bluuebunny/crossref_metadata_2025 huggingface dataset:
Narrow and wide field amacrine cells fire action potentials in response to depolarization and light stimulation
Authors: HEFLIN STEPHANIE J. , COOK PAUL B.
Published: July 2007

Action potentials in amacrine cells are important for lateral propagation of signals across the inner retina, but it is unclear how many subclasses of amacrine cells contain voltage-gated sodium channels or can fire action potentials. This study investigated the ability of amacrine cells with narrow (< 200 μm) and wide (> 200 μm) dendritic fields to fire action potentials in response to depolarizing current injections and light stimulation. The pattern of action potentials evoked by current injections revealed two distinct classes of amacrine cells; those that responded with a single action potential (single-spiking cells) and those that responded with repetitive action potentials (repetitive-spiking cells). Repetitive-spiking cells differed from single-spiking cells in several regards: Repetitive-spiking cells were more often wide field cells, while single-spiking cells were more often narrow field cells. Repetitive-spiking cells had larger action potential amplitudes, larger peak voltage-gated NaV currents lower action potential thresholds, and needed less current to induce action potentials. However, there was no difference in the input resistance, holding current or time constant of these two classes of cells. The intrinsic capacity to fire action potentials was mirrored in responses to light stimulation; single-spiking amacrine cells infrequently fired action potentials to light steps, while repetitive-spiking amacrine cells frequently fired numerous action potentials. These results indicate that there are two physiologically distinct classes of amacrine cells based on the intrinsic capacity to fire action potentials.
An exercise tissue Doppler and strain rate imaging study of diastolic myocardial dysfunction after Kawasaki syndrome in childhood
Authors: Arnold Raoul , Goebel Björn , Ulmer Herbert E. , Gorenflo Matthias , Poerner Tudor C.
Published: July 2007

Objective

Myocardial dysfunction due to coronary arterial lesions is an important complication after Kawasaki syndrome in childhood. Tissue Doppler echocardiography, and strain rate imaging, have shown their value in detecting regional myocardial dysfunction in coronary arterial disease. We aimed to examine the diagnostic value of these methods in patients with coronary arterial lesions after Kawasaki syndrome.

Methods

We assessed regional myocardial function in 17 asymptomatic patients with coronary arterial lesions. Follow-up coronary angiographies were available in all cases. Tissue Doppler echocardiography, and strain rate imaging, were performed at rest and during bicycle exercise. Examination included peak systolic and diastolic velocities, peak systolic strain and strain rate. We enrolled 17 age- and gender-matched persons to serve as a control group.

Results

Segmental left ventricular longitudinal function did not significantly differ between the groups with respect to peak systolic velocity, strain, and strain rate. Diastolic abnormalities were identified in segments supplied by coronary arteries with stenotic lesions. Peak diastolic velocity decreased significantly during exercise in those areas, from 77 plus or minus 34 to 59 plus or minus 56 millimetres per second, p smaller than 0.05. Under exercise, a peak diastolic velocity value under 90 millimetres per second enabled us to identify coronary arterial stenosis with a sensitivity of 75 percent and specificity of 64 percent.

Conclusions

After Kawasaki syndrome, diastolic impairment develops in segments supplied by stenotic coronary arteries before systolic dysfunction is detectable. Exercise tissue Doppler echocardiography has the potential to detect these subtle abnormalities, and help monitor progression of the disease.
The peoples of the north in the eyes of the Muslims of Umayyad al-Andalus (711–1031)
Authors: Bennison Amira K.
Published: July 2007

This article explores how the Muslim inhabitants of the Iberian peninsula, known in Arabic as al-Andalus, located themselves in space and time in relation to other ‘Europeans’. It has been asserted that Muslims did not show much interest in the peoples living beyond the boundaries of the Islamic world before European imperialism impacted upon them, and that much of what they did write was formulaic and predicated on the primordial religious enmity which existed between Muslims and non-Muslims. While true up to a point, this article attempts to nuance this argument, and point to ways in which the Muslims of al-Andalus did refer to other peoples and other epochs, and incorporate them into their worldview, thereby positioning themselves not only within the dār al-islām but also within a Mediterranean historical trajectory. It also looks at the ways in which northerners did participate in and shape Andalusi society, despite the reluctance of much Arabic writing to fully record or recognize this phenomenon.
Mesure non-invasive de la pression artérielle centrale: comment et pourquoi?
Authors: Pasche  , Feihl  , Liaudet  , Waeber
Published: July 2007

Jusqu'à ce jour, la pression artérielle a toujours été mesurée au niveau huméral par sphygmomanométrie. Il existe pourtant depuis quelques années un outil non invasif permettant d'estimer la pression régnant dans l'aorte. Cela est rendu possible grâce à la mesure par tonométrie d'aplanation de l'onde de pouls au niveau de l'artère radiale, avec conversion ultérieure en une onde de pression centrale par une méthode mathématique (fonction de transfert). Cette mesure peut nous renseigner au mieux sur la pression à proximité des organes cibles, une pression influencée par les ondes de réflexion connues pour augmenter la pression systolique en cas de compliance artérielle diminuée. De plus certaines études récentes montrent que pour une pression périphérique identique, des traitements antihypertenseurs différents n'ont pas le même impact sur la pression systolique centrale.
On the ionospheric and reconnection potentials of the earth: Results from global MHD simulations
Authors: Hu Y. Q. , Guo X. C. , Wang C.
Published: July 2007

The reconnection potential along the reconnection line provides a quantitative description of magnetic reconnection that dominates the solar wind‐magnetosphere coupling. To properly determine the reconnection potential is a first and crucial step in deeply understanding magnetospheric processes. This paper proposes three methods to calculate the reconnection potential based on data obtained by global magnetohydrodynamic simulations of the Earth’s magnetosphere‐ionosphere system. The simulations are limited to the due southward interplanetary magnetic field (IMF) case for simplicity. The three methods are all based on the line integration of electric field and differ in the choice of integration path, radial rays in the equatorial plane for method 1, last closed magnetic field lines for method 2, and IMF lines nearby the reconnection line for method 3. The effect of numerical diffusion of the algorithm is included approximately by an equivalent uniform resistivity. For a properly selected numerical resistivity, the three methods give answers of the reconnection potential, which are reasonably close to each other. The reconnection voltage is found to be larger than the transpolar potential, and the ratio between them increases with increasing ionospheric conductance. The fact that method 2 also gives reasonable answers means that the appearance of parallel electric field along the last closed magnetic field lines is responsible for the difference between the ionospheric and the reconnection potentials and between the transpolar potential and the reconnection voltage as well. We suggest that similar methods may be applicable to general cases with arbitrary IMF orientations.
Refining ancient carbon dioxide estimates: Significance of coccolithophore cell size for alkenone‐based pCO2 records
Authors: Henderiks Jorijntje , Pagani Mark
Published: July 2007

Long‐term alkenone‐based pCO2 records are widely applied in paleoclimate evaluations. These pCO2 estimates are based on records of the carbon isotope fractionation that occurs during marine haptophyte photosynthesis (ɛp37:2). In addition to the concentration of aqueous CO2 (CO2(aq)) the magnitude of ɛp37:2 is also influenced by algal growth rates and cell geometry. To date, the influence of haptophyte cell geometry on the expression of ancient ɛp37:2 values has received little attention. This study evaluates changes in cell geometry of ancient alkenone‐producing algae at Deep See Drilling Project Site 516 in the southwest Atlantic Ocean by analyzing individual coccolith dimensions, which are proportional to algal cell volume and surface area. We show that during part of the early Miocene, mean cell sizes of alkenone‐producing algae were smaller relative to modern Emiliania huxleyi. Cell size variations coincide with significant changes in ɛp37:2, with a distinct 6‰ decrease in ɛp37:2 at ∼20.3 Ma associated with a 27% increase in haptophyte cell sizes. These changes in cell size impact ɛp37:2‐based interpretations of growth rate variation and CO2(aq) estimates for this southwest Atlantic site. After correcting for cell geometry, CO2(aq) estimates at Site 516 are consistent with those reported from other oligotrophic sites during this time, resulting in overall low atmospheric pCO2 estimates (<350 ppmv) for the early Miocene.
High specificity but contrasting biodiversity of Sphagnum-associated bacterial and plant communities in bog ecosystems independent of the geographical region
Authors: Opelt Katja , Berg Christian , Schönmann Susan , Eberl Leo , Berg Gabriele
Published: July 2007

Mosses represent ecological niches that harbor a hitherto largely uncharacterized microbial diversity. To investigate which factors affect the biodiversity of bryophyte-associated bacteria, we analyzed the bacterial communities associated with two moss species, which exhibit different ecological behaviors and importance in bog ecosystems, Sphagnum magellanicum and Sphagnum fallax, from six temperate and boreal bogs in Germany and Norway. Furthermore, their surrounding plant communities were studied. Molecular analysis of bacterial communities was determined by single-strand conformation polymorphism (SSCP) analysis using eubacterial and genus-specific primers for the dominant genera Burkholderia and Serratia as well as by sequence analysis of a Burkholderia 16S rRNA gene clone library. Plant communities were analyzed by monitoring the abundance and composition of bryophyte and vascular plant species, and by determining ecological indicator values. Interestingly, we found a high degree of host specificity for associated bacterial and plant communities of both Sphagnum species independent of the geographical region. Calculation of diversity indices on the basis of SSCP gels showed that the S. fallax-associated communities displayed a statistically significant higher degree of diversity than those associated with S. magellanicum. In contrast, analyses of plant communities of Sphagnum-specific habitats resulted in a higher diversity of S. magellanicum-specific habitats for all six sites. The higher content of nutrients in the S. fallax-associated ecosystems can explain higher diversity of microorganisms.
Effects of cattle husbandry on abundance and activity of methanogenic archaea in upland soils
Authors: Radl Viviane , Gattinger Andreas , Chroňáková Alica , Němcová Anna , Čuhel Jiri , Šimek Miloslav , Munch Jean Charles , Schloter Michael , Elhottová Dana
Published: July 2007

In the present study, we tested the hypothesis that animal treading associated with a high input of organic matter would favour methanogenesis in soils used as overwintering pasture. Hence, methane emissions and methanogen populations were examined at sections with different degree of cattle impact in a Farm in South Bohemia, Czech Republic. In spring, methane emission positively corresponded to the gradient of animal impact. Applying phospholipid etherlipid analysis, the highest archaeal biomass was found in section severe impact (SI), followed by moderate impact (MI) and no impact. The same trend was observed for the methanogens as showed by real-time quantitative PCR analyses of methyl coenzyme M reductase (mcrA) genes. The detection of monounsaturated isoprenoid side chain hydrocarbons (i20:1) indicated the presence of acetoclastic methanogens in the cattle-impacted sites. This result was corroborated by the phylogenetic analysis of mcrA gene sequences obtained from section SI, which showed that 33% of the analysed clones belonged to the genus Methanosarcina. The majority of the sequenced clones (41%) showed close affiliations with uncultured rumen archaeons. This leads to the assumption that a substantial part of the methanogenic community in plot SI derived from the grazing cattle itself. Compared to the spring sampling, in autumn, a significant reduction in archaeal biomass and number of copies of mcrA genes was observed mainly for section MI. It can be concluded that after 5 months without cattle impact, the severely impact section maintained its methane production potential, whereas the methane production potential under moderate impact returned to background values.
Sulfite reductase‐mediated synthesis of gold nanoparticles capped with phytochelatin
Authors: Kumar Suresh Anil , Abyaneh Majid Kazemian , Gosavi Suresh W. , Kulkarni Sulabha K. , Ahmad Absar , Khan M. Islam
Published: July 2007

An enzymatic synthesis route to peptide‐capped gold nanoparticles has been developed. Gold nanoparticles were synthesized using α‐NADPH‐dependent sulfite reductase and phytochelatin in vitro. The gold ions were reduced in the presence of the enzyme sulfite reductase, leading to the formation of a stable gold hydrosol of dimensions 7–20 nm and were stabilized by the capping peptide. The nanoparticles were characterized by X‐ray diffraction, transmission electron microscopy, X‐ray photoelectron spectroscopy and UV–visible optical absorption. These studies will help in designing a rational enzymatic strategy for the synthesis of nanomaterials of different chemical compositions, shapes and sizes as well as their separation.
Poor correlation between BCG vaccination-induced T cell responses and protection against tuberculosis
Authors: Mittrücker Hans-Willi , Steinhoff Ulrich , Köhler Anne , Krause Marion , Lazar Doris , Mex Peggy , Miekley Delia , Kaufmann Stefan H. E.
Published: July 2007

Mycobacterium bovis
bacille Calmette–Guérin (BCG) is the most widely used live bacterial vaccine. However, limited information is available correlating route and dose of vaccination and induction of specific T cell responses with protection against tuberculosis. We compared efficacy of oral and systemic vaccination and correlated vaccine-induced T cell responses with protection in experimental tuberculosis of mice. After oral and systemic vaccination, we observed profound differences in persistence and dissemination of BCG and frequencies and location of specific IFN-γ-secreting CD4
+
and CD8
+
T cells. Yet, both vaccination routes caused comparable levels of protection against aerosol challenge with
Mycobacterium tuberculosis
. Protection correlated best with rapid accumulation of specific CD8
+
T cells in infected tissues of challenged mice. In contrast, specific IFN-γ production by CD4
+
T cells reflected the load of
M. tuberculosis
rather than the strength of protection. Our data question the measurement of IFN-γ secretion by CD4
+
T cells and emphasize the need for new biomarkers for evaluation of tuberculosis vaccine efficacies.
In vivo
imaging of T cell delivery to tumors after adoptive transfer therapy
Authors: Pittet Mikael J. , Grimm Jan , Berger Cedric R. , Tamura Takahiko , Wojtkiewicz Gregory , Nahrendorf Matthias , Romero Pedro , Swirski Filip K. , Weissleder Ralph
Published: July 2007

Adoptive transfer therapy of
in vitro
-expanded tumor-specific cytolytic T lymphocytes (CTLs) can mediate objective cancer regression in patients. Yet, technical limitations hamper precise monitoring of posttherapy T cell responses. Here we show in a mouse model that fused single photon emission computed tomography and x-ray computed tomography allows quantitative whole-body imaging of
111
In-oxine-labeled CTLs at tumor sites. Assessment of CTL localization is rapid, noninvasive, three-dimensional, and can be repeated for longitudinal analyses. We compared the effects of lymphodepletion before adoptive transfer on CTL recruitment and report that combined treatment increased intratumoral delivery of CTLs and improved antitumor efficacy. Because
111
In-oxine is a Food and Drug Administration-approved clinical agent, and human SPECT-CT systems are available, this approach should be clinically translatable, insofar as it may assess the efficacy of immunization procedures in individual patients and lead to development of more effective therapies.
Epigenetic characterization of hematopoietic stem cell differentiation using miniChIP and bisulfite sequencing analysis
Authors: Attema Joanne L. , Papathanasiou Peter , Forsberg E. Camilla , Xu Jian , Smale Stephen T. , Weissman Irving L.
Published: July 2007

Hematopoietic stem cells (HSC) produce all blood cell lineages by virtue of their capacity to self-renew and differentiate into progenitors with decreasing cellular potential. Recent studies suggest that epigenetic mechanisms play an important role in controlling stem cell potency and cell fate decisions. To investigate this hypothesis in HSC, we have modified the conventional chromatin immunoprecipitation assay allowing for the analysis of 50,000 prospectively purified stem and progenitor cells. Together with bisulfite sequencing analysis, we found that methylated H3K4 and AcH3 and unmethylated CpG dinucleotides colocalize across defined regulatory regions of lineage-affiliated genes in HSC. These active epigenetic histone modifications either accumulated or were replaced by increased DNA methylation and H3K27 trimethylation in committed progenitors consistent with gene expression. We also observed bivalent histone modifications at a lymphoid-affiliated gene in HSC and downstream transit-amplifying progenitors. Together, these data support a model in which epigenetic modifications serve as an important mechanism to control HSC multipotency.
Amnesia produced by altered release of neurotransmitters after intraamygdala injections of a protein synthesis inhibitor
Authors: Canal Clinton E. , Chang Qing , Gold Paul E.
Published: July 2007

Amnesia produced by protein synthesis inhibitors such as anisomycin provides major support for the prevalent view that the formation of long-lasting memories requires
de novo
protein synthesis. However, inhibition of protein synthesis might disrupt other neural functions to interfere with memory formation. Intraamygdala injections of anisomycin before inhibitory avoidance training impaired memory in rats tested 48 h later. Release of norepinephrine (NE), dopamine (DA), and serotonin, measured at the site of anisomycin infusions, increased quickly by ≈1,000–17,000%, far above the levels seen under normal conditions. NE and DA release later decreased far below baseline for several hours before recovering at 48 h. Intraamygdala injections of a β-adrenergic receptor antagonist or agonist, each timed to blunt effects of increases and decreases in NE release after anisomycin, attenuated anisomycin-induced amnesia. In addition, similar to the effects on memory seen with anisomycin, intraamygdala injections of a high dose of NE before training impaired memory tested at 48 h after training. These findings suggest that altered release of neurotransmitters may mediate amnesia produced by anisomycin and, further, raise important questions about the empirical bases for many molecular theories of memory formation.
Gap junctions on hippocampal mossy fiber axons demonstrated by thin-section electron microscopy and freeze–fracture replica immunogold labeling
Authors: Hamzei-Sichani Farid , Kamasawa Naomi , Janssen William G. M. , Yasumura Thomas , Davidson Kimberly G. V. , Hof Patrick R. , Wearne Susan L. , Stewart Mark G. , Young Steven R. , Whittington Miles A. , Rash John E. , Traub Roger D.
Published: July 2007

Gap junctions have been postulated to exist between the axons of excitatory cortical neurons based on electrophysiological, modeling, and dye-coupling data. Here, we provide ultrastructural evidence for axoaxonic gap junctions in dentate granule cells. Using combined confocal laser scanning microscopy, thin-section transmission electron microscopy, and grid-mapped freeze–fracture replica immunogold labeling, 10 close appositions revealing axoaxonic gap junctions (≈30–70 nm in diameter) were found between pairs of mossy fiber axons (≈100–200 nm in diameter) in the stratum lucidum of the CA3b field of the rat ventral hippocampus, and one axonal gap junction (≈100 connexons) was found on a mossy fiber axon in the CA3c field of the rat dorsal hippocampus. Immunogold labeling with two sizes of gold beads revealed that connexin36 was present in that axonal gap junction. These ultrastructural data support computer modeling and
in vitro
electrophysiological data suggesting that axoaxonic gap junctions play an important role in the generation of very fast (>70 Hz) network oscillations and in the hypersynchronous electrical activity of epilepsy.
Sodium channels amplify spine potentials
Authors: Araya Roberto , Nikolenko Volodymyr , Eisenthal Kenneth B. , Yuste Rafael
Published: July 2007

Dendritic spines mediate most excitatory synapses in the brain. Past theoretical work and recent experimental evidence have suggested that spines could contain sodium channels. We tested this by measuring the effect of the sodium channel blocker tetrodotoxin (TTX) on depolarizations generated by two-photon uncaging of glutamate on spines from mouse neocortical pyramidal neurons. In practically all spines examined, uncaging potentials were significantly reduced by TTX. This effect was postsynaptic and spatially localized to the spine and occurred with uncaging potentials of different amplitudes and in spines of different neck lengths. Our data confirm that spines from neocortical pyramidal neurons are electrically isolated from the dendrite and indicate that they have sodium channels and are therefore excitable structures. Spine sodium channels could boost synaptic potentials and facilitate action potential backpropagation.
A closer look at energy transduction in muscle
Authors: Onishi Hirofumi , Morales Manuel F.
Published: July 2007

Muscular force is the sum of unitary force interactions generated as filaments of myosins move forcibly along parallel filaments of actins, understanding that the free energy required comes from myosin-catalyzed ATP hydrolysis. Using results from conventional biochemistry, our own mutational studies, and diffraction images from others, we attempt, in molecular detail, an account of a unitary interaction, i.e., what happens after a traveling myosin head, bearing an ADP-P
i
, reaches the next station of an actin filament in its path. We first construct a reasonable model of the myosin head and actin regions that meet to form the “weakly bound state”. Separately, we consider Holmes' model of the rigor state [Holmes, K. C., Angert, I., Kull, F. J., Jahn, W. & Schröder, R. R. (2003)
Nature
425, 423–427], supplemented with several heretofore missing residues, thus realizing the “strongly bound state.” Comparing states suggests how influences initiated at the interface travel elsewhere in myosin to discharge various functions, including striking the actins. Overall, state change seems to occur by attachment of a hydrophobic triplet (Trp-546, Phe-547, and Pro-548) of myosin to an actin conduit with a hydrophobic guiding rail (Ile-341, Ile-345, Leu-349, and Phe-352) and the subsequent linear movement of the triplet along the rail.
Mago Nashi Is Essential for Spermatogenesis inMarsilea
Authors: van der Weele Corine M. , Tsai Chia-Wei , Wolniak Stephen M.
Published: July 2007

Spermatogenesis in Marsilea vestita is a rapid process that is activated by placing dry microspores into water. Nine division cycles produce seven somatic cells and 32 spermatids, where size and position define identity. Spermatids undergo de novo formation of basal bodies in a particle known as a blepharoplast. We are interested in mechanisms responsible for spermatogenous initial formation. Mago nashi (Mv-mago) is a highly conserved gene present as stored mRNA and stored protein in the microspore. Mv-mago protein increases in abundance during development and it localizes at discrete cytoplasmic foci (Mago-dots). RNA interference experiments show that new Mv-mago protein is required for development. With Mv-mago silenced, asymmetric divisions become symmetric, cell fate is disrupted, and development stops. The α-tubulin protein distribution, centrin translation, and Mv-PRP19 mRNA distribution are no longer restricted to the spermatogenous cells. Centrin aggregations, resembling blepharoplasts, occur in jacket cells. Mago-dots are undetectable after the silencing of Mv-mago, Mv-Y14, or Mv-eIF4AIII, three core components of the exon junction complex (EJC), suggesting that Mago-dots are either EJCs in the cytoplasm, or Mv-mago protein aggregations dependent on EJCs. Mv-mago protein and other EJC components apparently function in cell fate determination in developing male gametophytes of M. vestita.
p180 Is Involved in the Interaction between the Endoplasmic Reticulum and Microtubules through a Novel Microtubule-binding and Bundling Domain
Authors: Ogawa-Goto Kiyoko , Tanaka Keiko , Ueno Tomonori , Tanaka Keisuke , Kurata Takeshi , Sata Tetsutaro , Irie Shinkichi
Published: July 2007

p180 was originally reported as a ribosome-binding protein on the rough endoplasmic reticulum membrane, although its precise role in animal cells has not yet been elucidated. Here, we characterized a new function of human p180 as a microtubule-binding and -modulating protein. Overexpression of p180 in mammalian cells induced an elongated morphology and enhanced acetylated microtubules. Consistently, electron microscopic analysis clearly revealed microtubule bundles in p180-overexpressing cells. Targeted depletion of endogenous p180 by small interfering RNAs led to aberrant patterns of microtubules and endoplasmic reticulum in mammalian cells, suggesting a specific interaction between p180 and microtubules. In vitro sedimentation assays using recombinant polypeptides revealed that p180 bound to microtubules directly and possessed a novel microtubule-binding domain (designated MTB-1). MTB-1 consists of a predicted coiled-coil region and repeat domain, and strongly promoted bundle formation both in vitro and in vivo when expressed alone. Overexpression of p180 induced acetylated microtubules in cultured cells in an MTB-1-dependent manner. Thus, our data suggest that p180 mediates interactions between the endoplasmic reticulum and microtubules mainly through the novel microtubule-binding and -bundling domain MTB-1.
Designing tools to evaluate fishery management strategies: can the scientific community deliver?
Authors: Schnute Jon T. , Maunder Mark N. , Ianelli James N.
Published: July 2007

Schnute, J. T., Maunder, M. N., and Ianelli, J. N. 2007. Designing tools to evaluate fishery management strategies: can the scientific community deliver? – ICES Journal of Marine Science, 64: 1077–1084. Techniques for quantitative fishery management have evolved rapidly during a period when computers, programming languages, and computational algorithms have also changed dramatically. Despite these advances, many stock assessment methods remain untested. A process of management strategy evaluation (MSE) could potentially rectify this problem, but it would require a framework in which to conduct systematic tests. We survey the tools currently used for stock assessments and discuss the development of new standards for testing management procedures. A successful project would depend on human skills scattered among various nations, organizations, and academic disciplines. Analogies from civil engineering illustrate the discipline and collaboration required for an effective outcome. If the world community of fishery scientists could design, build, and support such a project, it would revolutionize the theory, teaching, and practice of scientific fishery management.
Potential Impact of Pyrethroid Resistance in Helicoverpa zea to the Midwest Processing Industry: Sweet Corn and Snap Beans
Authors: Flood Brian R. , Rabaey Thomas L.
Published: July 2007

Midwest food processors are well positioned to avoid major crop losses, and product contamination resulting from pyrethroid resistance in corn earworm (CEW), Helicoverpa zea (Boddie). However, we do recognize risks associated with late-season plantings, particularly for sweet corn and snap beans. CEW usually migrate into the production areas by late July to mid-August. Crops at risk for most Midwest locations primarily include sweet corn planted after 10 June and snap beans planted after 10 July (about 25% of the Midwest acreage). Pyrethroid insecticides continue to be the commercial standard, with alternative chemistries either ineffective or more expensive. The CEW “treatment window” for sweet corn is from row tassel to dark brown silk and, for snap beans, from bloom to 10 days before harvest. In sweet corn, CEW is only vulnerable as an adult, egg, or early instar feeding on the silk. If left untreated, or with insecticide failure, we anticipate a loss of about one square inch of kernels per larva (2 cases/ton of final cut-corn product). The loss of kernels and the creation of black kernels from contamination associated with feeding injury are estimated to have a market cost in excess of $100/acre, or $6 million for Midwest sweet corn and snap beans. We currently have no effective alternative insecticides for CEW for either crop. In the short term, processors will likely use higher rates of pyrethroids, shorter intervals, and/or additional treatments. Long term, we will increasingly rely on a “process-out” approach to husk out, wash out, and vision-sort larval contaminants and damaged kernels.

Accepted for publication 23 February 2007. Published 19 July 2007.
Improving our Understanding of Helicoverpa zea Migration in the Midwest: Assessment of Source Populations
Authors: Sandstrom Michael A. , Changnon David , Flood Brian R.
Published: July 2007

Corn earworm (Helicoverpa zea) (CEW) generally are not able to overwinter annually in the Upper Midwest, thus they must migrate northward to affect the primary vegetable-growing locations in this area. Migration of CEW is highly dependent on the weather. Provided a source region in the southern United States, migration of CEW from south to north appeared to occur when a high-pressure system was located in the eastern United States and a low-pressure system and attendant frontal boundary was observed to the east of the Rocky Mountains and/or northern plains states. Southerly wind flow located west of the high and east of the low forms an “insect pump.” Convection cells allowed CEW to lift and advance from their source region northward in the low-level insect pump. When CEW encountered an area of downward motion during their northward flight, such as a frontal boundary or a light precipitation area, they had a tendency to “drop out” of the sky into fields below, an area referred to as the “Drop Zone.” Favorable weather patterns for CEW migration and subsequent infestation of fields in north-central Illinois were confirmed by high CEW trap counts at Rochelle over the last four decades.

Accepted for publication 5 September 2006. Published 19 July 2007.
Percutaneous Versus Surgical Tracheotomy: An Updated Meta‐Analysis
Authors: Oliver Eric R. , Gist Amber , Gillespie M Boyd
Published: July 2007

Objective: Perform an updated meta‐analysis investigating differences in complication rates, procedure times, and costs between percutaneous dilational tracheotomy (PDT), operating room surgical tracheotomy (ST), and bedside surgical tracheotomy (BST).

Methods: Meta‐analysis using the Mantel‐Haenszel fixed effects model. Prospective and randomized trials comparing ST with PDT from 1999 to present were identified through two independent searches. Outcome measures analyzed included mortality, early complications, late complications, procedure times, and cost.

Results: Fourteen studies were identified (1,273 patients) that satisfied the search criteria. Analysis of randomized studies demonstrated significantly more minor early complications with PDT compared with ST (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.01–2.66). Randomized studies comparing PDT with BST demonstrated significantly more early complications with PDT (OR, 4.66; 95% CI, 1.46–14.91). There was no significant difference in late serious complications in studies that randomized patients to ST or PDT (OR, 1.39; 95% CI, 0–16,000). PDT is significantly faster to perform than ST (OR, 0.51; 95% CI, 95% 0.49–0.53). BST and PDT have similar costs, and both are less expensive than ST.

Conclusions: Although significantly faster than ST, PDT has more early complications compared with open tracheotomy in the operating room or at the bedside. The long‐term complications of the two techniques appear comparable but have not been thoroughly investigated. These findings suggest that a team approach between surgeons and critical care specialists is essential to select the appropriate tracheotomy technique for a given patient.
Hard Palate Necrosis After Bilateral Internal Maxillary Artery Embolization for Epistaxis
Authors: Guss Joel , Cohen Marc A. , Mirza Natasha
Published: July 2007

Superselective embolization is an effective method of treating epistaxis that is refractory to conservative treatment. Soft tissue necrosis is a rare complication owing to the extensive collateral blood supply of the head and neck. We describe the case of a patient who developed unilateral necrosis of the mucosa overlying the hard palate after undergoing bilateral internal maxillary artery embolization. The presence of a nasopharyngeal balloon and bilateral nasal packs for 2 days after embolization may have compressed collateral vessels in the soft palate and nose and contributed to this complication. Packing should be removed as soon as possible after embolization.
Excision repair cross‐complementation group 1 predicts progression‐free and overall survival in non‐small cell lung cancer patients treated with platinum‐based chemotherapy
Authors: Azuma Koichi , Komohara Yoshihiro , Sasada Tetsuro , Terazaki Yasuhiro , Ikeda Jiro , Hoshino Tomoaki , Itoh Kyogo , Yamada Akira , Aizawa Hisamichi
Published: July 2007

Expression of excision repair cross‐complementation group 1 (ERCC1), p53, or thioredoxin (TRX) is reported to be correlated with resistance to platinum‐based drugs. The authors evaluated whether ERCC1, p53, or TRX expression could predict progression‐free and/or overall survival in relapsed non‐small cell lung cancer (NSCLC) patients treated with platinum‐based chemotherapy. Immunohistochemistry was used to examine the expression of these three proteins in resected lung tumor samples obtained from 67 patients treated with platinum‐based chemotherapy against recurrent tumors after curative resection. Immunostaining for ERCC1, p53, and TRX was positive in 29, 35, and 24 patients, respectively. Patients negative for ERCC1 had a significantly longer median progression‐free (44 vs 26 weeks, P = 0.0075) and overall (73 vs 44 weeks, P = 0.0006) survival than those positive for ERCC1. Patients negative for p53 expression had a significantly longer median overall (70 vs 62 weeks, P = 0.0289), but not progression‐free (37.5 vs 36 weeks, P = 0.2465), survival than those positive for p53 expression. From multivariate analysis, negative ERCC1 expression (hazard ratio [HR] = 1.3740, P = 0.0147) was a significantly favorable factor for progression‐free survival, and negative ERCC1 expression (HR = 1.6533, P = 0.0018) and better performance status (HR = 1.9117, P = 0.0017) were significantly favorable factors for overall survival. This retrospective study indicates that immunostaining for ERCC1 may be useful for predicting survival in NSCLC patients receiving platinum‐based chemotherapy against recurrent tumors after curative resection and can provide critical information for planning personalized chemotherapy. (Cancer Sci 2007; 98: 1336–1343)
Sesamin, a lignan of sesame, down‐regulates cyclin D1 protein expression in human tumor cells
Authors: Yokota Tomoya , Matsuzaki Youichirou , Koyama Makoto , Hitomi Toshiaki , Kawanaka Mayumi , Enoki‐Konishi Masako , Okuyama Yusuke , Takayasu Junko , Nishino Hoyoku , Nishikawa Akiyoshi , Osawa Toshihiko , Sakai Toshiyuki
Published: July 2007

Sesamin is a major lignan constituent of sesame and possesses multiple functions such as antihypertensive, cholesterol‐lowering, lipid‐lowering and anticancer activities. Several groups have previously reported that sesamin induces growth inhibition in human cancer cells. However, the nature of this growth inhibitory mechanism remains unknown. The authors here report that sesamin induces growth arrest at the G1 phase in cell cycle progression in the human breast cancer cell line MCF‐7. Furthermore, sesamin dephosphorylates tumor‐suppressor retinoblastoma protein (RB). It is also shown that inhibition of MCF‐7 cell proliferation by sesamin is correlated with down‐regulated cyclin D1 protein expression, a proto‐oncogene that is overexpressed in many human cancer cells. It was found that sesamin‐induced down‐regulation of cyclin D1 was inhibited by proteasome inhibitors, suggesting that sesamin suppresses cyclin D1 protein expression by promoting proteasome degradation of cyclin D1 protein. Sesamin down‐regulates cyclin D1 protein expression in various kinds of human tumor cells, including lung cancer, transformed renal cells, immortalized keratinocyte, melanoma and osteosarcoma. Furthermore, depletion of cyclin D1 protein using small interfering RNA rendered MCF‐7 cells insensitive to the growth inhibitory effects of sesamin, implicating that cyclin D1 is at least partially related to the antiproliferative effects of sesamin. Taken together, these results suggest that the ability of sesamin to down‐regulate cyclin D1 protein expression through the activation of proteasome degradation could be one of the mechanisms of the antiproliferative activity of this agent. (Cancer Sci 2007; 98: 1447–1453)
Chemically synthesized sugar‐cholestanols possess a preferential anticancer activity involving promising therapeutic potential against human esophageal cancer
Authors: Faried Ahmad , Faried Leri S. , Nakagawa Takashi , Yamauchi Takahito , Kitani Mami , Sasabe Hiroyuki , Nishimura Toyo , Usman Nurhayat , Kato Hiroyuki , Asao Takayuki , Kuwano Hiroyuki , Yazawa Shin
Published: July 2007

The understanding of the cell signaling pathways and the molecular events leading to cell death of cancer cells will provide in‐depth perspective into the identification and development of potent anticancer agents. A balance between cell proliferation and cell death has been raised as a rational target for the management of malignant tumors. In the present study, the authors demonstrated that chemically synthesized sugar‐cholestanols consisting of GlcNAcβ‐, Galβ‐ and GlcNAcβ1,3Galβ‐cholestanols exerted a strong inhibiting activity against cell proliferation of esophageal cancer cells, but cholestanol itself did not show such an activity against the same cancer cells at all. In addition to their predominant role as an antiproliferation agent, evidence based on the molecular analyses suggested that sugar‐cholestanols played a regulatory role in multiple signal transduction pathways inducing apoptosis through both the death signal‐extrinsic and the mitochondria‐intrinsic pathways. Sugar‐cholestanols seemed to be more susceptible to esophageal cancer cells than to non‐cancerous esophageal cells at the very early event of their exposure and, further, to suppress specifically the expression of vascular endothelial growth factor. Taken together, these novel functions of sugar‐cholestanols indicate that they could have promising therapeutic potential against human esophageal cancer. (Cancer Sci2007; 98: 1358–1367)
Quantifying adherence to treatment and its relationship to quality of life in a well‐characterized haemophilia population
Authors: DU TREIL S. , RICE J. , LEISSINGER C. A.
Published: July 2007

Summary.  It is known that chronically ill patients adhere to medical treatment plans only 50% of the time [1]. Adherence to treatment with factor infusion therapy in haemophilia patients is essential to stop bleeding. It also prevents both acute and chronic life and limb threatening complications. This study, performed in a well‐described haemophilia population, was completed in an effort to understand the critical issue of adherence in patients with haemophilia. A major component of the methodology of this study was the development of a unique scoring system to quantify adherence. Adherence scores in patients on On‐Demand treatment strategies were then compared to those on High Intensity treatment strategies. Quality of life (QoL) studies were also performed on the study population to assess the association of treatment regimen and adherence scores to QoL measures. Results of this study demonstrated that adherence to On‐Demand therapy was significantly greater than adherence to High Intensity treatment regimens and in children, High Intensity treatment regimens, which included prophylaxis, correlated with better QoL scores in body pain. It is envisioned that the development of an objective scoring system for adherence will prove useful in future studies of adherence as well as in the development of intervention strategies that can overcome barriers to adherence in haemophilia patients.
A comparison of e‐learning in Scotland's colleges and secondary schools: the case of National Qualifications in ‘Core Skills’
Authors: Davidson J.K. , Elliot D.L.
Published: July 2007

Abstract  This paper investigates and compares the utilization of online resources to support teaching and learning in two different educational sectors with overlapping student groups in Scotland: secondary schools and further education (FE) colleges. The online ‘Core Skills’ materials included Numeracy, Communication, Information Technology (IT), Problem Solving and Working With Others. The research involved two large‐scale national surveys with representative samples of staff drawn from secondary schools and FE colleges, and four qualitative case studies purposively selected to represent a range of geographic locations. The most popular resources were for Numeracy. In the majority of colleges, respondents' attitudes to the materials were positive and the e‐resources were used in conjunction with other teaching approaches. The evidence suggested that less motivated learners benefited from the materials when they were contextualized. Among secondary teacher respondents, however, the resources were virtually unknown. The majority of secondary teachers reported that they needed time to evaluate the materials and that they would benefit from specific training related to curriculum‐linked e‐resources. In conclusion, as the Numeracy materials have been found useful, e‐learning in mathematics warrants further investigation among less motivated students who are currently not achieving their potential in secondary schools.
Bacillus subtilis RecG branch migration translocase is required for DNA repair and chromosomal segregation
Authors: Sanchez Humberto , Carrasco Begoña , Cozar M. Castillo , Alonso Juan C.
Published: July 2007

The absence of Bacillus subtilis RecG branch migration translocase causes a defect in cell proliferation, renders cells very sensitive to DNA‐damaging agents and increases ∼150‐fold the amount of non‐partitioned chromosomes. Inactivation of recF, addA, recH, recV or recU increases both the sensitivity to DNA‐damaging agents and the chromosomal segregation defect of recG mutants. Deletion of recS or recN gene partially suppresses cell proliferation, DNA repair and segregation defects of ΔrecG cells, whereas deletion of recA only partially suppresses the segregation defect of ΔrecG cells. Deletion of recG and ripX render cells with very poor viability, extremely sensitive to DNA‐damaging agents, and with a drastic segregation defect. After exposure to mitomycin C recG or ripX cells show a drastic defect in chromosome partitioning (∼40% of the cells), and this defect is even larger (∼60% of the cells) in recG ripX cells. Taken together, these data indicate that: (i) RecG defines a new epistatic group (η), (ii) RecG is required for proper chromosomal segregation even in the presence of other proteins that process and resolve Holliday junctions, and (iii) different avenues could process Holliday junctions.
The essential peptidoglycan glycosyltransferase MurG forms a complex with proteins involved in lateral envelope growth as well as with proteins involved in cell division in Escherichia coli
Authors: Mohammadi Tamimount , Karczmarek Aneta , Crouvoisier Muriel , Bouhss Ahmed , Mengin‐Lecreulx Dominique , Den Blaauwen Tanneke
Published: July 2007

In Escherichia coli many enzymes including MurG are directly involved in the synthesis and assembly of peptidoglycan. MurG is an essential glycosyltransferase catalysing the last intracellular step of peptidoglycan synthesis. To elucidate its role during elongation and division events, localization of MurG using immunofluorescence microscopy was performed. MurG exhibited a random distribution in the cell envelope with a relatively higher intensity at the division site. This mid‐cell localization was dependent on the presence of a mature divisome. Its localization in the lateral cell wall appeared to require the presence of MreCD. This could be indicative of a potential interaction between MurG and other proteins. Investigating this by immunoprecipitation revealed the association of MurG with MreB and MraY in the same protein complex. In view of this, the loss of rod shape of ΔmreBCD strain could be ascribed to the loss of MurG membrane localization. Consequently, this could prevent the localized supply of the lipid II precursor to the peptidoglycan synthesizing machinery involved in cell elongation. It is postulated that the involvement of MurG in the peptidoglycan synthesis concurs with two complexes, one implicated in cell elongation and the other in division. A model representing the first complex is proposed.