proteins under neutral pH conditions. By coating the microchannel surface with a basic polymer, polyE‐323, basic proteins, which have pI values of over 7.5, could be separated and detected by µchip‐CE/MS on quadrupole (Q) and time‐of‐flight (TOF) hybrid instruments. By increasing the cone and collision voltages during the analysis by µchip‐CE/ESI‐MS of a small protein, some product ions, which contain the sequence information, could also be obtained, i.e., ‘top‐down’ analysis of the protein could be accomplished with this µchip‐CE/MS system. To our knowledge, this is the first report of ‘top‐down’ analysis of a protein by µchip‐CE/MS. Since it requires a much shorter time and a smaller sample amount for analysis than the conventional liquid chromatography (LC)/ESI‐MS method, µchip‐CE/MS promises to be suitable for the high‐throughput characterization of proteins. Copyright © 2006 John Wiley & Sons, Ltd.
Identification of the aromatase inhibitors anastrozole and exemestane in human urine using liquid chromatography/tandem mass spectrometry
Authors: Mareck Ute , Geyer Hans , Guddat Sven , Haenelt Nadine , Koch Anja , Kohler Maxie , Opfermann Georg , Thevis Mario , Schänzer Wilhelm
Published: May 2006

Anastrozole (2,2′‐[5‐(1H‐1,2,4‐triazol‐1‐ylmethyl)‐1.3‐phenylene]bis(2‐methylpropionitrile)) and exemestane (6‐methylenandrostan‐1,4‐diene‐3,17‐dione) are therapeutically used to treat hormone‐sensitive breast cancer in postmenopausal women. For doping purposes they may be used to counteract adverse effects of an extensive abuse of anabolic androgenic steroids (gynaecomastia) and to increase plasma testosterone concentrations. Excretion study urine samples and spot urine samples from women suffering from metastatic breast cancer, being treated with anastrozole or exemestane, were collected and analyzed to develop/optimize a detection system for anastrozole and exemestane to allow the identification of athletes who do not comply with the internationally prohibited use of these cancer drugs. The assay was based on liquid‐liquid extraction after enzymatic hydrolysis following liquid chromatography/tandem mass spectrometry (LC/MS/MS). Anastrozole, exemestane and its main metabolite (17‐dihydroexemestane) were identified in urine by comparison of mass spectra and retention times with respective reference substances. An assay validation for the analysis of anastrozole and exemestane was performed regarding lower limits of detection (anastrozole: 0.02 ng/mL; exemestane: 3.1 ng/mL; dihydroexemestane: 0.5 ng/mL), interday precisions (6.6–11.1%, 4.9–9.1% and 5.6–8.3% for low [10 ng/mL], medium [50 ng/mL] and high [100 ng/mL] concentration) and recoveries (ranged from 85–97%). Copyright © 2006 John Wiley & Sons, Ltd.
Evaluation of the in vivo receptor occupancy for the behavioral effects of cannabinoids using a radiolabeled cannabinoid receptor agonist, R‐[125/131I]AM2233
Authors: Dhawan Jasbeer , Deng Hongfeng , Gatley S. John , Makriyannis Alexandros , Akinfeleye Tolulope , Bruneus Magalie , Dimaio Alexis A. , Gifford Andrew N.
Published: May 2006

G‐protein coupled receptors exist in both high and low agonist affinity conformations, with tracer levels of agonist radioligands preferentially binding to the former. The goal of the present study was to characterize the in vivo binding of the aminoalkyindole‐based, CB1 receptor agonist,R‐[125/131I]AM2233 ((2‐[125/131I]iodo‐phenyl)‐[1‐(1‐methyl‐piperidin‐2‐yl‐methyl)‐1H‐indol‐3‐yl]‐methanone), and to use this radiotracer to selectively measure the receptor occupancy by the related CB1 receptor agonist, WIN55212‐2, to the agonist‐preferring affinity state of the receptor. In mouse locomotor assays, both WIN55212‐2 and AM2233 (racemic) produced an ∼60% reduction in activity at 1 mg/kg, (i.v.) and completely inhibited activity at 3 mg/kg, confirming their agonist nature. In ex vivo autoradiography, preferential uptake ofR‐[131I]AM2233 was apparent in CB1 receptor‐rich areas, including globus pallidus, substantia nigra, striatum, cerebellum, and hippocampus. Overall brain uptake ofR‐[131I]AM2233 was 1.3% injected activity/g at 5 min in mice. Coinjection of 3 mg/kg (i.v.) SR141716A, a CB1 receptor antagonist, withR‐[125I]AM2233 inhibited the radiotracer binding almost to nonspecific levels in the striatum, globus pallidus, and substantia nigra, although residual binding to a non‐CB1 receptor remained in the hippocampus. In contrast to the effect of SR141716A, coinjection of 10 mg/kg (i.v.) WIN55212‐2, a high dose that produced an immediate and profound immobility and catalepsy in the mice, reduced CB1 receptor‐specific binding ofR‐[125I]AM2233 in CB1 receptor‐rich areas by only 21–43%. These observations suggest that the behavioral effects of CB1 receptor agonists are manifested with a relatively small fraction of the agonist‐preferring affinity state of the receptor occupied. Synapse 60:93–101, 2006. © 2006 Wiley‐Liss, Inc.
Exocytotic release of creatine in rat brain
Authors: Almeida Ligia S. , Salomons Gajja S. , Hogenboom Francois , Jakobs Cornelis , Schoffelmeer Anton N.M.
Published: May 2006

The guanidino compound creatine has been shown to occur throughout the brain affecting energy metabolism and mental performance and to act at central GABAA receptors as a partial agonist. Therefore, we examined the possibility that creatine may in fact represent a neuromodulator that is released in the brain in an action‐potential dependent manner. To that end, we studied the uptake of [3H]creatine and its electrically evoked release from superfused rat brain slices as well as the evoked release of endogenously synthesized creatine. [3H]creatine was accumulated in neocortex slices in a Na+‐dependent manner, consistent with the involvement of the Na+‐dependent SLC6A8 creatine transporter. Most importantly, the electrically evoked release of [3H]creatine from neocortex slices (like that from caudate putamen and hippocampus slices) as well as the evoked release of endogenous (unlabeled) creatine was abolished when Ca2+ was omitted from the superfusion medium or in the presence of theNa+‐channel blocker tetrodotoxin (TTX). Moreover, blockade of K+‐channels by 4‐aminopyridine (4‐AP) strongly enhanced the electrically evoked release of [3H]creatine as well as that of endogenous creatine. These in vitro data indicate that creatine is not only synthesized and taken up by central neurons, but also released in an action‐potential dependent (exocytotic) manner, providing strong evidence for its role as a neuromodulator in the brain. Synapse 60:118–123, 2006. © 2006 Wiley‐Liss, Inc.
Antipsychotic pathway genes with expression altered in opposite direction by antipsychotics and amphetamine
Authors: Ko Françoise , Tallerico Teresa , Seeman Philip
Published: May 2006

To develop a new strategy for identifying possible psychotic‐ or antipsychotic‐related pathway genes, rats were treated with clinical doses of haloperidol and clozapine for 4 days, and the altered expression of genes was compared with the genes altered in expression after amphetamine sensitization. The objective was to identify genes with expression altered in the same direction by haloperidol and clozapine but in the opposite direction in the amphetamine‐sensitized rat striatum. These criteria were met by 21 genes, consisting of 15 genes upregulated by amphetamine, and 6 genes downregulated by amphetamine. Of the 21 genes, 15 are not presently identified, and only 3 genes (cathepsin K, GRK6, and a gene with accession number AI177589) are located in chromosome regions known to be associated with schizophrenia. Synapse 60:141–151, 2006. © 2006 Wiley‐Liss, Inc.
Self‐definition of women experiencing a nontraditional graduate fellowship program
Authors: Buck Gayle A. , Leslie‐Pelecky Diandra L. , Lu Yun , Plano Clark Vicki L. , Creswell John W.
Published: May 2006

Women continue to be underrepresented in the fields of science, technology, engineering, and mathematics (STEM). One factor contributing to this underrepresentation is the graduate school experience. Graduate programs in STEM fields are constructed around assumptions that ignore the reality of women's lives; however, emerging opportunities may lead to experiences that are more compatible for women. One such opportunity is the Graduate Teaching Fellows in K–12 Education (GK–12) Program, which was introduced by the National Science Foundation in 1999. Although this nontraditional graduate program was not designed explicitly for women, it provided an unprecedented context in which to research how changing some of the basic assumptions upon which a graduate school operates may impact women in science. This exploratory case study examines the self‐definition of 8 women graduate students who participated in a GK–12 program at a major research university. The findings from this case study contribute to higher education's understanding of the terrain women graduate students in the STEM areas must navigate as they participate in programs that are thought to be more conducive to their modes of self‐definition while they continue to seek to be successful in the historically Eurocentric, masculine STEM fields. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 852–873, 2006
Normal fetal motility: an overview
Authors: de Vries J. I. P. , Fong B. F.
Published: May 2006

After 35 years of real‐time two‐dimensional sonography, and now that 4D sonography is within our grasp, this article presents an overview of present‐day knowledge of normal fetal motility. A literature search was carried out on articles from 1970, using the keywords: ‘fetal’, ‘movements’, ‘motility’, ‘movement patterns’, ‘ultrasound’ and ‘sonography’. Inclusion criteria were human studies and use of real‐time sonography. Articles were screened for type of motor assessment procedure, in terms of whether they: specified movements for participating body parts (specific movement pattern, SMP), were qualitative (performance in terms of speed and amplitude), were quantitative, identified behavioral states, stated the duration of observation, and specified gestational age. We noted developmental milestones obtained for each study aim. One of four aims was identified for each article, depending on whether it focused on emergence, development, or continuity after birth of the movement patterns, or on the relationship of various motor aspects to other parameters that evaluate fetal condition, such as blood flow and fetal heart rate. A total of 109 relevant articles was identified, examining 9862 fetuses. Assessment was performed primarily with analysis of SMPs (89%); 52% also included non‐SMPs (NSMPs), 78% included quantification, 24% assessment of quality, and 32% behavioral states. The duration of observation was 1 h or longer in 50% of the studies. The focus in 28 studies was on emergence, in 44 it was on development, in five it was on continuity and in 32 it was on relationship of the movements with other parameters of fetal well‐being. A few milestones identified were determination of the strictly age‐related emergence of SMPs and behavioral states, the highly reproducible quality of SMPs throughout gestation, the age‐related trends in quantified SMPs, the continuity in quality and quantity after birth, and the close relationship between motility and heart‐rate variability, flow parameters, and behavioral states. Periods of longest inactivity recorded before 20 weeks were 13 min; after 30 weeks they were 45 min. Much insight was obtained into the development of motility and its relationship to other parameters from those articles applying comparable assessment procedures. An assessment procedure with well‐defined SMPs, qualitative and quantitative aspects of SMPs and NSMPs, and an observation period dependent on age are advocated for future research. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Sequential triage in the first trimester may enhance advanced ultrasound scanning in population screening for trisomy 21
Authors: Gyselaers W. J. A. , Roets E. R. A. , Van Holsbeke C. D. Y. J. , Vereecken A. J. , Van Herck E. J. H. , Straetmans D. P. L. , Ombelet W. U. A. M. , Nijhuis J. G.
Published: May 2006

Objective

To design a trisomy 21 screening protocol for sequential triage in the first trimester, and to evaluate whether it reduces the need for advanced ultrasound scanning to such an extent that this could be dealt with by a limited number of well‐trained sonographers only.

Methods

Screening results of 31 trisomy 21 affected pregnancies and 16 096 unaffected pregnancies from the first trimester screening program of Algemeen Medisch Laboratorium in Antwerp, Belgium, were used to define high‐risk, intermediate‐risk and low‐risk groups. A serum screening result (age, pregnancy‐associated plasma protein‐A (PAPP‐A) and free beta‐human chorionic gonadotropin (β‐hCG)) of ≥1 : 30 and/or a nuchal translucency thickness (NT) measurement of ≥ 3.5 mm were classified as high risk. A serum screening result of < 1 : 1000 together with an NT of < 3.5 mm were classified as low risk. Other results were considered intermediate risk, for which further advanced ultrasound screening would be indicated. This protocol was then evaluated prospectively in another population of 13 493 first‐trimester pregnancies.

Results

Of the total population, 1.9% was identified as being high risk (14 trisomy 21 pregnancies and 222 unaffected pregnancies; prevalence, 1 : 17), 59.6% was identified as being low risk (three trisomy 21 pregnancies and 9615 unaffected pregnancies; prevalence, 1 : 3206) and 38.4% was identified as being intermediate risk (10 trisomy 21 pregnancies and 6190 unaffected pregnancies; prevalence, 1 : 620). A similar distribution was found in the prospective arm of the study. There was no reduction of overall screening performance compared with our current first‐trimester combined screening program. The number of intermediate‐risk pregnancies was sufficiently low as to enable advanced ultrasound scanning by well‐trained sonographers only.

Conclusion

In population screening for fetal trisomy 21, sequential triage in the first trimester can be achieved using very simple methods. Pregnancies at high or at low risk can be identified easily and the number of pregnancies at intermediate risk can be reduced sufficiently to enable advanced ultrasound scanning by well‐trained sonographers only. A prospective study is needed to evaluate the performance of this approach and to compare its results with current combined or integrated screening algorithms. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Visibility of the polypropylene tape after tension‐free vaginal tape (TVT) procedure in women with stress urinary incontinence: comparison of introital ultrasound and magnetic resonance imaging in vitro and in vivo
Authors: Schuettoff S. , Beyersdorff D. , Gauruder‐Burmester A. , Tunn R.
Published: May 2006

Objective

To determine whether introital sonography and magnetic resonance imaging (MRI) after TVT (tension‐free vaginal tape) insertion can depict the polypropylene tape, and thus be used for patient follow‐up.

Methods

The study comprised an experimental part, which investigated in‐vitro visualization of the polypropylene tape in a model (phantom), and a clinical part, in which 20 women (mean age, 53.4 years) with clinically and urodynamically proven stress urinary incontinence without prolapse were investigated by introital ultrasound and MRI before and 13 months after the TVT procedure.

Results

In the phantom, the polypropylene tape was depicted with a low signal intensity by MRI and as a highly echogenic structure by ultrasound. In the clinical study, introital ultrasound in a mediosagittal orientation depicted the vaginal tape in all patients: it was located under either the midurethra (n = 16) or the lower urethra (n = 4), and in either the muscular coat of the urethra (n = 8) or in the urethrovaginal space (n = 12), the tape was either flat (n = 6) or curled up (n = 14), and there was no retropubic visualization of the tape. Overall, depiction by MRI was limited, and was poorer in comparison with ultrasound, especially when the tape had a sub‐ or paraurethral location. Retropubically, however, MRI identified the tape near the periosteum of the pubic bone (55% of cases), in the retropubic space (37.5% of cases), or near the bladder wall (7.5% of cases).

Conclusion

Sonography is recommended for evaluation of the suburethral and paraurethral tape portions, while MRI is suitable for retropubic evaluation after the TVT procedure. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
New models to predict depth of infiltration in endometrial carcinoma based on transvaginal sonography
Authors: De Smet F. , De Brabanter J. , Van den Bosch T. , Pochet N. , Amant F. , Van Holsbeke C. , Moerman P. , De Moor B. , Vergote I. , Timmerman D.
Published: May 2006

Objectives

Preoperative knowledge of the depth of myometrial infiltration is important in patients with endometrial carcinoma. This study aimed at assessing the value of histopathological parameters obtained from an endometrial biopsy (Pipelle®de Cornier; results available preoperatively) and ultrasound measurements obtained after transvaginal sonography with color Doppler imaging in the preoperative prediction of the depth of myometrial invasion, as determined by the final histopathological examination of the hysterectomy specimen (the gold standard).

Methods

We first collected ultrasound and histopathological data from 97 consecutive women with endometrial carcinoma and divided them into two groups according to surgical stage (Stages Ia and Ib vs. Stages Ic and higher). The areas (AUC) under the receiver–operating characteristics curves of the subjective assessment of depth of invasion by an experienced gynecologist and of the individual ultrasound parameters were calculated. Subsequently, we used these variables to train a logistic regression model and least squares support vector machines (LS‐SVM) with linear and RBF (radial basis function) kernels. Finally, these models were validated prospectively on data from 76 new patients in order to make a preoperative prediction of the depth of invasion.

Results

Of all ultrasound parameters, the ratio of the endometrial and uterine volumes had the largest AUC (78%), while that of the subjective assessment was 79%. The AUCs of the blood flow indices were low (range, 51–64%). Stepwise logistic regression selected the degree of differentiation, the number of fibroids, the endometrial thickness and the volume of the tumor. Compared with the AUC of the subjective assessment (72%), prospective evaluation of the mathematical models resulted in a higher AUC for the LS‐SVM model with an RBF kernel (77%), but this difference was not significant.

Conclusions

Single morphological parameters do not improve the predictive power when compared with the subjective assessment of depth of myometrial invasion of endometrial cancer, and blood flow indices do not contribute to the prediction of stage. In this study an LS‐SVM model with an RBF kernel gave the best prediction; while this might be more reliable than subjective assessment, confirmation by larger prospective studies is required. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Reflections on the Evaluation of a Cambodian Youth Dance Program
Authors: Coppens Nina M. , Page Ruth , Thou Tim Chan
Published: May 2006

Evaluating a youth program whose goals are to provide instruction in Cambodian dance, increase awareness and pride in Cambodian culture, promote healthy behaviors, and create linkages within the community has been a challenge. A primary source of conflict was incorporating evaluation methods that were required of all funded programs with our own specifically tailored measures. One of our concerns was that the required tools were not culturally appropriate for our participants. Our experiences reinforce the importance of forming partnerships that embrace principles of respect, equity, and empowerment among all involved before establishing a research agenda. The choices we made and did not make contributed to our struggles and frustration and also to the insight that was gained. Our analysis examines the importance of clear communication, cultural awareness, tailoring evaluation, and meaningful participation. We believe that the lessons we learned will help facilitate the conduct of culturally sensitive community‐based research.