bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review of Olmesartan Medoxomil Monotherapy: Antihypertensive Efficacy Similar to That of Other Angiotensin II Receptor Blocker/Hydrochlorothiazide Combinations?
Authors: Greathouse Mark
Published: June 2007

Angiotensin II receptor blockers (ARBs) have been available in the United States since 1995. These agents have demonstrated antihypertensive efficacy at least similar to that of agents from other antihypertensive classes. Recent large‐scale, randomized, controlled clinical trials have demonstrated that ARBs offer cardiovascular and renal protective benefits independent of their effects on systemic blood pressure (BP), which make them valuable as first‐line antihypertensive agents, especially in high‐risk patients. However, as is the case with other antihypertensive classes, monotherapy with the first‐available ARBs (losartan potassium, valsartan, and irbesartan) may not provide sufficient BP reduction to achieve currently recommended BP goals in many patients. The diuretic hydrochlorothiazide is frequently added to enhance the ability of ARBs to lower BP. Several head‐to‐head comparison studies have shown differences in antihypertensive efficacy among the available ARBs. The newest ARB, olmesartan medoxomil, was recently compared with losartan potassium, irbesartan, and valsartan in a prospective, head‐to‐head, randomized trial. In this study, olmesartan medoxomil demonstrated a significantly greater reduction in diastolic BP, the primary end point, compared with the other three ARBs. Further, a review of the absolute reductions in diastolic BP achieved with olmesartan medoxomil monotherapy appears comparable to that of previously available ARBs when they are used in combination with hydrochlorothiazide. These comparisons may have important clinical implications regarding the optimal choice of first‐line antihypertensive therapy.
Measuring the Structure of Road Networks
Authors: Xie Feng , Levinson David
Published: June 2007

Spatial networks display both topologic and geometric variations in their structure. This study investigates the measurement of a road network structure. Existing measures of heterogeneity, connectivity, accessibility, and interconnectivity are reviewed and three supplemental measures are proposed, including measures of entropy, connection patterns, and continuity. The proposed measures were applied to 16 test networks, which were derived from four idealized base networks: 90°, 45°, 30°, and completely connected. The results show that the differentiated structures of road networks can be evaluated by the measure of entropy; predefined connection patterns of arterial roads can be identified and quantified by the measures of ringness, webness, beltness, circuitness, and treeness. A measure of continuity evaluates the quality of a network from the perspective of travelers. Proposed measures could be used to describe the structural attributes of complicated road networks quantitatively, to compare different network structures, and to explore the structural evolution of networks in the spatial and temporal context. These measures can find application in urban planning and transportation practice.
IN‐LAKE WATER QUALITY MANAGEMENT PLAN FOR A RECREATIONAL LAKE IN CENTRAL ILLINOIS1
Authors: Raman Raman K. , Evans Ralph L.
Published: June 2007

Johnson Sauk Trail Lake remains highly eutrophic, even though the watershed has long been returned to an undisturbed condition with permanent vegetative cover and with little or no land disturbance in the watershed. Internal regeneration of nutrients has been identified as the major source of nutrients to the lake. Lake destratification, selective harvesting and removal of weeds, and control of algal blooms using chelated copper sulfate application followed by potassium permanganate application have all been chosen as management techniques for improving water quality conditions in the lake. These in‐lake techniques are considered not as palliative measures, but as necessary tools in enhancing the lake's water quality characteristics.
Epitaxial calcium oxide films deposited on gallium nitride surfaces
Authors: Losego Mark D. , Mita Seiji , Collazo Ramon , Sitar Zlatko , Maria Jon-Paul
Published: June 2007

Solid solutions of rocksalt oxides are proposed for lattice-matched dielectrics in gallium nitride (GaN) electronics. This article explores the epitaxial growth of the rocksalt oxide calcium oxide (CaO) by molecular beam epitaxy on gallium nitride surfaces. As a possible end member to a rocksalt oxide solid solution, it is important to understand the processing space that allows for epitaxial CaO growth. Exposing the GaN surface to the oxidant flux prior to the metal flux is shown to be critical in eliminating polycrystalline growth. The effect of deposition temperature, metal flux, and oxidant flux on the film’s epitaxial crystalline quality is also examined. Optimal epitaxial quality is found for growth temperatures of ⩾600°C and near oxygen pressures of 10−6Torr. Thermal stability of the CaO∕GaN interface is experimentally evaluated. No reaction phases are observed by x-ray diffraction up to 850°C in air and >1100°C in a reducing atmosphere. However, CaO films are found to be extremely reactive with H2O, forming Ca(OH)2 within a few hours when exposed to ambient atmosphere at room temperature.
Properties of Fe-doped, thick, freestanding GaN crystals grown by hydride vapor phase epitaxy
Authors: Polyakov A. Y. , Smirnov N. B. , Govorkov A. V. , Vdovin V. I. , Markov A. V. , Shlensky A. A. , Prebble Ed , Hanser Drew , Zavada J. M. , Pearton S. J.
Published: June 2007

The electrical properties, deep level spectra, optical transmission, and luminescence spectra were measured on freestanding GaN crystals grown by hydride vapor phase epitaxy. The samples are semi-insulating n type with room temperature resistivity of 3.8×109Ωcm and high electron mobility of 715cm2∕Vs. The Fermi level in these samples is pinned by a Fe-related level near Ec−0.57eV that could be due to the Fe2+∕Fe3+ transition. This level manifests itself also as a strong blue luminescence band peaked near 2.85eV. An additional Fe-related band with optical threshold near 1.6eV is observed in optical transmission spectra. The samples are paramagnetic, suggesting an absence of significant Fe precipitation.
Fabrication of GaN suspended photonic crystal membranes and resonant nanocavities on Si(111)
Authors: Rosenberg A. , Bussmann K. , Kim Mijin , Carter Michael W. , Mastro M. A. , Holm Ronald T. , Henry Richard L. , Caldwell Joshua D. , Eddy Charles R.
Published: June 2007

The authors demonstrate the fabrication of suspended photonic crystal membranes in GaN films deposited on Si(111). The photonic crystal patterns fabricated in these membranes consisted of triangular arrays of holes having diameters in the range of 70–175nm, with a lattice spacing of 200–500nm. The patterns included optical cavity structures (groups of missing holes), which are predicted to exhibit resonances in the visible to near-IR spectral region. Such suspended photonic crystal membranes may serve as the basis for efficient wavelength-scale GaN-based light emitters monolithically integrated with Si.
Field emission from GaN and (Al,Ga)N∕GaN nanorod heterostructures
Authors: Deb Parijat , Westover Tyler , Kim Hogyoung , Fisher Timothy , Sands Timothy
Published: June 2007

Vacuum field emission from GaN and (Al,Ga)N∕GaN nanorods with pyramidal tips has been measured. The turn-on fields, defined at a current density of 0.1μA∕cm2, were found to be 38.7 and 19.3V∕μm, for unintentionally doped GaN and (Al,Ga)N∕GaN nanorods, respectively. The 5nm (Al,Ga)N layer reduced the electron affinity at the surface, thereby lowering the turn-on field and increasing the current density. The nanostructures exhibit a field enhancement factor of approximately 65 and the work function of the (Al,Ga)N∕GaN nanorod heterostructure was estimated to be 2.1eV. The stability of the emission characteristics and the simple fabrication method suggest that intentionally doped and optimized (Al,Ga)N∕GaN nanorod heterostructures may prove suitable for field-emission device.
Mask material effects in cryogenic deep reactive ion etching
Authors: Sainiemi L. , Franssila S.
Published: June 2007

Cryogenic silicon etching in inductively coupled SF6∕O2 plasma has been studied, especially the behavior of mask materials. Suitability of eight different mask materials for cryogenic silicon deep reactive ion etching has been investigated. Three of the five photoresists suffered from cracking during cryogenic etching. We clarified the stages of the etching process and identified two mechanisms behind the cracking: thermal expansion mismatch and mechanical deformation from wafer clamping and backside helium pressure. Also thickness of the photoresist plays a role in cracking, but, contrary to common conception that all thick resists suffer from cracking in cryogenic etching, we found that SU-8 negative resist did not crack, even for very thick layers. This is explained to be due to its high cross-linking density. All three hard mask materials had high selectivities and were free of cracking problems. However, aluminum mask resulted in poor surface quality, while thermally grown SiO2 and amorphous Al2O3 deposited by atomic layer deposition showed smooth surfaces and sidewalls. Silicon dioxide had selectivity of 150:1, while Al2O3 selectivity was 66 000:1. This extreme selectivity of Al2O3 mask, combined with good surface quality, is shown to be highly beneficial in both shallow and through-wafer etching.
Direct-write composition patterning of InGaN by focused thermal beam during molecular-beam epitaxy
Authors: Chen X. , Schaff W. J. , Eastman L. F.
Published: June 2007

A direct-write patterning of InGaN during molecular-beam epitaxy has been achieved by using in situ focused thermal beam. The surface of growing InGaN is exposed to a 50μm diameter pulse laser beam that is directed to controlled locations. Indium (In) mole fraction is reduced from 0.85 where it is adjacent to laser exposure, and to 0.75 where exposure takes place, whereas it is 0.81 away from exposed regions during a nominal 78nm deposition on a thick InGaN buffer. The effect of local heating increases surface diffusion of In without evaporating the written materials. One additional feature of direct-write patterning is the enhancement of photoluminescence efficiency, which increases by a factor of 7 compared to nonwritten regions. Gray scale features with composition variations are also demonstrated by laser direct write.
Spontaneous formation of Si nanocones vertically aligned to Si wafers
Authors: Tsuji Yoshiko , Nakamura Shinichi , Noda Suguru
Published: June 2007

A simple, practical method was developed to automatically align single crystalline Si nanocones (SiNCs) vertical to a Si substrate. Double heteroepitaxial structure of Si∕CoSi2 on a Si (100) substrate was prepared by sputtering, and Si was then deposited on the surface via chemical vapor deposition with SiH2Cl2∕H2 reaction gas. When Si was deposited at 900°C, SiNCs were fabricated vertical to the substrate, had a tip curvature of about 100nm, and had a number density of (0.9–35)×108∕m2. A CoSi2 nanocrystal was clearly visible on the tip of each SiNC. These CoSi2 nanocrystals were formed by agglomeration of the Si∕CoSi2 layer, and catalyzed the Si growth during chemical vapor deposition. In conclusion, the alignment of the fabricated SiNCs could be controlled by utilizing agglomeration in the Si∕CoSi2∕Si double heteroepitaxial structure.
Ordered silicon nanostructures by ion beam induced glancing angle deposition
Authors: Patzig Christian , Rauschenbach Bernd , Erfurth Wilfried , Milenin Alexey
Published: June 2007

Various silicon nanostructures (twofold chevrons and three- and fourfold spirals) were grown on silicon [111] substrates prepatterned with a two-dimensional square lattice of blocks with different block size and periodicity via ion beam induced glancing angle deposition at room temperature, in combination with a controlled substrate rotation. Top view and cross-section scanning electron microscopy pictures reveal that form, size, and periodicity of the structures are strongly dependent on the size and periodicity of the seeding space and differ widely from structures grown on plain substrates. It is shown that the growth of periodically arranged nanostructures, which is important for many possible applications, including photonic crystals, on prepatterned substrates is only possible if the periodicity of the seeding spaces matches the natural lateral dimensions of the structures grown on bare substrates.
Characterization and control of unconfined lateral diffusion under stencil masks
Authors: Rácz Zoltán , Seabaugh Alan
Published: June 2007

A quantitative study of the spreading behavior of electron-beam-evaporated Al, Au, Cr, Ge, Pt, and Ti on oxidized Si substrates has been performed using translated stencil masks. At least two mechanisms are needed to account for the lateral spreading of the deposited materials: The deposition edge moves by a Fickian diffusion with a diffusion coefficient of 6.7nm2∕s at 45°C which is approximately independent of the deposited material. Once under the stencil mask, the deposited material spreads 0.1–2μm (at 45°C for under 2h), in a thin layer as a result of surface diffusion. The evaporation in N2 or O2 at 50μTorr significantly suppresses the spreading with Ti showing the greatest reduction of (7–8)×.
GdGaO: A gate dielectric for GaAs metal-oxide-semiconductor field-effect transistors
Authors: Holland M. , Stanley C. R. , Reid W. , Thayne I. , Paterson G. W. , Long A. R. , Longo P. , Scott J. , Craven A. J. , Gregory R.
Published: June 2007

Gd x Ga 0.4 − x O 0.6 ∕ Ga 2 O 3 dielectric stacks have been grown on (001)GaAs to form a III-V∕oxide with a low interface state density and a high conduction band offset. Photoluminescence is used to compare the stacks with low interface state density Ga2O3–GaAs layers. Rutherford backscattering and electron energy loss spectroscopy are used to investigate the Gd compositional variation with depth and this is related to the interface state density. The effect of Gd flux and atomic oxygen on the growth rate is reported. The leakage current through GdxGa0.4−xO0.6∕Ga2O3 stacks is compared with ones using only Ga2O3 as the oxide.
Analyses of chamber wall coatings during the patterning of ultralow-k materials with a metal hard mask: Consequences on cleaning strategies
Authors: Chevolleau T. , Darnon M. , David T. , Posseme N. , Torres J. , Joubert O.
Published: June 2007

Changes in chamber wall conditions (e.g., chemical surface composition) are identified as one of the main causes of process drifts leading to changes in the process performance (etch rates, etch profiles, selectivity, uniformity, etc.). The impact of a metal hard mask on the coating formed on the chamber walls during the dielectric etching process and reactor dry cleaning procedure has been investigated. The authors have used a technique based on x-ray photoelectron spectroscopy to monitor the chemical composition of the layer deposited on an electrically floating sample placed on the top of a patterned wafer exposed to typical plasma processing conditions (coatings deposited on the floating sample are representative of those deposited on the chamber walls). They have patterned porous SiOCH damascene structures using a TiN hard mask. After hard mask opening in a silicon etcher using Cl2 based plasmas, they have shown that the chamber walls are coated by a thin SiOCl coating containing small concentrations of Ti. After photoresist ashing in the same etcher (with an O2 plasma), the chamber wall coating is oxidized leading to the formation of a mixed SiOx–TiOx deposit. The cleaning strategy to remove this coating from the chamber walls consists in using a two step cleaning procedure: (1) a Cl2 based plasma (Ti removal), followed by (2) a SF6∕O2 plasma (SiOCl species removal). During low-k etching in an oxide etcher with a fluorocarbon based chemistry, the chamber walls are coated by a fluorocarbon layer containing a significant concentration of Ti. They have developed a two step cleaning procedure: (1) a SF6 plasma to remove the fluorocarbon layer and Ti based species and (2) an O2 flash plasma (for a short time) to clean up the chamber walls from the remaining carbon.
Effect of Al composition on filtering of threading dislocations by AlxIn1−xSb∕AlyIn1−ySb heterostructures grown on GaAs (001)
Authors: Edirisooriya M. , Mishima T. D. , Santos M. B.
Published: June 2007

Using transmission electron microscopy images, the threading dislocation density was studied near the surface of a buffer layer consisting of an Al0.10In0.90Sb matrix layer and two AlxIn1−xSb interlayers grown on a GaAs (001) substrate. The aluminum composition x in the interlayer was varied from 0.10 to 0.30 with an increment of 0.05. The buffer layer with two Al0.25In0.75Sb interlayers showed the lowest threading dislocation density above the top interface of the second interlayer. An InSb quantum well grown on a 1.5-μm-thick buffer structure with two Al0.25In0.75Sb interlayers has a 21% higher electron mobility at 65K than an InSb quantum well grown on a 1.5-μm-thick Al0.10In0.90Sb buffer without an interlayer.
Novelty and versatility of self-catalytic nanowire growth: A case study with InN nanowires
Authors: He Maoqi , Noor Mohammad S.
Published: June 2007

Various novel features have been discussed of the self-catalytic nanowire growth technique with application to InN nanowire growths. It is hard to grow InN nanowires due to the very low dissociation temperature (500–600°C) of InN and the very low dissociation rate of NH3 at this low temperature. However, scanning electron microscopy images show that the self-catalytic technique very efficiently produced long, uniform, single-crystal InN nanowires. Unlike most other methods, the technique is also versatile enough to produce a wide variety of nanowires standing and lying on the substrates. It is also useful to grow nanowires by the conventional vapor-liquid-solid formalism. Energy-dispersive spectroscopy showed that the composition of the nanowires is that of InN. X-ray diffraction patterns indicated that these nanowires had a pure hexagonal wurtzite structure.
Defect-free two-dimensional-photonic crystal structures on a nonlinear optical polymer patterned by nanoimprint lithography
Authors: Okinaka Motoki , Inoue Shin-ichiro , Tsukagoshi Kazuhito , Aoyagi Yoshinobu
Published: June 2007

Defect-free two-dimensional-photonic crystal (PC) structures have been patterned by nanoimprint lithography onto a nonlinear optical (NLO) polymer to fully control the photonic band structure. Defect-free PC structures are obtained in the case of samples from which a sufficient amount of solvent has been removed, and sharp dips are observed in the reflectance spectrum. In samples with defects, the dips of the spectrum are broadened due to the disruption of the periodicity. Results suggest that the spatial distribution and amount of the residual solvent in the NLO polymer needs to be controlled to reduce the defect density.
An operator solution for the hydrogen atom using the phase as an additional variable
Authors: Martínez-y-Romero R. P. , Núñez-Yépez H. N. , Salas-Brito A. L.
Published: June 2007

We discuss an operator solution for the bound states of the non-relativistic hydrogen atom. The method adds the phase of a state and its associated operator to the set of variables of the system. The augmented set of operators is found to form a closed set of commutation relations thus comprising an operator Lie algebra. From these relations, the energy spectrum and bounded radial eigenfunctions are calculated. Our approach is analogous to the one employed to compute the angular momentum spectrum and eigenfunctions but with operators satisfying an su(1,1) Lie algebra instead of su(2). This method, with the same operator algebra and minor modifications, may be used to solve the Dirac relativistic hydrogen atom.
Vegetative
Clostridium difficile
Survives in Room Air on Moist Surfaces and in Gastric Contents with Reduced Acidity: a Potential Mechanism To Explain the Association between Proton Pump Inhibitors and
C. difficile
-Associated Diarrhea?
Authors: Jump Robin L. P. , Pultz Michael J. , Donskey Curtis J.
Published: June 2007

Proton pump inhibitors (PPIs) have been identified as a risk factor for
Clostridium difficile
-associated diarrhea (CDAD), though the mechanism is unclear because gastric acid does not kill
C. difficile
spores. We hypothesized that the vegetative form of
C. difficile
, which is killed by acid, could contribute to disease pathogenesis if it survives in room air and in gastric contents with elevated pH. We compared the numbers of
C. difficile
spores and vegetative cells in stools of patients prior to and during the treatment of CDAD. We assessed the survival of vegetative cells on moist or dry surfaces in room air versus anaerobic conditions and in human gastric contents, in pH-adjusted gastric contents, and in gastric contents from individuals receiving PPI therapy. Stool samples obtained from patients prior to the initiation of antibiotic treatment for
C. difficile
contained ∼10-fold more vegetative cells than spores. On dry surfaces, vegetative
C. difficile
cells died rapidly, whereas they remained viable for up to 6 h on moist surfaces in room air. Vegetative
C. difficile
cells had only marginal survival in gastric contents at low pH; adjustment to a pH of >5 resulted in survival similar to that in the phosphate-buffered saline control. The survival of vegetative
C. difficile
in gastric contents obtained from patients receiving PPIs was also increased at a pH of >5. The ability of the vegetative form of
C. difficile
to survive on moist surfaces and in gastric contents with an elevated pH suggests a potential mechanism by which PPI therapy could increase the risk of acquiring
C. difficile
.
Pneumolysin Causes Neuronal Cell Death through Mitochondrial Damage
Authors: Braun Johann S. , Hoffmann Olaf , Schickhaus Miriam , Freyer Dorette , Dagand Emilie , Bermpohl Daniela , Mitchell Tim J. , Bechmann Ingo , Weber Joerg R.
Published: June 2007

Bacterial toxins such as pneumolysin are key mediators of cytotoxicity in infections. Pneumolysin is a pore-forming toxin released by
Streptococcus pneumoniae
, the major cause of bacterial meningitis. We found that pneumolysin is the pneumococcal factor that accounts for the cell death pathways induced by live bacteria in primary neurons. The pore-forming activity of pneumolysin is essential for the induction of mitochondrial damage and apoptosis. Pneumolysin colocalized with mitochondrial membranes, altered the mitochondrial membrane potential, and caused the release of apoptosis-inducing factor and cell death. Pneumolysin induced neuronal apoptosis without activating caspase-1, -3, or -8. Wild-type pneumococci also induced apoptosis without activation of caspase-3, whereas pneumolysin-negative pneumococci activated caspase-3 through the release of bacterial hydrogen peroxide. Pneumolysin caused upregulation of X-chromosome-linked inhibitor of apoptosis protein and inhibited staurosporine-induced caspase activation, suggesting the presence of actively suppressive mechanisms on caspases. In conclusion, our results indicate additional functions of pneumolysin as a mitochondrial toxin and as a determinant of caspase-independent apoptosis. Considering this, blocking of pneumolysin may be a promising cytoprotective strategy in pneumococcal meningitis and other infections.
Effectiveness of biomedical risk assessment as an aid for smoking cessation: a systematic review
Authors: Bize Raphaël , Burnand Bernard , Mueller Yolanda , Cornuz Jacques
Published: June 2007

Objective:To determine the efficacy of biomedical risk assessment (eg, exhaled carbon monoxide (CO), or genetic susceptibility to lung cancer) as an aid for smoking cessation.

Data sources:Cochrane Tobacco Addiction Group Specialized Register, Cochrane Central Register of Controlled Trials, Medline (1966–2004) and EMBASE (1980–2004).

Study selection:Randomised controlled smoking cessation interventions using biomedical tests with at least 6 months follow-up.

Data extraction:Two reviewers independently screened all search results (titles and abstracts) for possible inclusion. Each reviewer then extracted data from the selected studies, and assessed their methodological quality based on the CONSORT (Consolidated Standards of Reporting Trials) statement criteria.

Data synthesis:Of 4049 retrieved references, eight trials were retained for data extraction and analysis. Three trials isolated the effect of exhaled CO on smoking cessation rates resulting in the following ORs and 95% CIs: 0.73 (0.38 to 1.39), 0.93 (0.62 to 1.41) and 1.18 (0.84 to 1.64). Measurement of exhaled CO and spirometry were used together in three trials, resulting in the following ORs (95% CI): 0.60 (0.25 to 1.46), 2.45 (0.73 to 8.25) and 3.50 (0.88 to 13.92). Spirometry results alone were used in one other trial with an OR (95% CI) of 1.21 (0.60 to 2.42). Ultrasonography of carotid and femoral arteries performed on light smokers gave an OR (95% CI) of 3.15 (1.06 to 9.31).

Conclusions:Scarcity and limited quality of the current evidence does not support the hypothesis that biomedical risk assessment increases smoking cessation as compared with the standard treatment.
COLLISIONS OF TRANSACTINIDES: SUPERHEAVY NUCLEI AND GIANT NUCLEAR MOLECULES
Authors: ZAGREBAEV VALERY , GREINER WALTER
Published: June 2007

Low energy collisions of very heavy nuclei (238 U +238 U , 232 Th +250 Cf and 238 U +248 Cm ) have been studied within the realistic dynamical model based on multi-dimensional Langevin equations. Large charge and mass transfer was found due to the "inverse quasi-fission" process leading to formation of survived superheavy long-lived neutron-rich nuclei. In many events lifetime of the composite system consisting of two touching nuclei turns out to be rather long; sufficient for spontaneous positron formation from super-strong electric field, a fundamental QED process.
Renin Gene Polymorphisms and Haplotypes, Blood Pressure, and Responses to Renin-Angiotensin System Inhibition
Authors: Moore Niamh , Dicker Patrick , O’Brien John K. , Stojanovic Milos , Conroy Ronán M. , Treumann Achim , O’Brien Eoin T. , Fitzgerald Desmond , Shields Denis , Stanton Alice V.
Published: June 2007

Renin catalyzes the rate-limiting step of the renin-angiotensin system. A T allele variant at position −5312 within a distal enhancer region has been reported to increase in vitro renin gene transcription. Among 387 White bank employees, ambulatory blood pressures were higher in 133 −5312T allele carriers than in 254 CC homozygotes—mean differences [99% confidence interval] between carriers and homozygotes for daytime and night-time systolic/diastolic pressure were 2.5[0.4,4.6]/1.7[0.2,3.2] and 2.4[0.5,4.4]/1.5[0.1,2.9] respectively. Ambulatory pressure estimates for the only common renin haplotype including the −5312T variant (−5312T, 5090C, 5912A, 9479A, 10194G), were statistically significantly higher than estimates for all other haplotypes. Among 259 White hypertensive participants in a randomized double-blind clinical trial comparing a renin antagonist, aliskiren, with an angiotensin receptor blocker, losartan, plasma renin activity did not differ with renin −5312C/T genotype. Nocturnal blood pressure reductions with losartan 100 mg daily were significantly greater in −5312T allele carriers than in CC homozygotes (mean[standard error]; −12.9[3.7]/−7.9[2.4] versus −7.1[2.5]/−4.2[1.6]) whereas with aliskiren 150 and 300 mg daily, lesser reductions were observed in −5312T allele carriers than in CC homozygotes (−5.4[2.0]/−4.1[1.3] versus −10.1[1.4]/−6.5[1.1];
P
<0.03 for treatment×genotype interaction for night-time systolic and diastolic pressures). Hence, the −5312 renin C/T enhancer polymorphism does contribute to blood pressure variation in Whites and also appears to predict responses to inhibition of the renin–angiotensin system. These findings suggest that genotyping at this locus may aid in the identification of susceptibility to hypertension and in the selection of optimal therapy for individual hypertensive patients.
Transcript-level annotation of Affymetrix probesets improves the interpretation of gene expression data
Authors: Yu Hui , Wang Feng , Tu Kang , Xie Lu , Li Yuan-Yuan , Li Yi-Xue
Published: June 2007

Background

The wide use of Affymetrix microarray in broadened fields of biological research has made the probeset annotation an important issue. Standard Affymetrix probeset annotation is at gene level, i.e. a probeset is precisely linked to a gene, and probeset intensity is interpreted as gene expression. The increased knowledge that one gene may have multiple transcript variants clearly brings up the necessity of updating this gene-level annotation to a refined transcript-level.

Results

Through performing rigorous alignments of the Affymetrix probe sequences against a comprehensive pool of currently available transcript sequences, and further linking the probesets to the International Protein Index, we generated transcript-level or protein-level annotation tables for two popular Affymetrix expression arrays, Mouse Genome 430A 2.0 Array and Human Genome U133A Array. Application of our new annotations in re-examining existing expression data sets shows increased expression consistency among synonymous probesets and strengthened expression correlation between interacting proteins.

Conclusion

By refining the standard Affymetrix annotation of microarray probesets from the gene level to the transcript level and protein level, one can achieve a more reliable interpretation of their experimental data, which may lead to discovery of more profound regulatory mechanism.
High occurrence of BRCA1 intragenic rearrangements in hereditary breast and ovarian cancer syndrome in the Czech Republic
Authors: Vasickova Petra , Machackova Eva , Lukesova Miroslava , Damborsky Jiri , Horky Ondrej , Pavlu Hana , Kuklova Jitka , Kosinova Veronika , Navratilova Marie , Foretova Lenka
Published: June 2007

Background

Alterations in the highly penetrant cancer susceptibility gene BRCA1 are responsible for the majority of hereditary breast and/or ovarian cancers. However, the number of detected germline mutations has been lower than expected based upon genetic linkage data. Undetected deleterious mutations in the BRCA1 gene in some high-risk families could be due to the presence of intragenic rearrangements as deletions, duplications or insertions spanning whole exons. Standard PCR-based screening methods are mainly focused on detecting point mutations and small insertions/deletions, but large rearrangements might escape detection.

The purpose of this study was to determine the type and frequency of large genomic rearrangements in the BRCA1 gene in hereditary breast and ovarian cancer cases in the Czech Republic.

Methods

Multiplex ligation-dependent probe amplification (MLPA) was used to examine BRCA1 rearrangements in 172 unrelated patients with hereditary breast and/or ovarian cancer syndrome without finding deleterious mutation after complete screening of whole coding regions of BRCA1/2 genes. Positive MLPA results were confirmed and located by long-range PCR. The breakpoints of detected rearrangements were characterized by sequencing.

Results

Six different large deletions in the BRCA1 gene were identified in 10 out of 172 unrelated high-risk patients: exons 1A/1B and 2 deletion; partial deletion of exon 11 and exon 12; exons 18 and 19 deletion; exon 20 deletion; exons 21 and 22 deletion; and deletion of exons 5 to 14. The breakpoint junctions were localized and further characterized. Destabilization and global unfolding of the mutated BRCT domains explain the molecular and genetic defects associated with the exon 20 in-frame deletion and the exon 21 and 22 in-frame deletion, respectively.

Conclusion

Using MLPA, mutations were detected in 6% of high-risk patients previously designated as BRCA1/2 mutation-negative. The breakpoints of five out of six large deletions detected in Czech patients are novel. Screening for large genomic rearrangements in the BRCA1 gene in the Czech high-risk patients is highly supported by this study.
The Best in CytoJournal: 2006
Authors: Cohen Michael B
Published: June 2007

This year CytoJournal celebrates the second full year of publication with its Best of CytoJournal: 2006. Like last year, it recognizes the work of the authors in thyroid FNAB. And, importantly, this years award, which was handed out at USCAP, was endowed by a gift from the Pathikonda family.
Frontotemporal Dementias: A Review
Authors: Weder Natalie D , Aziz Rehan , Wilkins Kirsten , Tampi Rajesh R
Published: June 2007

Dementia is a clinical state characterized by loss of function in multiple cognitive domains. It is a costly disease in terms of both personal suffering and economic loss. Frontotemporal dementia (FTD) is the term now preferred over Picks disease to describe the spectrum of non-Alzheimers dementias characterized by focal atrophy of the frontal and anterior temporal regions of the brain. The prevalence of FTD is considerable, though specific figures vary among different studies. It occurs usually in an age range of 35–75 and it is more common in individuals with a positive family history of dementia. The risk factors associated with this disorder include head injury and family history of FTD. Although there is some controversy regarding the further syndromatic subdivision of the different types of FTD, the three major clinical presentations of FTD include: 1) a frontal or behavioral variant (FvFTD), 2) a temporal, aphasic variant, also called Semantic dementia (SD), and 3) a progressive aphasia (PA). These different variants differ in their clinical presentation, cognitive deficits, and affected brain regions. Patients with FTD should have a neuropsychiatric assessment, neuropsychological testing and neuroimaging studies to confirm and clarify the diagnosis. Treatment for this entity consists of behavioral and pharmacological approaches. Medications such as serotonin reuptake inhibitors, antipsychotics, mood stabilizer and other novel treatments have been used in FTD with different rates of success. Further research should be directed at understanding and developing new diagnostic and therapeutic modalities to improve the patients' prognosis and quality of life.
A Novel Synthetic Route to Quinazoline-2,4-dione Dimer Derivatives
Authors: Nikpour Farzad , Sheikh Davood
Published: June 2007

A novel and simple one-pot synthesis of some quinazoline-2,4-dione dimer derivatives has been described via the condensation reaction of anthranilic acid derivatives with semicarbazide hydrochloride under reflux condition in DMF. The reactions proceed without use of any catalyst.
Structural Characteristic of Outermost Surface of Cubic Mesoporous Silica Film
Authors: Inoue Takashi , Gunjishima Itaru , Kumai Yoko , Inagaki Shinji , Okamoto Atsuto
Published: June 2007

The outermost surface structure of a calcined cubic mesoporous silica film was observed for the first time by high-resolution field emission scanning microscopy, which showed a periodic pore arrangement with inherent cage openings and one-dimensional grooves on the surface. The grooves are formed to be the interconnected A-cages associated along the <100> direction on the {210} crystallographic plane of SBA-1.
Self-assembly of Amphiphilic Benzo-15-crown-5 Azoprobes in Response to Alkali Metal Ions in Water
Authors: Sato Fuyuki , Sakamoto Kouki , Umemoto Wakako , Hashimoto Takeshi , Hayashita Takashi
Published: June 2007

The amphiphilic benzo-15-crown-5 (B15C5) azoprobes exhibit a self-assembly in response to alkali metal ions in water based on the exciton interaction of the phenylazo groups in the probes, and the most selective response to K+ was obtained for an azoprobe possessing a hexyl spacer unit.
Experience with a perfo-suction system for the recovery of schistosomes from laboratory rodents
Authors: Jackson T. F. H. G. , Dettman C. D. , Higgins-Opitz Susan B.
Published: June 2007

Worm recoveries are an integral part of research work in schistosomiasis. An improved quantitative technique for the recovery of schistosome worms from laboratory rodents is described. Up to 95-100% of the worms are normally recovered, and up to 80 animals can be perfused per day.
Identification of rat T and B lymphocytes by surface marker analysis
Authors: Koestner Adelaide W. , Koestner A. , Krakowka S. , Ringler Sue S.
Published: June 2007

The majority of thymocytes in suspension (72·1%) formed nonimmune rosettes with guineapig erythrocytes but not with erythrocytes from sheep, cats, dogs, pigs, or man. In contrast, only a minority of cells from lymph node (2·1%) or spleen (1·4%) rosetted with guinea pig erythrocytes. Treatment of guineapig erythrocytes with neuraminidase or 2-S-aminoethyl-isothiouronium bromide did not enhance rosette formation. Adherence of the erythrocytes to tissue sections was achieved in the thymic cortex and T-cell-dependent areas of lymph node and spleen. Absorbed equine anti-rat antithymocyte serum bound 98% thymocytes and 70·0, 35·1 and 44·6% lymphocytes from peripheral blood, spleen and lymph nodes respectively.

Surface immunoglobulin was demonstrated on 2·2% thymocytes, 35% peripheral-blood lymphocytes and 43 and 51% cells from lymph nodes and spleen respectively. Complement receptors were determined in suspension with erythrocyte-antibody-complement complexes. Rosetting was observed in 44% splenic, 29% lymph node and 3% thymocyte cellular suspension. The presence of Fc receptors for IgG was assessed by determining the pattern of binding of erythrocyte-antibody complexes to frozen tissue sections. For rats, antithymocyte serum is the method of choice for T cells, whereas SIg determination is the most reliable B-cell marker.
Association of germfree mice with intestinal microfloras obtained from 'normal' mice
Authors: Koopman J. P. , Mullink J. W. M. A , Prins R. A. , Welling G. W. , Hectors M. P. C.
Published: June 2007

A cultured microflora obtained from the caecum of a 'normal' mouse was given to 4 groups of germfree mice and was supplied 1x, 2x, 3x and 4x respectively at 5-day intervals. Another group received a 10-7 dilution of the caecal flora while a group associated with an 'SPF' flora served as control. The difference (measured by 8 parameters) between mice supplied with the cultured flora or with a 10-7 dilution, both given once only, was small. Supplying the flora 3x resulted in more 'normal' mice compared with mice which received the flora once or twice.

The caeca of specified-pathogen-free mice contained more bacteria per gram (microscopic bacterial count), less aerobic and anaerobic bacteria per gram (viable counts), while the yield as percentage of the microscopic bacterial count was lower as compared with the group to which a cultured flora was supplied 4 times.
Genetic analysis of renal function in mice. 2. Strain differences in clearances of sodium, potassium, osmolar and free water, and their correlations with body and kidney weight
Authors: Hackbarth H. , Hackbarth D.
Published: June 2007

There was greater than 4-fold strain differences in the clearances of sodium, potassium, osmolality and free water among mice of 24 inbred strains and F1 hybrids. These differences were detectable in spite of high within-strain variations. Even under highly standardized conditions about 50% of the total variance was ascribed to the within-strain component. Males showed more significant strain differences than females, and there were more differences between strains for osmolar and free water clearances than for sodium or potassium. Most environmental correlations were not significant, while many significant genetic correlations were found between the clearances and bodyweight and, less strongly to kidney weight. Bodyweight was therefore selected as a common base, and the exponent was about 0·80 for both sodium and potassium clearance.
Experimental study of the effects on rabbits of the injectable contraceptive medroxyprogesterone acetate, cholesterol feeding and drug-atherogenic diet combination
Authors: Al-Shebib T. H. , Al Zubaidy A. J. , Al-Hashimi A. S.
Published: June 2007

Medroxyprogesterone acetate was given alone or in combination with a cholesterol-rich diet. Total serum cholesterol levels in treated rabbits was significantly different from those of the control on most occasions during the experiment, and in the controls it remained essentially the same throughout the experimental period. There was a relationship between lesions induced and the raised serum cholesterol, but there was no regression of the appearance of fibrous plaques after discontinuation of the cholesterol supplement.
Genetic analyses of the vertebral anomalies of the IS strain of rat and the development of a BN congenic line with the anomalies
Authors: Yamada J. , Nikaido Hiroko , Moritake S. , Maekawa R.
Published: June 2007

It is suggested that the anomalies in the IS rat are controlled by one or several genic factor(s) unrelated to LG I, II, IV, V, and VI and the LGs containing Amy-1 and Cs-1 loci.
Reproduction, infant survival and productivity of a colony of common marmosets (Callithrix jacchus jacchus)
Authors: Poole Trevor B. , Evans Rosemary G.
Published: June 2007

Starting with 4 pairs of marmosets, 204 young were successfully reared during 6 years. They were kept in family groups of 2-10. Litter size varied from 1-4; singletons (2%), twins (35%), triplets (55%), and quadruplets (8%). The mean annual increase of weaned young was 3·24 per pair.

The median interbirth interval was 154 days. Of 46 pairs of marmosets, 8 failed to produce young.

Approximately 11% of young born were stillborn and a further 32% of all young born died within 3 weeks; perinatal mortality is largely a result of the failure of parents to rear more than 2 young. In only 2 of 68 triplet births did the parents rear the young unaided.

53% of young born were males but differential mortality reduced the final sex ratio for live young to 50·5% males. Females did not accept and rear the young after caesarian sections.

The linear regression of the growth curve from 5-17 months (where y = weight in grams and x = months) could be expressed as y = 16·6 x + 163·6.

The data from 4 marmoset colonies are compared and the relative efficiency of breeding methods discussed.
Hybrid production in owl monkeys (Aotus trivirgatus)
Authors: Simpson Judith S. , Jones Alison C.
Published: June 2007

A colony of owl monkeys was established with 63 breeding pairs, paired according to matching karyotypes. 3 pairs were formed as a result of limited space, even though karyotypes were considered incompatible. 2 of these pairs produced offspring.
Polytetraftuoroethylene (PTFE): a new material for the construction of gastrointestinal cannulae
Authors: Hirst B. H. , Storey G. E. , Venables C. W.
Published: June 2007

The advantages of polytetrafluoroethylene cannulae are that they are resistant to chemical attack, light in weight, not brittle, inexpensive, adaptable, and they cause minimal tissue reaction. The design of cannulae for cannulation of gastric and duodenal fistulae, and drainage of pouches of the stomach is described. Similar cannulae offer many possibilities for use in other systems.
Method for determining the osmotic fragility curves of erythrocytes in birds
Authors: Viscor G. , Palomeque J.
Published: June 2007

The osmotic fragility of erythrocytes in 3 species of birds ( Gallus gallus domesticus, Coturnix coturnix Japonica, Columba livia) and the rat was determined. The results of this study point to a smaller osmotic fragility. Birds, with elliptical erythrocytes, have a lower osmotic fragility than species with round erythrocytes, like most of the mammals.
Haemobartonella muris: case report and investigation of transplacental transmission
Authors: Owen Dawn G.
Published: June 2007

Infection with Haemobartonella muris was confirmed in a group of breeding rats. Possible transplacental transmission was investigated, but none of the off-spring from 6 litters became infected.
Monophasic and diphasic patterns of the circadian caecotrophy rhythm of rabbits
Authors: Jilge Burghart
Published: June 2007

The circadian caecotrophy rhythm was synchronized with the light-dark cycle of 12 : 12 h. During this the rabbits practised caecotrophy regularly during the light period. While most rabbits manifested 1 caecotrophy per 24 h (monophasic caecotrophy), some had an additional caecotrophy during the dark period (diphasic caecotrophy). During continuous light the circadian caecotrophy rhythm ran free monophasically, even in those rabbits which were diphasic under the preceding 12 : 12 regime. The average period length amounted to 24·7 ± 0·3 h. Following restoration of the 12 : 12 routine animals reestablished their original caecotrophy pattern.

In a further test the caecotrophy pattern remained constant during a constant 12 : 12 regimen, but changed in 7 of 16 animals when the photoperiod was reduced first to 60 min and then to 2 × 60 min light every 24 h. The reduction of the lit time resulted in an increased occurrence of diphasic animals. Details of synchronization of the caecotrophy rhythm with the different light-dark schedules are given. These results accord with data obtained in nocturnal rodent species.
Rate of movement of marker particles in the digestive tract of the rabbit
Authors: Jilge Burghart
Published: June 2007

Using small (50-100 μm) and large (800-1000 μm) polystyrene particles as a marker substance, transit through the gastrointestinal tract of the rabbit was studied during the formation of hard and soft faeces (caecotrophe). Both fractions of the marker were transported at an equal rate during soft faeces formation. During the formation of hard faeces a significantly higher amount of small particles was present in the caecum, whereas in the distal colon and rectum the number of large particles was elevated significantly.
Malocclusion in inbred strain-2 weanling guineapigs
Authors: Rest Joan R. , Richards Trevor , Ball Sarah E.
Published: June 2007

The incidence of malocclusion was recorded for 4 years. Malocclusion occurred only in animals less than 2 months old. The incidence was significantly reduced ( P > 0·001) by breeding from animals without affected siblings: it is suggested that malocclusion in this colony has a genetic basis.
An outbreak of hepatitis in marmosets in a zoological collection
Authors: Lucke Vanda M. , Bennett Alison M.
Published: June 2007

12 marmosets of 3 different species died of hepatitis during a period of 5 months. The lesions closely resembled those of virus hepatitis in man but material from these animals and from in-contact marmosets failed to reveal the presence of hepatitis A. This together with certain aspects of the epidemiology of the disease suggests that the outbreak was not caused by a virus of human origin but possibly by a virus indigenous to the marmoset or tamarin.
Influence of Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris on the mortality pattern of mice after lethal irradiation with γ rays
Authors: Matsumoto Tsuneya
Published: June 2007

The mortality patterns and the LD50/30 for mice free from Enterobacteriaceae, mice contaminated with Enterohacter cloacae, and mice inoculated with Escherichia coli, Klebsiella pneumoniae or Proteus vulgaris were examined after whole-body irradiation with γ rays. No clear differences were observed among the infected groups, but there were clear differences between them and those negative for Enterobacteriaceae. The LD50/30 of Enterobacteriaceae-positive mice was similar to that for conventional mice. All 4 nonpathogenic Enterobacteriaceae had very similar detrimental effects on mice after lethal irradiation.
Obtaining alveolar macrophages from small laboratory rodents
Authors: Moolenbeek C.
Published: June 2007

A simple apparatus is described for harvesting, if necessary under sterile conditions, alveolar macrophages from rats, mice, guineapigs and golden hamsters.
Experimental iron deficiency in the Syrian hamster (Mesocricetus auratus)
Authors: Rennie J. S. , Macdonald D. G. , Douglas T. A.
Published: June 2007

Animal models of iron deficiency commonly involve rearing weanling animals on an iron-free synthetic diet. This paper describes an alternative using a combination of repeated venesection and low dietary iron.