bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron microscopy of mammalian cells in the absence of fixing, freezing, dehydration, or specimen coating
Authors: Stokes D. J. , Rea S. M. , Best S. M. , Bonfield W.
Published: June 2010

Human osteoblast‐like (bone‐forming) cells were imaged using environmental scanning electron microscopy (ESEM). The cells were hydrated, unfrozen, and uncoated. Specimens were cooled to 3°C and imaged in water vapor, with partial pressures varying from saturated conditions to a humidity of approximately 50%, relative to pure water. The ESEM images show the presence of cell nuclei, nucleoli, and cytoplasmic membranes. Comparisons between chemically fixed and unfixed specimens (neither dried nor coated) show that cell morphologies are similar in both cases. These results are compared with a fixed, dried, carbon‐coated specimen. Thermodynamic and kinetic arguments are used to show that humidities significantly lower than 100% correspond to metastable states suitable for stabilizing hydrated biological tissues and cells. The ability to perform observations with minimal specimen preparation is potentially useful for studying interactions between mammalian cells and biomaterials that are developed for tissue engineering. The methods employed are equally applicable to the study of specimens in the biological, materials, and physical sciences where careful control over specimen stability is required.
Quantitative measurements of charging in a gaseous environment
Authors: Tang Xiaohu , Joy David C.
Published: June 2010

Charge accumulation in insulating or semiconducting samples due to electron beam irradiation is one of the key problems in electron microscopy. One of the most promising techniques for reducing the severity of such charging is to surround the sample with a low‐pressure atmosphere of a gas. The charging behavior of a number of materials, surrounded by a variety of gases, has been determined to identify the important factors which control charging under these conditions. The magnitude of the surface potential was deduced from an analysis of xray spectra from the surface. The relationship between surface charge, gas pressure, and gas type are measured, and the charging reduction efficiency (CRE) is compared.
Comparison in spatial spreads of secondary electron information between scanning ion and scanning electron microscopy
Authors: Ishitani Tohru , Ohya Kaoru
Published: June 2010

Monte Carlo simulations have been carried out to compare the spatial spreads of secondary electron (SE) information in scanning ion microscopy (SIM) with scanning electron microscopy (SEM). Under Ga ion impacts, the SEs are excited by three kinds of collision‐partners, that is, projectile ion, recoiled target atom, and target electron. The latter two partners dominantly contribute to the total SE yield γ for the materials of low atomic number Z2. For the materials of high Z2, on the other hand, the projectile ions dominantly contribute to γ. These Z2 dependencies generally cause the γ yield to decrease with an increasing Z2, in contrast with the SE yield δ under electron impacts. Most of the SEs are produced in the surface layer of about 5λ in depth (λ: the mean free path of SEs), as they are independent of the incident probe. Under 30 keV Ga ion impacts, the spatial spread of SE information is roughly as small as 10 nm, decreasing with an increasing Z2. Under 10 keV electron impacts, the SE1 excited by the primary electrons has a small spatial spread of about 5λ, but the SEII excited by the backscattered electrons has a large one of several 10 to several 100 nanometers, decreasing with an increasing Z2. The main cause of a small spread of SE information at ion impact is the short ranges of the projectile ions returning to the surface to escape as backscattered ions, the recoiled target atoms, and the target electrons in collision cascade. The 30 keV Ga‐SIM imaging is better than the 10 keV SEM imaging in spatial resolution for the structure/material measurements. Here, zero‐size probes are assumed.
Possibility of charge contrast imaging of polymeric materials
Authors: Gauvin Raynald , Robertson Kevin , Leberre Jean‐Francois , Finch James , Griffin Brendan J.
Published: June 2010

Preliminary results illustrate the possibility of charge contrast imaging (CCI) of polymeric materials. Possible CCI images of low‐density polyethylene and polyvinyl chloride reveal details that may aid in the characterization of the microstructure of polymeric materials. These pictures were obtained with a Hitachi S‐3000N variable pressure scanning electron microscope with the environmental secondary electron detector (ESED).
Using monte carlo simulation for accurate critical dimension metrology of super small isolated poly‐lines
Authors: Karabekov Albert , Zoran Oren , Rosenberg Zvika , Eytan Guy
Published: June 2010

With the reduction of critical dimensions (CD) of physical gate lines, standard methods for evaluating bottom CD from the scanning electron microscope (SEM) signal become inaccurate. The two peaks, originating from the line edges, merge into a single peak, and the correct position of the topographical top and bottom points is not clear. A general Monte Carlo simulation program, developed to model SEM signals, was used to analyze the signals emerging from ultra small silicon lines. By correlating the simulated signals with the features, we deduced the location of the top and bottom points. This analysis was done for lines with various CDs, sidewall angles, and corner rounding, as well as for different spot sizes. This work shows the feasibility of using SEM for measuring ultranarrow features and supply data for algorithm development.
Dynamic three‐dimensional visualization of collagen matrix remodeling and cytoskeletal organization in living corneal fibroblasts
Authors: Petroll W. Matthew , Cavanagh H. Dwight , Jester James V.
Published: June 2010

The remodeling of extracellular matrices by cells plays a defining role in developmental morphogenesis and wound healing, as well as in tissue engineering. Three‐dimensional (3‐D) type I collagen matrices have been used extensively as an in vitro model for studying cell‐induced matrix reorganization at the macroscopic level. However, few studies have directly assessed the dynamic process of 3‐D matrix remodeling at the cellular and sub‐cellular level. We recently developed an experimental model for investigating cell‐matrix mechanical interactions by plating green fluorescen protein (GFP)‐zyxin transfected cells inside fibrillar collagen matrices and performing high‐magnification time‐lapse differential interference microscopy (DIC) and wide‐field fluorescent imaging. In this study, we extend this experimental model by performing four‐dimensional (4‐D) reflected light and fluorescent confocal imaging (using either visible light or multiphoton excitation) of living corneal fibroblasts transfected to express GFP‐zyxin or GFP‐α‐actinin, 18 h after plating inside 3‐D collagen matrices. Reflected light confocal imaging allowed detailed visualization of the cells and the fibrillar collagen surrounding them. By overlaying maximum intensity projections of reflected light and GFP‐zyxin or GFP‐α‐actinin images and generating stereo pair reconstructions, 3‐D interactions between focal adhesions and collagen fibrils in living cells could be visualized directly. Focal adhesions were generally oriented parallel to the direction of collagen fibril alignment in front of the cell. Killing the cells induced relaxation of transient cell‐induced tension on the matrix; however, significant permanent remodeling always remained. Time‐lapse 3‐D imaging demonstrated an active response to the Rho‐kinase inhibitor Y‐27632, as indicated by cell elongation, extracellular matrix relaxation, and extension of pseudopodial processes. It is interesting that, at higher cell densities, groups of collagen fibrils were compacted and aligned into straps between neighboring cells. Overall, the continued development and application of this new approach should provide important insights into the basic underlying biochemical and biomechanical regulatory mechanisms controlling matrix remodeling by corneal fibroblasts.
Quantitative electron probe microanalysis of rough targets: Testing the peak‐to‐local background method
Authors: Newbury Dale E.
Published: June 2010

Rough samples with topography on a scale that is much greater than the micrometer dimensions of the electron interaction volume present an extreme challenge to quantitative electron beam x‐ray microanalysis with energy‐dispersive x‐ray spectrometry. Conventional quantitative analysis procedures for flat, bulk specimens become subject to large systematic errors due to the action of geometric effects on electron scattering and the x‐ray absorption path compared with the ideal flat sample. The best practical approach is to minimize geometric effects through specimen reorientation using a multiaxis sample stage to obtain the least compromised spectrum. When rough samples must be analyzed, corrections for geometric factors are possible by the peak‐to‐local background (P/B) method. Correction factors as a function of photon energy can be determined by the use of reference background spectra that are either measured locally or calculated from pure element spectra and estimated compositions. Significant improvements in accuracy can be achieved with the P/B method over conventional analysis with simple normalization.
Practical method for high‐resolution imaging of polymers by low‐voltage scanning electron microscopy
Authors: Gaillard Cedric , Stadelmann Pierre A. , Plummer Christopher J. G. , Fuchs Gilbert
Published: June 2010

Morphologic characterization of polymers by scanning electron microscopy (SEM) is often made difficult by their sensitivity to electron beam damage. We describe here a specimen preparation method for the imaging of polymer blends by low‐voltage SEM (LV‐SEM) that improves their stability in the electron beam and hence facilitates focusing and recording of high magnification images. Its application to nanosized core‐shell latexes embedded in a polymethylmethacrylate matrix and semicrystalline polypropylene/ethylene‐propylene rubber blends is discussed.
Reduction in acquisition time of scanning electron microscopy image using complex hysteresis smoothing
Authors: Oho Eisaku
Published: June 2010

Complex hysteresis smoothing (CHS), which was developed for noise removal of scanning electron microscopy (SEM) images some years ago, is utilized in acquisition of an SEM image. When using CHS together, recording time can be reduced without problems by about one‐third under the condition of SEM signal with a comparatively high signal‐to‐noise ratio (SNR). We do not recognize artificiality in a CHS‐filtered image, because it has some advantages, that is, no degradation of resolution, only one easily chosen processing parameter (this parameter can be fixed and used in this study), and no processing artifacts. This originates in the fact that its criterion for distinguishing noise depends simply on the amplitude of the SEM signal. The automation of reduction in acquisition time is not difficult, because CHS successfully works for almost all varieties of SEM images with a fairly high SNR.
Using the atomic force microscope to observe and study the ultrastructure of the living biu‐87 cells of the human bladder cancer
Authors: Chen Bin , Wang Qi , Han Li
Published: June 2010

In this study, the ultrastructure of living BIU‐87 cells of human bladder cancer was mapped using atomic force microscopy to reveal the dynamic change of single cancerous cell division. Simultaneously, the feasibility and functional reliability of the atomic force microscope (AFM) were established and a laboratory model using AFM to study living cancerous cells was created. In this experiment, BIU‐87 cells of human bladder cancer were cultured by conventional methods and grown in gelatin‐treated dishes. A thermostat was used for preserving the cell's living temperature. Scanning of these cells using AFM was carried out in physiologic condition. The AFM images of the ultrastructure of living BIU‐87 cells as well as those of the cell's membrane and cytoskeleton were very clear. The dynamic phenomenon of single cell division was observed. It was concluded that the AFM was able to observe and depict the ultrastructure of living cells of human bladder cancer directly and in real time. This experimental model is expected to play an important role in elucidating the cancerous mechanism of bladder normal cells at the atomic or nanometer level.
Compact multiphoton/single photon laser scanning microscope for spectral imaging and fluorescence lifetime imaging
Authors: Ulrich Volker , Fischer Peter , Riemann Iris , König Karsten
Published: June 2010

An inverted fluorescence microscope was upgraded into a compact three‐dimensional laser scanning microscope (LSM) of 65 × 62 × 48 cm dimensions by means of a fast kHz galvoscanner unit, a piezodriven z‐stage, and a picosecond (ps) 50 MHz laser diode at 405 nm. In addition, compact turn‐key near infrared femtosecond lasers have been employed to perform multiphoton fluorescence and second harmonic generation (SHG) microscopy. To expand the features of the compact LSM, a time‐correlated single photon counting unit as well as a Sagnac interferometer have been added to realize fluorescence lifetime imaging (FLIM) and spectral imaging. Using this unique five‐dimensional microscope, TauMap, single‐photon excited (SPE), and two‐photon excited (TPE) cellular fluorescence as well as intratissue autofluorescence of water plant leaves have been investigated with submicron spatial resolution, <270 ps temporal resolution, and 10 nm spectral resolution.
Composition and stress analysis in Si structures using micro‐raman spectroscopy
Authors: McCarthy J. , Perova T. S. , Moore R. A. , Bhattacharya S. , Gamble H. , Armstrong B. M.
Published: June 2010

Strained silicon (Si) technology enables improvements in complementary metal oxide semiconductor (CMOS) performance and functionality via replacement of the bulk, cubic‐crystal Si substrate with an Si substrate that contains a tetragonally distorted, biaxially strained Si thin film at the surface. Here we use Raman spectroscopy to allow us to characterise growth processes of strained si, and to characterise the resulting level of strain/stress in the si and the effect it has on the underlying layer of graded SiGe.
Secondary and backscattered electron imaging of weathered chromian spinel
Authors: Pooley Gregory D.
Published: June 2010

Secondary (SE) and backscattered electron (BSE) imaging as well as x‐ray microanalysis have demonstrated that the weathering of chromian spinel occurs as a progressive form of alteration. Numerous chemical discriminant analysis methods based on the composition of chromian spinel are used to locate valuable deposits of minerals. These methods will be misleading if the correct interpretation of the weathering of chromian spinel and the subsequent pattern of changes in its mineral chemistry are not properly assessed using scanning electron microscopy. This assessment is vital in understanding the geological processes involved and the economic potential of any indicated deposit. Minerals such as chromian spinel, pyrope garnet, and picroilmenite are considered to be highly resistant to weathering and abrasion and are therefore useful in the search for associated valuable deposits of diamond, nickel, platinum, and gold. Known as indicator minerals, they are usually present in relatively large concentrations compared with the target mineral (e.g., diamond) and form large and often subtle dispersion anomalies adjacent to the deposit. Chromian spinel has long been regarded as a stable indicator mineral; however, detailed SE and BSE imaging indicates that many of the chromian spinels that are routinely examined using scanning electron microscopes (SEM) and microprobes are extensively altered. Secondary electron and BSE imaging of weathered chromian spinel in a normal SEM provides valuable data on the form and chemical style of the alteration. Secondary electron imaging of weathered chromian spinel in the environmental SEM (ESEM) not only enhances the difference in atomic number between unaltered and altered areas but also allows high‐resolution imaging of these very fine replacement textures.
The structure of proteoglycan aggregate determined by atomic force microscopy
Authors: Yeh Ming‐Long , Luo Zong‐Ping
Published: June 2010

Proteoglycan aggregate is the major extracellular matrix component in cartilage, comprising about 18% of the dry weight of hyaline cartilage. The proteoglycan aggregate is the major substance in cartilage which resists compression in the joint. The purpose of this study was to utilize the newly developed imaging technique, Atomic force Microscopy (AFM), to visualize the ultrastructure of proteoglycan aggregates. The proteoglycan aggregate molecules were imaged in air using the tapping mode of the AFM. The images illustrated the ultrastructure of the aggregates, especially the individual proteoglycan and the core hyaluronic acid. In addition to the length and width of each molecule, the height of the proteoglycan aggregates and the individual proteoglycans could be directly measured. The images of the ultrastructures of proteoglycan aggregates visualized from the AFM are comparable with those using conventional electron microscopy approaches. Nevertheless, the sample preparation for AFM imaging does not involve fixation, staining, coating, and other routine procedures required for traditional electron microscopy imaging. Thus, this technique could be a simple alternative approach for future analysis of proteoglycan aggregate and its assembly.
Steps of Al/Si nanocluster studied by scanning tunneling microscope moiré method
Authors: Shang Haixia , Xie Huimin , Dai Fulong , Xue Qi‐Kun , Jia Jinfeng
Published: June 2010

The surface stress around the steps of Al/Si (111)‐7×7 artificial nanocluster array has been studied by the scanning tunneling microscope (STM) Moiré method. The distributions of σij(εij) near the selected step edge are precisely quantified by Moiré pattern. Observation by STM reveals the details of stress distribution that varies around steps and other defects of the surface. The experimental results show that the intrinsic surface stress tensors are quite different in the upper and lower terraces near a step, which provides indirect evidence that the exchange incorporation occurs for Al atoms on the Si (111) surface. The study also provides valuable data regarding control of the growth mode of artificial nanostructures by manipulating the growth conditions and kinetics.
Cholesterol crystals rupture biological membranes and human plaques during acute cardiovascular events‐a novel insight into plaque rupture by scanning electron microscopy
Authors: Abela George S. , Aziz Kusai
Published: June 2010

Plaque rupture and/or erosion are considered the leading cause of cardiovascular events. To elucidate this process, we demonstrated that during cholesterol crystallization the occupied volume increases rapidly and sharp–tipped crystals cut through thin biological membranes in their path. The amount of cholesterol correlated directly with both peak level and rate of crystal growth (r = 0.98; r = 0.99; p < 0.01, respectively). These observations suggest that crystallization of cholesterol in atherosclerotic plaques can induce cap rupture and/or erosion. Observations by scanning electron microscopy confirmed similar findings of cholesterol crystals perforating the lumen surface in human coronary artery segments with ruptured plaque.
Shot noise in electron‐beam lithography and line‐width measurements
Authors: Kruit P. , Steenbrink S. W. H. K.
Published: June 2010

Electron‐beam lithography is used extensively in nanoscience and technology for making masks for the semiconductor industry and, on a limited scale, for maskless lithography: that is, writing the patterns directly on the chip. We expect the latter application to extend in the years to come. Control of the dimensions of the written structures is essential in the semiconductor industry. For 45 nm generation, which is presently under development and should reach production at the end of the decade, the required control over the line width is between 1.5 and 5 nm, depending on the application. One of the factors of influence on the line‐width control is the statistics in the number of electrons illuminating the resist. This effect gives line edge roughness, or in other words a lack of control over the local position of a resist edge. This has long been recognized and often discussed. Recently, we developed an analytic model for the line edge position variation, which we shall illustrate and expand in this paper. The model, supported by Monte Carlo simulations, demonstrates that the line‐width variation is inversely proportional to the dose used for the illumination of the resist. This makes it impossible to increase the lithography throughput by developing ultrasensitive resists. For 45 nm features written with a typical resolution of 30 nm, a 30 μC/cm2 resist gives 3 nm line‐width variation over line segments of 45 nm long. The line width is usually measured in an adapted critical dimension scanning electron microscope (CD‐SEM). This measurement needs to be more precise than the result of the lithography step, so the requirements are typically sub‐nm. Apart from all the problems to avoid systematic errors, this measurement also suffers from statistical variations, resulting from the finite number of electrons used for the measurement. In this paper we shall derive an estimate for that variation with a similar model as used for the shot noise effect in the lithography step. One of the conclusions is that for the most precise measurements of the line width it is not advisable to tune the CD‐SEM for the best resolution. It is better to allow a larger probe size of the electron beam because that can be accompanied by a much larger current and thus a decrease in the noise level.
Subcompartmentalized Polymer Hydrogel Capsules with Selectively Degradable Carriers and Subunits
Authors: Kulygin Olga , Price Andrew D. , Chong Siow‐Feng , Städler Brigitte , Zelikin Alexander N. , Caruso Frank
Published: June 2010

Subcompartmentalized hydrogel capsules (SHCs) with selectively degradable carriers and subunits are designed for potential applications in drug delivery and microencapsulated biocatalysis. Thiolated poly(methacrylic acid) and poly(N‐vinyl pyrrolidone) are used to assemble 3‐µm‐diameter carrier capsules and 300‐nm‐diameter subunits, independently stabilized by a diverse range of covalent linkages. This paper presents examples of SHCs with tens of subcompartments and their successful drug loading, as well as selective degradation of the SHC carrier and/or subunits in response to multiple chemical stimuli.
Nanog Regulates Primordial Germ Cell Migration Through Cxcr4b
Authors: Sánchez-Sánchez Ana Virginia , Camp Esther , Leal-Tassias Aránzazu , Atkinson Stuart P. , Armstrong Lyle , Díaz-Llopis Manuel , Mullor José L.
Published: June 2010

Gonadal development in vertebrates depends on the early determination of primordial germ cells (PGCs) and their correct migration to the sites where the gonads develop. Several genes have been implicated in PGC specification and migration in vertebrates. Additionally, some of the genes associated with pluripotency, such as Oct4 and Nanog, are expressed in PGCs and gonads, suggesting a role for these genes in maintaining pluripotency of the germ lineage, which may be considered the only cell type that perpetually maintains stemness properties. Here, we report that medaka Nanog (Ol-Nanog) is expressed in the developing PGCs. Depletion of Ol-Nanog protein causes aberrant migration of PGCs and inhibits expression of Cxcr4b in PGCs, where it normally serves as the receptor of Sdf1a to guide PGC migration. Moreover, chromatin immunoprecipitation analysis demonstrates that Ol-Nanog protein binds to the promoter region of Cxcr4b, suggesting a direct regulation of Cxcr4b by Ol-Nanog. Simultaneous overexpression of Cxcr4b mRNA and depletion of Ol-Nanog protein in PGCs rescues the migration defective phenotype induced by a loss of Ol-Nanog, whereas overexpression of Sdf1a, the ligand for Cxcr4b, does not restore proper PGC migration. These results indicate that Ol-Nanog mediates PGC migration by regulating Cxcr4b expression.
Does levator ani injury affect cystocele type?
Authors: Eisenberg V. H. , Chantarasorn V. , Shek K. L. , Dietz H. P.
Published: June 2010

Objective

To determine the prevalence of levator ani injury in patients with different types of cystocele, as defined by translabial ultrasound, in order to shed light on potential pathophysiological mechanisms.

Methods

The datasets of 222 women who had undergone a physical examination, urodynamic testing and four‐dimensional (4D) pelvic floor ultrasound were evaluated offline for prolapse, levator ani hiatal dimensions and levator ani trauma using tomographic ultrasound imaging (TUI), blinded against all clinical and urodynamic data. Cystoceles reaching below the symphysis pubis on ultrasound examination were classified based on bladder neck position, retrovesical angle (RVA) and urethral rotation as Green II (cystourethrocele) or Green III (cystocele with intact RVA).

Results

Of 102 women who had a cystocele reaching below the symphysis pubis, 63 were classified as a Green type II cystocele and 39 as a Green type III cystocele. Women with Green type III cystoceles were older (59.4 vs. 48.7 years, P < 0.001), and had more severe prolapse (71 vs. 43%, P = 0.004) and objective voiding dysfunction (39 vs. 18%, P = 0.018). Women with Green III cystoceles also had larger hiatal dimensions and were more often diagnosed with an avulsion of the levator ani muscle (69 vs. 35%, P = 0.001).

Conclusion

A cystocele with an intact RVA is more likely to be associated with avulsion injury of the levator ani muscle and thus more likely to be caused by birth‐related trauma. This contradicts the commonly held belief that such cystoceles are caused by central rather than by lateral fascial defects. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Surgical Mammography Reporting in a Limited Resource Environment
Authors: Mouton John P. , Apffelstaedt Justus , Baatjes Karin
Published: June 2010

Background

Lack of resources and dedicated breast radiology has forced professionals other than radiologists to read mammography. We report a series of surgeon‐read mammography in a developing country.

Methods

Data were collected prospectively form January 2003 to June 2008 for all mammography performed at a tertiary hospital. The data acquired were demographics, previous treatment for breast pathology, and indication for and outcome of mammography, including diagnostic procedures and their results. The results were benchmarked against standard performance indicators.

Results

Of 8,743 mammograms performed, 1,468 were for palpable lumps; the cancer diagnosis rate was 640 per 1,000 investigations (for 885 of these reported as compatible with malignancy, the cancer diagnosis rate was 95%; for 183 reported as indeterminate 60%, for 400 reported as benign/no abnormality 4%). Of 4,998 cancer follow‐up mammograms, the cancer diagnosis rate was 15 per 1,000. For 76 of these reported as compatible with malignancy, the cancer diagnosis rate was 67%, for 161 reported as indeterminate, the biopsy rate was 36%, and cancer diagnosis rates of biopsy was 41%. Of 75 cancers diagnosed, 26 were locally recurrent after breast conservation and 49 new contralateral primaries, 84% of these were stage 0–I. Of 2,001 mammograms performed for screening, the biopsy rate was 4.5% and the cancer diagnosis rate of biopsy was 27%; the overall cancer diagnosis rate was 11 per 1,000 examinations; 96% of these were stage 0–1.

Conclusions

Dedicated breast surgeons are equally proficient at mammography interpretation as radiologists. In resource‐restricted environments, nonavailability of dedicated breast radiologists should not preclude development of breast units.
Solution structure of the N‐terminal domain of the archaeal D‐family DNA polymerase small subunit reveals evolutionary relationship to eukaryotic B‐family polymerases
Authors: Yamasaki Kazuhiko , Urushibata Yuji , Yamasaki Tomoko , Arisaka Fumio , Matsui Ikuo
Published: June 2010

Archaea‐specific D‐family DNA polymerase forms a heterotetramer consisting of two large polymerase subunits and two small exonuclease subunits. We analyzed the structure of the N‐terminal 200 amino‐acid regulatory region of the small subunit by NMR and revealed that the N‐terminal ∼70 amino‐acid region is folded. The structure consists of a four‐α‐helix bundle including a short parallel β‐sheet, which is similar to the N‐terminal regions of the B subunits of human DNA polymerases α and ε, establishing evolutionary relationships among these archaeal and eukaryotic polymerases. We observed monomer–dimer equilibrium of this domain, which may be related to holoenzyme architecture and/or functional regulation.
Abi1/Hssh3bp1 pY213 links Abl kinase signaling to p85 regulatory subunit of PI‐3 kinase in regulation of macropinocytosis in LNCaP cells
Authors: Dubielecka Patrycja M. , Machida Kazuya , Xiong Xiaoling , Hossain Sajjad , Ogiue-Ikeda Mari , Carrera Ana C. , Mayer Bruce J. , Kotula Leszek
Published: June 2010

MINT‐7908027:
Abi1 (uniprotkb:Q8IZP0) binds (MI:0407) to Lck (uniprotkb:P06239) by array technology (MI:0008)
Role of brominated diphenly ether‐209 in the differentiation of neural stem cells in vitro
Authors: Zhang Chunfang , Liu Xianbao , Chen Dunjin
Published: June 2010

Brominated diphenly ether‐209 (BDE‐209, decaBDE) is among the most common flame retardants. In a previous study, it was confirmed that exposure to BDE‐209 can decrease learning and memory in mice. However, it is still unknown whether BDE‐209 has an effect on cultured neural stem cells (NSCs). To analyse the role of BDE‐209 in the differentiation of neural stem cells, NSCs obtained from neonatal rats were cultured as neurospheres in DMEM/F12 medium that contained different concentrations of BDE‐209 for 7 days. BDE‐209 was found to inhibit neurite outgrowth and the differentiation of NSCs into neurons in a concentration‐dependent manner. BDE‐209 also enhanced the ratio of differentiation of NSCs into glial cells.
Cytoarchitectural impairments in the medium spiny neurons of theNucleus Accumbenscore of hyperactive juvenile rats
Authors: González‐Burgos I. , García‐Martínez S. , Velázquez‐Zamora D.A. , Ponce‐Rolón R.
Published: June 2010

Dopaminergic activity in the Nucleus Accumbens has been strongly implicated in the motor hyperactivity associated with Attention deficit hyperactivity disorder. Dopaminergic and glutamatergic terminals converge on the dendritic spines of medium spiny neurons of the nucleus accumbens core, which modulate the excitatory glutamatergic activity. In this work, a Golgi study was carried out to investigate the effects of dopamine depletion on the cytoarchitecture of dendritic spines of nucleus accumbens core medium spiny neurons. The dopaminergic system of newborn male rats was lesioned intracisternally by using 6‐hydroxydopamine, and subsequently, the motor activity, spine density, and the proportion of thin, stubby, mushroom, wide, branched, and double spines was compared to those in control and intact animals. Motor activity was significantly increased in the dopamine‐depleted animals and while the spine density was reduced, there was no change in the proportion of the specific types of spines. Larger thin spines were observed in the dopamine‐depleted animals. Indeed, dopamine depletion may lead to spine retraction due to the disregulation of spine development, and/or an increase in glutamatergic activity. The enlargement of thin spines may suggest a compensatory mechanism to increase the efficiency of synaptic inputs in response to a decrease in spines number. Together, the present findings suggest an alteration to the excitatory/inhibitory balance on dendritic spines of medium spiny neurons of the nucleus accumbens core in hyperactive juvenile rats following early dopamine depletion.
Progress in understanding melanoma propagation
Authors: Shackleton Mark , Quintana Elsa
Published: June 2010

Melanoma, like most cancers, is a disease that wreaks havoc mostly through its propensity to spread and establish secondary tumors at sites that are anatomically distant from the primary tumor. The consideration of models of cancer progression is therefore important to understand the essence of this disease. Previous work has suggested that melanoma may propagate according to a cancer stem cell (CSC) model in which rare tumorigenic and bulk non‐tumorigenic cells are organized into stable hierarchies within tumors. However, recent studies using assays that are more permissive for revealing tumorigenic potential indicate that it will not be possible to cure patients by focusing research and therapy on rare populations of cells within melanoma tumors. Studies of the nature of tumorigenic melanoma cells reveal that these cells may gain a growth, metastasis and/or therapy resistance advantage by acquiring new genetic mutations and by reversible epigenetic mechanisms. In this light, efforts to link the phenotypes, genotypes and epigenotypes of melanoma cells with differences in their in vivo malignant potential provide the greatest hope of advancing the exciting progress finally being made against this disease.
Cost analysis of intubation‐related tracheal injury using a national database
Authors: Bhatti Nasir I. , Mohyuddin Atta , Reaven Nancy , Funk Susan E. , Laeeq Kulsoom , Pandian Vinciya , Mirski Marek , Feller‐Kopman David
Published: June 2010

Objective

To perform risk analysis of tracheal injuries caused by endotracheal intubation (ETI) and to estimate the financial impact of these sequelae.

Study Design

Cost analysis using a national database.

Settings

The Agency for Healthcare Research and Quality (AHRQ) 2006 National Inpatient Sample.

Subjects and Methods

We identified clinical manifestations and treatments of complications associated with endotracheal tubes and codified them into International Classification of Disease‐ninth revision diagnosis and procedure codes, intentionally excluding alternative etiologies of tracheal injury. Using the AHRQ 2006 National Inpatient Sample, we then compared patients with tracheal injury coded during the medical or surgical stay for length of stay (LOS) and mean hospital cost with diagnosis‐related group (DRG)‐matched controls; we also examined readmissions treating tracheal injury.

Results

Tracheal injury presents as tracheal stenosis, tracheomalacia, tracheoesophageal fistula, laryngotracheal ulceration, and vocal cord paralysis. A total of 3232 discharge records met criteria for tracheal injury from ETI within the index hospital stay. Average LOS for patients with tracheal injury (6.3 days; 95% confidence interval [CI] 6.0‐6.3) exceeded LOS in the uncomplicated sample (5.2 days; CI 5.1‐5.3) by 1.1 days. The average hospital cost was $1888 higher with tracheal injury ($10,375 [CI $9762‐$10,988] vs $8487 [CI $8266‐$8669]). LOS for procedures treating prior tracheal injury averaged 4.7 days and cost an average of $11,025 per discharge.

Conclusion

Tracheal injury from ETI is associated with a significant increase in healthcare costs that accrue both during the index admission and during subsequent hospitalizations required to treat the injury.
Poly(glycerol sebacate)‐engineered plugs to repair chronic tympanic membrane perforations in a chinchilla model
Authors: Wieland Aaron M. , Sundback Cathryn A. , Hart Allison , Kulig Katherine , Masiakos Peter T. , Hartnick Christopher J.
Published: June 2010

Objective

To evaluate the degree of neovascularization and efficacy of repair of chronic tympanic membrane perforations in a chinchilla model using poly(glycerol sebacate) (PGS), a novel bioengineered scaffold material.

Study Design

A feasibility study in which chinchilla ears with chronic perforations were randomly assigned to repair with PGS plugs or Gelfilm overlay myringoplasty.

Setting

Interventions were performed in the animal care facility of a tertiary care academic institution.

Subjects and Methods

Sixteen adult female chinchillas. Perforations were established under microscopic visualization with thermal cautery. The animals were examined six weeks later, and those ears with stable perforations were randomly assigned to repair with PGS or Gelfilm. All ears were evaluated six weeks after repair, and resected membranes underwent histological evaluation.

Results

Chronic perforations were established in 22 of 32 (69%) chinchilla tympanic membranes. Nineteen tympanic membranes were included in the study group (3 ears were excluded secondary to death from anesthesia during the repair); 11 were implanted with PGS, and eight underwent Gelfilm myringoplasty. Of the 11 tympanic membranes implanted with PGS, 10 were healed at six weeks, while six of the eight tympanic membranes repaired with Gelfilm had healed at six weeks. Imaging of the medial mucosal and lateral epithelial surfaces of the tympanic membranes revealed PGS plug incorporation with neovascularization. Histology demonstrated a confluent cell layer on both sides of the graft.

Conclusions

PGS plugs are easily placed and allow for perforation closure and graft neovascularization in a chinchilla model.
Detecting cholesteatoma with non‐echo planar (HASTE) diffusion‐weighted magnetic resonance imaging
Authors: Huins Charlie T. , Singh Arvind , Lingam Ravi Kumar , Kalan Ali
Published: June 2010

Objective

The purpose of this study was to evaluate the diagnostic performance of half‐Fourier‐acquisition single‐shot turbo‐spin‐echo (HASTE) diffusion‐weighted magnetic resonance imaging (DWMRI) in the detection of cholesteatoma.

Study Design

Prospective blinded comparative study.

Setting

London teaching hospital.

Subjects and Methods

Subjects comprised 32 consecutive patients with suspected primary or residual cholesteatoma. HASTE DWMRI was performed on all patients an average of three months before mastoid surgery and evaluated for the presence of cholesteatoma. Radiological findings were correlated with intraoperative findings.

Results

HASTE DWMRI accurately predicted the presence or absence of cholesteatoma in 30 of 32 patients. Residual cholesteatoma was correctly diagnosed by DWMRI in 12 of 14 cases and correctly excluded in six, with two false‐negative results caused by movement artifact and keratin pearls less than 2 mm. All primary cholesteatomas were correctly identified. Sensitivity and specificity were 0.93 (95% confidence interval [CI] 0.75‐0.99) and 1.00 (95% CI 0.54‐1.0), respectively, whereas positive and negative predictive values were 1.00 (95% CI 0.86‐1.00) and 0.75 (95% CI 0.35‐0.97), respectively.

Conclusion

Our study supports the increasing but small body of evidence that non–echo‐planar imaging (i.e., HASTE) DWMRI performs well in the detection of cholesteatoma. We propose that HASTE DWMRI should be performed on all patients before their second‐look surgery to provide valuable information to the operating surgeon.
Hemostasis in thyroid surgery: Harmonic scalpel versus other techniques—a meta‐analysis
Authors: Ecker Thomas , Carvalho Andre Lopes , Choe Jun‐Ho , Walosek Gudrun , Preuss Klaus Juergen
Published: June 2010

Objective

The objective is to systematically review the literature studying the harmonic scalpel versus other hemostatic techniques in thyroid surgical patients. Although thyroidectomy is one of the most common surgical procedures, the safest, most efficient, and cost‐effective way to achieve hemostasis is hotly debated.

Data Sources

We searched the electronic databases Medline and the Cochrane Library using relevant search strategies.

Review Methods

Two reviewers (G.W., T.E.) independently assessed titles and abstracts of 72 identified studies. Twelve prospective randomized controlled studies were considered relevant and included in this meta‐analysis (1153 patients).

Results

In all studies, operating time was reduced by using the harmonic scalpel. Compared with surgical hemostasis by suture ligation or suture/clip ligation combined with electrocauterization or electrothermal bipolar vessel sealer (n = 602), the mean operating time reduction for the harmonic scalpel was equivalent to 22.67 minutes (95% CI, −27.98; −17.37, P < 0.00001) or nearly 25 percent of the total operating room time. When harmonic scalpel was used, blood loss was reduced significantly by 20.03 mL (95% CI, −27.83; −12.22, P < 0.00001), and a mean reduction in postoperative pain (0.86 points [95% CI, −1.60; −0.13, P = 0.02]) was measured. Length of stay was reduced by 0.12 days (95% CI, −0.25; 0.00, P = 0.05). Differences regarding volume of drainage fluid were in favor of harmonic scalpel but not statistically significant; complications were similar in both groups.

Conclusion

There is clear evidence that using the harmonic scalpel for hemostasis in thyroid surgery significantly reduces operating time and blood loss and that it is not associated with an increase in volume of drainage fluid, complication rate, or hospital stay.
Effect of transforming growth factor‐β1 antisense oligonucleotides on matrix metalloproteinases and their inhibitors in keloid fibroblasts
Authors: Bran Gregor M. , Goessler Ulrich R. , Baftiri Ariton , Hormann Karl , Riedel Frank , Sadick Haneen
Published: June 2010

Objective

To identify changes in the expression of matrixmetalloproteinases (MMPs) and their specific inhibitors tissue inhibitors of metalloproteinases (TIMPs) after targeting of transforming growth factor‐β1 (TGF‐β1) with antisense oligonucleotides.

Study Design

Cross‐sectional study.

Setting

The study was performed on tissue samples from nine patients with keloid scars after otoplasty presenting to the Otolaryngology–Head and Neck Surgery Department of the University Hospital in Mannheim, Germany.

Subjects and Methods

Keloid fibroblasts and normal fibroblasts were harvested from auricular keloid scars and healthy skin regions of the same patients during resection procedure of the keloid. Cells were placed in monolayer cultures. Expression of MMPs and TIMPs were analyzed by immunohistochemistry. The effect of TGF‐β1 targeting using antisense oligonucleotides on the expression of both protein groups in keloid‐derived fibroblasts was analyzed by enzyme‐linked immunosorbent assay and reverse‐transcription polymerase chain reaction.

Results

Immunohistochemical investigation demonstrated increased expression of MMP‐2, ‐3, ‐9, and ‐13 and TIMP‐1 and ‐2. TGF‐β1 antisense therapy significantly down‐regulated MMP secretion in vitro.

Conclusion

Usage of TGF‐β1 antisense oligodeoxynucleotides (ODNs) may show a potential chemopreventive or therapeutic option for keloids by blocking the effect of TGF‐β1. Furthermore, antisense ODNs can be used as an investigative approach toward a better understanding of molecular mechanisms in keloid pathophysiology.
Clinical consensus statement: Diagnosis and management of nasal valve compromise
Authors: Rhee John S. , Weaver Edward M. , Park Stephen S. , Baker Shan R. , Hilger Peter A. , Kriet J. David , Murakami Craig , Senior Brent A. , Rosenfeld Richard M. , DiVittorio Danielle
Published: June 2010

Objective

To create a clinical consensus statement to address ambiguities and disparities in the diagnosis and management of nasal valve compromise (NVC).

Subjects and Methods

An updated systematic review of the literature was conducted. In addition, a Modified Delphi Method was used to refine expert opinion and facilitate a consensus position.

Results

After two rounds of surveys and conference calls, 36 items reached consensus, six items reached near consensus, and 10 items reached no consensus. The categories that had the greatest percentage of consensus or near consensus items were as follows: definition, history and physical examination, outcome measures, and management. Conversely, the categories with greater percentage of no consensus items were adjunctive tests and coding.

Conclusion

The consensus panel agreed that NVC is a distinct clinical entity that is best evaluated with history and physical examination findings. Endoscopy and photography are useful but not routinely indicated, whereas radiographic studies are not useful in evaluating NVC. Other objective nasal outcome measures may not be useful or accepted for NVC. Nasal steroid medication is not useful for treatment of NVC in the absence of rhinitis, and mechanical treatments may be useful in selected patients. Surgical treatment is the primary mode of treatment of NVC, but bill coding remains ambiguous and confusing.
Extracts from The Cochrane Library: Interventions for acute otitis externa
Authors: Burton Martin J. , Singer Michael , Rosenfeld Richard M.
Published: June 2010

The “Cochrane Corner” is a quarterly section in the Journal that highlights systematic reviews relevant to otolaryngology–head and neck surgery, with invited commentary to aid clinical decision making. This installment features a Cochrane Review titled “Interventions for acute otitis externa,” which supports topical therapy as the treatment of choice, but is unable to draw conclusions about the comparative efficacy of available topical preparations.
Systematics and molecular phylogeny of two African stem borer genera,SciomesaTams & Bowden andCarelisBowden (Lepidoptera: Noctuidae)
Authors: Moyal P. , Le Ru B. , Conlong D. , Cugala D. , Defabachew B. , Matama-Kauma T. , Pallangyo B. , Van den Berg J.
Published: June 2010

Currently, the systematics of the African noctuid stem borers of the subtribe Sesamiina, which include major pests of cereals, is confused. In addition, their ecology is poorly known, as are the factors influencing their evolution. In this paper, we address these shortcomings for two genera of the Sesamiina,SciomesaTams & Bowden andCarelisBowden. Mixed Bayesian phylogenetic analysis, which included their host plants and two mitochondrial genes, showed the genusSciomesato be polyphyletic. Two new genera were created,PirateoleaandFeraxinia. The genusCarelisproved to be paraphyletic and was subdivided into two sub-genera. The generaSciomesa,CarelisandPirateolea(named the ‘Sciomesagenus group’) share morphological traits, and the phylogenetic analysis showed that they had a common ancestor living on Cyperaceae and that they were distant from the genusFeraxiniabelonging to another clade which had an ancestor living on Poaceae. Seven new species were described:Sciomesa gnosiasp. n.,Sciomesia buasp. n.,Pirateolea nolagen. n, sp. n.,Feraxinia serenagen. n., sp. n.,Carelis australissp. n.,Carelis transversasp. n. andCarelis agnaesp. n. Ten species were sunk as synonyms:Sciomesa mesoscia(Hampson) syn. n.,Sciomesa mirificaLaporte syn. n.,Sciomesa constantiniLaporte syn. n. andSciomesa etchecopariLaporte syn. n. are synonyms ofSciomesa mesophaea(Aurivillius);Acrapex sparsipuctaLaporte syn. n. is a synonym ofSciomesa excelsa(Laporte) comb. n.;Acrapex congitaeLaporte syn. n.,Sesamia minutaLaporte syn. n. andSesamia minusculaLaporte syn. n. are synonyms ofSciomesa boulardi(Laporte) comb. n.;Acrapex bryaeLaporte syn. n. andAcrapex fayeiLaporte syn. n. are synonyms ofFeraxinia jemjemensis(Laporte) comb. n. Eleven new combinations were created:Sciomesa excelsa(Laporte) comb. n.,Sciomesa boulardi(Laporte) comb. n.,Sciomesa punctipennis(Krüger) comb. n.,Pirateolea piscator(Fletcher) comb. n.,Pirateolea argocyma(Fletcher) comb. n.,Pirateolea cyclophora(Fletcher) comb. n.,Pirateolea ochroneura(Fletcher) comb. n.,Pirateolea funebris(Krüger) comb. n.,Feraxinia nyei(Fletcher) comb. n.,Feraxinia jemjemensis(Laporte) comb. n. andCarelis biluma(Nye) comb. n.
ON THE OSOFSKY–SMITH THEOREM
Authors: CRIVEI SEPTIMIU , NĂSTĂSESCU CONSTANTIN , TORRECILLAS BLAS
Published: June 2010

We recall a version of the Osofsky–Smith theorem in the context of a Grothendieck category and derive several consequences of this result. For example, it is deduced that every locally finitely generated Grothendieck category with a family of completely injective finitely generated generators is semi-simple. We also discuss the torsion-theoretic version of the classical Osofsky theorem which characterizes semi-simple rings as those rings whose every cyclic module is injective.